Add: Game UI test:

- Ensures FXML loads and controller initializes without errors.

README.md

@@ -36,7 +36,6 @@ This protocol handles game state synchronization, player actions, lobby and glob
 ├── documents/               # Project resources and documentation
 │   ├── images/              # Images for README and documentation
 │   ├── diary                # Diary files for each organizational meetup
-│   ├── blog                 # Blog files covering project-related topics
 │   ├── docs                 # Documentation
 │   ├── milestones/          # Milestone deliverables (6 milestones)
 │   └── (Other resources)    # Additional project materials

build.gradle

@@ -4,6 +4,7 @@ plugins {
     id 'org.openjfx.javafxplugin' version '0.1.0'
     id 'checkstyle'
     id 'com.diffplug.spotless' version '7.0.2'
+    id 'jacoco'
 }
 
 group = 'ch.unibas.dmi.dbis'
@@ -41,8 +42,17 @@ dependencies {
     implementation 'org.json:json:20240303'
 }
 
+jacoco {
+    toolVersion = "0.8.14"
+}
+
+jacocoTestReport {
+    dependsOn test
+}
+
 test {
     useJUnitPlatform()
+    finalizedBy jacocoTestReport
 }
 
 checkstyle {

config/checkstyle/suppressions.xml

@@ -21,4 +21,7 @@
 
     <!-- Allow for compacter line seperators -->
     <suppress checks="EmptyLineSeparator" files=".*Test\.java"/>
+
+    <!-- Allow longer method length in composition root -->
+    <suppress checks="MethodLength" files="ServerApp.java"/>
 </suppressions>

documents/blog/README.md

@@ -1,28 +0,0 @@
-# Blog
-
-## Purpose
-This folder contains a collection of blog posts documenting the development process of our application. These blogs serve two key purposes:
-
-1. **For External Audiences**
-
-    The blogs provide insights into the internal program flow and the interaction between components without requiring readers to dive into the source code. They offer a mixed-level overview of how different parts of the system work together.
-
-2. **For Our Team**
-
-    The blogs serve as a record of our decision-making process. By documenting what decisions were made and why, we can track the evolution of our design choices and understand the reasoning behind them. This is invaluable for maintaining consistency across the team.
-
-But keep in mind that these blogs **do not replace** the detailed source code documentation.
-
-## Format
-All blog posts follow the naming convention: `<YYYY-MM-DD>_<Title>.md`
-
-## Blog Posts
-
-### General
-*(No posts yet)*
-
-### Client
-*(No posts yet)*
-
-### Server
-*(No posts yet)*

documents/diary/09-04.md

@@ -0,0 +1,9 @@
+# Besprechung über Veränderung der Aufgabenteilung
+
+## Verschieben von Aufgaben
+
+Da die Implementation der client server Kommunikation länger dauerte als geplant, wurden achivements erfüllt, die erst bei späteren Meilensteinen relevant sein werden.
+
+## Aufgabeverteilung
+
+Um zu vermeiden, dass sich Personen erst lange Zeit in den Code anderer einarbeiten müssen um zu helfen, wurden Dokumentation und das Erstellen von Materialien für MS4 auf ein Teammitgleid (Jona) ausgelagert um das Projekt nicht zu verlangsamen

documents/diary/10-04.md

@@ -0,0 +1,38 @@
+# Neue Aufgabenteilung für MS4 (10.04)
+
+## Kurzfassung
+
+Offene Meilensteine wurden überprüft und Personen zugewiesen. Ziel ist, verbleibende Funktionen (Game List, Username-Integration, Lobby/Chat-Funktionen) bis zum nächsten Sprint stabil zu machen.
+
+## Offene Aufgaben
+
+- Broadcast: Offen (Priorität niedrig)
+- Username-Integration: In Backend integrieren und frontend Anpasungen (wichtig)
+- Demo: Kernfunktion vorhanden, muss getestet werden
+- Game List: Backend fehlt vollständig
+- Chat: Globaler Chat und Lobby-Chat müssen eingebunden werden
+- Lounging: Support für mehrere Lobbys und Spielerlisten
+- QA: Präsentation und Dokumentation
+- Rules to Code: Vorstellung und Integration
+- "Shall we play a game": Flag zum Umschalten zwischen Demo- und Normalmodus
+- Whisper: Funktion (siehe Zuordnung)
+- Zeitplan: Verschiebung von nicht-kritischen Punkten
+
+## Aufgaben & Zustänextrdigkeiten
+
+- Jona
+ 	- Command Line: Parsing, Option für Username-Eingabe (Start vs. Lobby)
+ 	- Game List: Implementierung (Datenstruktur, Commands, Backend-Anbindung)
+ 	- Lounging: Mehrere Lobbys, Liste aller Spieler
+
+- Lars
+ 	- QA: Präsentation und ausgeschriebenes Dokument
+
+- Mathis
+ 	- Whisper-Chat: Fertigstellung
+ 	- Lobby-Chat: Integration
+
+- Julian
+ 	- Game Engine: Fertigstellung
+ 	- Flag: Umschalten zwischen Demo- und echter Game Engine
+ 	- Rules to Code: Vorstellung

documents/diary/README.md

@@ -1,7 +1,7 @@
 # Meeting Diary
 
 This folder holds the notes and documentation of all team meetings throughout the project.
-The notes are organised by **milestones (1–6)** so that everyone can easily see what was discussed and decided at each stage. Each sub-header below links to the actual Markdown file containing the details.
+The notes are organized by **milestones (1–6)** so that everyone can easily see what was discussed and decided at each stage. Each sub-header below links to the actual Markdown file containing the details.
 
 ## Milestone 1
 ### [24. February 2026](24-02.md)
@@ -14,19 +14,28 @@ The notes are organised by **milestones (1–6)** so that everyone can easily se
 - Finalizing structure of network protocol
 
 
-## Milestone 2
-*(Meeting notes to be added here when available)*
+## Milestone 2
+### [14. March 2025](14-03.md)
+- Discussion of LobbyScreen, GameScreen, and Chatbox structure
+- Endscreen postponed to MS3
 
 
-## Milestone 3
-*(Meeting notes to be added here when available)*
+## Milestone 3
+None, as milestone 3 covered the assessment of individual technical understanding through evaluation.
 
 
-## Milestone 4
-*(Meeting notes to be added here when available)*
+## Milestone 4
+### [09. April 2026](09-04.md)
+- Task redistribution due to delays in client-server communication
+- Documentation and MS4 materials assigned to Jona
+
+### [10. April 2026](10-04.md)
+- Review and assignment of open milestones
+- Focus on stabilizing Game List, Username-Integration, Lobby/Chat functions
+- Task list for remaining features and QA
 
 
-## Milestone 5
+## Milestone 5
 *(Meeting notes to be added here when available)*
 
 

documents/docs/game-engine/README.md

@@ -4,3 +4,4 @@
 - [Game Engine Architecture](game-engine-architecture.md)
 - [Casono Rules Easy Description](casono-rules-easy-description.md)
 - [Game engine implementation](game-engine-implementation.md)
+- [Casonso Manual](casono-manual.md)

documents/docs/game-engine/casono-manual.md

@@ -0,0 +1,162 @@
+# Casono Manual
+
+> Hinweis: Eine vereinfachte Einführung finden Sie in der Datei [Casono Rules – Easy Description](casono-rules-easy-description.md).
+> Dieses Dokument beschreibt den Ablauf eines Pokerspiels anhand eines Beispiels.
+<!-- vim-markdown-toc GFM -->
+
+* [1. Spielübersicht](#1-spielübersicht)
+    * [Grundregeln](#grundregeln)
+* [2. Sitzposition & Dealer-Button](#2-sitzposition--dealer-button)
+* [3. Blinds (Pflichteinsätze)](#3-blinds-pflichteinsätze)
+* [4. Spielablauf im Detail](#4-spielablauf-im-detail)
+    * [4.1 Preflop (erste Setzrunde)](#41-preflop-erste-setzrunde)
+    * [4.2 Flop (3 Gemeinschaftskarten)](#42-flop-3-gemeinschaftskarten)
+    * [4.3 Turn (4. Gemeinschaftskarte)](#43-turn-4-gemeinschaftskarte)
+    * [4.4 River (5. Gemeinschaftskarte)](#44-river-5-gemeinschaftskarte)
+* [5. Showdown (Kartenvergleich)](#5-showdown-kartenvergleich)
+* [6. Poker-Handrangfolge](#6-poker-handrangfolge)
+* [7. Wichtige Grundprinzipien](#7-wichtige-grundprinzipien)
+    * [Reihenfolge beachten](#reihenfolge-beachten)
+    * [Klare Aktionen](#klare-aktionen)
+    * [Ein Spieler – eine Hand](#ein-spieler--eine-hand)
+    * [Fehlerhafte Einsätze](#fehlerhafte-einsätze)
+* [8. Strategische Einordnung](#8-strategische-einordnung)
+
+<!-- vim-markdown-toc -->
+
+## 1. Spielübersicht
+
+Texas Hold’em ist ein strategisches Kartenspiel für mehrere Spieler. 
+Ziel ist es, den Pot (alle gesetzten Chips) zu gewinnen, entweder durch:
+
+- die beste Kartenkombination am Ende der Runde
+- oder indem alle anderen Spieler vorher aussteigen (Fold)
+
+### Grundregeln
+
+- Jeder Spieler erhält 2 verdeckte Karten (Hole Cards)
+- Es werden 5 Gemeinschaftskarten offen in der Mitte ausgelegt
+- Jeder Spieler bildet die beste 5-Karten-Kombination aus:
+  - eigenen Karten
+  - und Gemeinschaftskarten
+
+- Zu Spielbeginn erhält jeder Spieler ein Startgeld von 20000 Chips ($)
+
+## 2. Sitzposition & Dealer-Button
+
+Der sogenannte Dealer-Button bestimmt die Positionen am Tisch:
+
+- Er zeigt an, wer als „Geber“ (Dealer) fungiert
+- Die Positionen rotieren im Uhrzeigersinn nach jeder Runde
+
+Die Position ist entscheidend, da sie bestimmt:
+
+- die Reihenfolge der Aktionen
+- wer die Blinds setzen muss
+
+## 3. Blinds (Pflichteinsätze)
+
+Vor jeder Runde werden zwei verpflichtende Einsätze geleistet:
+
+- **Small Blind** (kleiner Blind): 100 Chips – gesetzt vom Spieler links neben dem Dealer
+- **Big Blind** (großer Blind): 200 Chips - gesetzt vom Spieler zwei Plätze links vom Dealer
+
+Diese Einsätze sorgen dafür, dass:
+
+- ein Startpot entsteht
+- jede Runde aktiv gespielt wird
+
+## 4. Spielablauf im Detail
+
+### 4.1 Preflop (erste Setzrunde)
+
+Nach dem Austeilen der Karten beginnt die erste Setzrunde.
+
+Der Spieler links vom Big Blind eröffnet die Runde.
+
+Jeder Spieler hat folgende Optionen:
+
+- **Fold** – Karten ablegen und aussteigen
+- **Call** – Einsatz mitgehen
+- **Raise** – Einsatz erhöhen
+
+### 4.2 Flop (3 Gemeinschaftskarten)
+
+- Drei Karten werden offen auf den Tisch gelegt
+- Eine neue Setzrunde beginnt
+- Die Setzrunde beginnt jetzt immer beim ersten aktiven Spieler links vom Dealer (im Uhrzeigersinn).
+
+Ab diesem Zeitpunkt können alle Spieler ihre Strategie anhand zusätzlicher Informationen anpassen.
+
+### 4.3 Turn (4. Gemeinschaftskarte)
+
+- Die vierte Karte wird aufgedeckt
+- Eine weitere Setzrunde folgt
+
+Die Einsätze werden oft höher, da sich stärkere Hände entwickeln.
+
+### 4.4 River (5. Gemeinschaftskarte)
+
+- Die letzte Karte wird aufgedeckt
+- Letzte Setzrunde
+
+Dies ist die finale Entscheidungsphase:
+
+- Maximierung des Gewinns
+- oder Minimierung von Verlusten
+
+## 5. Showdown (Kartenvergleich)
+
+Wenn nach der letzten Setzrunde mindestens zwei Spieler verbleiben:
+
+- Alle verbleibenden Spieler decken ihre Karten auf
+- Die **beste 5-Karten-Kombination gewinnt**
+
+Wichtig:
+
+- Die Karten „sprechen für sich“ – die beste Hand zählt unabhängig von Ansagen
+
+## 6. Poker-Handrangfolge
+
+Die Stärke der Hände ist eindeutig festgelegt (von schwach nach stark):
+
+1. High Card (höchste Einzelkarte)
+2. One Pair (ein Paar)
+3. Two Pair (zwei Paare)
+4. Three of a Kind (Drilling)
+5. Straight (Straße)
+6. Flush (Farbe)
+7. Full House
+8. Four of a Kind (Vierling)
+9. Straight Flush
+10. Royal Flush
+
+Je höher die Kombination, desto stärker die Hand.
+
+## 7. Wichtige Grundprinzipien
+
+### Reihenfolge beachten
+
+Spieler müssen immer der Reihe nach handeln.
+
+### Klare Aktionen
+
+Alle Aktionen müssen eindeutig sein:
+
+- Einsätze klar ansagen oder eindeutig setzen
+
+### Ein Spieler – eine Hand
+
+- Spieler dürfen ihre Karten nicht teilen oder gemeinsam spielen
+
+### Fehlerhafte Einsätze
+
+- Unklare oder falsche Einsätze können korrigiert werden, abhängig von der Spielsituation (nur wenn der Einsatz außerhalb der gültigen Grenzen liegt; zu hohe oder unzulässige Beträge werden blockiert und nicht automatisch korrigiert)
+
+## 8. Strategische Einordnung
+
+Texas Hold’em ist kein reines Glücksspiel. Der Erfolg basiert auf:
+
+- Wahrscheinlichkeiten (Mathematik)
+- Einschätzung von Gegnern (Psychologie)
+- Positionsspiel und Timing

documents/docs/game-engine/casono-markdown-render-engine.js

@@ -0,0 +1,84 @@
+const marked = {
+    parse: function (md) {
+        if (!md) return "";
+
+        let toc = [];
+
+        md = md.replace(/^(#{1,3})\s+(.*)$/gim, (m, hashes, title) => {
+            const level = hashes.length;
+
+            const id = title
+                .toLowerCase()
+                .trim()
+                .replace(/[^\wäöüß]+/g, "-")
+                .replace(/-+/g, "-")
+                .replace(/^-|-$/g, "");
+
+            toc.push({ level, title, id });
+
+            return `
+                <h${level} id="${id}" class="cm-h${level}">
+                    ${title}
+                </h${level}>
+            `;
+        });
+
+        md = md.replace(/```([\s\S]*?)```/g, (_, code) => {
+            return `<pre class="cm-code"><code>${escapeHtml(code)}</code></pre>`;
+        });
+
+        md = md.replace(/!\[(.*?)\]\((.*?)\)/gim,
+            `<img alt="$1" src="$2" class="cm-img">`
+        );
+
+        md = md.replace(/\[(.*?)\]\((.*?)\)/gim,
+            `<a href="$2" target="_blank" class="cm-link">$1</a>`
+        );
+
+        md = md.replace(/`(.*?)`/gim,
+            `<code class="cm-inline">$1</code>`
+        );
+
+        md = md.replace(/\*\*(.*?)\*\*/gim, "<b>$1</b>");
+        md = md.replace(/\*(.*?)\*/gim, "<i>$1</i>");
+
+        md = md.replace(/^\s*-\s(.+)$/gim, "<li>$1</li>");
+        md = wrapLists(md);
+
+        md = md
+            .replace(/\n{2,}/g, "</p><p>")
+            .replace(/^(?!<h|<ul|<pre|<li|<\/)(.+)$/gim, "<p>$1</p>");
+
+        return buildToc(toc) + md;
+    }
+};
+
+function buildToc(items) {
+    if (!items.length) return "";
+
+    let html = `<div class="cm-toc">`;
+
+    items.forEach(i => {
+        html += `
+            <div class="cm-toc-item level-${i.level}">
+                <a href="#${i.id}">${i.title}</a>
+            </div>
+        `;
+    });
+
+    html += `</div>`;
+    return html;
+}
+
+function wrapLists(html) {
+    return html.replace(/(<li>.*?<\/li>)/gs, "<ul>$1</ul>");
+}
+
+function escapeHtml(text) {
+    return text
+        .replace(/&/g, "&amp;")
+        .replace(/</g, "&lt;")
+        .replace(/>/g, "&gt;");
+}
+
+window.marked = marked;

documents/docs/game-engine/casono-rules-easy-description.md

@@ -1,56 +1,42 @@
 # Casono Rules Easy Description
 
-> Source: https://www.youtube.com/watch?v=h-1WyU5Wqsw&pp=ygUZbGVybmVuIHBva2VyIHRleGFzIGhvbGRlbQ%3D%3D
+> Quelle: https://www.youtube.com/watch?v=h-1WyU5Wqsw&pp=ygUZbGVybmVuIHBva2VyIHRleGFzIGhvbGRlbQ%3D%3D
 <!-- vim-markdown-toc GFM -->
 
-* [Deustch](#deustch)
-    * [Blinds (Small Blind & Big Blind)](#blinds-small-blind--big-blind)
-    * [Erste Setzrunde (Preflop)](#erste-setzrunde-preflop)
-    * [Beispiel Preflop](#beispiel-preflop)
-    * [Flop (3 Gemeinschaftskarten)](#flop-3-gemeinschaftskarten)
-    * [Beispiel Flop](#beispiel-flop)
-    * [Turn (4. Karte)](#turn-4-karte)
-    * [River (5. Karte)](#river-5-karte)
-    * [Showdown (Gewinnentscheidung)](#showdown-gewinnentscheidung)
-    * [Poker Hand Rankings (Gewichtung)](#poker-hand-rankings-gewichtung)
-    * [Fazit](#fazit)
-* [English](#english)
-    * [Blinds (Small Blind & Big Blind)](#blinds-small-blind--big-blind-1)
-    * [First Betting Round (Preflop)](#first-betting-round-preflop)
-    * [Preflop Example](#preflop-example)
-    * [Flop (3 Community Cards)](#flop-3-community-cards)
-    * [Flop Example](#flop-example)
-    * [Turn (4th Card)](#turn-4th-card)
-    * [River (5th Card)](#river-5th-card)
-    * [Showdown (Winning Decision)](#showdown-winning-decision)
-    * [Poker Hand Rankings (Hierarchy)](#poker-hand-rankings-hierarchy)
-    * [Conclusion](#conclusion)
+* [Blinds (Small Blind & Big Blind)](#blinds-small-blind--big-blind)
+* [Erste Setzrunde (Preflop)](#erste-setzrunde-preflop)
+* [Beispiel Preflop](#beispiel-preflop)
+* [Flop (3 Gemeinschaftskarten)](#flop-3-gemeinschaftskarten)
+* [Beispiel Flop](#beispiel-flop)
+* [Turn (4. Karte)](#turn-4-karte)
+* [River (5. Karte)](#river-5-karte)
+* [Showdown (Gewinnentscheidung)](#showdown-gewinnentscheidung)
+* [Poker Hand Rankings (Gewichtung)](#poker-hand-rankings-gewichtung)
+* [Fazit](#fazit)
 
 <!-- vim-markdown-toc -->
 
-## Deutsch
-
-Der Pokertisch ist ein unglaublich faszinierender Erlebnisraum, in dem man sehr viel lernen kann: über sich selbst, über andere Menschen und über Fragen wie: wie treffe ich eigentlich Entscheidungen, wie gehe ich mit Stress und Unsicherheit um und wie gut ich darin bin, mich in andere hineinzuversetzen und Situationen richtig einzuschätzen.
+Der Pokertisch ist ein unglaublich faszinierender Erlebnisraum, in dem man sehr viel lernen kann: über sich selbst, über andere Menschen und über Fragen wie: Wie treffe ich eigentlich Entscheidungen, wie gehe ich mit Stress und Unsicherheit um und wie gut ich darin bin, mich in andere hineinzuversetzen und Situationen richtig einzuschätzen.
 
 Damit Du in diesem Erlebnisraum starten kannst, ist es – wie bei jedem Spiel – notwendig, zuerst die Grundregeln und den Spielablauf zu verstehen.
 
 Also los geht es:
 
-Wir haben am Tisch **4 Spieler**: Julian, Mathis, Jona und Lars. Jeder Spieler startet mit **20.000 Chips**. Jeder bekommt **2 Karten auf die Hand** und es gibt zusätzlich **5 Gemeinschaftskarten**, die später in der Mitte aufgedeckt werden.
+Wir haben am Tisch **4 Spieler**: Julian, Mathis, Jona und Lars. Jeder Spieler startet mit **20000 Chips ($)**. Jeder bekommt **2 Karten auf die Hand** und es gibt zusätzlich **5 Gemeinschaftskarten**, die später in der Mitte aufgedeckt werden.
 
-![1. image](./images/1.png)
+![1. image](./images/1-1.svg)
 
 Die Spieler sitzen in folgender Reihenfolge: Julian, Mathis, Jona und Lars. Einer davon hat den Dealer-Button, der bestimmt, wer die Karten austeilt und von wo die Runde beginnt. Dieser Button wandert nach jeder Runde im Uhrzeigersinn weiter und verändert damit die Position ständig.
 
 Regel: *34 Button Placement and Movement 🟢*
 
-### Blinds (Small Blind & Big Blind)
+## Blinds (Small Blind & Big Blind)
 
 Bevor die Karten verteilt werden, gibt es zwei Pflicht-Einsätze:
 
 Der Small Blind und der Big Blind. Der Big Blind ist immer doppelt so hoch wie der Small Blind.
 
-![2. image](./images/2.png)
+![2. image](./images/2-1.svg)
 
 Regel: *32 Dead Button 🟡*
 
@@ -58,7 +44,7 @@ Diese Einsätze sorgen dafür, dass sofort ein Pot entsteht und das Spiel überh
 
 Danach werden die Karten verteilt: zuerst Small Blind, dann Big Blind und dann im Uhrzeigersinn alle anderen Spieler.
 
-### Erste Setzrunde (Preflop)
+## Erste Setzrunde (Preflop)
 
 Die erste Setzrunde beginnt immer bei dem Spieler links vom Big Blind.
 
@@ -73,251 +59,108 @@ Regel: *41 Methods of Calling 🟢*
 Regel: *42 Methods of Raising 🟢*
 Regel: *50 Acting in Turn 🟢*
 
-### Beispiel Preflop
+## Beispiel Preflop
 
-Julian schaut seine Karten an und entscheidet sich direkt für einen Call von **600 Chips**.
+Julian schaut seine Karten an und entscheidet sich direkt für einen Raise von **600 Chips**.
 
-![3. image](./images/3.png)
+![3. image](./images/3-1.svg)
 
 Mathis sieht seine Karten an und merkt, dass sie nicht gut sind, also foldet er und steigt aus.
 
-![4. image](./images/4.png)
+![4. image](./images/4-1.svg)
 
 Jona ist nun dran und entscheidet sich ebenfalls für einen Call, weil seine Hand spielbar ist.
 
-![5. image](./images/5.png)
+![5. image](./images/5-1.svg)
 
 Lars schaut seine Karten an, erkennt eine starke Hand und erhöht auf **1200 Chips**.
 
-![6. image](./images/6.png)
+![6. image](./images/6-1.svg)
 
 Damit verändert sich sofort die Situation: Julian und Jona müssen entscheiden, ob sie diesen Raise bezahlen, selbst erhöhen oder aussteigen.
 
-### Flop (3 Gemeinschaftskarten)
+## Flop (3 Gemeinschaftskarten)
 
 Jetzt werden **3 Gemeinschaftskarten** in die Mitte gelegt. Ab hier verändert sich das Spiel komplett, weil alle Spieler zusätzliche Informationen bekommen.
 
-![7. image](./images/7.png)
+Die Setzrunde beginnt jetzt immer beim ersten aktiven Spieler links vom Dealer (im Uhrzeigersinn).
+
+![7. image](./images/7-1.svg)
 
 Es beginnt eine neue Setzrunde.
 
 Regel: *49 Accepted Action 🟢*
 
-### Beispiel Flop
+## Beispiel Flop
 
-Lars setzt **1000 Chips** als Erstes. Julian entscheidet sich mitzugehen (Call), weil seine Karten durch die Gemeinschaftskarten stärker geworden sind.
+Jona setzt **1000 Chips** als Erstes. Lars entscheidet sich mitzugehen (Call), weil seine Karten durch die Gemeinschaftskarten stärker geworden sind.
 
-![8. image](./images/8.png)
+Julian steigt aus, weil er keine gute Verbindung mehr sieht. Mathis ist bereits raus.
 
-Jona steigt aus, weil er keine gute Verbindung mehr sieht. Mathis ist bereits raus.
+![8. image](./images/8-1.svg)
 
-### Turn (4. Karte)
+## Turn (4. Karte)
 
 Jetzt kommt die **4. Gemeinschaftskarte**.
 
 Wieder beginnt eine neue Setzrunde.
 
-Lars setzt diesmal **3000 Chips**. Julian bezahlt erneut (Call), weil seine Hand weiterhin gut spielbar ist.
+Jona setzt diesmal **3000 Chips**. Lars bezahlt erneut (Call), weil seine Hand weiterhin gut spielbar ist.
 
-![9. image](./images/9.png)
+![9. image](./images/9-1.png)
 
 Regel: *53 Action Out of Turn 🟡*
 
-### River (5. Karte)
+## River (5. Karte)
 
 Jetzt wird die letzte Gemeinschaftskarte aufgedeckt.
 
 Dies ist die letzte Entscheidung im Spiel.
 
-Lars setzt **5000 Chips**.
+Jona setzt **5000 Chips**.
 
-![10. image](./images/10.png)
+![10. image](./images/10-1.png)
 
-Julian muss jetzt entscheiden: Fold, Call oder Raise auf **10000 Chips**.
+Lars muss jetzt entscheiden: Fold, Call oder Raise auf 10000 Chips.
 
 Regel: *54 Pot Size Bets 🟡*
 
-### Showdown (Gewinnentscheidung)
+## Showdown (Gewinnentscheidung)
 
 Wenn nach der letzten Setzrunde noch zwei Spieler übrig sind, kommt es zum Showdown.
 
 Beide Spieler zeigen ihre Karten offen. Gewonnen hat die **beste 5-Karten-Kombination aus Handkarten und Gemeinschaftskarten**.
 
-![11. image](./images/11.png)
+![11. image](./images/11-1.png)
 
 Regel: *12 Cards Speak at Showdown 🟢*
 Regel: *16 Face Up for All-Ins 🟢*
 Regel: *17 Non All-In Showdowns 🟢*
 
-Wenn Julian den letzten Einsatz bezahlt, werden die Hände verglichen. Wenn er foldet, gewinnt Lars automatisch den gesamten Pot.
+Wenn Lars den letzten Einsatz bezahlt, werden die Hände verglichen. Wenn er foldet, gewinnt Jona automatisch den gesamten Pot.
 
-### Poker Hand Rankings (Gewichtung)
+## Poker Hand Rankings (Gewichtung)
 
 Die Kartenkombinationen sind klar geordnet – von schwach bis extrem stark:
 
-![12. image](./images/12.png)
+<img src="./images/12.png" height="600">
 
 Je höher die Kombination, desto stärker die Hand und desto wahrscheinlicher der Gewinn.
 
-Julian: 2. Paar: 
+Jona: 2. Paar: 
 
-![13. image](./images/13.png)
+![13. image](./images/13-1.png)
 
 Lars: 1. Paar:
 
-![14. image](./images/14.png)
+![14. image](./images/14-1.png)
 
-Da zwei Paare in der Rangfolge über einem einzelnen Paar stehen, gewinnt Julian diese Runde.
+Da zwei Paare in der Rangfolge über einem einzelnen Paar stehen, gewinnt Jona diese Runde.
 
-### Fazit
+## Fazit
 
 Poker ist kein Glücksspiel im klassischen Sinn, sondern ein Spiel aus Strategie, Psychologie und Mathematik. Jede Entscheidung von Julian, Mathis, Jona oder Lars verändert die komplette Dynamik am Tisch. Wer die Regeln versteht, versteht nicht nur Karten, sondern auch Menschen und Entscheidungen unter Druck.
 
 Regel: *67 One Player One Hand 🟢*
 Regel: *52 Incorrect Bets 🟡*
 Regel: *57 Non-Standard Betting 🟡*
-
-## English
-
-The poker table is an incredibly fascinating experiential space where you can learn a great deal: about yourself, about other people, and about questions such as: How do I actually make decisions? How do I handle stress and uncertainty? And how good am I at empathizing with others and correctly assessing situations?
-
-To enter this experiential space, it’s necessary—like with any game—to first understand the basic rules and game flow.
-
-So let’s begin:
-
-We have **4 players** at the table: Julian, Mathis, Jona, and Lars. Each player starts with **20,000 chips**. Each receives **2 hole cards**, and there are **5 community cards** that will later be revealed in the center.
-
-![1. image](./images/1.png)
-
-The players are seated as follows: Julian, Mathis, Jona, and Lars. One of them holds the dealer button, which determines who deals the cards and where the round begins. This button moves clockwise after each hand, constantly changing the positions.
-
-Rule: *34 Button Placement and Movement 🟢*
-
-### Blinds (Small Blind & Big Blind)
-
-Before cards are dealt, there are two mandatory bets:
-
-The Small Blind and the Big Blind. The Big Blind is always double the amount of the Small Blind.
-
-![2. image](./images/2.png)
-
-Rule: *32 Dead Button 🟡*
-
-These forced bets ensure that a pot exists from the start, making the game begin with everyone already involved.
-
-After this, the cards are dealt: first to the Small Blind, then the Big Blind, and then clockwise to all other players.
-
-### First Betting Round (Preflop)
-
-The first betting round always begins with the player to the left of the Big Blind.
-
-Now each player must decide:
-
-* Fold (exit the hand)
-* Call (match the current bet)
-* Raise (increase the bet)
-
-Rule: *40 Methods of Betting 🟢*  
-Rule: *41 Methods of Calling 🟢*  
-Rule: *42 Methods of Raising 🟢*  
-Rule: *50 Acting in Turn 🟢*
-
-### Preflop Example
-
-Julian looks at his cards and decides to Call for **600 chips**.
-
-![3. image](./images/3.png)
-
-Mathis sees his cards and realizes they aren’t strong, so he Folds and exits the hand.
-
-![4. image](./images/4.png)
-
-Jona is next and decides to Call as well, because his hand is playable.
-
-![5. image](./images/5.png)
-
-Lars looks at his cards, recognizes a strong hand, and Raises to **1200 chips**.
-
-![6. image](./images/6.png)
-
-This immediately changes the situation: Julian and Jona must now decide whether to call this raise, re-raise, or fold.
-
-### Flop (3 Community Cards)
-
-Now **3 community cards** are placed face-up in the center. From this point, the game changes completely, as all players gain additional information.
-
-![7. image](./images/7.png)
-
-A new betting round begins.
-
-Rule: *49 Accepted Action 🟢*
-
-### Flop Example
-
-Lars bets **1,000 chips** first. Julian decides to Call because his hand has improved with the community cards.
-
-![8. image](./images/8.png)
-
-Jona folds, as he no longer sees a strong connection. Mathis is already out.
-
-### Turn (4th Card)
-
-Now the **4th community card** is revealed.
-
-Another betting round begins.
-
-Lars bets **3,000 chips** this time. Julian calls again, as his hand remains strong.
-
-![9. image](./images/9.png)
-
-Rule: *53 Action Out of Turn 🟡*
-
-### River (5th Card)
-
-Now the final community card is revealed.
-
-This is the last decision point in the hand.
-
-Lars bets **5,000 chips**.
-
-![10. image](./images/10.png)
-
-Julian must now decide: Fold, Call, or even Raise to **10,000 chips**.
-
-Rule: *54 Pot Size Bets 🟡*
-
-### Showdown (Winning Decision)
-
-If two or more players remain after the final betting round, a showdown occurs.
-
-All active players reveal their cards. The winner is the one with the **best 5-card combination using any combination of their hole cards and the community cards**.
-
-![11. image](./images/11.png)
-
-Rule: *12 Cards Speak at Showdown 🟢*  
-Rule: *16 Face Up for All-Ins 🟢*  
-Rule: *17 Non All-In Showdowns 🟢*
-
-If Julian calls the final bet, the hands are compared. If he folds, Lars wins the entire pot automatically.
-
-### Poker Hand Rankings (Hierarchy)
-
-The card combinations are clearly ranked—from weakest to strongest:
-
-![12. image](./images/12.png)
-
-The higher the combination, the stronger the hand, and the greater the chance of winning.
-
-Julian: Two Pair:
-
-![13. image](./images/13.png)
-
-Lars: One Pair:
-
-![14. image](./images/14.png)
-
-Since two pair ranks higher than one pair, Julian wins this round.
-
-### Conclusion
-
-Poker is not gambling in the traditional sense, but rather a game of strategy, psychology, and mathematics. Every decision made by Julian, Mathis, Jona, or Lars changes the entire dynamic at the table. Understanding the rules means not only understanding cards, but also people and decision-making under pressure.

documents/docs/game-engine/manual.html

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+            padding: 2px 5px;
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+</head>
+
+<body>
+
+<div id="content"></div>
+
+<script>
+
+    window.addEventListener("DOMContentLoaded", () => {
+        const markdown = `
+# Casono Manual
+
+Hinweis: Eine vereinfachte Einführung finden Sie in der Datei [Casono Rules – Easy Description](casono-rules-easy-description.md).
+Dieses Dokument beschreibt den Ablauf eines Pokerspiels anhand eines Beispiels.
+
+## 1. Spielübersicht
+
+Texas Hold’em ist ein strategisches Kartenspiel für mehrere Spieler.
+Ziel ist es, den Pot (alle gesetzten Chips) zu gewinnen, entweder durch:
+
+- die beste Kartenkombination am Ende der Runde
+- oder indem alle anderen Spieler vorher aussteigen (Fold)
+
+### Grundregeln
+
+- Jeder Spieler erhält 2 verdeckte Karten (Hole Cards)
+- Es werden 5 Gemeinschaftskarten offen in der Mitte ausgelegt
+- Jeder Spieler bildet die beste 5-Karten-Kombination aus:
+  - eigenen Karten
+  - und Gemeinschaftskarten
+
+- Zu Spielbeginn erhält jeder Spieler ein Startgeld von 20000 Chips ($)
+
+## 2. Sitzposition & Dealer-Button
+
+Der sogenannte Dealer-Button bestimmt die Positionen am Tisch:
+
+- Er zeigt an, wer als „Geber“ (Dealer) fungiert
+- Die Positionen rotieren im Uhrzeigersinn nach jeder Runde
+
+Die Position ist entscheidend, da sie bestimmt:
+
+- die Reihenfolge der Aktionen
+- wer die Blinds setzen muss
+
+## 3. Blinds (Pflichteinsätze)
+
+Vor jeder Runde werden zwei verpflichtende Einsätze geleistet:
+
+- **Small Blind** (kleiner Blind): 100 Chips – gesetzt vom Spieler links neben dem Dealer
+- **Big Blind** (großer Blind): 200 Chips - gesetzt vom Spieler zwei Plätze links vom Dealer
+
+Diese Einsätze sorgen dafür, dass:
+
+- ein Startpot entsteht
+- jede Runde aktiv gespielt wird
+
+## 4. Spielablauf im Detail
+
+### 4.1 Preflop (erste Setzrunde)
+
+Nach dem Austeilen der Karten beginnt die erste Setzrunde.
+
+Der Spieler links vom Big Blind eröffnet die Runde.
+
+Jeder Spieler hat folgende Optionen:
+
+- **Fold** – Karten ablegen und aussteigen
+- **Call** – Einsatz mitgehen
+- **Raise** – Einsatz erhöhen
+
+### 4.2 Flop (3 Gemeinschaftskarten)
+
+- Drei Karten werden offen auf den Tisch gelegt
+- Eine neue Setzrunde beginnt
+- Die Setzrunde beginnt jetzt immer beim ersten aktiven Spieler links vom Dealer (im Uhrzeigersinn).
+
+Ab diesem Zeitpunkt können alle Spieler ihre Strategie anhand zusätzlicher Informationen anpassen.
+
+### 4.3 Turn (4. Gemeinschaftskarte)
+
+- Die vierte Karte wird aufgedeckt
+- Eine weitere Setzrunde folgt
+
+Die Einsätze werden oft höher, da sich stärkere Hände entwickeln.
+
+### 4.4 River (5. Gemeinschaftskarte)
+
+- Die letzte Karte wird aufgedeckt
+- Letzte Setzrunde
+
+Dies ist die finale Entscheidungsphase:
+
+- Maximierung des Gewinns
+- oder Minimierung von Verlusten
+
+## 5. Showdown (Kartenvergleich)
+
+Wenn nach der letzten Setzrunde mindestens zwei Spieler verbleiben:
+
+- Alle verbleibenden Spieler decken ihre Karten auf
+- Die **beste 5-Karten-Kombination gewinnt**
+
+Wichtig:
+
+- Die Karten „sprechen für sich“ – die beste Hand zählt unabhängig von Ansagen
+
+## 6. Poker-Handrangfolge
+
+Die Stärke der Hände ist eindeutig festgelegt (von schwach nach stark):
+
+1. High Card (höchste Einzelkarte)
+2. One Pair (ein Paar)
+3. Two Pair (zwei Paare)
+4. Three of a Kind (Drilling)
+5. Straight (Straße)
+6. Flush (Farbe)
+7. Full House
+8. Four of a Kind (Vierling)
+9. Straight Flush
+10. Royal Flush
+
+Je höher die Kombination, desto stärker die Hand.
+
+## 7. Wichtige Grundprinzipien
+
+### Reihenfolge beachten
+
+Spieler müssen immer der Reihe nach handeln.
+
+### Klare Aktionen
+
+Alle Aktionen müssen eindeutig sein:
+
+- Einsätze klar ansagen oder eindeutig setzen
+
+### Ein Spieler – eine Hand
+
+- Spieler dürfen ihre Karten nicht teilen oder gemeinsam spielen
+
+### Fehlerhafte Einsätze
+
+- Unklare oder falsche Einsätze können korrigiert werden, abhängig von der Spielsituation (nur wenn der Einsatz außerhalb der gültigen Grenzen liegt; zu hohe oder unzulässige Beträge werden blockiert und nicht automatisch korrigiert)
+
+## 8. Strategische Einordnung
+
+Texas Hold’em ist kein reines Glücksspiel. Der Erfolg basiert auf:
+
+- Wahrscheinlichkeiten (Mathematik)
+- Einschätzung von Gegnern (Psychologie)
+- Positionsspiel und Timing
+        `;
+
+        document.getElementById("content").innerHTML =
+            marked.parse(markdown);
+
+        document.querySelectorAll("#content a").forEach(link => {
+            link.addEventListener("click", (e) => {
+                const href = link.getAttribute("href");
+
+                if (href && href.endsWith(".md")) {
+                    e.preventDefault();
+                    alert("You cannot load an external MD file using `file:///` without a server.");
+                }
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+</script>
+
+<noscript>
+    <div style="
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+        font-family: Arial, sans-serif;
+        background-color: #0d9e3b;
+        color: #ffffff;
+        text-align: center;
+    ">
+        <h2>JavaScript is disabled</h2>
+
+        <p>
+            The Casono Browser requires JavaScript for the <br>
+            Casono Markdown Render Engine to display content correctly.<br><br>
+
+            For security, JavaScript is disabled by default in the Casono Browser and should only be enabled when needed.
+        </p>
+
+        <p>
+            Please enable JavaScript in your Browser settings and reload the page.
+        </p>
+
+        <img src="images/activate-js.png" alt="JavaScript aktivieren Anleitung" style="max-width: 100%; margin-top: 20px; border-radius: 10px;">
+    </div>
+</noscript>
+
+</body>
+</html>

documents/milestones/ms-4/qa-concept.tex

@@ -0,0 +1,144 @@
+\documentclass{article}
+\setlength{\parindent}{0pt}
+\usepackage[a4paper,margin=2.5cm]{geometry}
+\usepackage{listings}
+
+% External links
+\usepackage{hyperref}
+
+% Colored text
+\usepackage{xcolor}
+
+% Customized table
+\usepackage{float}
+\usepackage{array}
+\newcolumntype{L}[1]{>{\raggedright\arraybackslash}p{#1}}
+\usepackage{booktabs}
+
+\title{QS-Konzept für MS4}
+\author{Syntax Syndicate - Casono}
+\begin{document}
+\maketitle
+
+
+\section{Einleitung}
+Dieses Dokument beschreibt die Software-Qualitätssicherung für unser Mehrspieler-Spiel \textit{Casono}. Es wird als Teil der Programmierprojekt-Vorlesung (ehemals bekannt als cs108) an der Universität Basel von uns entwickelt.\\
+
+Dieses Konzept basiert auf der \textit{DIN ISO 9126} und ist demzufolge in folgende Themenbereiche unterteilt:
+\begin{itemize}
+  \item \textbf{Konstruktives Qualitätsmanagement} - Maßnahmen, die \emph{während} der Entwicklung ergriffen werden, um die Qualität von Anfang an sicherzustellen.
+  Einschließlich technischer Standards, Werkzeuge und internen Organisation.
+  \item \textbf{Analytisches Qualitätsmanagement} - Maßnahmen zur \emph{Kontrolle und Untersuchung} des bestehenden Produkts, durch Anwendung automatisierte Analysen, Metrik-Schwellenwerte und Unit-Tests.
+\end{itemize}
+
+
+\section{Konstruktives Qualitätsmanagement}
+Ein konstruktives Qualitätsmanagement umfasst alle Maßnahmen, die proaktiv Mängel verhindern, indem gemeinsame Standards, Prozesse und Werkzeuge festgelegt werden, die jedes Teammitglied während der Entwicklung einhält.
+
+\subsection{Technische Maßnahmen}
+
+\subsubsection{JavaDoc}
+Alle öffentlichen Klassen, Interfaces, Records und Methoden müssen durch JavaDoc dokumentiert werden.\\
+Als Teil der GitLab-Build-Pipeline wird JavaDoc auf Richtigkeit überprüft. Werden strukturelle Fehler wie ungültige Referenzen erkannt, wird der Merge verhindert.\\
+Unsere aktuelle Grundlage sind daher 0 Fehler. Für den kommenden Meilenstein ist aber unser Ziel, die Regelungen weiter zu verschärfen, sodass auch Warnungen einen Merge verhindern.\\
+
+Unsere implizite Form für JavaDoc-Kommentare ist wie folgt:
+\begin{itemize}
+  \item Eine prägnante Zusammenfassung in einem Satz in der ersten Zeile
+  \item Zusätzliche Informationen oder Beispiele in weiteren Absätzen.
+  \item Dokumentation aller Parameter (\texttt{@param}), Rückgabewerte (\texttt{@return}) und Fehler (\texttt{@throws}).
+\end{itemize}
+Beginnend mit dem fünften Meilenstein soll diese Form ebenfalls durch einen Job in der CI-Pipeline überprüft werden.
+
+\newpage
+\subsubsection{Logging}
+Das Projekt verwendet Log4J~2 (\texttt{log4j-api} und \texttt{log4j-core} zur Laufzeit) zusammen mit Jansi für eine farbige Konsolenausgabe.
+Das Format der Ausgabe ist durch eine Konfigurationsdatei vereinheitlicht.\\
+
+Die Protokollstufen werden wie folgt einheitlich verwendet:
+\begin{itemize}
+  \item \texttt{DEBUG} für interne Zustandsänderungen
+  \item \texttt{INFO} für Lebenszyklusereignisse wie Serverstart, Verbindungsaufbau/-trennung des Clients
+  \item \texttt{WARN} für behebbare Anomalien
+  \item \texttt{ERROR} für nicht behebbare Fehler
+\end{itemize}
+
+\subsection{Organisatorische Maßnahmen}
+
+\subsubsection{Teamkultur und die \texttt{CONTRIBUTORS}-Datei}
+Das Stammverzeichnis des GitLab-Repositories enthält eine Datei namens \texttt{CONTRIBUTORS.md}, die die Teamkonventionen dokumentiert: 
+\begin{itemize}
+  \item Die Verwendung von Branches - Feature-Branches werden in \texttt{main} zusammengeführt
+  \item Merge-Richtlinie - CI muss bestanden werden. Keine ausdrückliche Genehmigung durch Kollegen erforderlich \footnote{Diese Regelung wird sich voraussichtlich ändern. Siehe dazu den Abschnitt zur \texttt{CODEOWNERS}-Datei.}
+  \item Namenskonventionen für Branches und Commits
+  \item Code-Stil - Google-Java-Format, AOSP-Variante, Einrückung mit vier Leerzeichen
+  \item Jede Änderung beginnt mit einem Issue oder Task in GitLab, bevor mit der Umsetzung begonnen wird
+  \item Branch-Namen folgen dem Muster \texttt{<typ>/<kurzbeschreibung>} gemäß \href{https://conventional-branch.github.io/}{Conventional Branch} Standard
+  \item Commit-Messages folgen dem \href{https://www.conventionalcommits.org/en/v1.0.0/}{Conventional Commits} Standard
+  \item Code-Style wird durch Linter (Checkstyle) und Formatter (Spotless, Google/AOSP Java Style) automatisiert überprüft
+  \item Merge Anfragen müssen eine Beschreibung enthalten und auf das zugehörige Issue oder den Task verweisen
+  \item Zusammenarbeit und Kommunikation erfolgen bevorzugt über Issue-Kommentare, nicht über private Nachrichten
+\end{itemize}
+
+\subsubsection{GitLab-Task- und Issue-Vorlagen für Fortschrittsverfolgung}
+GitLab-Vorlagen für Tasks und Issues werden für alle geplanten Arbeitselemente verwendet. Die Aufgabenvorlage sorgt für eine einheitliche Struktur, die die Fortschrittsverfolgung erleichtert und das Risiko vager oder unvollständiger Arbeitselemente reduziert.
+
+Durch die Vergabe von Labels kann Tasks und Issues weiterer Kontext gegeben werden.
+
+
+\newpage
+\section{Analytisches Qualitätsmanagement}
+\subsection{Analytische Verfahren}
+
+\subsubsection{Eigentumsrechte an Programmcode über GitLab \texttt{CODEOWNERS}}
+Beginnend mit dem fünften Meilenstein soll eine \texttt{CODEOWNERS}-Datei erstellt werden, welche Teammitgliedern die Eigentumsrechte an bestimmten Teilen des Programmcodes zuspricht.
+Wollen andere Teammitglieder Änderungen an diesen Teilen vornehmen, muss der Eigentümer sie freigeben.\\
+Aktuell ist jedoch noch unklar, ob diese Funktion genutzt werden kann, da die Instanz mindestens die \textit{Premium}-Stufe haben muss.
+
+\subsubsection{Automatisiertes CI-Linting und Build-Verifizierung}
+Jeder Push und jede Merge-Anfrage löst die CI-Pipeline aus.
+
+Für Pushes und Merge-Anfrage setzt sich die Pipeline aus folgenden Phasen zusammen:
+\begin{enumerate}
+  \item \textbf{Linting-Phase} \textcolor{blue}{[Push, MR]} - Checkstyle und Spotless überprüfen, ob der Programmcode dem vereinbarten Stil entspricht.
+  \item \textbf{Build-Phase} \textcolor{blue}{[Push, MR]} - \texttt{./gradlew assemble} prüft, ob das gesamte Projekt fehlerfrei kompiliert werden kann.
+  \item \textbf{Checkstyle-Report} \textcolor{blue}{[MR]} - Ein zusätzlicher Checkstyle-Report wird für Merge-Anfragen erzeugt und als Code-Quality-Report bereitgestellt.
+  \item \textbf{Javadoc-Prüfung} \textcolor{blue}{[MR]} - JavaDoc wird auf Korrektheit geprüft.
+  \item \textbf{Test-Phase} \textcolor{blue}{[Push, MR]} - Automatisierte Tests werden ausgeführt und ein Testreport erzeugt.
+\end{enumerate}
+Fehlschlagende Jobs verhindern einen Push nicht, jedoch wird ein Merge so lange verhindert, bis alle Jobs fehlerfrei abgeschlossen werden können.
+
+\subsection{Testverfahren}
+Unit-Tests werden mit \textit{JUnit 5} geschrieben und in der Testphase der CI-Pipeline ausgeführt. Ein fehlgeschlagener Test blockiert die Merge-Anfrage.
+
+Als weiteres Werkzeug verwenden wir \textit{JaCoCo} für die Ermittlung der Testabdeckung. \\
+Die aktuelle Testabdeckung ist wie folgt:
+
+\begin{table}[H]
+  \centering
+  \renewcommand{\arraystretch}{1.4}
+  \begin{tabular}{L{7.5cm} r r}
+    \toprule
+    \textbf{Paketname (gekürzt)}        & \textbf{Instr.\ Cov.} & \textbf{Branch Cov.} \\
+    \midrule
+    \texttt{client.chat}                                & 0\,\%  & 0\,\% \\
+    \texttt{client.game}                                & 0\,\%  & 0\,\% \\
+    \texttt{client.network}                             & 3\,\%  & 1\,\% \\
+    \texttt{client.ui} (von Abdeckung ausgeschlossen)   & 0\,\%  & 0\,\% \\
+    \texttt{server.app.checks}                          & 0\,\%  & 0\,\% \\
+    \texttt{server.app.commands}                        & 0\,\%  & 0\,\% \\
+    \texttt{server.domain.game}                         & 94\,\%  & 91\,\% \\
+    \texttt{server.domain.*}                            & 45\,\%  & 37\,\% \\
+    \texttt{server.network.transport}                   & 0\,\%  & 0\,\% \\
+    \texttt{server.network.protocol}                    & 0\,\%  & 0\,\% \\
+    \texttt{server.network.*}                           & 2\,\%  & 1\,\% \\
+    \midrule
+    \textbf{Summe}                          & \textbf{12\,\%} & \textbf{9\,\%} \\
+    \bottomrule
+  \end{tabular}
+\end{table}
+
+Unser Ziel ist es, realistische Anforderungen an unsere Testabdeckung zu stellen.
+Bis zum fünften Meilenstein wollen wir daher für wichtige Bereiche, wie die Game-Engine und interne Komponenten des Netzwerks, eine möglichst hohe Abdeckung von mindestens 50\% erzielen. 
+
+\end{document}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/Main.java

@@ -7,6 +7,12 @@ import org.apache.logging.log4j.Logger;
 
 /** Main entry point for Casono application. Handles client and server startup. */
 public final class Main {
+
+    private static final int MIN_ARGS_FOR_USERNAME = 3;
+    private static final int ARGS_COUNT_SERVER = 2;
+    private static final int ARGS_COUNT_CLIENT_MIN = 2;
+    private static final int ARGS_COUNT_CLIENT_WITH_USER = 3;
+
     /**
      * Main entry point for Casono.
      *
@@ -17,10 +23,13 @@ public final class Main {
             printUsage();
             System.exit(1);
         }
-
         switch (args[0]) {
             case "server" -> ServerApp.start(args[1]);
-            case "client" -> ClientApp.start(args[1]);
+            case "client" -> {
+                String address = args[1];
+                String username = args.length >= MIN_ARGS_FOR_USERNAME ? args[2] : null;
+                ClientApp.start(address, username);
+            }
             default -> {
                 printUsage();
                 System.exit(1);
@@ -29,12 +38,15 @@ public final class Main {
     }
 
     private static boolean isValid(String[] args) {
-        if (args.length != 2) {
+        if (args.length < ARGS_COUNT_SERVER) {
             return false;
         }
 
         return switch (args[0]) {
-            case "server", "client" -> true;
+            case "server" -> args.length == ARGS_COUNT_SERVER;
+            case "client" ->
+                    args.length == ARGS_COUNT_CLIENT_MIN
+                            || args.length == ARGS_COUNT_CLIENT_WITH_USER;
             default -> false;
         };
     }
@@ -45,7 +57,7 @@ public final class Main {
                 """
                 Usage:
                   java -jar xyz.jar server <listenPort>
-                  java -jar xyz.jar client <serverIp>:<serverPort>
+                  java -jar xyz.jar client <serverIp>:<serverPort> [<username>]
                 """);
     }
 }

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/ClientApp.java

@@ -1,51 +1,131 @@
 package ch.unibas.dmi.dbis.cs108.casono.client;
 
-/**
- * Entry point for the Casono client application. Handles client startup and connection parameters.
- */
+import ch.unibas.dmi.dbis.cs108.casono.client.network.ClientService;
+import ch.unibas.dmi.dbis.cs108.casono.client.network.LobbyClient;
+import ch.unibas.dmi.dbis.cs108.casono.client.network.LoginResult;
 import ch.unibas.dmi.dbis.cs108.casono.client.ui.Launcher;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
 /**
- * Entry point for the Casono client application. Handles client startup and connection parameters.
+ * Entry point and bootstrap helper for the Casono client application.
  *
- * <p>Default constructor for the application.
+ * <p>Responsibilities: - Parse CLI args (host:port, optional username) - Store username centrally
+ * so UI can reuse it - Create a shared ClientService and do startup LOGIN
  */
 public class ClientApp {
 
     private static final Logger LOGGER = LogManager.getLogger(ClientApp.class);
 
+    /** Shared client connection used when a username is provided at startup. */
+    private static volatile ClientService sharedClientService;
+
+    private static volatile String sharedUsername;
+
     /** Default constructor. */
     public ClientApp() {
         // Default constructor
     }
 
-    /**
-     * Starts the client application with the given address.
-     *
-     * @param arg Address in the format "ip:port".
-     * @throws IllegalArgumentException if the address format is invalid.
-     */
-    public static void start(String arg) {
+    public static ClientService getSharedClientService() {
+        return sharedClientService;
+    }
+
+    private static void setSharedClientService(ClientService cs) {
+        sharedClientService = cs;
+    }
+
+    public static String getSharedUsername() {
+        return sharedUsername;
+    }
+
+    public static void updateSharedUsername(String username) {
+        setSharedUsername(normalizeUsername(username));
+    }
+
+    private static String normalizeUsername(String username) {
+        if (username == null || username.isBlank()) {
+            return null;
+        }
+        return username.trim();
+    }
+
+    private static void setSharedUsername(String username) {
+        sharedUsername = username;
+        LOGGER.info("sharedUsername set to '{}'", getSharedUsername());
+    }
+
+    public static void start(String arg, String username) {
+        String[] hostPort = parseHostAndPort(arg);
+        String host = hostPort[0];
+        int port = Integer.parseInt(hostPort[1]);
+        String normalizedUsername = normalizeUsername(username);
+
+        configureServerProperties(host, port);
+        setSharedUsername(normalizedUsername);
+
+        performStartupLogin(host, port, normalizedUsername);
+
+        launchUI(arg);
+    }
+
+    private static String[] parseHostAndPort(String arg) {
         String[] parts = arg.split(":", 2);
         if (parts.length != 2) {
-            throw new IllegalArgumentException("Address must be in format <ip>:<port>.");
+            throw new IllegalArgumentException("The address must be in the format <ip>:<port>.");
         }
-        String host = parts[0];
-        int port = Integer.parseInt(parts[1]);
+        return parts;
+    }
 
+    private static void configureServerProperties(String host, int port) {
         LOGGER.info("You've selected the client. It will connect port {} at host {}", port, host);
-        // Expose the chosen host/port to the UI via system properties so controllers
-        // (which read System.getProperty("casono.server.host"/"casono.server.port"))
-        // can obtain the correct connection information.
         System.setProperty("casono.server.host", host);
-        System.setProperty("casono.server.port", Integer.toString(port));
-        // Forward the original address argument to the launcher as well.
-        Launcher.main(new String[] {arg});
+        System.setProperty("casono.server.port", String.valueOf(port));
+    }
+
+    private static void performStartupLogin(String host, int port, String username) {
+        try {
+            ClientService clientService = new ClientService(host, port);
+            setSharedClientService(clientService);
+            LobbyClient lobbyClient = new LobbyClient(clientService);
+            LoginResult res = lobbyClient.login(username);
+
+            if (res != null && res.getUsername() != null && !res.getUsername().isBlank()) {
+                setSharedUsername(res.getUsername().trim());
+            }
+
+            String assignedUsername = null;
+            String assignedId = null;
+            if (res != null) {
+                assignedUsername = res.getUsername();
+                assignedId = res.getId();
+            }
+            LOGGER.info("Assigned username='{}' id={}", assignedUsername, assignedId);
+        } catch (RuntimeException e) {
+            LOGGER.warn(
+                    "Could not establish initial connection for startup login: {}", e.getMessage());
+        }
+    }
+
+    private static void launchUI(String arg) {
+        String username = getSharedUsername();
+        if (username == null || username.isBlank()) {
+            Launcher.main(new String[] {arg});
+            return;
+        }
+        Launcher.main(new String[] {arg, username});
     }
 
     public static void main(String[] args) {
-        start(args[0]);
+        if (args == null || args.length == 0) {
+            throw new IllegalArgumentException("Address argument required: <host:port>");
+        }
+
+        String username = null;
+        if (args.length > 1) {
+            username = normalizeUsername(args[1]);
+        }
+
+        start(args[0], username);
     }
 }

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/chat/ChatController.java

@@ -1,13 +1,24 @@
 package ch.unibas.dmi.dbis.cs108.casono.client.chat;
 
+import ch.unibas.dmi.dbis.cs108.casono.client.ClientApp;
 import ch.unibas.dmi.dbis.cs108.casono.client.network.ChatClient;
 import ch.unibas.dmi.dbis.cs108.casono.client.network.ClientService;
 import ch.unibas.dmi.dbis.cs108.casono.client.ui.chatui.ChatBoxController;
+import ch.unibas.dmi.dbis.cs108.casono.client.ui.chatui.ChatViewController;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.parsing.RequestParameter;
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.Timer;
 import java.util.TimerTask;
+import java.util.WeakHashMap;
+import java.util.function.Consumer;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.jspecify.annotations.Nullable;
 
 /**
@@ -16,7 +27,13 @@ import org.jspecify.annotations.Nullable;
  */
 public class ChatController {
 
-    private final String username;
+    /** Ensures one active message poller per physical ClientService connection. */
+    private static final Map<ClientService, ChatController> ACTIVE_CONTROLLERS =
+            new WeakHashMap<>();
+
+    private volatile String username;
+
+    private final ClientService clientService;
 
     private final ChatClient chatClient;
 
@@ -24,9 +41,14 @@ public class ChatController {
         return chatBoxController;
     }
 
-    private final ChatBoxController chatBoxController;
+    public void setChatBoxController(ChatBoxController chatBoxController) {
+        this.chatBoxController = chatBoxController;
+    }
+
+    private ChatBoxController chatBoxController;
     private int lobbyId = -1;
     private final Timer timer;
+    private final Consumer<List<String>> serverEventListener;
 
     public record ChatKey(ChatType type, @Nullable String targetUser) {
         public ChatKey(ChatType type) {
@@ -38,10 +60,21 @@ public class ChatController {
         return chatModelMap;
     }
 
-    private Map<ChatKey, ChatModel> chatModelMap;
+    private final Map<ChatKey, ChatModel> chatModelMap;
 
     private static final long REFRESH_TIME = 1000;
 
+    /** List of all users connected to the server, to safe them locally on the client */
+    private final List<String> localUserList;
+
+    public List<String> getLocalUserList() {
+        return this.localUserList;
+    }
+
+    public final Map<ChatController.ChatKey, ChatViewController> activeChatControllers;
+
+    private final Logger logger;
+
     /**
      * Constructor, adds TimerTask to be sent to the server regularly
      *
@@ -50,36 +83,76 @@ public class ChatController {
      */
     public ChatController(String username, ClientService clientService) {
         this.username = username;
+        this.clientService = clientService;
         chatClient = new ChatClient(clientService);
         chatModelMap = new LinkedHashMap<>();
+        localUserList = new ArrayList<>();
         this.chatBoxController = new ChatBoxController(username, this);
-        this.timer = new Timer();
+        this.logger = LogManager.getLogger(ChatController.class);
+        this.serverEventListener = this::handleServerEvent;
+        this.activeChatControllers = new HashMap<>();
+
+        registerAsActiveController(clientService);
+        clientService.addEventListener(serverEventListener);
+
+        this.timer = new Timer(true);
         timer.schedule(
                 new TimerTask() {
                     @Override
                     public void run() {
-                        receiveMessage();
+                        try {
+                            receiveMessage();
+                            checkWhisperUsers();
+                        } catch (RuntimeException e) {
+                            logger.warn("Chat refresh failed: {}", e.getMessage());
+                        }
                     }
                 },
                 0,
                 REFRESH_TIME);
     }
 
+    private void registerAsActiveController(ClientService clientService) {
+        synchronized (ACTIVE_CONTROLLERS) {
+            ChatController oldController = ACTIVE_CONTROLLERS.get(clientService);
+            if (oldController != null && oldController != this) {
+                oldController.shutdown();
+                logger.info("Replaced previous ChatController poller for shared ClientService");
+            }
+            ACTIVE_CONTROLLERS.put(clientService, this);
+        }
+    }
+
     /**
-     * Method to be activated, if a lobby has be chosen. It will update the UI and add a new
+     * Method to be activated, if a lobby has been chosen. It will update the UI and add a new
      * ChatModel to hold the Data for the Lobby Chat
      *
      * @param lobbyId
      */
     public void setLobbyChat(int lobbyId) {
         this.lobbyId = lobbyId;
+        ChatKey key = new ChatKey(ChatType.LOBBY);
+        ChatModel existingModel = chatModelMap.get(key);
+        if (existingModel != null) {
+            existingModel.lobbyId = lobbyId;
+            return;
+        }
         ChatModel lobbyChatModel = new ChatModel(ChatType.LOBBY, username, lobbyId, null);
-        chatModelMap.put(new ChatKey(ChatType.LOBBY), lobbyChatModel);
-        this.chatBoxController.addChatTab("Lobby", lobbyChatModel);
+        chatModelMap.put(key, lobbyChatModel);
+        this.chatBoxController.addChatTab("LOBBY", lobbyChatModel, ChatType.LOBBY);
     }
 
-    /** method to get all messages from the server */
+    /**
+     * Method to process the Messages that got polled by the {@link ChatClient}.
+     *
+     * <p>Case distinction for every message: - Messages identified with ChatType.LOBBY -> check if
+     * they belong to the users lobby. - Messages identified with ChatType.GLOBAL -> check if the
+     * target user of that Message is the user, or the message got sent by the user.
+     *
+     * <p>All Messages get added to a particular {@link ChatModel}, if the checks passed.
+     */
     public void receiveMessage() {
+        String currentUsername = getCurrentUsername();
         List<Message> newMessages = chatClient.getMessages();
         if (!newMessages.isEmpty()) {
             for (Message msg : newMessages) {
@@ -88,28 +161,39 @@ public class ChatController {
                         chatModelMap.get(new ChatKey(ChatType.GLOBAL)).addMessage(msg);
                         break;
                     case ChatType.LOBBY:
-                        if (msg.lobbyId == lobbyId) {
+                        if (msg.lobbyId == getActiveLobbyChatId()) {
                             chatModelMap
                                     .computeIfAbsent(
                                             new ChatKey(ChatType.LOBBY),
                                             (_key) ->
                                                     new ChatModel(
                                                             ChatType.LOBBY,
-                                                            username,
+                                                            currentUsername,
                                                             msg.lobbyId,
                                                             null))
                                     .addMessage(msg);
                         }
                         break;
                     case ChatType.WHISPER:
-                        if (msg.target.equals(username)) {
-                            if (chatModelMap.containsKey(
-                                    new ChatKey(ChatType.WHISPER, msg.sender))) {
-                                chatModelMap
-                                        .get(new ChatKey(ChatType.WHISPER, msg.sender))
-                                        .addMessage(msg);
+                        if (msg.target.equals(currentUsername)
+                                || msg.sender.equals(currentUsername)) {
+                            ChatKey key;
+                            if (msg.target.equals(currentUsername)) {
+                                key = new ChatKey(ChatType.WHISPER, msg.sender);
                             } else {
-                                chatBoxController.addWhisperChat(msg.sender);
+                                key = new ChatKey(ChatType.WHISPER, msg.target);
+                            }
+                            if (chatModelMap.containsKey(key)) {
+                                chatModelMap.get(key).addMessage(msg);
+                            } else {
+                                ChatModel chatModel =
+                                        new ChatModel(
+                                                ChatType.WHISPER,
+                                                currentUsername,
+                                                lobbyId,
+                                                key.targetUser());
+                                chatBoxController.addWhisperChat(key.targetUser(), chatModel);
+                                chatModel.addMessage(msg);
                             }
                         }
                         break;
@@ -118,6 +202,176 @@ public class ChatController {
         }
     }
 
+    /**
+     * Method to get the lobbyId of the currently active lobby chat, to check if incoming lobby
+     * messages belong to the same lobby.
+     *
+     * @return the lobbyId of the currently active lobby chat.
+     */
+    private int getActiveLobbyChatId() {
+        ChatModel lobbyModel = chatModelMap.get(new ChatKey(ChatType.LOBBY));
+        if (lobbyModel != null) {
+            return lobbyModel.lobbyId;
+        }
+        return lobbyId;
+    }
+
+    /**
+     * Method to process the usernames of other users connected to the server, after they got polled
+     * by the {@link ChatClient}.
+     *
+     * <p>Checks for every one of the usernames, if it is already in the list localUserList and if
+     * not adds them. For every new User added in the List, they get added as an option to start a
+     * Whisper Chat with.
+     */
+    public synchronized void checkWhisperUsers() {
+        List<String> users = chatClient.getUsers();
+        Set<String> remoteUsers = new HashSet<>();
+        String currentUsername = getCurrentUsername();
+
+        for (String user : users) {
+            if (user == null || !user.contains("=")) {
+                continue;
+            }
+            String value = user.split("\\=", 2)[1].trim();
+            if (value.isBlank() || value.equals(currentUsername)) {
+                continue;
+            }
+            remoteUsers.add(value);
+        }
+
+        for (String known : new ArrayList<>(localUserList)) {
+            if (!remoteUsers.contains(known)) {
+                localUserList.remove(known);
+                chatBoxController.removeWhisperUser(known);
+            }
+        }
+
+        for (String remote : remoteUsers) {
+            addWhisperUser(remote);
+        }
+    }
+
+    /**
+     * Registers a whisper target locally and updates the UI if it is a new user.
+     *
+     * @param user target username
+     */
+    public synchronized void addWhisperUser(String user) {
+        if (user == null || user.isBlank()) {
+            return;
+        }
+        if (!(localUserList.contains(user) || user.equals(getCurrentUsername()))) {
+            localUserList.add(user);
+            logger.info("adding new whisper user");
+            chatBoxController.addWhisperUser(user);
+        }
+    }
+
+    public synchronized void updateUsername(String newUsername) {
+        if (newUsername == null || newUsername.isBlank()) {
+            return;
+        }
+        String oldUsername = this.username;
+        this.username = newUsername.trim();
+        chatBoxController.setUsername(this.username);
+
+        if (oldUsername != null && !oldUsername.equals(this.username)) {
+            localUserList.remove(oldUsername);
+            chatBoxController.removeWhisperUser(oldUsername);
+        }
+    }
+
+    private void handleServerEvent(List<String> lines) {
+        if (lines == null || lines.isEmpty()) {
+            return;
+        }
+
+        List<RequestParameter> params;
+        try {
+            params = ClientService.convertToRequestParameters(lines);
+        } catch (RuntimeException e) {
+            return;
+        }
+        String event = null;
+        String oldUsername = null;
+        String newUsername = null;
+
+        for (RequestParameter p : params) {
+            if ("EVENT".equalsIgnoreCase(p.key())) {
+                event = p.value();
+            } else if ("OLD_USERNAME".equalsIgnoreCase(p.key())) {
+                oldUsername = p.value();
+            } else if ("NEW_USERNAME".equalsIgnoreCase(p.key())) {
+                newUsername = p.value();
+            }
+        }
+
+        if (!"USERNAME_CHANGED".equalsIgnoreCase(event)) {
+            return;
+        }
+
+        applyUsernameMigration(oldUsername, newUsername);
+    }
+
+    private synchronized void applyUsernameMigration(String oldUsername, String newUsername) {
+        if (oldUsername == null
+                || newUsername == null
+                || oldUsername.isBlank()
+                || newUsername.isBlank()
+                || oldUsername.equals(newUsername)) {
+            return;
+        }
+
+        String currentUsername = getCurrentUsername();
+        if (oldUsername.equals(currentUsername)) {
+            updateUsername(newUsername);
+        }
+
+        ChatKey oldKey = new ChatKey(ChatType.WHISPER, oldUsername);
+        ChatKey newKey = new ChatKey(ChatType.WHISPER, newUsername);
+
+        ChatModel oldModel = chatModelMap.remove(oldKey);
+        ChatModel existingNewModel = chatModelMap.get(newKey);
+        if (oldModel != null) {
+            oldModel.setTarget(newUsername);
+            if (existingNewModel == null) {
+                chatModelMap.put(newKey, oldModel);
+            } else {
+                // Merge possible parallel history into the already existing new-key model.
+                for (Message msg : oldModel.messages) {
+                    existingNewModel.addMessage(msg);
+                }
+            }
+            chatBoxController.renameWhisperUser(oldUsername, newUsername);
+        }
+
+        localUserList.remove(oldUsername);
+        chatBoxController.removeWhisperUser(oldUsername);
+        if (!newUsername.equals(getCurrentUsername())) {
+            addWhisperUser(newUsername);
+        }
+    }
+
+    public String getCurrentUsername() {
+        String shared = ClientApp.getSharedUsername();
+        if (shared != null && !shared.isBlank()) {
+            return shared.trim();
+        }
+        return username;
+    }
+
+    /** Stops polling background tasks for this chat controller instance. */
+    public void shutdown() {
+        timer.cancel();
+        clientService.removeEventListener(serverEventListener);
+        synchronized (ACTIVE_CONTROLLERS) {
+            if (ACTIVE_CONTROLLERS.get(clientService) == this) {
+                ACTIVE_CONTROLLERS.remove(clientService);
+            }
+        }
+    }
+
     /**
      * method to send a message to the server
      *

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/chat/ChatModel.java

@@ -22,7 +22,7 @@ public class ChatModel {
     public final String username;
 
     /** The person to send the message to If the chat is a whisper chat */
-    private final String target;
+    private String target;
 
     private final IntegerProperty count;
 
@@ -82,4 +82,8 @@ public class ChatModel {
     public String getTarget() {
         return target;
     }
+
+    public void setTarget(String target) {
+        this.target = target;
+    }
 }

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/game/Card.java

@@ -2,6 +2,53 @@ package ch.unibas.dmi.dbis.cs108.casono.client.game;
 
 /** Represents a playing card with a value and suit. */
 public class Card {
-    public String value;
-    public String suit;
+    private String value;
+    private String suit;
+
+    /**
+     * Constructs a Card with the specified value and suit.
+     *
+     * @param value The value of the card (e.g., 2, 3, ..., 10, J, Q, K, A).
+     * @param suit The suit of the card (e.g., Hearts, Diamonds, Clubs, Spades).
+     */
+    public Card(String value, String suit) {
+        this.value = value;
+        this.suit = suit;
+    }
+
+    /**
+     * Retrieves the value of the card.
+     *
+     * @return The value of the card.
+     */
+    public String getValue() {
+        return value;
+    }
+
+    /**
+     * Retrieves the suit of the card.
+     *
+     * @return The suit of the card.
+     */
+    public String getSuit() {
+        return suit;
+    }
+
+    /**
+     * Sets the value of the card.
+     *
+     * @param value The value to set for the card.
+     */
+    public void setValue(String value) {
+        this.value = value;
+    }
+
+    /**
+     * Sets the suit of the card.
+     *
+     * @param suit The suit to set for the card.
+     */
+    public void setSuit(String suit) {
+        this.suit = suit;
+    }
 }

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/game/GameService.java

@@ -0,0 +1,156 @@
+package ch.unibas.dmi.dbis.cs108.casono.client.game;
+
+import ch.unibas.dmi.dbis.cs108.casono.client.network.GameClient;
+import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+public class GameService {
+
+    private static final Logger LOG = Logger.getLogger(GameService.class.getName());
+
+    private final GameClient client;
+    private GameState state;
+
+    /**
+     * Constructs a GameService with the specified GameClient.
+     *
+     * @param client The GameClient used to communicate with the server. Must not be null.
+     */
+    public GameService(GameClient client) {
+        if (client == null) {
+            throw new IllegalArgumentException("GameClient must not be null");
+        }
+
+        this.client = client;
+        LOG.info("GameService created");
+    }
+
+    /**
+     * Refreshes the game state by fetching the latest state from the server using the GameClient.
+     *
+     * @return The updated GameState after refreshing.
+     */
+    public GameState refresh() {
+        LOG.fine("Refreshing game state...");
+
+        GameState newState;
+        try {
+            newState = client.fetchGameState();
+        } catch (Exception e) {
+            // Shouldn't happen with the new GameClient, but keep service stable.
+            LOG.log(Level.WARNING, "refresh() failed: " + e.getMessage(), e);
+            return state;
+        }
+
+        if (newState == null) {
+            LOG.fine("No new state (null) -> keeping previous state");
+            return state;
+        }
+
+        this.state = newState;
+
+        LOG.info(
+                () ->
+                        "State updated: phase="
+                                + state.phase
+                                + " pot="
+                                + state.pot
+                                + " players="
+                                + (state.players != null ? state.players.size() : 0)
+                                + " community="
+                                + (state.communityCards != null ? state.communityCards.size() : 0));
+
+        return state;
+    }
+
+    /**
+     * Retrieves the current phase of the game.
+     *
+     * @return The current game phase as a string (e.g., "Pre-Flop", "Flop", "Turn", "River").
+     */
+    public int getPot() {
+        ensureState();
+        return state.pot;
+    }
+
+    /**
+     * Retrieves the current phase of the game.
+     *
+     * @return The current game phase as a string (e.g., "Pre-Flop", "Flop", "Turn", "River").
+     */
+    public List<Card> getCommunityCards() {
+        ensureState();
+        return state.communityCards != null ? state.communityCards : List.of();
+    }
+
+    /**
+     * Retrieves the list of players currently in the game.
+     *
+     * @return A list of Player objects representing the players in the game. A list of Player
+     *     objects representing the players in the game.
+     */
+    public List<Player> getPlayers() {
+        ensureState();
+        return state.players != null ? state.players : List.of();
+    }
+
+    /**
+     * Retrieves the index of the current player whose turn it is.
+     *
+     * @return The index of the current player in the players list, or -1 if not available.
+     */
+    public Player getWinner() {
+        ensureState();
+        if (state.winnerIndex < 0
+                || state.players == null
+                || state.winnerIndex >= state.players.size()) {
+            return null;
+        }
+        return state.players.get(state.winnerIndex);
+    }
+
+    /** Retrieves the current phase of the game. */
+    public void call() {
+        client.sendCall();
+    }
+
+    /** Retrieves the current phase of the game. */
+    public void fold() {
+        client.sendFold();
+    }
+
+    /**
+     * Retrieves the current phase of the game.
+     *
+     * @param amount The amount to bet. Must be a positive integer.
+     */
+    public void bet(int amount) {
+        client.sendBet(amount);
+    }
+
+    /**
+     * Retrieves the current phase of the game.
+     *
+     * @param amount The amount to raise. Must be a positive integer.
+     */
+    public void raise(int amount) {
+        client.sendRaise(amount);
+    }
+
+    /** Ensures that the game state has been initialized before accessing it. */
+    private void ensureState() {
+        if (state == null) {
+            throw new IllegalStateException("GameService used before any successful refresh()");
+        }
+    }
+
+    /**
+     * Returns the current GameState without refreshing from the server.
+     *
+     * @return The current GameState, or null if it has not been initialized yet.
+     */
+    public GameState peekStateOrNull() {
+        return state;
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/game/GameState.java

@@ -8,12 +8,14 @@ import java.util.List;
  * dealer position, active player, community cards, and player information.
  */
 public class GameState {
+    public List<Player> players = new ArrayList<>();
+    public List<Card> communityCards = new ArrayList<>();
+    public List<String> highscoreEntries = new ArrayList<>();
+
     public String phase;
     public int pot;
     public int currentBet;
     public int dealer;
     public int activePlayer;
-
-    public List<Card> communityCards = new ArrayList<>();
-    public List<Player> players = new ArrayList<>();
+    public int winnerIndex = -1;
 }

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/game/Player.java

@@ -8,10 +8,186 @@ import java.util.List;
  * (e.g., "active", "folded"), and their hole cards.
  */
 public class Player {
-    public String name;
-    public int chips;
-    public int bet;
-    public String state;
 
-    public List<Card> cards = new ArrayList<>();
+    private PlayerId id;
+    private int chips;
+    private int bet;
+    private PlayerState state;
+
+    private List<Card> cards = new ArrayList<>();
+
+    /**
+     * Constructs a new Player with default values. The player's state is set to ACTIVE by default.
+     */
+    public Player() {
+        this.state = PlayerState.ACTIVE;
+    }
+
+    /**
+     * Constructs a new Player with the specified ID and initial chip count. The player's state is
+     * set to ACTIVE by default.
+     *
+     * @param id The unique identifier for the player.
+     * @param chips The initial number of chips the player has.
+     */
+    public Player(PlayerId id, int chips) {
+        this.id = id;
+        this.chips = chips;
+        this.bet = 0;
+        this.state = PlayerState.ACTIVE;
+    }
+
+    /**
+     * Retrieves the unique identifier of the player.
+     *
+     * @return The player's ID.
+     */
+    public PlayerId getId() {
+        return id;
+    }
+
+    /**
+     * Sets the unique identifier of the player.
+     *
+     * @param id The player's ID to set.
+     */
+    public void setId(PlayerId id) {
+        this.id = id;
+    }
+
+    /**
+     * Returns the display name of the player. If the player's ID is not set, it returns an empty
+     * string.
+     *
+     * @return The player's name.
+     */
+    public String getName() {
+        return id != null ? id.value() : "";
+    }
+
+    /**
+     * Retrieves the current chip count of the player.
+     *
+     * @return The number of chips the player has.
+     */
+    public int getChips() {
+        return chips;
+    }
+
+    /**
+     * Sets the current chip count of the player.
+     *
+     * @param chips The number of chips to set for the player.
+     */
+    public void setChips(int chips) {
+        this.chips = chips;
+    }
+
+    /**
+     * Retrieves the current bet amount of the player.
+     *
+     * @return The amount the player has currently bet in the ongoing hand.
+     */
+    public int getBet() {
+        return bet;
+    }
+
+    /**
+     * Sets the current bet amount of the player.
+     *
+     * @param bet The amount the player has currently bet in the ongoing hand to set.
+     */
+    public void setBet(int bet) {
+        this.bet = bet;
+    }
+
+    /**
+     * Retrieves the current state of the player (e.g., ACTIVE, FOLDED, ALL_IN).
+     *
+     * @return The player's current state in the game.
+     */
+    public PlayerState getState() {
+        return state;
+    }
+
+    /**
+     * Sets the current state of the player (e.g., ACTIVE, FOLDED, ALL_IN).
+     *
+     * @param state The player's current state in the game to set.
+     */
+    public void setState(PlayerState state) {
+        this.state = state;
+    }
+
+    /**
+     * Checks if the player is currently the dealer.
+     *
+     * @return True if the player's state is DEALER, false otherwise.
+     */
+    public boolean isDealer() {
+        return state == PlayerState.DEALER;
+    }
+
+    /**
+     * Retrieves the list of hole cards currently held by the player.
+     *
+     * @return A list of Card objects representing the player's hole cards.
+     */
+    public List<Card> getCards() {
+        return cards;
+    }
+
+    /**
+     * Sets the list of hole cards currently held by the player.
+     *
+     * @param cards A list of Card objects representing the player's hole cards to set.
+     */
+    public void setCards(List<Card> cards) {
+        this.cards = cards;
+    }
+
+    /**
+     * Adds a card to the player's list of hole cards.
+     *
+     * @param card The Card object to be added to the player's hole cards.
+     */
+    public void addCard(Card card) {
+        this.cards.add(card);
+    }
+
+    /**
+     * Adds the specified amount of chips to the player's current chip count.
+     *
+     * @param amount The number of chips to add to the player's current chip count.
+     */
+    public void addChips(int amount) {
+        if (amount < 0) {
+            throw new IllegalArgumentException("Amount cannot be negative");
+        }
+        this.chips += amount;
+    }
+
+    /**
+     * Removes the specified amount of chips from the player's current chip count.
+     *
+     * @param amount The number of chips to remove from the player's current chip count.
+     */
+    public void removeChips(int amount) {
+        if (amount < 0) {
+            throw new IllegalArgumentException("Amount cannot be negative");
+        }
+        if (amount > this.chips) {
+            throw new IllegalArgumentException(
+                    "Not enough chips. Available: " + this.chips + ", Requested: " + amount);
+        }
+        this.chips -= amount;
+    }
+
+    /** Sets the player's state to FOLDED, indicating that they have folded in the current hand. */
+    public void fall() {
+        this.state = PlayerState.FOLDED;
+        if (this.id != null) {
+            this.id = PlayerId.of(this.id.value() + " (Fall)");
+        }
+    }
 }

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/game/PlayerId.java

@@ -0,0 +1,66 @@
+package ch.unibas.dmi.dbis.cs108.casono.client.game;
+
+import java.util.Objects;
+
+/** Represents a unique identifier for a player in the client domain. */
+public record PlayerId(String value) {
+
+    /**
+     * Constructs a PlayerId with the given string value, ensuring it is not null or empty.
+     *
+     * @param value the string value representing the player's unique identifier.
+     */
+    public PlayerId {
+        Objects.requireNonNull(value, "PlayerId cannot be null");
+        value = value.trim();
+
+        if (value.isEmpty()) {
+            throw new IllegalArgumentException("PlayerId cannot be empty");
+        }
+    }
+
+    /** Factory method to create a PlayerId. */
+    public static PlayerId of(String value) {
+        return new PlayerId(value);
+    }
+
+    /**
+     * Returns the string representation of the PlayerId, which is the encapsulated value.
+     *
+     * @return the string value of the PlayerId.
+     */
+    @Override
+    public String toString() {
+        return value;
+    }
+
+    /**
+     * Compares this PlayerId with another object for equality.
+     *
+     * @param o the object to compare to.
+     * @return true if this PlayerId is equal to the given object, false otherwise.
+     */
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+
+        PlayerId playerId = (PlayerId) o;
+        return Objects.equals(value, playerId.value);
+    }
+
+    /**
+     * Returns the hash code for this PlayerId.
+     *
+     * @return the hash code of the PlayerId.
+     */
+    @Override
+    public int hashCode() {
+        return Objects.hash(value);
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/game/PlayerState.java

@@ -0,0 +1,8 @@
+package ch.unibas.dmi.dbis.cs108.casono.client.game;
+
+/** Enumeration representing the possible states of a player in the poker game. */
+public enum PlayerState {
+    ACTIVE,
+    FOLDED,
+    DEALER
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/network/ChatClient.java

@@ -69,4 +69,23 @@ public class ChatClient {
         }
         return messages;
     }
+
+    /**
+     * Method to poll the usernames of all users currently connected to the server, by sending the
+     * "LIST_USERS" command.
+     *
+     * @return List of all usernames retrieved from the server.
+     */
+    public List<String> getUsers() {
+        logger.info("Asking server for list of users");
+        List<String> users = clientService.processCommand("LIST_USERS");
+        List<String> parameters = new ArrayList<>();
+        for (String line : users) {
+            String trimmed = line == null ? "" : line.trim();
+            if (trimmed.startsWith("USERNAME=")) {
+                parameters.add(trimmed);
+            }
+        }
+        return parameters;
+    }
 }

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/network/ClientService.java

@@ -5,13 +5,21 @@ import ch.unibas.dmi.dbis.cs108.casono.server.network.transport.RawPacket;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.transport.TcpTransport;
 import java.io.IOException;
 import java.net.Socket;
+import java.util.ArrayDeque;
 import java.util.ArrayList;
+import java.util.Deque;
 import java.util.List;
+import java.util.Map;
+import java.util.concurrent.ArrayBlockingQueue;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.CopyOnWriteArrayList;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.Future;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.concurrent.atomic.AtomicInteger;
+import java.util.function.Consumer;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import org.apache.logging.log4j.LogManager;
@@ -30,10 +38,17 @@ public class ClientService {
     private final ExecutorService executor;
     private final boolean offlineMode;
 
-    public static ArrayList<String> response;
     private final AtomicInteger idGenerator;
     private Logger logger;
 
+    private final Map<Integer, ArrayBlockingQueue<ParsedResponse>> pendingResponses =
+            new ConcurrentHashMap<>();
+    private final CopyOnWriteArrayList<Consumer<List<String>>> eventListeners =
+            new CopyOnWriteArrayList<>();
+    private Thread readerThread = null;
+    private final AtomicBoolean running = new AtomicBoolean(false);
+    private static final int READER_JOIN_TIMEOUT_MS = 500;
+
     /**
      * Constructs a ClientService with the given server IP and port. It establishes a socket
      * connection to the server and initializes the TcpTransport and ExecutorService for
@@ -43,7 +58,6 @@ public class ClientService {
      * @param port The port number of the server to connect to.
      */
     public ClientService(String ip, int port) {
-
         this.idGenerator = new AtomicInteger(0);
 
         this.logger = LogManager.getLogger(ClientService.class);
@@ -59,6 +73,156 @@ public class ClientService {
         }
 
         executor = Executors.newSingleThreadExecutor();
+
+        startReaderThread();
+    }
+
+    private void startReaderThread() {
+        running.set(true);
+        readerThread =
+                new Thread(
+                        () -> {
+                            while (running.get()) {
+                                try {
+                                    RawPacket rp = clienttcptransport.read();
+                                    processRawPacket(rp);
+                                } catch (IOException e) {
+                                    if (running.get()) {
+                                        logger.warn("IO error on transport reader", e);
+                                    }
+                                    break;
+                                } catch (InterruptedException e) {
+                                    Thread.currentThread().interrupt();
+                                    break;
+                                }
+                            }
+                        },
+                        "casono-client-reader");
+        readerThread.setDaemon(true);
+        readerThread.start();
+    }
+
+    private void processRawPacket(RawPacket rp) throws InterruptedException, IOException {
+        int rid = rp.requestId();
+        String responseText = rp.payload();
+        logger.info("Raw message '{}'", responseText);
+
+        ParsedPacket parsed = parsePacketContent(responseText);
+
+        logger.debug(
+                "Parsed response lines (rid={}, success={}, openBlocks={}): {}",
+                rid,
+                parsed.success,
+                parsed.blockStack.size(),
+                parsed.lines);
+
+        handleParsedResponse(rid, parsed.success, parsed.lines);
+    }
+
+    private ParsedPacket parsePacketContent(String responseText) {
+        boolean hasStatus = false;
+        boolean success = false;
+        List<String> lines = new ArrayList<>();
+        Deque<String> blockStack = new ArrayDeque<>();
+
+        for (String rawLine : responseText.split("\\n")) {
+            String line = rawLine;
+            String trimmed = line.trim();
+
+            if (!hasStatus) {
+                StatusCheckResult status = checkStatus(trimmed);
+                if (status != null) {
+                    success = status.success;
+                    hasStatus = true;
+                }
+                continue;
+            }
+
+            if (trimmed.isEmpty()) {
+                continue;
+            }
+
+            line = line.replaceFirst("^\\s+", "");
+            trimmed = line.trim();
+
+            if (isContainerStart(trimmed)) {
+                blockStack.push(trimmed);
+                lines.add(trimmed);
+                continue;
+            }
+
+            if ("END".equals(trimmed)) {
+                if (!blockStack.isEmpty()) {
+                    blockStack.pop();
+                    lines.add("END");
+                    continue;
+                }
+                break;
+            }
+
+            lines.add(line);
+        }
+
+        if (!hasStatus) {
+            success = inferStatus(responseText);
+        }
+
+        return new ParsedPacket(success, lines, blockStack);
+    }
+
+    private StatusCheckResult checkStatus(String trimmed) {
+        if ("+OK".equals(trimmed)) {
+            return new StatusCheckResult(true);
+        }
+        if (trimmed.startsWith("-ERR") || trimmed.startsWith("-ERROR")) {
+            return new StatusCheckResult(false);
+        }
+        return null;
+    }
+
+    private boolean inferStatus(String responseText) {
+        if (responseText.contains("+OK")) {
+            return true;
+        }
+        if (responseText.contains("-ERR") || responseText.contains("-ERROR")) {
+            return false;
+        }
+        return true;
+    }
+
+    private void handleParsedResponse(int rid, boolean success, List<String> lines)
+            throws InterruptedException {
+        if (rid == 0) {
+            for (Consumer<List<String>> l : eventListeners) {
+                try {
+                    l.accept(List.copyOf(lines));
+                } catch (Exception e) {
+                    logger.warn("Event listener threw", e);
+                }
+            }
+        } else {
+            ArrayBlockingQueue<ParsedResponse> q = pendingResponses.get(rid);
+            if (q != null) {
+                q.put(new ParsedResponse(success, lines));
+            } else {
+                logger.warn("No pending response queue for id {}", rid);
+            }
+        }
+    }
+
+    private record ParsedPacket(boolean success, List<String> lines, Deque<String> blockStack) {}
+
+    private record StatusCheckResult(boolean success) {}
+
+    private boolean isContainerStart(String token) {
+        return token.equals("LOBBIES")
+                || token.equals("LOBBY")
+                || token.equals("PLAYERS")
+                || token.equals("PLAYER")
+                || token.equals("USERS")
+                || token.equals("USER")
+                || token.equals("CARDS")
+                || token.equals("CARD");
     }
 
     /**
@@ -80,9 +244,11 @@ public class ClientService {
         return offlineMode;
     }
 
+    // Allow primitive values to contain hyphens (UUIDs) in addition to
+    // digits/words/colons
     static Pattern responseRex =
             Pattern.compile(
-                    "(?<key>\\w+)=(('(?<string>([^']|\\')+)')|(?<primVal>[+-]?[\\d\\w:]+))");
+                    "(?<key>\\w+)=(('(?<string>([^']|\\')+)')|(?<primVal>[+-]?[-\\d\\w:]+))");
 
     /**
      * Removes escape characters from a string, specifically converting escaped single quotes (\')
@@ -122,6 +288,19 @@ public class ClientService {
                 .toList();
     }
 
+    private static record ParsedResponse(boolean success, List<String> lines) {}
+
+    /**
+     * Register an event listener that receives unsolicited event payload lines (no status prefix).
+     */
+    public void addEventListener(Consumer<List<String>> listener) {
+        eventListeners.add(listener);
+    }
+
+    public void removeEventListener(Consumer<List<String>> listener) {
+        eventListeners.remove(listener);
+    }
+
     /**
      * Sends a command to the server and processes the multi-line response. It handles the protocol
      * handshake (expecting +OK), strips leading tabs from response lines, and collects them until
@@ -133,43 +312,51 @@ public class ClientService {
      *     occurs.
      */
     protected List<String> processCommand(String message) {
-        List<String> response = new ArrayList<>();
-        sendRequest(
-                () -> {
-                    try {
-                        writeToTransport(message);
-                        String responseText = null;
+        if (offlineMode) {
+            throw new RuntimeException("ClientService is offline");
+        }
 
-                        responseText = clienttcptransport.read().payload();
-                        logger.info("Raw message '" + responseText + "'");
-                        Boolean success = null;
-                        int count = 0;
-                        for (String line : responseText.split("\n")) {
-                            if (success == null) {
-                                if ("+OK".equals(line)) {
-                                    success = true;
-                                    continue;
+        int reqId = idGenerator.incrementAndGet();
+        ArrayBlockingQueue<ParsedResponse> q = new ArrayBlockingQueue<>(1);
+        pendingResponses.put(reqId, q);
 
-                                } else if (("-ERROR").equals(responseText)) {
-                                    success = false;
-                                }
-                                continue;
-                            } else if ("END".equals(line)) {
-                                break;
+        Future<?> writeFuture =
+                executor.submit(
+                        () -> {
+                            try {
+                                clienttcptransport.write(new RawPacket(reqId, message));
+                            } catch (IOException e) {
+                                throw new RuntimeException(e);
                             }
-                            line = line.replaceFirst("^\t", "");
-                            response.add(line);
-                        }
-                        if (success != null && success) {
-                            return;
-                        } else {
-                            throw new RuntimeException("Error in " + message + ": " + response);
-                        }
-                    } catch (Exception e) {
-                        throw getRuntimeException(e);
-                    }
-                });
-        return response;
+                        });
+
+        try {
+            writeFuture.get();
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            pendingResponses.remove(reqId);
+            throw new RuntimeException(e);
+        } catch (ExecutionException e) {
+            pendingResponses.remove(reqId);
+            throw getRuntimeException(e);
+        }
+
+        ParsedResponse pr;
+        try {
+            pr = q.take();
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            pendingResponses.remove(reqId);
+            throw new RuntimeException(e);
+        } finally {
+            pendingResponses.remove(reqId);
+        }
+
+        if (pr.success) {
+            return pr.lines;
+        }
+
+        throw new RuntimeException("Error in " + message + ": " + pr.lines);
     }
 
     /**
@@ -200,15 +387,14 @@ public class ClientService {
      * @return A RuntimeException representing the cause of the original exception.
      */
     private static RuntimeException getRuntimeException(Exception e) {
-        Throwable reason = e.getCause();
-        RuntimeException re;
-        if (reason == null) {
-            reason = e;
-        } else if (reason instanceof RuntimeException rte) {
-            re = rte;
+        Throwable cause = e.getCause();
+        if (cause == null) {
+            return e instanceof RuntimeException ? (RuntimeException) e : new RuntimeException(e);
         }
-        re = new RuntimeException(reason);
-        return re;
+        if (cause instanceof RuntimeException) {
+            return (RuntimeException) cause;
+        }
+        return new RuntimeException(cause);
     }
 
     /**
@@ -218,7 +404,17 @@ public class ClientService {
      */
     public void closeSocket() {
         try {
-            executor.shutdown();
+            running.set(false);
+            if (readerThread != null) {
+                readerThread.interrupt();
+                try {
+                    readerThread.join(READER_JOIN_TIMEOUT_MS);
+                } catch (InterruptedException ignored) {
+                    Thread.currentThread().interrupt();
+                }
+            }
+
+            executor.shutdownNow();
             clienttcptransport.close();
             socket.close();
             logger.info("Socket closed");
@@ -227,16 +423,9 @@ public class ClientService {
         }
     }
 
-    /**
-     * Method to write with the tcp transport to the server
-     *
-     * @param s - Message to be sent
-     * @throws IOException
-     */
-    private void writeToTransport(String s) throws IOException {
-        int id = this.idGenerator.incrementAndGet();
-        this.clienttcptransport.write(new RawPacket(id, s));
-    }
+    // removed unused helper writeToTransport; write is done via processCommand()
+    // which
+    // manages request ids and response matching
 
     public void ping() {
         processCommand("PING");

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/network/GameClient.java

@@ -3,97 +3,283 @@ package ch.unibas.dmi.dbis.cs108.casono.client.network;
 import ch.unibas.dmi.dbis.cs108.casono.client.game.Card;
 import ch.unibas.dmi.dbis.cs108.casono.client.game.GameState;
 import ch.unibas.dmi.dbis.cs108.casono.client.game.Player;
+import ch.unibas.dmi.dbis.cs108.casono.client.game.PlayerId;
+import ch.unibas.dmi.dbis.cs108.casono.client.game.PlayerState;
+import java.util.ArrayList;
 import java.util.List;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 /**
- * The GameClient class is responsible for communicating with the server to retrieve the current
- * game state. It sends a command to the server and parses the response into a structured GameState
- * object.
+ * Fetches and parses game state from server.
+ *
+ * <p>Protocol notes (based on your current server implementation): - Success replies contain:
+ * PHASE, POT, CURRENT_BET, DEALER, ACTIVE_PLAYER, then blocks: - CARD ... END (community cards on
+ * root level) - PLAYER ... (NAME/CHIPS/BET/STATE + optional CARD blocks for requesting player) ...
+ * END - Error replies contain: -ERR then CODE=..., MSG=..., END
+ *
+ * <p>Important: - The server does NOT wrap cards in a "CARDS" container. - CARD blocks appear
+ * either: - at root level -> community cards - inside PLAYER -> hole cards for that player (usually
+ * only for the requesting user)
  */
 public class GameClient {
 
+    private static final Logger LOG = Logger.getLogger(GameClient.class.getName());
+
     private final ClientService client;
+    private final int gameId;
+
+    public GameClient(ClientService client, int gameId) {
+        if (client == null) {
+            throw new IllegalArgumentException("ClientService must not be null");
+        }
 
-    /**
-     * Constructs a GameClient with the given ClientService for communication.
-     *
-     * @param client The ClientService instance used to send commands and receive responses from the
-     *     server.
-     */
-    public GameClient(ClientService client) {
         this.client = client;
+        this.gameId = gameId;
+        LOG.info(() -> "GameClient initialized for gameId=" + gameId);
     }
 
-    /**
-     * Retrieves the current game state from the server by sending a command and parsing the
-     * response.
-     *
-     * @return A GameState object representing the current state of the game.
-     */
-    public GameState getGameState() {
-        List<String> response = client.processCommand("GET_GAME_STATE");
-        return parseGameState(response);
+    public GameState fetchGameState() {
+        final String cmd = "GET_GAME_STATE GAME_ID=" + gameId;
+
+        List<String> lines;
+        try {
+            lines = client.processCommand(cmd);
+        } catch (Exception e) {
+            LOG.log(Level.SEVERE, "processCommand failed for " + cmd + ": " + e.getMessage(), e);
+            return null;
+        }
+
+        if (lines == null || lines.isEmpty()) {
+            LOG.warning("Empty server response for " + cmd);
+            return null;
+        }
+
+        LOG.info(() -> "GET_GAME_STATE raw lines count=" + lines.size() + " lines=" + lines);
+
+        String joined = String.join("\n", lines);
+
+        if (joined.contains("-ERR") || joined.contains("-ERROR")) {
+            String code = extractValue(joined, "CODE");
+            String msg = extractValue(joined, "MSG");
+            LOG.info(() -> "GET_GAME_STATE returned -ERR code=" + code + " msg=" + msg);
+
+            if ("GAME_NOT_STARTED".equalsIgnoreCase(code)) {
+                return null;
+            }
+            return null;
+        }
+
+        try {
+            GameState state = parseGameState(joined);
+            LOG.info(
+                    () ->
+                            "Parsed state: phase="
+                                    + state.phase
+                                    + " pot="
+                                    + state.pot
+                                    + " players="
+                                    + (state.players != null ? state.players.size() : 0)
+                                    + " community="
+                                    + (state.communityCards != null
+                                            ? state.communityCards.size()
+                                            : 0));
+            return state;
+        } catch (Exception e) {
+            LOG.log(Level.SEVERE, "Failed parsing game state. Payload=\n" + joined, e);
+            return null;
+        }
     }
 
-    /**
-     * Parses the raw response from the server into a structured GameState object.
-     *
-     * @param input The raw response string from the server.
-     * @return A GameState object representing the current state of the game.
-     */
-    private GameState parseGameState(List<String> input) {
+    public void sendCall() {
+        client.processCommand("CALL GAME_ID=" + gameId);
+    }
 
-        GameState state = new GameState();
+    public void sendFold() {
+        client.processCommand("FOLD GAME_ID=" + gameId);
+    }
 
-        // String[] lines = input.split("\n");
+    public void sendBet(int amount) {
+        client.processCommand("BET GAME_ID=" + gameId + " AMOUNT=" + amount);
+    }
 
-        Player currentPlayer = null;
-        Card currentCard = null;
+    public void sendRaise(int amount) {
+        client.processCommand("RAISE GAME_ID=" + gameId + " AMOUNT=" + amount);
+    }
 
-        for (String rawLine : input) {
+    private GameState parseGameState(String input) {
+        GameState s = new GameState();
+        s.players = new ArrayList<>();
+        s.communityCards = new ArrayList<>();
 
-            String line = rawLine.trim();
-
-            if (line.startsWith("+OK") || line.equals("END")) {
+        ParseState state = new ParseState();
+        for (String raw : input.split("\n")) {
+            String line = raw.trim();
+            if (line.isEmpty() || line.startsWith("+OK")) {
                 continue;
             }
 
-            if (line.startsWith("PHASE=")) {
-                state.phase = line.split("=")[1];
-            } else if (line.startsWith("POT=")) {
-                state.pot = Integer.parseInt(line.split("=")[1]);
-            } else if (line.startsWith("CURRENT_BET=")) {
-                state.currentBet = Integer.parseInt(line.split("=")[1]);
-            } else if (line.startsWith("DEALER=")) {
-                state.dealer = Integer.parseInt(line.split("=")[1]);
-            } else if (line.startsWith("ACTIVE_PLAYER=")) {
-                state.activePlayer = Integer.parseInt(line.split("=")[1]);
-            } else if (line.startsWith("PLAYER")) {
-                currentPlayer = new Player();
-                state.players.add(currentPlayer);
-            } else if (line.startsWith("NAME=") && currentPlayer != null) {
-                currentPlayer.name = line.split("=")[1];
-            } else if (line.startsWith("CHIPS=") && currentPlayer != null) {
-                currentPlayer.chips = Integer.parseInt(line.split("=")[1]);
-            } else if (line.startsWith("BET=") && currentPlayer != null) {
-                currentPlayer.bet = Integer.parseInt(line.split("=")[1]);
-            } else if (line.startsWith("STATE=") && currentPlayer != null) {
-                currentPlayer.state = line.split("=")[1];
-            } else if (line.startsWith("CARD")) {
-                currentCard = new Card();
-
-                if (currentPlayer != null) {
-                    currentPlayer.cards.add(currentCard);
-                } else {
-                    state.communityCards.add(currentCard);
-                }
-            } else if (line.startsWith("VALUE=") && currentCard != null) {
-                currentCard.value = line.split("=")[1];
-            } else if (line.startsWith("SUIT=") && currentCard != null) {
-                currentCard.suit = line.split("=")[1];
+            if (!parseGlobalField(s, line)
+                    && !parsePlayerStructure(s, state, line)
+                    && !parseCardData(state, line)
+                    && !parsePlayerData(state, line)) {
+                LOG.fine(() -> "Ignored line: '" + line + "'");
             }
         }
+        return s;
+    }
 
-        return state;
+    private boolean parseGlobalField(GameState s, String line) {
+        return switch (line) {
+            case String l when l.startsWith("PHASE=") -> {
+                s.phase = value(l);
+                yield true;
+            }
+            case String l when l.startsWith("POT=") -> {
+                s.pot = intVal(l);
+                yield true;
+            }
+            case String l when l.startsWith("CURRENT_BET=") -> {
+                s.currentBet = intVal(l);
+                yield true;
+            }
+            case String l when l.startsWith("DEALER=") -> {
+                s.dealer = intVal(l);
+                yield true;
+            }
+            case String l when l.startsWith("ACTIVE_PLAYER=") -> {
+                s.activePlayer = intVal(l);
+                yield true;
+            }
+            case String l when l.startsWith("WINNER=") -> {
+                s.winnerIndex = intVal(l);
+                yield true;
+            }
+            case String l when l.startsWith("HIGHSCORE=") -> {
+                s.highscoreEntries.add(value(l));
+                yield true;
+            }
+            default -> false;
+        };
+    }
+
+    private boolean parsePlayerStructure(GameState s, ParseState state, String line) {
+        if (line.equals("PLAYER")) {
+            state.currentPlayer = new Player();
+            s.players.add(state.currentPlayer);
+            state.currentCard = null;
+            state.insidePlayer = true;
+            return true;
+        }
+
+        if (line.equals("CARDS")) {
+            return true;
+        }
+
+        if (line.equals("CARD")) {
+            state.currentCard = new Card("", "");
+            if (state.insidePlayer && state.currentPlayer != null) {
+                state.currentPlayer.addCard(state.currentCard);
+            } else {
+                s.communityCards.add(state.currentCard);
+            }
+            return true;
+        }
+
+        if (line.equals("END")) {
+            if (state.currentCard != null) {
+                state.currentCard = null;
+            } else if (state.insidePlayer) {
+                state.insidePlayer = false;
+                state.currentPlayer = null;
+            }
+            return true;
+        }
+        return false;
+    }
+
+    private boolean parseCardData(ParseState state, String line) {
+        if (state.currentCard == null) {
+            return false;
+        }
+
+        if (line.startsWith("VALUE=")) {
+            state.currentCard.setValue(value(line));
+            return true;
+        }
+        if (line.startsWith("SUIT=")) {
+            state.currentCard.setSuit(value(line));
+            return true;
+        }
+        return false;
+    }
+
+    private boolean parsePlayerData(ParseState state, String line) {
+        if (state.currentPlayer == null) {
+            return false;
+        }
+
+        if (line.startsWith("USERNAME=") || line.startsWith("NAME=")) {
+            state.currentPlayer.setId(PlayerId.of(value(line)));
+            return true;
+        }
+
+        if (line.startsWith("CHIPS=")) {
+            state.currentPlayer.setChips(intVal(line));
+            return true;
+        }
+
+        if (line.startsWith("BET=")) {
+            state.currentPlayer.setBet(intVal(line));
+            return true;
+        }
+
+        if (line.startsWith("STATE=")) {
+            state.currentPlayer.setState(parseState(value(line)));
+            return true;
+        }
+
+        return false;
+    }
+
+    private static class ParseState {
+        Player currentPlayer;
+        Card currentCard;
+        boolean insidePlayer;
+    }
+
+    private static String value(String line) {
+        return line.split("=", 2)[1];
+    }
+
+    private static int intVal(String line) {
+        return Integer.parseInt(value(line));
+    }
+
+    private static PlayerState parseState(String s) {
+        if (s == null) {
+            return PlayerState.ACTIVE;
+        }
+
+        return switch (s.trim().toUpperCase()) {
+            case "ACTIVE" -> PlayerState.ACTIVE;
+            case "FOLDED" -> PlayerState.FOLDED;
+            case "DEALER" -> PlayerState.DEALER;
+            default -> PlayerState.ACTIVE;
+        };
+    }
+
+    private static String extractValue(String joined, String key) {
+        if (joined == null) {
+            return null;
+        }
+
+        for (String raw : joined.split("\n")) {
+            String line = raw.trim();
+            if (line.startsWith(key + "=")) {
+                return line.substring((key + "=").length()).replace("'", "");
+            }
+        }
+        return null;
     }
 }

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/network/LobbyClient.java

@@ -1,5 +1,9 @@
 package ch.unibas.dmi.dbis.cs108.casono.client.network;
 
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.parsing.RequestParameter;
+import java.util.ArrayList;
+import java.util.List;
+
 /**
  * The LobbyClient class is responsible for communicating with the server to manage game lobbies. It
  * provides methods to create a lobby, join a lobby, and fetch the current status of a lobby by
@@ -29,7 +33,25 @@ public class LobbyClient {
      * @return A string representing the current status of the lobby, as returned by the server.
      */
     public String fetchLobbyStatusString(int lobbyId) {
-        return client.processCommand("GET_LOBBY_STATUS ID=" + lobbyId).getFirst();
+        List<String> lines = client.processCommand("GET_LOBBY_STATUS ID=" + lobbyId);
+
+        // Prefer explicit STATUS parameter when available
+        List<RequestParameter> params = ClientService.convertToRequestParameters(lines);
+        for (RequestParameter p : params) {
+            if ("STATUS".equalsIgnoreCase(p.key())) {
+                return p.value();
+            }
+        }
+
+        // Fallback: some servers may return a plain token as the first line
+        if (!lines.isEmpty()) {
+            String first = lines.get(0).trim();
+            if ("CREATED".equalsIgnoreCase(first) || "RUNNING".equalsIgnoreCase(first)) {
+                return first.toUpperCase();
+            }
+        }
+
+        return null;
     }
 
     /**
@@ -38,8 +60,45 @@ public class LobbyClient {
      * @return The id of the newly created lobby, as returned by the server.
      */
     public int createLobby() {
-        String response = client.processCommand("CREATE_LOBBY").getFirst();
-        return Integer.parseInt(response);
+        List<String> lines = client.processCommand("CREATE_LOBBY");
+
+        List<RequestParameter> params = ClientService.convertToRequestParameters(lines);
+        for (RequestParameter p : params) {
+            if ("LOBBY_ID".equalsIgnoreCase(p.key())) {
+                return Integer.parseInt(p.value());
+            }
+        }
+
+        // Fallback for simple legacy/test servers that return the id as a single plain
+        // line
+        if (!lines.isEmpty()) {
+            try {
+                return Integer.parseInt(lines.get(0));
+            } catch (NumberFormatException ignored) {
+            }
+        }
+
+        throw new RuntimeException("No LOBBY_ID in response: " + lines);
+    }
+
+    /** Fetches the global highscores from the server. */
+    public List<String> getHighscores() {
+        List<String> lines = client.processCommand("GET_HIGHSCORES");
+        List<RequestParameter> params = ClientService.convertToRequestParameters(lines);
+
+        List<String> entries = new ArrayList<>();
+        for (RequestParameter p : params) {
+            if ("HIGHSCORE".equalsIgnoreCase(p.key())) {
+                entries.add(p.value());
+            }
+        }
+
+        return entries;
+    }
+
+    /** Clears all global highscores on the server. */
+    public void clearHighscores() {
+        client.processCommand("CLEAR_HIGHSCORES");
     }
 
     /**
@@ -48,8 +107,15 @@ public class LobbyClient {
      * @return The id of the lobby that the client is currently in, as returned by the server.
      */
     public int getLobbyId() {
-        String response = client.processCommand("GET_LOBBY_ID").getFirst();
-        return Integer.parseInt(response);
+        List<String> lines = client.processCommand("GET_LOBBY_ID");
+        if (lines.isEmpty()) {
+            throw new RuntimeException("GET_LOBBY_ID returned empty response");
+        }
+        try {
+            return Integer.parseInt(lines.get(0).trim());
+        } catch (NumberFormatException e) {
+            throw new RuntimeException("Invalid GET_LOBBY_ID response: " + lines, e);
+        }
     }
 
     /**
@@ -65,8 +131,129 @@ public class LobbyClient {
      * Logs in to the server with the given username by sending a "LOGIN" command.
      *
      * @param user The username to log in with.
+     * @return a {@link LoginResult} containing the assigned username and id as returned by the
+     *     server
      */
-    public void login(String user) {
-        client.processCommand("LOGIN USERNAME=" + user);
+    public LoginResult login(String user) {
+        String command = buildLoginCommand(user);
+        List<String> lines = client.processCommand(command);
+
+        List<RequestParameter> params = ClientService.convertToRequestParameters(lines);
+
+        String assigned = user;
+        String id = null;
+        for (RequestParameter p : params) {
+            if ("USERNAME".equalsIgnoreCase(p.key())) {
+                assigned = p.value();
+            } else if ("ID".equalsIgnoreCase(p.key())) {
+                id = p.value();
+            }
+        }
+        return new LoginResult(assigned, id);
+    }
+
+    private String buildLoginCommand(String username) {
+        if (username == null || username.isBlank()) {
+            return "LOGIN";
+        }
+        return "LOGIN USERNAME=" + username.trim();
+    }
+
+    /**
+     * Changes the username for the currently logged-in session.
+     *
+     * @param newUsername desired new username
+     * @return a {@link LoginResult} containing assigned username and id as returned by the server
+     */
+    public LoginResult changeUsername(String newUsername) {
+        List<String> lines = client.processCommand("CHANGE_USERNAME USERNAME=" + newUsername);
+
+        List<RequestParameter> params = ClientService.convertToRequestParameters(lines);
+
+        String assigned = newUsername;
+        String id = null;
+        for (RequestParameter p : params) {
+            if ("USERNAME".equalsIgnoreCase(p.key())) {
+                assigned = p.value();
+            } else if ("ID".equalsIgnoreCase(p.key())) {
+                id = p.value();
+            }
+        }
+        return new LoginResult(assigned, id);
+    }
+
+    /**
+     * Request the server for the list of available lobbies.
+     *
+     * @return list of LobbyInfo objects representing current lobbies
+     */
+    public List<LobbyInfo> getLobbyList() {
+        List<String> lines = client.processCommand("GET_LOBBY_LIST");
+
+        List<RequestParameter> params = ClientService.convertToRequestParameters(lines);
+
+        List<LobbyInfo> result = new ArrayList<>();
+
+        Integer currentId = null;
+        String currentName = null;
+        Integer currentPlayerCount = null;
+
+        for (RequestParameter p : params) {
+            String key = p.key().toUpperCase();
+            String val = p.value();
+            switch (key) {
+                case "ID":
+                    if (currentId != null) {
+                        result.add(
+                                new LobbyInfo(
+                                        currentId,
+                                        currentName,
+                                        currentPlayerCount == null ? 0 : currentPlayerCount));
+                        currentName = null;
+                        currentPlayerCount = null;
+                    }
+                    try {
+                        currentId = Integer.parseInt(val);
+                    } catch (NumberFormatException e) {
+                        currentId = null;
+                    }
+                    break;
+                case "NAME":
+                    currentName = val;
+                    break;
+                case "PLAYER_COUNT":
+                    try {
+                        currentPlayerCount = Integer.parseInt(val);
+                    } catch (NumberFormatException e) {
+                        currentPlayerCount = 0;
+                    }
+                    break;
+                default:
+                    break;
+            }
+        }
+
+        if (currentId != null) {
+            result.add(
+                    new LobbyInfo(
+                            currentId,
+                            currentName,
+                            currentPlayerCount == null ? 0 : currentPlayerCount));
+        }
+
+        return result;
+    }
+
+    /** Simple data holder for lobby metadata returned by the server. */
+    public static final class LobbyInfo {
+        public final int id;
+        public final String name;
+        public final int playerCount;
+
+        public LobbyInfo(int id, String name, int playerCount) {
+            this.id = id;
+            this.name = name;
+            this.playerCount = playerCount;
+        }
     }
 }

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/network/LoginResult.java

@@ -0,0 +1,38 @@
+package ch.unibas.dmi.dbis.cs108.casono.client.network;
+
+/**
+ * Result of a successful login request.
+ *
+ * <p>Holds the username assigned by the server and the server-side id as a string (UUID). The
+ * client previously attempted to parse the id as an integer which failed when the server returned a
+ * UUID; this class therefore stores the id as a {@link String}.
+ */
+public class LoginResult {
+    private final String username;
+    private final String id;
+
+    /**
+     * Create a login result.
+     *
+     * @param username the assigned username
+     * @param id the assigned id (UUID string) returned by the server
+     */
+    public LoginResult(String username, String id) {
+        this.username = username;
+        this.id = id;
+    }
+
+    /**
+     * @return the assigned username
+     */
+    public String getUsername() {
+        return username;
+    }
+
+    /**
+     * @return the assigned id as returned by the server (UUID string)
+     */
+    public String getId() {
+        return id;
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/ui/chatui/ChatBoxController.java

@@ -3,9 +3,16 @@ package ch.unibas.dmi.dbis.cs108.casono.client.ui.chatui;
 import ch.unibas.dmi.dbis.cs108.casono.client.chat.ChatController;
 import ch.unibas.dmi.dbis.cs108.casono.client.chat.ChatModel;
 import ch.unibas.dmi.dbis.cs108.casono.client.chat.ChatType;
+import ch.unibas.dmi.dbis.cs108.casono.client.chat.Message;
 import java.io.IOException;
 import java.net.URL;
+import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
+import java.util.concurrent.Callable;
+import java.util.concurrent.CompletableFuture;
+import javafx.application.Platform;
 import javafx.fxml.FXML;
 import javafx.fxml.FXMLLoader;
 import javafx.scene.Node;
@@ -13,6 +20,7 @@ import javafx.scene.control.MenuButton;
 import javafx.scene.control.MenuItem;
 import javafx.scene.control.Tab;
 import javafx.scene.control.TabPane;
+import javafx.scene.layout.HBox;
 import javafx.scene.layout.Priority;
 import javafx.scene.layout.VBox;
 
@@ -20,7 +28,7 @@ public class ChatBoxController {
 
     private String username;
 
-    private ChatController chatController;
+    private final ChatController chatController;
 
     @FXML private VBox chatBox;
 
@@ -28,15 +36,33 @@ public class ChatBoxController {
 
     @FXML private MenuButton addWhisperChatButton;
 
+    @FXML private HBox menuBox;
+
     private FXMLLoader fxmlLoader;
 
-    @FXML private List<MenuItem> whisperUsers;
+    private final List<String> activeWhisperChats;
 
-    private String ressource = "/ui-structure/components/chatui/chattab.fxml";
+    @FXML private final Map<String, Tab> usernameTabMap;
 
+    /**
+     * Constructor for the ChatBoxController, initializes the necessary fields and data structures
+     * for managing chat tabs and whisper chats.
+     *
+     * @param username The username of the current user.
+     * @param chatController The ChatController instance responsible for handling chat logic and
+     *     communication with the server.
+     */
     public ChatBoxController(String username, ChatController chatController) {
         this.username = username;
         this.chatController = chatController;
+        activeWhisperChats = new ArrayList<>();
+        usernameTabMap = new HashMap<>();
+    }
+
+    public void setUsername(String username) {
+        if (username != null && !username.isBlank()) {
+            this.username = username.trim();
+        }
     }
 
     /**
@@ -46,12 +72,11 @@ public class ChatBoxController {
      */
     @FXML
     public void initialize() {
-        ChatModel globalChatModel = new ChatModel(ChatType.GLOBAL, username, -1, null);
-        chatController
-                .getChatModelMap()
-                .put(new ChatController.ChatKey(ChatType.GLOBAL), globalChatModel);
-        addChatTab("GLOBAL", globalChatModel);
-        // TODO: Button to add new Whisper Chat
+        ChatType global = ChatType.GLOBAL;
+        ChatModel globalChatModel = new ChatModel(global, username, -1, null);
+        chatController.getChatModelMap().put(new ChatController.ChatKey(global), globalChatModel);
+        addChatTab("GLOBAL", globalChatModel, global);
+        addWhisperChatButton.setOnAction(event -> addWhisperChatButton.show());
     }
 
     /**
@@ -61,10 +86,73 @@ public class ChatBoxController {
      * @param targetUserName The username of the person to be added to the whisper list.
      */
     public void addWhisperUser(String targetUserName) {
-        MenuItem menuItem = new MenuItem(targetUserName);
-        whisperUsers.add(menuItem);
-        addWhisperChatButton.getItems().add(menuItem);
-        menuItem.setOnAction(event -> addWhisperChat(targetUserName));
+        Platform.runLater(
+                () -> {
+                    for (MenuItem existing : addWhisperChatButton.getItems()) {
+                        if (targetUserName.equals(existing.getText())) {
+                            return;
+                        }
+                    }
+                    MenuItem menuItem = new MenuItem(targetUserName);
+                    addWhisperChatButton.getItems().add(menuItem);
+                    menuItem.setOnAction(
+                            event ->
+                                    addWhisperChat(
+                                            targetUserName,
+                                            new ChatModel(
+                                                    ChatType.WHISPER,
+                                                    username,
+                                                    -1,
+                                                    targetUserName)));
+                });
+    }
+
+    public void removeWhisperUser(String targetUserName) {
+        Platform.runLater(
+                () ->
+                        addWhisperChatButton
+                                .getItems()
+                                .removeIf(item -> targetUserName.equals(item.getText())));
+    }
+
+    public void renameWhisperUser(String oldUsername, String newUsername) {
+        if (oldUsername == null
+                || newUsername == null
+                || oldUsername.isBlank()
+                || newUsername.isBlank()
+                || oldUsername.equals(newUsername)) {
+            return;
+        }
+
+        Platform.runLater(
+                () -> {
+                    for (MenuItem item : addWhisperChatButton.getItems()) {
+                        if (oldUsername.equals(item.getText())) {
+                            item.setText(newUsername);
+                            item.setOnAction(
+                                    event ->
+                                            addWhisperChat(
+                                                    newUsername,
+                                                    new ChatModel(
+                                                            ChatType.WHISPER,
+                                                            username,
+                                                            -1,
+                                                            newUsername)));
+                            break;
+                        }
+                    }
+
+                    Tab tab = usernameTabMap.remove(oldUsername);
+                    if (tab != null) {
+                        tab.setText(newUsername);
+                        usernameTabMap.put(newUsername, tab);
+                    }
+
+                    int idx = activeWhisperChats.indexOf(oldUsername);
+                    if (idx >= 0) {
+                        activeWhisperChats.set(idx, newUsername);
+                    }
+                });
     }
 
     /**
@@ -73,12 +161,17 @@ public class ChatBoxController {
      *
      * @param target The username of the recipient for the private messages.
      */
-    public void addWhisperChat(String target) {
-        ChatModel chatModel = new ChatModel(ChatType.WHISPER, username, -1, target);
-        chatController
-                .getChatModelMap()
-                .put(new ChatController.ChatKey(ChatType.WHISPER, target), chatModel);
-        addChatTab(target, chatModel);
+    public void addWhisperChat(String target, ChatModel chatModel) {
+        if (!activeWhisperChats.contains(target)) {
+            activeWhisperChats.add(target);
+            ChatType whisper = ChatType.WHISPER;
+            chatController
+                    .getChatModelMap()
+                    .put(new ChatController.ChatKey(whisper, target), chatModel);
+            addChatTab(target, chatModel, whisper);
+        } else {
+            chatTabPane.getSelectionModel().select(usernameTabMap.get(target));
+        }
     }
 
     /**
@@ -90,23 +183,88 @@ public class ChatBoxController {
      * @param chatModel The {@link ChatModel} containing the data and logic for this specific chat.
      * @throws RuntimeException If the FXML resource for the chat tab cannot be loaded.
      */
-    public void addChatTab(String title, ChatModel chatModel) {
+    public void addChatTab(String title, ChatModel chatModel, ChatType chatType) {
+        String ressource = "/ui-structure/components/chatui/chattab.fxml";
         URL resource = getClass().getResource(ressource);
         FXMLLoader fxmlLoader = new FXMLLoader(resource);
-        try {
-            ChatViewController chatViewController =
-                    new ChatViewController(this.chatController, chatModel, this.username);
-            fxmlLoader.setController(chatViewController);
-            Node load = fxmlLoader.load();
-            VBox.setVgrow(load, Priority.ALWAYS);
-            VBox vbox = new VBox();
-            VBox.setVgrow(vbox, Priority.ALWAYS);
-            vbox.getChildren().add(load);
-            chatModel.addListener((msg) -> chatViewController.showMessage(msg));
-            Tab newChat = new Tab(title, vbox);
-            this.chatTabPane.getTabs().add(newChat);
-        } catch (IOException e) {
-            throw new RuntimeException(e);
+        runOnPlatformSynchronized(
+                () -> {
+                    try {
+                        ChatViewController chatViewController =
+                                new ChatViewController(
+                                        this.chatController, chatModel, this.username);
+                        chatController.activeChatControllers.put(
+                                new ChatController.ChatKey(chatType), chatViewController);
+                        fxmlLoader.setController(chatViewController);
+                        Node load = fxmlLoader.load();
+                        VBox.setVgrow(load, Priority.ALWAYS);
+                        VBox vbox = new VBox();
+                        VBox.setVgrow(vbox, Priority.ALWAYS);
+                        vbox.getChildren().add(load);
+                        chatModel.addListener((msg) -> chatViewController.showMessage(msg));
+                        Tab newChat = new Tab(title, vbox);
+                        usernameTabMap.put(title, newChat);
+                        this.chatTabPane.getTabs().add(newChat);
+                        this.chatTabPane.getSelectionModel().select(newChat);
+                        return newChat;
+                    } catch (IOException e) {
+                        throw new RuntimeException(e);
+                    }
+                });
+    }
+
+    /**
+     * Helper Function to cope with a Threads problem occurring when the main JavaFX Thread performs
+     * the task to add a new whisper Chat tab, and the task is specified to runLater.
+     */
+    public static <T> T runOnPlatformSynchronized(Callable<T> code) {
+        if (Platform.isFxApplicationThread()) {
+            try {
+                return code.call();
+            } catch (Exception e) {
+                throw new RuntimeException(e);
+            }
+        } else {
+            CompletableFuture<T> futureLock = new CompletableFuture<>();
+            Platform.runLater(
+                    () -> {
+                        try {
+                            futureLock.complete(code.call());
+                        } catch (Exception e) {
+                            futureLock.completeExceptionally(e);
+                        }
+                    });
+            try {
+                return futureLock.get();
+            } catch (Throwable e) {
+                throw new RuntimeException(e);
+            }
+        }
+    }
+
+    public void loadChats() {
+        Map<ChatController.ChatKey, ChatModel> chatModelMap = chatController.getChatModelMap();
+        ChatController.ChatKey key = new ChatController.ChatKey(ChatType.GLOBAL);
+        ChatModel global = chatModelMap.get(key);
+        ChatViewController globalController = chatController.activeChatControllers.get(key);
+
+        for (String user : chatController.getLocalUserList()) {
+            addWhisperUser(user);
+        }
+
+        for (Message msg : global.messages) {
+            globalController.showMessage(msg);
+        }
+        for (String user : chatController.getLocalUserList()) {
+            ChatController.ChatKey whisperUserKey =
+                    new ChatController.ChatKey(ChatType.WHISPER, user);
+            if (chatModelMap.containsKey(whisperUserKey)) {
+                ChatModel whisperChatModel = chatModelMap.get(whisperUserKey);
+                addWhisperChat(user, whisperChatModel);
+                for (Message msg : whisperChatModel.messages) {
+                    chatController.activeChatControllers.get(whisperUserKey).showMessage(msg);
+                }
+            }
         }
     }
 }

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/ui/chatui/ChatViewController.java

@@ -68,11 +68,12 @@ public class ChatViewController implements Initializable {
         String message = inputField.getText().trim();
         if (!message.isEmpty()) {
             inputField.clear();
+            String currentUsername = controller.getCurrentUsername();
             Message msg =
                     new Message(
                             chatModel.getChattype(),
                             chatModel.lobbyId,
-                            username,
+                            currentUsername,
                             chatModel.getTarget(),
                             message);
             controller.onSendToNetwork(msg);

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/ui/gameui/CasinoGameUI.java

@@ -1,57 +1,171 @@
 package ch.unibas.dmi.dbis.cs108.casono.client.ui.gameui;
 
+import ch.unibas.dmi.dbis.cs108.casono.client.ClientApp;
+import ch.unibas.dmi.dbis.cs108.casono.client.chat.ChatController;
+import ch.unibas.dmi.dbis.cs108.casono.client.game.GameService;
+import ch.unibas.dmi.dbis.cs108.casono.client.game.PlayerId;
 import ch.unibas.dmi.dbis.cs108.casono.client.network.ClientService;
+import ch.unibas.dmi.dbis.cs108.casono.client.network.GameClient;
 import java.io.IOException;
+import java.util.UUID;
+import java.util.logging.Logger;
 import javafx.application.Application;
 import javafx.fxml.FXMLLoader;
+import javafx.scene.Parent;
 import javafx.scene.Scene;
 import javafx.stage.Stage;
 
+/**
+ * Main class for the Casono Game UI.
+ *
+ * <p>Starts the JavaFX application, loads the graphical user interface from the FXML file, and
+ * initializes the main stage for the game.
+ */
 public class CasinoGameUI extends Application {
 
-    // Static field for ClientService (workaround for JavaFX Application launch)
-    private static ClientService staticClientService;
+    private static final Logger LOG = Logger.getLogger(CasinoGameUI.class.getName());
 
-    public static void setClientService(ClientService clientService) {
-        staticClientService = clientService;
-    }
+    private static ClientService clientService;
+    private static ChatController chatController;
 
-    public static ClientService getClientService() {
-        return staticClientService;
-    }
+    private static String username;
+    private static int lobbyId = -1;
 
-    /** Default no-arg constructor. */
+    private static final int DEFAULT_WIDTH = 1200;
+    private static final int DEFAULT_HEIGHT = 800;
+    private static final int GUEST_ID_LENGTH = 8;
+
+    /** Default constructor for the CasinoGameUI application. */
     public CasinoGameUI() {
         // default no-arg constructor
     }
 
-    private static final int DEFAULT_WIDTH = 1200;
-    private static final int DEFAULT_HEIGHT = 800;
-
     /**
-     * Starts the main stage of the application.
+     * Sets the ClientService instance to be used by the application.
      *
-     * @param stage The main stage provided by the system.
-     * @throws IOException If the FXML file or resources cannot be loaded.
+     * @param clientService the ClientService instance to set
      */
-    @Override
-    public void start(Stage stage) throws IOException {
-        FXMLLoader fxmlLoader =
-                new FXMLLoader(CasinoGameUI.class.getResource("/ui-structure/Casinogameui.fxml"));
-        Scene scene = new Scene(fxmlLoader.load(), DEFAULT_WIDTH, DEFAULT_HEIGHT);
-        stage.setTitle("Casono (GAME)");
-
-        String iconPath = getClass().getResource("/images/logoinverted.png").toExternalForm();
-        stage.getIcons().add(new javafx.scene.image.Image(iconPath));
-        stage.setScene(scene);
-        stage.setFullScreen(true);
-        stage.show();
+    public static void setClientService(ClientService clientService) {
+        CasinoGameUI.clientService = clientService;
     }
 
     /**
-     * Entry point of the application.
+     * Sets the username to be used by the application.
      *
-     * @param args Command line arguments.
+     * @param username the username to set
+     */
+    public static void setUsername(String username) {
+        CasinoGameUI.username = username;
+    }
+
+    public static void setChatController(ChatController chatController) {
+        CasinoGameUI.chatController = chatController;
+    }
+
+    /**
+     * Sets the lobby ID to be used by the application.
+     *
+     * @param lobbyId the lobby ID to set
+     */
+    public static void setLobbyId(int lobbyId) {
+        CasinoGameUI.lobbyId = lobbyId;
+    }
+
+    /**
+     * The main entry point for the JavaFX application. This method is called after the application
+     * is
+     *
+     * @param stage the primary stage for this application, onto which the application scene can be
+     *     set. Applications may create other stages, if needed, but they will not be primary
+     *     stages.
+     * @throws IOException
+     */
+    @Override
+    public void start(Stage stage) throws IOException {
+
+        if (clientService == null) {
+            clientService = ClientApp.getSharedClientService();
+        }
+        if (clientService == null) {
+            throw new IllegalStateException(
+                    "CasinoGameUI: clientService is null. "
+                            + "Call CasinoGameUI.setClientService(...)"
+                            + " or start via ClientApp with a shared connection.");
+        }
+
+        String effectiveUsername = normalize(username);
+
+        if (effectiveUsername == null) {
+            effectiveUsername = normalize(ClientApp.getSharedUsername());
+        }
+
+        if (effectiveUsername == null) {
+            effectiveUsername =
+                    "Guest-" + UUID.randomUUID().toString().substring(0, GUEST_ID_LENGTH);
+        }
+
+        LOG.info(
+                "CasinoGameUI starting: effectiveUsername='"
+                        + effectiveUsername
+                        + "', injectedUsername='"
+                        + username
+                        + "', sharedUsername='"
+                        + ClientApp.getSharedUsername()
+                        + "', hasClientService="
+                        + (clientService != null));
+
+        FXMLLoader fxmlLoader =
+                new FXMLLoader(CasinoGameUI.class.getResource("/ui-structure/Casinogameui.fxml"));
+        Parent root = fxmlLoader.load();
+        CasinoGameController controller = fxmlLoader.getController();
+
+        if (lobbyId <= 0) {
+            throw new IllegalStateException("CasinoGameUI: lobbyId must be set before start()");
+        }
+
+        GameClient gameClient = new GameClient(clientService, lobbyId);
+        GameService gameService = new GameService(gameClient);
+        controller.setGameService(gameService);
+
+        controller.setMyPlayerId(PlayerId.of(effectiveUsername));
+        controller.setChatContext(effectiveUsername, clientService, lobbyId);
+
+        controller.startChat(chatController);
+
+        Scene scene = new Scene(root, DEFAULT_WIDTH, DEFAULT_HEIGHT);
+        stage.setTitle("Casono");
+
+        String iconPath = getClass().getResource("/images/logoinverted.png").toExternalForm();
+        stage.getIcons().add(new javafx.scene.image.Image(iconPath));
+
+        stage.setScene(scene);
+        stage.setFullScreen(true);
+        stage.setOnHidden(e -> controller.stop());
+        stage.show();
+
+        controller.start();
+    }
+
+    /**
+     * Normalizes a string by trimming whitespace and converting blank strings to null.
+     *
+     * @param s the string to normalize
+     * @return the normalized string, or null if the input is null or blank
+     */
+    private static String normalize(String s) {
+        if (s == null) {
+            return null;
+        }
+
+        String t = s.trim();
+        return t.isBlank() ? null : t;
+    }
+
+    /**
+     * The main method serves as the entry point for the application. It launches the JavaFX
+     * application.
+     *
+     * @param args command line arguments (not used)
      */
     public static void main(String[] args) {
         launch();

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/ui/gameui/gameuicomponents/CasinoBrowserController.java

@@ -4,17 +4,24 @@ import java.net.CookieHandler;
 import java.net.CookieManager;
 import java.net.CookiePolicy;
 import java.net.URI;
+import java.nio.file.Path;
+import java.nio.file.Paths;
 import java.util.HashSet;
+import java.util.Map;
 import java.util.Optional;
 import java.util.Set;
 import javafx.application.Platform;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
 import javafx.geometry.Insets;
 import javafx.geometry.Pos;
 import javafx.scene.Scene;
 import javafx.scene.control.Alert;
 import javafx.scene.control.Button;
 import javafx.scene.control.ButtonType;
+import javafx.scene.control.ContextMenu;
 import javafx.scene.control.Label;
+import javafx.scene.control.MenuItem;
 import javafx.scene.control.TextField;
 import javafx.scene.image.Image;
 import javafx.scene.image.ImageView;
@@ -63,6 +70,11 @@ public class CasinoBrowserController {
 
     private static final Logger LOGGER = LogManager.getLogger(CasinoBrowserController.class);
 
+    private static final ObservableList<String> URL_SUGGESTIONS =
+            FXCollections.observableArrayList(TRUSTED_DOMAINS);
+
+    private static ContextMenu autoCompleteMenu = new ContextMenu();
+
     private static final int LOGO_HEIGHT = 40;
     private static final int CORNER_RADIUS = 40;
     private static final int HBOX_SPACIN = 10;
@@ -74,12 +86,15 @@ public class CasinoBrowserController {
     private static final int ALERT_HEIGHT = 300;
     private static final String LOGO_PATH = "/images/logoinverted.png";
     private static final String LOGO_PATH_MAIN = "/images/logo.png";
+    private static final int MAX_AUTOCOMPLETE_RESULTS = 5;
 
     static {
         CookieHandler.setDefault(COOKIE_MANAGER);
 
         TRUSTED_DOMAINS.add("wikipedia.org");
+        TRUSTED_DOMAINS.add("youtube.com");
         TRUSTED_DOMAINS.add("github.com");
+        TRUSTED_DOMAINS.add("search.brave.com");
         TRUSTED_DOMAINS.add("oracle.com");
         TRUSTED_DOMAINS.add("stackoverflow.com");
         TRUSTED_DOMAINS.add("docs.oracle.com");
@@ -94,10 +109,63 @@ public class CasinoBrowserController {
         TRUSTED_DOMAINS.add("metager.de");
         TRUSTED_DOMAINS.add("unibas.ch");
         TRUSTED_DOMAINS.add("mojeek.com");
-        TRUSTED_DOMAINS.add("searx.be ");
+        TRUSTED_DOMAINS.add("searx.be");
         TRUSTED_DOMAINS.add("startpage.com");
     }
 
+    /** Aliases for common websites. */
+    private static final java.util.Map<String, String> ALIASES =
+            Map.ofEntries(
+                    Map.entry("wiki", "wikipedia.org"),
+                    Map.entry("yt", "youtube.com"),
+                    Map.entry("bra", "search.brave.com"),
+                    Map.entry("bs", "search.brave.com"),
+                    Map.entry("gh", "github.com"),
+                    Map.entry("google", "google.com"),
+                    Map.entry("duck", "duckduckgo.com"),
+                    Map.entry("bing", "bing.com"),
+                    Map.entry("meta", "metager.de"),
+                    Map.entry("mojeek", "mojeek.com"),
+                    Map.entry("searx", "searx.be"),
+                    Map.entry("startpage", "startpage.com"),
+                    Map.entry("stack", "stackoverflow.com"),
+                    Map.entry("so", "stackoverflow.com"),
+                    Map.entry("oracle", "oracle.com"),
+                    Map.entry("docs", "docs.oracle.com"),
+                    Map.entry("mdn", "developer.mozilla.org"),
+                    Map.entry("maven", "maven.apache.org"),
+                    Map.entry("gradle", "gradle.org"),
+                    Map.entry("spring", "spring.io"),
+                    Map.entry("jetbrains", "jetbrains.com"),
+                    Map.entry("uni", "unibas.ch"));
+
+    /**
+     * Resolves user input into a valid URL.
+     *
+     * @param input User input from the URL field, which can be a full URL, a domain name, or an
+     *     alias.
+     * @return A properly formatted URL string that can be loaded by the browser, or the original
+     *     input if it cannot be resolved.
+     */
+    private static String resolveInputToUrl(String input) {
+        if (input == null || input.isBlank()) {
+            return input;
+        }
+
+        input = input.trim();
+
+        String alias = ALIASES.get(input.toLowerCase());
+        if (alias != null) {
+            return "https://" + alias;
+        }
+
+        if (input.matches("^[a-zA-Z][a-zA-Z0-9+.-]*://.*")) {
+            return input;
+        }
+
+        return "https://" + input;
+    }
+
     private static boolean javascriptEnabled = false;
 
     /** Deletes all cookies stored during the current browser session. */
@@ -124,6 +192,15 @@ public class CasinoBrowserController {
                     WebView webView = new WebView();
                     WebEngine engine = webView.getEngine();
 
+                    engine.locationProperty()
+                            .addListener(
+                                    (obs, oldUrl, newUrl) -> {
+                                        if (isDownloadUrl(newUrl)) {
+                                            LOGGER.warn("Download navigation blocked: " + newUrl);
+                                            engine.getLoadWorker().cancel();
+                                        }
+                                    });
+
                     engine.setJavaScriptEnabled(false);
 
                     configurePopupBlocker(engine);
@@ -203,9 +280,9 @@ public class CasinoBrowserController {
         engine.setCreatePopupHandler(
                 config -> {
                     Alert alert = new Alert(Alert.AlertType.WARNING);
-                    alert.setTitle("Popup blockiert");
+                    alert.setTitle("Popup blocked");
                     alert.setHeaderText(null);
-                    alert.setContentText("Popup wurde aus Sicherheitsgründen blockiert.");
+                    alert.setContentText("Casono Browser blocked a security threat.");
 
                     try {
                         var stream = CasinoBrowserController.class.getResourceAsStream(LOGO_PATH);
@@ -283,9 +360,90 @@ public class CasinoBrowserController {
         urlField.getStyleClass().add("gray-input-field");
         HBox.setHgrow(urlField, Priority.ALWAYS);
 
+        urlField.textProperty()
+                .addListener(
+                        (obs, oldText, newText) -> {
+                            if (newText == null || newText.isBlank()) {
+                                autoCompleteMenu.hide();
+                                return;
+                            }
+
+                            String input = newText.toLowerCase();
+
+                            String aliasMatch = ALIASES.get(input);
+                            if (aliasMatch != null) {
+                                autoCompleteMenu.getItems().clear();
+
+                                MenuItem item = new MenuItem(aliasMatch);
+                                item.setOnAction(
+                                        e -> {
+                                            urlField.setText("https://" + aliasMatch);
+                                            autoCompleteMenu.hide();
+                                        });
+
+                                autoCompleteMenu.getItems().add(item);
+                                autoCompleteMenu.show(urlField, javafx.geometry.Side.BOTTOM, 0, 0);
+                                return;
+                            }
+
+                            updateSuggestions(input, urlField);
+                        });
+
+        urlField.focusedProperty()
+                .addListener(
+                        (obs, oldVal, newVal) -> {
+                            if (!newVal) {
+                                autoCompleteMenu.hide();
+                            }
+                        });
+
         return urlField;
     }
 
+    /**
+     * Updates the autocomplete suggestions based on the current input in the URL field. Suggestions
+     * are filtered from the list of trusted domains and sorted to prioritize those that start with
+     * the input.
+     *
+     * @param input The current text input from the URL field, used to filter and sort suggestions.
+     * @param urlField The TextField for the URL input, used to position the autocomplete menu and
+     *     update its content.
+     */
+    private static void updateSuggestions(String input, TextField urlField) {
+        autoCompleteMenu.getItems().clear();
+
+        URL_SUGGESTIONS.stream()
+                .filter(
+                        domain ->
+                                domain.toLowerCase().startsWith(input)
+                                        || domain.toLowerCase().contains(input))
+                .sorted(
+                        (a, b) -> {
+                            boolean aStarts = a.startsWith(input);
+                            boolean bStarts = b.startsWith(input);
+                            return Boolean.compare(!aStarts, !bStarts);
+                        })
+                .limit(MAX_AUTOCOMPLETE_RESULTS)
+                .forEach(
+                        domain -> {
+                            MenuItem item = new MenuItem(domain);
+
+                            item.setOnAction(
+                                    e -> {
+                                        urlField.setText("https://" + domain);
+                                        autoCompleteMenu.hide();
+                                    });
+
+                            autoCompleteMenu.getItems().add(item);
+                        });
+
+        if (!autoCompleteMenu.getItems().isEmpty()) {
+            autoCompleteMenu.show(urlField, javafx.geometry.Side.BOTTOM, 0, 0);
+        } else {
+            autoCompleteMenu.hide();
+        }
+    }
+
     /**
      * Security Label
      *
@@ -305,7 +463,7 @@ public class CasinoBrowserController {
      * @return Toggle button
      */
     public static Button createJsToggle(WebEngine engine) {
-        Button jsToggle = new Button("JS EINSCHALTEN");
+        Button jsToggle = new Button("JS TURN ON");
         jsToggle.getStyleClass().add("red-button");
 
         jsToggle.setOnAction(
@@ -319,7 +477,7 @@ public class CasinoBrowserController {
                         jsToggle.getStyleClass().add("yellow-button");
 
                     } else {
-                        jsToggle.setText("JS EINSCHALTEN");
+                        jsToggle.setText("JS TURN ON");
                         jsToggle.getStyleClass().removeAll("yellow-button");
                         jsToggle.getStyleClass().add("red-button");
                     }
@@ -410,7 +568,16 @@ public class CasinoBrowserController {
      */
     public static void configureUrlEvents(
             WebEngine engine, TextField urlField, Label securityLabel) {
-        urlField.setOnAction(e -> loadUrlSafely(engine, urlField.getText(), securityLabel));
+        urlField.setOnKeyPressed(
+                e -> {
+                    if (e.getCode() == KeyCode.ENTER) {
+                        if (!autoCompleteMenu.isShowing()) {
+                            String resolved = resolveInputToUrl(urlField.getText());
+                            urlField.setText(resolved);
+                            loadUrlSafely(engine, resolved, securityLabel);
+                        }
+                    }
+                });
         engine.locationProperty().addListener((obs, o, n) -> urlField.setText(n));
     }
 
@@ -468,25 +635,54 @@ public class CasinoBrowserController {
      */
     private static void loadUrlSafely(WebEngine engine, String url, Label securityLabel) {
         try {
-            if (!url.startsWith("http")) {
+            if (!url.matches("^[a-zA-Z][a-zA-Z0-9+.-]*://.*")) {
                 url = "https://" + url;
             }
 
             URI uri = new URI(url);
+            String scheme = uri.getScheme();
 
-            // HTTPS required
-            if (!"https".equalsIgnoreCase(uri.getScheme())) {
+            String fullUrl = uri.toString();
+
+            if (isDownloadUrl(fullUrl)) {
+                securityLabel.setText("BLOCKED DOWNLOAD");
+
+                LOGGER.warn("Download blocked: " + fullUrl);
+                return;
+            }
+
+            if ("file".equalsIgnoreCase(scheme)) {
+                Path allowed =
+                        Paths.get(
+                                        System.getProperty("user.dir"),
+                                        "documents",
+                                        "docs",
+                                        "game-engine",
+                                        "manual.html")
+                                .normalize();
+
+                Path requested = Paths.get(uri).normalize();
+
+                if (requested.equals(allowed)) {
+                    securityLabel.setText("LOCAL OK");
+                    engine.load(uri.toString());
+                } else {
+                    securityLabel.setText("BLOCKED");
+                }
+                return;
+            }
+
+            if (!"https".equalsIgnoreCase(scheme)) {
                 securityLabel.setText("BLOCKED");
                 return;
             }
 
             String host = uri.getHost();
-            if (host == null) {
+            if (host == null || host.isBlank()) {
                 securityLabel.setText("ERROR");
                 return;
             }
 
-            // Secure Domain Check
             boolean trusted =
                     TRUSTED_DOMAINS.stream()
                             .anyMatch(domain -> host.equals(domain) || host.endsWith("." + domain));
@@ -500,9 +696,11 @@ public class CasinoBrowserController {
             } else {
                 securityLabel.setText("SAFE");
             }
+
             engine.load(uri.toString());
+
         } catch (Exception e) {
-            securityLabel.setText("ERROR");
+            securityLabel.setText("INVALID");
         }
     }
 
@@ -519,7 +717,7 @@ public class CasinoBrowserController {
         alert.setHeaderText("This website is unknown");
         String content =
                 host
-                        + "\n\nThis site has not been verified by the Casono browser.\n"
+                        + "\n\nThis site has not been verified by the Casono Browser.\n"
                         + "Do you still want to open it?";
         alert.setContentText(content);
 
@@ -545,4 +743,18 @@ public class CasinoBrowserController {
 
         return true;
     }
+
+    /**
+     * Checks if a given URL points to a downloadable file based on its extension.
+     *
+     * @param url the URL to check
+     * @return true if the URL is likely a download link, false otherwise
+     */
+    private static boolean isDownloadUrl(String url) {
+        if (url == null) {
+            return false;
+        }
+
+        return url.matches(".*\\.(exe|zip|dmg|msi|apk|jar|pdf)(\\?.*)?$");
+    }
 }

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/ui/gameui/gameuicomponents/HighscoreViewController.java

@@ -0,0 +1,114 @@
+package ch.unibas.dmi.dbis.cs108.casono.client.ui.gameui.gameuicomponents;
+
+import ch.unibas.dmi.dbis.cs108.casono.client.network.LobbyClient;
+import java.util.List;
+import javafx.fxml.FXML;
+import javafx.scene.Node;
+import javafx.scene.control.Label;
+import javafx.scene.control.ListView;
+import javafx.scene.input.MouseEvent;
+import javafx.stage.Stage;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+/** Controller for the highscore popup window. */
+public class HighscoreViewController {
+
+    private static final Logger LOGGER = LogManager.getLogger(HighscoreViewController.class);
+
+    @FXML private ListView<String> highscoreList;
+    @FXML private Label statusLabel;
+    @FXML private Node highscoreRoot;
+
+    private LobbyClient lobbyClient;
+    private double dragOffsetX;
+    private double dragOffsetY;
+
+    public void setLobbyClient(LobbyClient lobbyClient) {
+        this.lobbyClient = lobbyClient;
+    }
+
+    /** Starts dragging the window from anywhere in the popup. */
+    @FXML
+    public void onPopupPressed(MouseEvent event) {
+        Stage stage = getStage();
+        if (stage == null) {
+            return;
+        }
+
+        dragOffsetX = stage.getX() - event.getScreenX();
+        dragOffsetY = stage.getY() - event.getScreenY();
+    }
+
+    /** Moves the popup window while the mouse is dragged anywhere on the popup. */
+    @FXML
+    public void onPopupDragged(MouseEvent event) {
+        Stage stage = getStage();
+        if (stage == null) {
+            return;
+        }
+
+        stage.setX(event.getScreenX() + dragOffsetX);
+        stage.setY(event.getScreenY() + dragOffsetY);
+    }
+
+    /** Returns the popup stage if the root is already attached to a scene. */
+    private Stage getStage() {
+        if (highscoreRoot == null || highscoreRoot.getScene() == null) {
+            return null;
+        }
+
+        return (Stage) highscoreRoot.getScene().getWindow();
+    }
+
+    /** Loads current highscores from the server and refreshes the list. */
+    @FXML
+    public void refreshHighscores() {
+        if (highscoreList == null || statusLabel == null) {
+            return;
+        }
+
+        if (lobbyClient == null) {
+            statusLabel.setText("Lobby client not initialized.");
+            return;
+        }
+
+        try {
+            List<String> entries = lobbyClient.getHighscores();
+            highscoreList.getItems().setAll(entries);
+            statusLabel.setText(
+                    entries.isEmpty() ? "No highscores yet." : entries.size() + " entries loaded.");
+        } catch (RuntimeException e) {
+            LOGGER.error("Failed to load highscores: {}", e.getMessage());
+            statusLabel.setText("Failed to load highscores.");
+        }
+    }
+
+    /** Clears all highscores globally on the server and reloads the list. */
+    @FXML
+    public void clearHighscores() {
+        if (lobbyClient == null || statusLabel == null) {
+            return;
+        }
+
+        try {
+            lobbyClient.clearHighscores();
+            refreshHighscores();
+            statusLabel.setText("Highscores cleared.");
+        } catch (RuntimeException e) {
+            LOGGER.error("Failed to clear highscores: {}", e.getMessage());
+            statusLabel.setText("Failed to clear highscores.");
+        }
+    }
+
+    /** Closes the highscore popup window. */
+    @FXML
+    public void closeWindow() {
+        if (highscoreList == null || highscoreList.getScene() == null) {
+            return;
+        }
+
+        Stage stage = (Stage) highscoreList.getScene().getWindow();
+        stage.close();
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/ui/gameui/gameuicomponents/PlayerStatusController.java

@@ -0,0 +1,173 @@
+package ch.unibas.dmi.dbis.cs108.casono.client.ui.gameui.gameuicomponents;
+
+import ch.unibas.dmi.dbis.cs108.casono.client.game.Player;
+import ch.unibas.dmi.dbis.cs108.casono.client.game.PlayerState;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+import javafx.fxml.FXML;
+import javafx.scene.control.Label;
+import javafx.scene.image.Image;
+import javafx.scene.image.ImageView;
+import javafx.scene.layout.HBox;
+import javafx.scene.layout.Pane;
+import javafx.scene.layout.VBox;
+
+/**
+ * Controller for displaying a player's status in the poker game, including their name, chip count
+ * and whether they are the dealer.
+ */
+public class PlayerStatusController {
+
+    private static final Logger LOGGER = Logger.getLogger(PlayerStatusController.class.getName());
+
+    @FXML private Label playerName;
+    @FXML private Label playerMoney;
+    @FXML private ImageView dealerIcon;
+    @FXML private Pane parent;
+    @FXML private VBox playerStatusBox;
+    @FXML private HBox statusInnerBoxTop;
+    @FXML private HBox statusInnerBoxBottom;
+
+    private Image dealerImage;
+    private Player player;
+    private boolean turnHighlighted;
+    private static final String DEALER_IMAGE_PATH = "/images/chip-dealer-blue-5.png";
+    private static final double DEALER_ICON_X_FACTOR = 0.8;
+    private static final String TURN_HIGHLIGHT_STYLE_CLASS = "player-status-active-turn";
+
+    /** Initialize the controller, load dealer image, and set up bindings. */
+    @FXML
+    public void initialize() {
+
+        try {
+            var url = getClass().getResource(DEALER_IMAGE_PATH);
+
+            if (url != null) {
+                dealerImage = new Image(url.toExternalForm(), true);
+                dealerIcon.setImage(dealerImage);
+            } else {
+                LOGGER.warning("Dealer image not found in resources!");
+            }
+
+        } catch (Exception e) {
+            LOGGER.log(Level.SEVERE, "Error loading dealer image", e);
+        }
+
+        dealerIcon.layoutXProperty().bind(parent.widthProperty().multiply(DEALER_ICON_X_FACTOR));
+        dealerIcon.setVisible(false);
+    }
+
+    /**
+     * Bind player to UI
+     *
+     * @param player The player whose status is to be displayed.
+     */
+    public void setPlayer(Player player) {
+        this.player = player;
+        if (player == null) {
+            turnHighlighted = false;
+        }
+        refresh();
+        updateTurnHighlightStyle();
+    }
+
+    /** Refresh UI safely */
+    public void refresh() {
+
+        if (player == null) {
+            playerName.setText("-");
+            playerMoney.setText("0 $");
+            dealerIcon.setVisible(false);
+            return;
+        }
+
+        // NAME (safe)
+        String name = player.getName();
+        playerName.setText(name != null ? name : "-");
+
+        // MONEY
+        playerMoney.setText(player.getChips() + " $");
+
+        // DEALER
+        boolean isDealer = player.getState() == PlayerState.DEALER;
+
+        dealerIcon.setVisible(isDealer);
+
+        if (isDealer && dealerImage != null) {
+            dealerIcon.setImage(dealerImage);
+        }
+    }
+
+    /**
+     * Highlight or unhighlight this player slot as the currently active turn.
+     *
+     * @param highlighted true if this slot should be highlighted, false otherwise.
+     */
+    public void setTurnHighlighted(boolean highlighted) {
+        this.turnHighlighted = highlighted;
+        updateTurnHighlightStyle();
+    }
+
+    /**
+     * Check whether the controller is currently bound to the provided player.
+     *
+     * @param candidate the player to compare against.
+     * @return true if both represent the same player.
+     */
+    public boolean hasPlayer(Player candidate) {
+        if (player == null
+                || candidate == null
+                || player.getId() == null
+                || candidate.getId() == null) {
+            return false;
+        }
+
+        return player.getId().equals(candidate.getId());
+    }
+
+    /**
+     * External quick update
+     *
+     * @param name The player's name to display.
+     * @param chips The player's chip count to display.
+     */
+    public void updatePlayer(String name, int chips) {
+        playerName.setText(name != null ? name : "-");
+        playerMoney.setText(chips + " $");
+    }
+
+    /**
+     * Force dealer state
+     *
+     * @param isDealer Whether the player is the dealer or not.
+     */
+    public void setDealer(boolean isDealer) {
+        dealerIcon.setVisible(isDealer);
+
+        if (isDealer && dealerImage != null) {
+            dealerIcon.setImage(dealerImage);
+        }
+    }
+
+    /**
+     * Update the visual style of the player status box to indicate whether it's currently this
+     * player's turn.
+     */
+    private void updateTurnHighlightStyle() {
+        if (statusInnerBoxTop == null || statusInnerBoxBottom == null) {
+            return;
+        }
+
+        if (turnHighlighted) {
+            if (!statusInnerBoxTop.getStyleClass().contains(TURN_HIGHLIGHT_STYLE_CLASS)) {
+                statusInnerBoxTop.getStyleClass().add(TURN_HIGHLIGHT_STYLE_CLASS);
+            }
+            if (!statusInnerBoxBottom.getStyleClass().contains(TURN_HIGHLIGHT_STYLE_CLASS)) {
+                statusInnerBoxBottom.getStyleClass().add(TURN_HIGHLIGHT_STYLE_CLASS);
+            }
+        } else {
+            statusInnerBoxTop.getStyleClass().remove(TURN_HIGHLIGHT_STYLE_CLASS);
+            statusInnerBoxBottom.getStyleClass().remove(TURN_HIGHLIGHT_STYLE_CLASS);
+        }
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/ui/lobbyui/Casinomainui.java

@@ -19,8 +19,8 @@ public class Casinomainui extends Application {
         // Default constructor
     }
 
-    private static final int SCENE_WIDTH = 1200;
-    private static final int SCENE_HEIGHT = 800;
+    public static final int SCENE_WIDTH = 1200;
+    public static final int SCENE_HEIGHT = 800;
 
     @Override
     /**

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/ui/lobbyui/CasinomainuiController.java

@@ -1,9 +1,18 @@
 package ch.unibas.dmi.dbis.cs108.casono.client.ui.lobbyui;
 
+import ch.unibas.dmi.dbis.cs108.casono.client.ClientApp;
+import ch.unibas.dmi.dbis.cs108.casono.client.chat.ChatController;
 import ch.unibas.dmi.dbis.cs108.casono.client.network.ClientService;
 import ch.unibas.dmi.dbis.cs108.casono.client.network.LobbyClient;
+import ch.unibas.dmi.dbis.cs108.casono.client.ui.gameui.gameuicomponents.HighscoreViewController;
+import java.io.IOException;
+import java.net.URL;
 import javafx.application.Platform;
 import javafx.fxml.FXML;
+import javafx.fxml.FXMLLoader;
+import javafx.scene.Node;
+import javafx.scene.Parent;
+import javafx.scene.Scene;
 import javafx.scene.control.Alert;
 import javafx.scene.control.Alert.AlertType;
 import javafx.scene.control.Button;
@@ -14,6 +23,8 @@ import javafx.scene.image.ImageView;
 import javafx.scene.layout.AnchorPane;
 import javafx.scene.layout.VBox;
 import javafx.scene.shape.Rectangle;
+import javafx.stage.Stage;
+import javafx.stage.StageStyle;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
 
@@ -30,18 +41,24 @@ public class CasinomainuiController {
     @FXML private VBox casinoTable;
     @FXML private TextField usernameField;
     @FXML private Button loginButton;
+    @FXML private AnchorPane chatContainer;
 
     private LobbyButtonTranslationManager translationManager;
     private LobbyButtonGridManager gridManager;
     private int nextButtonId = 1;
     private LobbyClient lobbyClient;
+    private ChatController chatController;
 
-    /** Default constructor for dependency injection by FXMLLoader. */
+    /** Default constructor used by FXMLLoader. */
     public CasinomainuiController() {
         // Default constructor
     }
 
-    /** Initializes the UI components and sets default values. */
+    /**
+     * Initializes the UI components and sets default values. If a shared {@link ClientService}
+     * exists (created at application start), the controller reuses it so the connection remains
+     * open and already-logged-in.
+     */
     @FXML
     public void initialize() {
         titleLabel.setText("Casono");
@@ -51,16 +68,18 @@ public class CasinomainuiController {
         translationManager = LobbyButtonTranslationManager.getInstance();
         String host = System.getProperty("casono.server.host");
         int port = Integer.parseInt(System.getProperty("casono.server.port"));
-        ClientService clientService;
-        try {
-            clientService = new ClientService(host, port);
-        } catch (RuntimeException e) {
-            LOGGER.warn(
-                    "Could not connect to server {}:{} — starting in offline mode: {}",
-                    host,
-                    port,
-                    e.getMessage());
-            clientService = new ClientService(true); // offline mode
+        ClientService clientService = ClientApp.getSharedClientService();
+        if (clientService == null) {
+            try {
+                clientService = new ClientService(host, port);
+            } catch (RuntimeException e) {
+                LOGGER.warn(
+                        "Could not connect to server {}:{} — starting in offline mode: {}",
+                        host,
+                        port,
+                        e.getMessage());
+                clientService = new ClientService(true); // offline mode
+            }
         }
         gridManager =
                 new LobbyButtonGridManager(
@@ -68,15 +87,89 @@ public class CasinomainuiController {
         // LobbyClient will use the provided ClientService; in offline mode calls will
         // fail with RuntimeException
         lobbyClient = new LobbyClient(clientService);
+        // Fetch existing lobbies from server on startup so newly-created lobbies
+        // by other clients are immediately visible.
+        try {
+            if (!lobbyClient.getClientService().isOffline()) {
+                var lobbies = lobbyClient.getLobbyList();
+                int bid = nextButtonId;
+                for (var li : lobbies) {
+                    try {
+                        translationManager.addLobbyButton(bid++, li.id);
+                    } catch (Exception e) {
+                        LOGGER.warn("Could not add lobby button: {}", e.getMessage());
+                    }
+                }
+                nextButtonId = bid;
+            }
+        } catch (RuntimeException e) {
+            LOGGER.warn("Failed to fetch lobby list at startup: {}", e.getMessage());
+        }
         casinoTable.getChildren().clear();
         casinoTable.getChildren().add(gridManager.getGridPane());
         gridManager.renderLobbyButtons();
+
+        String sharedUsername = ClientApp.getSharedUsername();
+        updateUsernameFieldPresentation(sharedUsername);
+        if (loginButton != null) {
+            loginButton.setText(
+                    sharedUsername != null && !sharedUsername.isBlank() ? "Change Name" : "Login");
+        }
+
+        initializeChat(clientService);
+    }
+
+    /**
+     * Initializes the chat UI if a valid ClientService is available. If the client is offline or
+     * the
+     *
+     * @param clientService
+     */
+    private void initializeChat(ClientService clientService) {
+        if (clientService == null || clientService.isOffline() || chatContainer == null) {
+            return;
+        }
+        try {
+            String username = resolveChatUsername();
+            chatController = new ChatController(username, clientService);
+            URL resource = getClass().getResource("/ui-structure/components/chatui/chatbox.fxml");
+            FXMLLoader loader = new FXMLLoader(resource);
+            loader.setController(chatController.getChatBoxController());
+            Node chatNode = loader.load();
+            chatContainer.getChildren().setAll(chatNode);
+            AnchorPane.setTopAnchor(chatNode, 0.0);
+            AnchorPane.setBottomAnchor(chatNode, 0.0);
+            AnchorPane.setLeftAnchor(chatNode, 0.0);
+            AnchorPane.setRightAnchor(chatNode, 0.0);
+            gridManager.setChatController(chatController);
+        } catch (IOException e) {
+            LOGGER.warn("Could not initialize lobby chat UI: {}", e.getMessage());
+        }
+    }
+
+    /**
+     * Resolves the username to be used in the chat. It first checks for a shared username set at
+     * the
+     *
+     * @return The resolved username, or "Guest" if no valid username is found.
+     */
+    private String resolveChatUsername() {
+        String shared = ClientApp.getSharedUsername();
+        if (shared != null && !shared.isBlank()) {
+            return shared.trim();
+        }
+        if (usernameField != null
+                && usernameField.getText() != null
+                && !usernameField.getText().isBlank()) {
+            return usernameField.getText().trim();
+        }
+        return "Guest";
     }
 
     /** Handles the login button action. Validates input and calls LobbyClient.login(). */
     @FXML
     public void handleLoginButton() {
-        String username = usernameField.getText();
+        String username = usernameField == null ? null : usernameField.getText();
         if (username == null || username.isBlank()) {
             showAlert("Please enter a username.");
             return;
@@ -90,12 +183,63 @@ public class CasinomainuiController {
             showAlert("Offline mode: cannot send login to server.");
             return;
         }
+
+        String trimmed = username.trim();
         try {
-            lobbyClient.login(username);
-            showAlert("Login sent: " + username);
+            var result = lobbyClient.login(trimmed);
+            String assigned = result != null ? result.getUsername() : trimmed;
+            ClientApp.updateSharedUsername(assigned);
+            if (chatController != null) {
+                chatController.updateUsername(assigned);
+            }
+            updateUsernameFieldPresentation(assigned);
+            if (loginButton != null) {
+                loginButton.setText("Change Name");
+            }
+            return;
+        } catch (RuntimeException loginError) {
+            if (!containsProtocolError(loginError, "ALREADY_LOGGED_IN")) {
+                LOGGER.error("Login failed: {}", loginError.getMessage());
+                showAlert("Login failed: " + loginError.getMessage());
+                return;
+            }
+            LOGGER.info("Session already logged in, trying username change");
+        }
+
+        try {
+            var result = lobbyClient.changeUsername(trimmed);
+            String assigned = result != null ? result.getUsername() : trimmed;
+            ClientApp.updateSharedUsername(assigned);
+            if (chatController != null) {
+                chatController.updateUsername(assigned);
+            }
+            updateUsernameFieldPresentation(assigned);
+            if (loginButton != null) {
+                loginButton.setText("Change Name");
+            }
         } catch (RuntimeException e) {
-            LOGGER.error("Login failed: {}", e.getMessage());
-            showAlert("Login failed: " + e.getMessage());
+            LOGGER.error("Change username failed: {}", e.getMessage());
+            showAlert("Change username failed: " + e.getMessage());
+        }
+    }
+
+    private boolean containsProtocolError(RuntimeException error, String code) {
+        String msg = error.getMessage();
+        return msg != null && msg.contains(code);
+    }
+
+    private void updateUsernameFieldPresentation(String username) {
+        if (usernameField == null) {
+            return;
+        }
+
+        if (username != null && !username.isBlank()) {
+            usernameField.setText(username.trim());
+            usernameField.positionCaret(usernameField.getText().length());
+            usernameField.setPromptText("Username");
+        } else {
+            usernameField.clear();
+            usernameField.setPromptText("Username");
         }
     }
 
@@ -114,10 +258,17 @@ public class CasinomainuiController {
     /** Handles the exit button action to close the application. */
     @FXML
     public void handleexitbutton() {
+        if (chatController != null) {
+            chatController.shutdown();
+        }
         Platform.exit();
     }
 
-    /** Handles creation of a new lobby button. */
+    /**
+     * Handles creation of a new lobby button. Attempts to create a lobby on the server via the
+     * {@link LobbyButtonGridManager} and registers the new button in the local translation manager.
+     * Errors are logged and displayed as an informational alert.
+     */
     @FXML
     public void handleCreateLobbyButton() {
         if (translationManager.isFull()) {
@@ -142,4 +293,36 @@ public class CasinomainuiController {
             LOGGER.error("Failed to create or add lobby: {}", e.getMessage());
         }
     }
+
+    /** Opens the highscore popup from the lobby UI. */
+    @FXML
+    public void handleOpenHighscores() {
+        try {
+            FXMLLoader loader =
+                    new FXMLLoader(
+                            getClass()
+                                    .getResource(
+                                            "/ui-structure/gameuicomponents/HighscoreView.fxml"));
+            Parent root = loader.load();
+
+            HighscoreViewController controller = loader.getController();
+            controller.setLobbyClient(lobbyClient);
+            controller.refreshHighscores();
+
+            Stage stage = new Stage();
+            stage.initStyle(StageStyle.TRANSPARENT);
+            stage.setTitle("Casono Highscores");
+            String iconPath = getClass().getResource("/images/logoinverted.png").toExternalForm();
+            stage.getIcons().add(new Image(iconPath));
+            Scene scene = new Scene(root);
+            scene.setFill(javafx.scene.paint.Color.TRANSPARENT);
+            stage.setScene(scene);
+            stage.show();
+            stage.setAlwaysOnTop(true);
+            stage.toFront();
+        } catch (IOException e) {
+            LOGGER.warn("Could not open highscore window: {}", e.getMessage());
+            showAlert("Could not open highscore window.");
+        }
+    }
 }

src/main/java/ch/unibas/dmi/dbis/cs108/casono/client/ui/lobbyui/LobbyButtonGridManager.java

@@ -1,7 +1,11 @@
 package ch.unibas.dmi.dbis.cs108.casono.client.ui.lobbyui;
 
+import ch.unibas.dmi.dbis.cs108.casono.client.ClientApp;
+import ch.unibas.dmi.dbis.cs108.casono.client.chat.ChatController;
 import ch.unibas.dmi.dbis.cs108.casono.client.network.ClientService;
 import ch.unibas.dmi.dbis.cs108.casono.client.network.LobbyClient;
+import ch.unibas.dmi.dbis.cs108.casono.client.ui.gameui.CasinoGameUI;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.parsing.RequestParameter;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -27,6 +31,8 @@ public class LobbyButtonGridManager {
     private static final int REFRESH_INTERVAL_SECONDS = 5;
     private static final int INITIAL_DELAY_SECONDS = 5;
     private static final int COLS = 4;
+    private static final int MAX_BUTTONS = 8;
+    private static final int GUEST_ID_LENGTH = 8;
 
     private static final Logger LOGGER = LogManager.getLogger(LobbyButtonGridManager.class);
 
@@ -38,6 +44,8 @@ public class LobbyButtonGridManager {
     private final LobbyButtonTranslationManager translationManager;
     private final LobbyClient lobbyClient;
 
+    private ChatController chatController;
+
     private final ConcurrentHashMap<String, Image> imageCache = new ConcurrentHashMap<>();
 
     private final ExecutorService executor = Executors.newCachedThreadPool();
@@ -53,7 +61,7 @@ public class LobbyButtonGridManager {
         this.translationManager = LobbyButtonTranslationManager.getInstance();
         this.lobbyClient = lobbyClient;
 
-        startPeriodicRefresh(REFRESH_INTERVAL_SECONDS, INITIAL_DELAY_SECONDS);
+        startPeriodicRefresh(INITIAL_DELAY_SECONDS, REFRESH_INTERVAL_SECONDS);
     }
 
     public LobbyButtonGridManager(
@@ -62,6 +70,109 @@ public class LobbyButtonGridManager {
             ClientService clientService) {
 
         this(gridPane, translationManager, new LobbyClient(clientService));
+
+        // Subscribe to server-initiated events so closed lobbies are removed
+        // immediately
+        clientService.addEventListener(this::handleClientServiceEvent);
+    }
+
+    private static record EventInfo(String event, String lobbyId) {}
+
+    private EventInfo extractEventInfo(List<RequestParameter> params) {
+        String evt = null;
+        String lidStr = null;
+        for (RequestParameter p : params) {
+            if ("EVENT".equalsIgnoreCase(p.key())) {
+                evt = p.value();
+            } else if ("LOBBY_ID".equalsIgnoreCase(p.key())) {
+                lidStr = p.value();
+            }
+        }
+        return new EventInfo(evt, lidStr);
+    }
+
+    private Integer tryParseInt(String s) {
+        try {
+            return Integer.parseInt(s);
+        } catch (NumberFormatException ex) {
+            return null;
+        }
+    }
+
+    private void handleLobbyClosed(int lid) {
+        LOGGER.info(
+                "LOBBY_CLOSED event for lobby {} — mapping before: {}",
+                lid,
+                translationManager.getButtonIdToLobbyId());
+        // find button id(s) for this lobby and remove mapping
+        Map<Integer, Integer> mapping = translationManager.getButtonIdToLobbyId();
+        Integer toRemove = null;
+        for (Map.Entry<Integer, Integer> e : mapping.entrySet()) {
+            if (e.getValue() != null && e.getValue().intValue() == lid) {
+                toRemove = e.getKey();
+                break;
+            }
+        }
+        if (toRemove != null) {
+            LOGGER.info(
+                    "Removing mapping for button {} -> lobby {} (LOBBY_CLOSED event)",
+                    toRemove,
+                    lid);
+            translationManager.removeLobbyButton(toRemove);
+            LOGGER.debug("Mapping after removal: {}", translationManager.getButtonIdToLobbyId());
+            javafx.application.Platform.runLater(this::renderLobbyButtons);
+        }
+    }
+
+    private void handleLobbyCreated(int lid) {
+        LOGGER.info(
+                "LOBBY_CREATED event for lobby {} — mapping before: {}",
+                lid,
+                translationManager.getButtonIdToLobbyId());
+
+        Map<Integer, Integer> mapping = translationManager.getButtonIdToLobbyId();
+
+        // If this lobby is already known, nothing to do
+        if (mapping.containsValue(lid)) {
+            LOGGER.debug("Lobby {} already mapped, skipping", lid);
+            return;
+        }
+
+        // find next free button id (1..MAX_BUTTONS)
+        for (int candidate = 1; candidate <= MAX_BUTTONS; candidate++) {
+            if (!mapping.containsKey(candidate)) {
+                try {
+                    translationManager.addLobbyButton(candidate, lid);
+                    LOGGER.info("Mapped new lobby {} to button {}", lid, candidate);
+                    LOGGER.debug(
+                            "Mapping after add: {}", translationManager.getButtonIdToLobbyId());
+                    javafx.application.Platform.runLater(this::renderLobbyButtons);
+                    break;
+                } catch (Exception ex) {
+                    // grid full? try next candidate
+                    LOGGER.debug("Could not map created lobby {}: {}", lid, ex.getMessage());
+                }
+            }
+        }
+    }
+
+    private void handleClientServiceEvent(List<String> lines) {
+        EventInfo info = extractEventInfo(ClientService.convertToRequestParameters(lines));
+
+        if (info.event() == null || info.lobbyId() == null) {
+            return;
+        }
+
+        Integer lid = tryParseInt(info.lobbyId());
+        if (lid == null) {
+            return;
+        }
+
+        if ("LOBBY_CLOSED".equalsIgnoreCase(info.event())) {
+            handleLobbyClosed(lid);
+        } else if ("LOBBY_CREATED".equalsIgnoreCase(info.event())) {
+            handleLobbyCreated(lid);
+        }
     }
 
     private void startPeriodicRefresh(long initialDelay, long period) {
@@ -72,15 +183,40 @@ public class LobbyButtonGridManager {
     private void refreshMappings() {
         Map<Integer, Integer> mapping = translationManager.getButtonIdToLobbyId();
 
+        // Always attempt to sync with server-side lobby list so clients that start
+        // after a lobby was created will discover it. This keeps the local mapping
+        // in sync with the server without requiring a restart.
+        List<LobbyClient.LobbyInfo> serverLobbies = null;
+        java.util.Set<Integer> serverIds = new java.util.HashSet<>();
+        try {
+            serverLobbies = lobbyClient.getLobbyList();
+            if (serverLobbies != null) {
+                for (var li : serverLobbies) {
+                    serverIds.add(li.id);
+                }
+            }
+            reconcileWithServerLobbies(serverLobbies);
+        } catch (Exception ex) {
+            LOGGER.debug("Could not fetch lobby list: {}", ex.getMessage());
+        }
+
         if (mapping.isEmpty()) {
-            return;
+            // mapping may still be empty after reconciliation
+            if (translationManager.getButtonIdToLobbyId().isEmpty()) {
+                return;
+            }
+            mapping = translationManager.getButtonIdToLobbyId();
         }
 
         List<Map.Entry<Integer, Integer>> entries = new ArrayList<>(mapping.entrySet());
 
         for (Map.Entry<Integer, Integer> e : entries) {
             int buttonId = e.getKey();
-            int lobbyId = e.getValue();
+            Integer lobbyIdObj = e.getValue();
+            if (lobbyIdObj == null) {
+                continue;
+            }
+            int lobbyId = lobbyIdObj.intValue();
 
             CompletableFuture.supplyAsync(
                             () -> {
@@ -94,16 +230,88 @@ public class LobbyButtonGridManager {
                             executor)
                     .thenAccept(
                             status -> {
+                                // Do not remove a mapping just because the status fetch
+                                // temporarily returned null. Only remove mappings when
+                                // the server no longer lists the lobby (reconcileWithServerLobbies
+                                // handles removals based on authoritative server list).
                                 if (status == null) {
-                                    translationManager.removeLobbyButton(buttonId);
-
-                                    javafx.application.Platform.runLater(
-                                            this::updateLobbyButtonImages);
+                                    if (!serverIds.contains(lobbyId)) {
+                                        translationManager.removeLobbyButton(buttonId);
+                                        javafx.application.Platform.runLater(
+                                                this::renderLobbyButtons);
+                                    } else {
+                                        // treat as created/running later; keep mapping
+                                        LOGGER.debug(
+                                                "Missing status for lobby {} - keeping mapping",
+                                                lobbyId);
+                                    }
                                 }
                             });
         }
     }
 
+    private void reconcileWithServerLobbies(List<LobbyClient.LobbyInfo> serverLobbies) {
+        if (serverLobbies == null) {
+            return;
+        }
+
+        Map<Integer, Integer> mapping = translationManager.getButtonIdToLobbyId();
+
+        // Build set of lobby ids returned by server
+        java.util.Set<Integer> serverIds = new java.util.HashSet<>();
+        for (var li : serverLobbies) {
+            serverIds.add(li.id);
+        }
+
+        LOGGER.debug("Reconciling mappings. serverIds={} mapping={}", serverIds, mapping);
+
+        // Remove mappings for lobbies that no longer exist
+        java.util.List<Integer> toRemove = new java.util.ArrayList<>();
+        for (var e : mapping.entrySet()) {
+            Integer lid = e.getValue();
+            if (lid == null) {
+                continue;
+            }
+            if (!serverIds.contains(lid)) {
+                toRemove.add(e.getKey());
+            }
+        }
+        for (Integer bid : toRemove) {
+            LOGGER.info(
+                    "Reconciling: removing mapping for button {} (server no longer lists lobby)",
+                    bid);
+            translationManager.removeLobbyButton(bid);
+        }
+
+        // Add server lobbies that are not yet mapped
+        for (var li : serverLobbies) {
+            if (mapping.containsValue(li.id)) {
+                continue;
+            }
+            // find next free button id (1..MAX_BUTTONS)
+            for (int candidate = 1; candidate <= MAX_BUTTONS; candidate++) {
+                if (!mapping.containsKey(candidate)) {
+                    try {
+                        translationManager.addLobbyButton(candidate, li.id);
+                        LOGGER.info(
+                                "Reconciling: added mapping button {} -> lobby {}",
+                                candidate,
+                                li.id);
+                        break;
+                    } catch (Exception ex) {
+                        // grid full? try next candidate
+                        LOGGER.debug(
+                                "Could not add mapping for lobby {}: {}", li.id, ex.getMessage());
+                    }
+                }
+            }
+        }
+
+        if (!toRemove.isEmpty() || !serverLobbies.isEmpty()) {
+            javafx.application.Platform.runLater(this::renderLobbyButtons);
+        }
+    }
+
     public void renderLobbyButtons() {
         gridPane.getChildren().clear();
 
@@ -118,7 +326,11 @@ public class LobbyButtonGridManager {
 
         for (int index = 0; index < buttonIds.size(); index++) {
             Integer buttonId = buttonIds.get(index);
-            int lobbyId = mapping.get(buttonId);
+            Integer lobbyIdObj = mapping.get(buttonId);
+            if (lobbyIdObj == null) {
+                continue;
+            }
+            int lobbyId = lobbyIdObj.intValue();
 
             Button btn = createLobbyButton(buttonId, lobbyId);
 
@@ -171,9 +383,8 @@ public class LobbyButtonGridManager {
                             LobbyStatus status = parseLobbyStatus(statusStr);
 
                             String path =
-                                    getImagePathForButton(
-                                            buttonId,
-                                            status == null ? LobbyStatus.CREATED : status);
+                                    getImagePathForLobby(
+                                            lobbyId, status == null ? LobbyStatus.CREATED : status);
 
                             Image img = safeLoadImage(path);
 
@@ -208,11 +419,11 @@ public class LobbyButtonGridManager {
         }
     }
 
-    private String getImagePathForButton(int buttonId, LobbyStatus status) {
+    private String getImagePathForLobby(int lobbyId, LobbyStatus status) {
 
         String statusStr = status == LobbyStatus.CREATED ? "created" : "running";
 
-        return String.format(BUTTON_IMAGE_TEMPLATE, buttonId, statusStr);
+        return String.format(BUTTON_IMAGE_TEMPLATE, lobbyId, statusStr);
     }
 
     private Image safeLoadImage(String path) {
@@ -253,7 +464,11 @@ public class LobbyButtonGridManager {
         }
 
         for (Integer buttonId : mapping.keySet()) {
-            int lobbyId = mapping.get(buttonId);
+            Integer lobbyIdObj = mapping.get(buttonId);
+            if (lobbyIdObj == null) {
+                continue;
+            }
+            int lobbyId = lobbyIdObj.intValue();
 
             CompletableFuture.supplyAsync(
                             () -> {
@@ -266,7 +481,7 @@ public class LobbyButtonGridManager {
                             executor)
                     .thenAccept(
                             status -> {
-                                String path = getImagePathForButton(buttonId, status);
+                                String path = getImagePathForLobby(lobbyId, status);
 
                                 javafx.application.Platform.runLater(
                                         () -> {
@@ -341,11 +556,25 @@ public class LobbyButtonGridManager {
                             });
 
                     try {
-                        ch.unibas.dmi.dbis.cs108.casono.client.ui.gameui.CasinoGameUI
-                                .setClientService(lobbyClient.getClientService());
+                        var cs = lobbyClient.getClientService();
 
-                        new ch.unibas.dmi.dbis.cs108.casono.client.ui.gameui.CasinoGameUI()
-                                .start(gameStage);
+                        CasinoGameUI.setClientService(cs);
+                        CasinoGameUI.setLobbyId(lobbyId);
+                        CasinoGameUI.setChatController(chatController);
+
+                        String username = ClientApp.getSharedUsername();
+                        if (username == null || username.isBlank()) {
+                            username =
+                                    "Guest-"
+                                            + java.util
+                                                    .UUID
+                                                    .randomUUID()
+                                                    .toString()
+                                                    .substring(0, GUEST_ID_LENGTH);
+                        }
+                        CasinoGameUI.setUsername(username);
+
+                        new CasinoGameUI().start(gameStage);
 
                     } catch (Exception e) {
                         LOGGER.error("Game UI failed: {}", e.getMessage());
@@ -362,7 +591,7 @@ public class LobbyButtonGridManager {
         return lobbyClient;
     }
 
-    public void refreshNow() {
-        refreshMappings();
+    public void setChatController(ChatController chatController) {
+        this.chatController = chatController;
     }
 }

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/ServerApp.java

@@ -1,17 +1,56 @@
 package ch.unibas.dmi.dbis.cs108.casono.server;
 
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.change_username.ChangeUsernameHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.change_username.ChangeUsernameParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.change_username.ChangeUsernameRequest;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.check_nick.CheckUsernameHandler;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.check_nick.CheckUsernameParser;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.check_nick.CheckUsernameRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.bet.PlayerBetHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.bet.PlayerBetParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.bet.PlayerBetRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.call.PlayerCallHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.call.PlayerCallParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.call.PlayerCallRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.fold.PlayerFoldHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.fold.PlayerFoldParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.fold.PlayerFoldRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.get_game_state.GetGameStateHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.get_game_state.GetGameStateParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.get_game_state.GetGameStateRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.raise.PlayerRaiseHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.raise.PlayerRaiseParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.raise.PlayerRaiseRequest;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.get_message_count.GetMessageCountHandler;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.get_message_count.GetMessageCountParser;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.get_message_count.GetMessageCountRequest;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.get_next_message.GetNextMessageHandler;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.get_next_message.GetNextMessageParser;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.get_next_message.GetNextMessageRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.highscore.clear_highscores.ClearHighscoresHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.highscore.clear_highscores.ClearHighscoresParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.highscore.clear_highscores.ClearHighscoresRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.highscore.get_highscores.GetHighscoresHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.highscore.get_highscores.GetHighscoresParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.highscore.get_highscores.GetHighscoresRequest;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.list_users.ListUsersHandler;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.list_users.ListUsersParser;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.list_users.ListUsersRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.create_lobby.CreateLobbyHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.create_lobby.CreateLobbyParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.create_lobby.CreateLobbyRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.get_lobby_list.GetLobbyListHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.get_lobby_list.GetLobbyListParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.get_lobby_list.GetLobbyListRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.get_lobby_status.GetLobbyStatusHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.get_lobby_status.GetLobbyStatusParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.get_lobby_status.GetLobbyStatusRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.join_lobby.JoinLobbyHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.join_lobby.JoinLobbyParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.join_lobby.JoinLobbyRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.start_game.StartGameHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.start_game.StartGameParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.start_game.StartGameRequest;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.login.LoginHandler;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.login.LoginParser;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.login.LoginRequest;
@@ -24,9 +63,12 @@ import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.ping.PingRequest;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.send_message.SendMessageHandler;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.send_message.SendMessageParser;
 import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.send_message.SendMessageRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyCleanupJob;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyManager;
 import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.UserCleanupJob;
 import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.UserRegistry;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.NetworkManager;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandHandler;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandHandlerExecutor;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandRouter;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.command.parsing.CommandParserDispatcher;
@@ -49,7 +91,10 @@ public class ServerApp {
     private static final int USER_CLEANUP_JOB_RECONNECT_THRESHOLD = 10;
     private static final int SESSION_DISCONNECT_JOB_DELAY = 0;
     private static final int SESSION_DISCONNECT_JOB_PERIOD = 2;
-    private static final int SESSION_DISCONNECT_JOB_TIMEOUT = 5;
+    private static final int SESSION_DISCONNECT_JOB_TIMEOUT = 30;
+    private static final int LOBBY_EXPIRY_SECONDS = 30;
+    private static final int LOBBY_CLEANUP_INITIAL_DELAY_SECONDS = 5;
+    private static final int LOBBY_CLEANUP_PERIOD_SECONDS = 5;
 
     public static void start(String arg) {
         int port = Integer.parseInt(arg);
@@ -85,12 +130,31 @@ public class ServerApp {
                 SESSION_DISCONNECT_JOB_PERIOD,
                 TimeUnit.SECONDS);
 
-        registerCommands(dispatcher, router, responseDispatcher, userRegistry);
+        LobbyManager lobbyManager = new LobbyManager();
+        registerCommands(
+                dispatcher,
+                router,
+                responseDispatcher,
+                userRegistry,
+                new CommandContext(lobbyManager, sessionManager));
+
+        scheduler.scheduleAtFixedRate(
+                new LobbyCleanupJob(
+                        lobbyManager,
+                        sessionManager,
+                        responseDispatcher,
+                        Duration.ofSeconds(LOBBY_EXPIRY_SECONDS)),
+                LOBBY_CLEANUP_INITIAL_DELAY_SECONDS,
+                LOBBY_CLEANUP_PERIOD_SECONDS,
+                TimeUnit.SECONDS);
 
         NetworkManager networkManager = new NetworkManager(port, sessionManager, router);
         networkManager.start();
     }
 
+    private static record CommandContext(
+            LobbyManager lobbyManager, SessionManager sessionManager) {}
+
     /**
      * Registers command parsers and handlers.
      *
@@ -102,7 +166,8 @@ public class ServerApp {
             CommandParserDispatcher parserDispatcher,
             CommandRouter commandRouter,
             ResponseDispatcher responseDispatcher,
-            UserRegistry userRegistry) {
+            UserRegistry userRegistry,
+            CommandContext context) {
         parserDispatcher.register("PING", new PingParser());
         commandRouter.register(PingRequest.class, new PingHandler(responseDispatcher));
 
@@ -115,13 +180,23 @@ public class ServerApp {
         commandRouter.register(
                 LoginRequest.class, new LoginHandler(responseDispatcher, userRegistry));
 
+        parserDispatcher.register("CHANGE_USERNAME", new ChangeUsernameParser());
+        commandRouter.register(
+                ChangeUsernameRequest.class,
+                new ChangeUsernameHandler(
+                        responseDispatcher,
+                        userRegistry,
+                        context.lobbyManager(),
+                        context.sessionManager()));
+
         parserDispatcher.register("LOGOUT", new LogoutParser());
         commandRouter.register(
                 LogoutRequest.class, new LogoutHandler(responseDispatcher, userRegistry));
 
         parserDispatcher.register("SEND_MESSAGE", new SendMessageParser());
         commandRouter.register(
-                SendMessageRequest.class, new SendMessageHandler(responseDispatcher, userRegistry));
+                SendMessageRequest.class,
+                new SendMessageHandler(responseDispatcher, userRegistry, context.lobbyManager()));
 
         parserDispatcher.register("GET_MESSAGE_COUNT", new GetMessageCountParser());
         commandRouter.register(
@@ -136,5 +211,98 @@ public class ServerApp {
         parserDispatcher.register("LIST_USERS", new ListUsersParser());
         commandRouter.register(
                 ListUsersRequest.class, new ListUsersHandler(responseDispatcher, userRegistry));
+
+        // GET_LOBBY_LIST registration
+        parserDispatcher.register("GET_LOBBY_LIST", new GetLobbyListParser());
+        commandRouter.register(
+                GetLobbyListRequest.class,
+                (CommandHandler<GetLobbyListRequest>)
+                        new GetLobbyListHandler(responseDispatcher, context.lobbyManager()));
+
+        // GET_GAME_STATE registration
+        parserDispatcher.register("GET_GAME_STATE", new GetGameStateParser());
+        commandRouter.register(
+                GetGameStateRequest.class,
+                (CommandHandler<GetGameStateRequest>)
+                        new GetGameStateHandler(
+                                responseDispatcher, context.lobbyManager(), userRegistry));
+
+        parserDispatcher.register("GET_HIGHSCORES", new GetHighscoresParser());
+        commandRouter.register(
+                GetHighscoresRequest.class,
+                (CommandHandler<GetHighscoresRequest>)
+                        new GetHighscoresHandler(responseDispatcher));
+
+        parserDispatcher.register("CLEAR_HIGHSCORES", new ClearHighscoresParser());
+        commandRouter.register(
+                ClearHighscoresRequest.class,
+                (CommandHandler<ClearHighscoresRequest>)
+                        new ClearHighscoresHandler(responseDispatcher));
+
+        // BET registration
+        parserDispatcher.register("BET", new PlayerBetParser());
+        commandRouter.register(
+                PlayerBetRequest.class,
+                (CommandHandler<PlayerBetRequest>)
+                        new PlayerBetHandler(
+                                responseDispatcher, userRegistry, context.lobbyManager()));
+
+        // RAISE registration
+        parserDispatcher.register("RAISE", new PlayerRaiseParser());
+        commandRouter.register(
+                PlayerRaiseRequest.class,
+                (CommandHandler<PlayerRaiseRequest>)
+                        new PlayerRaiseHandler(
+                                responseDispatcher, userRegistry, context.lobbyManager()));
+
+        // CALL registration
+        parserDispatcher.register("CALL", new PlayerCallParser());
+        commandRouter.register(
+                PlayerCallRequest.class,
+                (CommandHandler<PlayerCallRequest>)
+                        new PlayerCallHandler(
+                                responseDispatcher, userRegistry, context.lobbyManager()));
+
+        // FOLD registration
+        parserDispatcher.register("FOLD", new PlayerFoldParser());
+        commandRouter.register(
+                PlayerFoldRequest.class,
+                (CommandHandler<PlayerFoldRequest>)
+                        new PlayerFoldHandler(
+                                responseDispatcher, userRegistry, context.lobbyManager()));
+
+        // GET_LOBBY_STATUS registration
+        parserDispatcher.register("GET_LOBBY_STATUS", new GetLobbyStatusParser());
+        commandRouter.register(
+                GetLobbyStatusRequest.class,
+                (CommandHandler<GetLobbyStatusRequest>)
+                        new GetLobbyStatusHandler(
+                                responseDispatcher, context.lobbyManager(), userRegistry));
+
+        // CREATE_LOBBY registration
+        parserDispatcher.register("CREATE_LOBBY", new CreateLobbyParser());
+        commandRouter.register(
+                CreateLobbyRequest.class,
+                (CommandHandler<CreateLobbyRequest>)
+                        new CreateLobbyHandler(
+                                responseDispatcher,
+                                context.lobbyManager(),
+                                context.sessionManager()));
+
+        // JOIN_LOBBY registration
+        parserDispatcher.register("JOIN_LOBBY", new JoinLobbyParser());
+        commandRouter.register(
+                JoinLobbyRequest.class,
+                (CommandHandler<JoinLobbyRequest>)
+                        new JoinLobbyHandler(
+                                responseDispatcher, context.lobbyManager(), userRegistry));
+
+        // START_GAME registration
+        parserDispatcher.register("START_GAME", new StartGameParser());
+        commandRouter.register(
+                StartGameRequest.class,
+                (CommandHandler<StartGameRequest>)
+                        new StartGameHandler(
+                                responseDispatcher, context.lobbyManager(), userRegistry));
     }
 }

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/checks/GameLobbyExistsCheck.java

@@ -0,0 +1,75 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.checks;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.bet.PlayerBetRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.call.PlayerCallRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.fold.PlayerFoldRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.raise.PlayerRaiseRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.Lobby;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyId;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyManager;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.User;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.UserRegistry;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.checks.HandlerCheck;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.Request;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.ErrorResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.Response;
+import java.util.Optional;
+
+/**
+ * Checks whether a target lobby exists for game action commands.
+ *
+ * <p>Supported commands are BET, CALL, FOLD and RAISE. If a request specifies a GAME_ID, the check
+ * validates that this lobby exists. Otherwise, it validates that the logged-in user is in a lobby.
+ */
+public class GameLobbyExistsCheck implements HandlerCheck {
+    private final UserRegistry userRegistry;
+    private final LobbyManager lobbyManager;
+
+    public GameLobbyExistsCheck(UserRegistry userRegistry, LobbyManager lobbyManager) {
+        this.userRegistry = userRegistry;
+        this.lobbyManager = lobbyManager;
+    }
+
+    @Override
+    public Optional<Response> check(Request request) {
+        Integer gameId = extractGameId(request);
+        User user = userRegistry.getBySessionId(request.getSessionId()).get();
+
+        Lobby lobby;
+        if (gameId != null) {
+            lobby = lobbyManager.getLobby(LobbyId.of(gameId));
+        } else {
+            lobby = lobbyManager.getLobbyByUsername(user.getName());
+        }
+
+        if (lobby != null) {
+            return Optional.empty();
+        }
+
+        if (gameId != null) {
+            return Optional.of(
+                    new ErrorResponse(request.getContext(), "LOBBY_NOT_FOUND", "Lobby not found"));
+        }
+
+        return Optional.of(
+                new ErrorResponse(request.getContext(), "NOT_IN_LOBBY", "User not in a lobby"));
+    }
+
+    private Integer extractGameId(Request request) {
+        if (request instanceof PlayerBetRequest) {
+            return ((PlayerBetRequest) request).getGameId();
+        }
+        if (request instanceof PlayerCallRequest) {
+            return ((PlayerCallRequest) request).getGameId();
+        }
+        if (request instanceof PlayerFoldRequest) {
+            return ((PlayerFoldRequest) request).getGameId();
+        }
+        if (request instanceof PlayerRaiseRequest) {
+            return ((PlayerRaiseRequest) request).getGameId();
+        }
+
+        throw new IllegalStateException(
+                "GameLobbyExistsCheck is only supported for BET, CALL, FOLD and RAISE requests");
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/add_player/AddPlayerHandler.java

@@ -0,0 +1,33 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.add_player;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.User;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.UserRegistry;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.ErrorResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.OkResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.dispatcher.ResponseDispatcher;
+import java.util.Optional;
+
+/** Handler for the ADD_PLAYER command. */
+public class AddPlayerHandler extends CommandHandler<AddPlayerRequest> {
+    private final UserRegistry userRegistry;
+
+    public AddPlayerHandler(UserRegistry userRegistry, ResponseDispatcher responseDispatcher) {
+        super(responseDispatcher);
+        this.userRegistry = userRegistry;
+    }
+
+    @Override
+    public void execute(AddPlayerRequest request) {
+        Optional<User> created =
+                userRegistry.registerIfAvailable(
+                        request.getName(), request.getContext().sessionId());
+        if (created.isEmpty()) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(request.getContext(), "NAME_TAKEN", "Name already taken"));
+            return;
+        }
+
+        responseDispatcher.dispatch(new OkResponse(request.getContext()));
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/add_player/AddPlayerParser.java

@@ -0,0 +1,20 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.add_player;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.parsing.CommandParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.PrimitiveRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.accessor.RequestParameterAccessor;
+
+/** Parser for the ADD_PLAYER command. */
+public class AddPlayerParser implements CommandParser<AddPlayerRequest> {
+    @Override
+    public AddPlayerRequest parse(PrimitiveRequest primitiveRequest) {
+        RequestParameterAccessor accessor =
+                new RequestParameterAccessor(primitiveRequest.parameters());
+
+        String name = accessor.require("NAME");
+
+        int chips = accessor.require("CHIPS", Integer::parseInt);
+
+        return new AddPlayerRequest(primitiveRequest.context(), name, chips);
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/add_player/AddPlayerRequest.java

@@ -0,0 +1,24 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.add_player;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.Request;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+
+/** Request data for the ADD_PLAYER command. */
+public class AddPlayerRequest extends Request {
+    private final String name;
+    private final int chips;
+
+    public AddPlayerRequest(RequestContext context, String name, int chips) {
+        super(context);
+        this.name = name;
+        this.chips = chips;
+    }
+
+    public String getName() {
+        return name;
+    }
+
+    public int getChips() {
+        return chips;
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/change_username/ChangeUsernameHandler.java

@@ -0,0 +1,112 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.change_username;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyManager;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.User;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.UserRegistry;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.ErrorResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.SuccessResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.builder.ResponseBodyBuilder;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.dispatcher.ResponseDispatcher;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.sessions.Session;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.sessions.SessionManager;
+import java.util.Optional;
+import java.util.regex.Pattern;
+
+/** Handles CHANGE_USERNAME requests for already logged-in users. */
+public class ChangeUsernameHandler extends CommandHandler<ChangeUsernameRequest> {
+    private static final Pattern VALID_USERNAME = Pattern.compile("[a-zA-Z0-9_-]+");
+    private final UserRegistry userRegistry;
+    private final LobbyManager lobbyManager;
+    private final SessionManager sessionManager;
+
+    /**
+     * @param responseDispatcher dispatcher used for responses
+     * @param userRegistry registry containing all users
+     * @param lobbyManager lobby manager used to keep lobby/game mappings in sync
+     * @param sessionManager session manager used to broadcast rename events
+     */
+    public ChangeUsernameHandler(
+            ResponseDispatcher responseDispatcher,
+            UserRegistry userRegistry,
+            LobbyManager lobbyManager,
+            SessionManager sessionManager) {
+        super(responseDispatcher);
+        this.userRegistry = userRegistry;
+        this.lobbyManager = lobbyManager;
+        this.sessionManager = sessionManager;
+    }
+
+    @Override
+    public void execute(ChangeUsernameRequest request) {
+        Optional<User> user = userRegistry.getBySessionId(request.getSessionId());
+        if (user.isEmpty()) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(
+                            request.getContext(),
+                            "USER_NOT_LOGGED_IN",
+                            "This session is not associated with an active user."));
+            return;
+        }
+
+        String newUsername = request.getUsername() == null ? "" : request.getUsername().trim();
+        if (newUsername.isEmpty() || !VALID_USERNAME.matcher(newUsername).matches()) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(
+                            request.getContext(),
+                            "INVALID_USERNAME",
+                            "Only letters, numbers, '_' and '-' are allowed."));
+            return;
+        }
+
+        User currentUser = user.get();
+        String oldUsername = currentUser.getName();
+        boolean changed = userRegistry.changeUsername(currentUser.getId(), newUsername);
+        if (!changed) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(
+                            request.getContext(),
+                            "USERNAME_TAKEN",
+                            "The requested username is already taken."));
+            return;
+        }
+
+        boolean lobbySynced =
+                lobbyManager == null || lobbyManager.renamePlayer(oldUsername, newUsername);
+        if (!lobbySynced) {
+            userRegistry.changeUsername(currentUser.getId(), oldUsername);
+            responseDispatcher.dispatch(
+                    new ErrorResponse(
+                            request.getContext(),
+                            "RENAME_CONFLICT",
+                            "Could not update username in current lobby/game state."));
+            return;
+        }
+
+        responseDispatcher.dispatch(
+                new ChangeUsernameResponse(
+                        request.getContext(), currentUser.getName(), currentUser.getId()));
+
+        broadcastUsernameChanged(oldUsername, currentUser.getName());
+    }
+
+    private void broadcastUsernameChanged(String oldUsername, String newUsername) {
+        if (sessionManager == null) {
+            return;
+        }
+
+        for (Session session : sessionManager.getAllSessions()) {
+            RequestContext ctx = new RequestContext(session.getId(), 0);
+            SuccessResponse ev =
+                    new SuccessResponse(
+                            ctx,
+                            new ResponseBodyBuilder()
+                                    .param("EVENT", "USERNAME_CHANGED")
+                                    .param("OLD_USERNAME", oldUsername)
+                                    .param("NEW_USERNAME", newUsername)
+                                    .build()) {};
+            responseDispatcher.dispatch(ev);
+        }
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/change_username/ChangeUsernameParser.java

@@ -0,0 +1,15 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.change_username;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.parsing.CommandParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.PrimitiveRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.accessor.RequestParameterAccessor;
+
+/** Parses CHANGE_USERNAME requests. */
+public class ChangeUsernameParser implements CommandParser<ChangeUsernameRequest> {
+    @Override
+    public ChangeUsernameRequest parse(PrimitiveRequest primitiveRequest) {
+        RequestParameterAccessor accessor =
+                new RequestParameterAccessor(primitiveRequest.parameters());
+        return new ChangeUsernameRequest(primitiveRequest.context(), accessor.require("USERNAME"));
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/change_username/ChangeUsernameRequest.java

@@ -0,0 +1,25 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.change_username;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.Request;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+
+/** Request used to change the username of the current session user. */
+public class ChangeUsernameRequest extends Request {
+    private final String username;
+
+    /**
+     * @param context request context for responses
+     * @param username desired new username
+     */
+    public ChangeUsernameRequest(RequestContext context, String username) {
+        super(context);
+        this.username = username;
+    }
+
+    /**
+     * @return desired new username
+     */
+    public String getUsername() {
+        return username;
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/change_username/ChangeUsernameResponse.java

@@ -0,0 +1,23 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.change_username;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.UserId;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.SuccessResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.builder.ResponseBodyBuilder;
+
+/** Response for successful username changes. */
+public class ChangeUsernameResponse extends SuccessResponse {
+    /**
+     * @param context request context
+     * @param username current username after the rename operation
+     * @param id user id of renamed user
+     */
+    public ChangeUsernameResponse(RequestContext context, String username, UserId id) {
+        super(
+                context,
+                new ResponseBodyBuilder()
+                        .param("USERNAME", username)
+                        .param("ID", id.value())
+                        .build());
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/bet/PlayerBetHandler.java

@@ -0,0 +1,102 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.bet;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.app.checks.GameLobbyExistsCheck;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.checks.UserLoggedInCheck;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.GameController;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.player.PlayerId;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.Lobby;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyId;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyManager;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.User;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.UserRegistry;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.ErrorResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.OkResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.dispatcher.ResponseDispatcher;
+import java.util.Optional;
+
+/**
+ * Handler for the `BET` command.
+ *
+ * <p>This handler validates the request (amount >= 0), resolves the user and target lobby (by
+ * `GAME_ID` when provided or by session username otherwise), checks that a game is running and then
+ * forwards the action to the {@code GameController}.
+ *
+ * <p>On failure the handler dispatches an {@link ErrorResponse} with an appropriate error code
+ * (e.g. {@code INVALID_AMOUNT}, {@code NOT_IN_LOBBY}, {@code LOBBY_NOT_FOUND}, {@code
+ * GAME_NOT_STARTED}, {@code GAME_ACTION_FAILED}). On success it dispatches an {@link OkResponse}.
+ */
+public class PlayerBetHandler extends CommandHandler<PlayerBetRequest> {
+    private final UserRegistry userRegistry;
+    private final LobbyManager lobbyManager;
+
+    /**
+     * Creates a new {@code PlayerBetHandler}.
+     *
+     * @param responseDispatcher dispatcher used to send responses back to the client
+     * @param userRegistry registry to resolve users from session ids
+     * @param lobbyManager manager used to lookup lobbies and their game controllers
+     */
+    public PlayerBetHandler(
+            ResponseDispatcher responseDispatcher,
+            UserRegistry userRegistry,
+            LobbyManager lobbyManager) {
+        super(responseDispatcher);
+        this.userRegistry = userRegistry;
+        this.lobbyManager = lobbyManager;
+        addCheck(new UserLoggedInCheck(userRegistry));
+        addCheck(new GameLobbyExistsCheck(userRegistry, lobbyManager));
+    }
+
+    /**
+     * Execute the bet request: validate parameters, resolve lobby and game, and forward the bet
+     * action to the game controller. Sends an {@link ErrorResponse} on failure or an {@link
+     * OkResponse} on success.
+     *
+     * @param request the parsed {@link PlayerBetRequest}
+     */
+    @Override
+    public void execute(PlayerBetRequest request) {
+        if (request.getAmount() < 0) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(
+                            request.getContext(), "INVALID_AMOUNT", "Amount must be non-negative"));
+            return;
+        }
+
+        Optional<User> opt = userRegistry.getBySessionId(request.getSessionId());
+        if (opt.isEmpty()) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(request.getContext(), "NOT_LOGGED_IN", "User not logged in"));
+            return;
+        }
+
+        String username = opt.get().getName();
+
+        Integer gameId = request.getGameId();
+        Lobby lobby;
+        if (gameId != null) {
+            lobby = lobbyManager.getLobby(LobbyId.of(gameId));
+        } else {
+            lobby = lobbyManager.getLobbyByUsername(username);
+        }
+
+        GameController game = lobby.getGameController();
+        if (game == null) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(
+                            request.getContext(), "GAME_NOT_STARTED", "Game not started"));
+            return;
+        }
+
+        try {
+            game.playerBet(PlayerId.of(username), request.getAmount());
+        } catch (Exception e) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(request.getContext(), "GAME_ACTION_FAILED", e.getMessage()));
+            return;
+        }
+
+        responseDispatcher.dispatch(new OkResponse(request.getContext()));
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/bet/PlayerBetParser.java

@@ -0,0 +1,40 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.bet;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.parsing.CommandParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.PrimitiveRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.accessor.RequestParameterAccessor;
+
+/**
+ * Parser for the `BET` command.
+ *
+ * <p>Parses the request parameters and builds a {@link PlayerBetRequest}. Expected parameters:
+ *
+ * <ul>
+ *   <li>`GAME_ID` (optional) - numeric id of the lobby/game to target
+ *   <li>`AMOUNT` (required) - amount to bet
+ * </ul>
+ */
+public class PlayerBetParser implements CommandParser<PlayerBetRequest> {
+    /**
+     * Parse a primitive request into a {@link PlayerBetRequest}.
+     *
+     * @param primitiveRequest the raw parsed request containing parameters and context
+     * @return a {@link PlayerBetRequest} with the parsed values (gameId may be null)
+     */
+    @Override
+    public PlayerBetRequest parse(PrimitiveRequest primitiveRequest) {
+        RequestParameterAccessor accessor =
+                new RequestParameterAccessor(primitiveRequest.parameters());
+
+        Integer gameId = null;
+        try {
+            gameId = accessor.optional("GAME_ID", null, Integer::parseInt);
+        } catch (Exception e) {
+            // parse handled by framework
+        }
+
+        int amount = accessor.require("AMOUNT", Integer::parseInt);
+
+        return new PlayerBetRequest(primitiveRequest.context(), gameId, amount);
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/bet/PlayerBetRequest.java

@@ -0,0 +1,45 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.bet;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.Request;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+
+/**
+ * Request for the `BET` command.
+ *
+ * <p>Contains the optional target `gameId` and the `amount` the player wants to bet.
+ */
+public class PlayerBetRequest extends Request {
+    private final Integer gameId;
+    private final int amount;
+
+    /**
+     * Creates a new {@code PlayerBetRequest}.
+     *
+     * @param context the request context
+     * @param gameId optional game id of the targeted lobby (may be {@code null})
+     * @param amount the bet amount (non-negative)
+     */
+    public PlayerBetRequest(RequestContext context, Integer gameId, int amount) {
+        super(context);
+        this.gameId = gameId;
+        this.amount = amount;
+    }
+
+    /**
+     * Returns the optional target game id.
+     *
+     * @return the game id or {@code null} if not provided
+     */
+    public Integer getGameId() {
+        return gameId;
+    }
+
+    /**
+     * Returns the requested bet amount.
+     *
+     * @return the bet amount
+     */
+    public int getAmount() {
+        return amount;
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/call/PlayerCallHandler.java

@@ -0,0 +1,90 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.call;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.app.checks.GameLobbyExistsCheck;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.checks.UserLoggedInCheck;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.GameController;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.player.PlayerId;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.Lobby;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyId;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyManager;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.User;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.UserRegistry;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.ErrorResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.OkResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.dispatcher.ResponseDispatcher;
+import java.util.Optional;
+
+/**
+ * Handler for the `CALL` command.
+ *
+ * <p>This handler validates the session, resolves the lobby (by `GAME_ID` when provided or by
+ * session username otherwise), checks for a running game and forwards the call action to the {@code
+ * GameController}.
+ */
+public class PlayerCallHandler extends CommandHandler<PlayerCallRequest> {
+    private final UserRegistry userRegistry;
+    private final LobbyManager lobbyManager;
+
+    /**
+     * Creates a new {@code PlayerCallHandler}.
+     *
+     * @param responseDispatcher dispatcher used to send responses back to the client
+     * @param userRegistry registry to resolve users from session ids
+     * @param lobbyManager manager used to lookup lobbies and their game controllers
+     */
+    public PlayerCallHandler(
+            ResponseDispatcher responseDispatcher,
+            UserRegistry userRegistry,
+            LobbyManager lobbyManager) {
+        super(responseDispatcher);
+        this.userRegistry = userRegistry;
+        this.lobbyManager = lobbyManager;
+        addCheck(new UserLoggedInCheck(userRegistry));
+        addCheck(new GameLobbyExistsCheck(userRegistry, lobbyManager));
+    }
+
+    /**
+     * Execute the call request: resolve lobby by `GAME_ID` if present, otherwise by session user,
+     * verify game is running, and forward the call to the game controller.
+     *
+     * @param request the parsed {@link PlayerCallRequest}
+     */
+    @Override
+    public void execute(PlayerCallRequest request) {
+        Optional<User> opt = userRegistry.getBySessionId(request.getSessionId());
+        if (opt.isEmpty()) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(request.getContext(), "NOT_LOGGED_IN", "User not logged in"));
+            return;
+        }
+
+        String username = opt.get().getName();
+
+        Integer gameId = request.getGameId();
+        Lobby lobby;
+        if (gameId != null) {
+            lobby = lobbyManager.getLobby(LobbyId.of(gameId));
+        } else {
+            lobby = lobbyManager.getLobbyByUsername(username);
+        }
+
+        GameController game = lobby.getGameController();
+        if (game == null) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(
+                            request.getContext(), "GAME_NOT_STARTED", "Game not started"));
+            return;
+        }
+
+        try {
+            game.playerCall(PlayerId.of(username));
+        } catch (RuntimeException e) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(request.getContext(), "GAME_ACTION_FAILED", e.getMessage()));
+            return;
+        }
+
+        responseDispatcher.dispatch(new OkResponse(request.getContext()));
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/call/PlayerCallParser.java

@@ -0,0 +1,28 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.call;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.parsing.CommandParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.PrimitiveRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.accessor.RequestParameterAccessor;
+
+/**
+ * Parser for the `CALL` command.
+ *
+ * <p>Accepts an optional `GAME_ID` parameter. If provided, the handler will target the specified
+ * lobby; otherwise the server resolves the lobby by the requesting session's user.
+ */
+public class PlayerCallParser implements CommandParser<PlayerCallRequest> {
+    @Override
+    public PlayerCallRequest parse(PrimitiveRequest primitiveRequest) {
+        RequestParameterAccessor accessor =
+                new RequestParameterAccessor(primitiveRequest.parameters());
+
+        Integer gameId = null;
+        try {
+            gameId = accessor.optional("GAME_ID", null, Integer::parseInt);
+        } catch (Exception e) {
+            // parse errors handled by framework
+        }
+
+        return new PlayerCallRequest(primitiveRequest.context(), gameId);
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/call/PlayerCallRequest.java

@@ -0,0 +1,34 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.call;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.Request;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+
+/**
+ * Request for the `CALL` command.
+ *
+ * <p>Contains an optional `gameId` when the client targets a specific lobby, otherwise the server
+ * will resolve the lobby from the requesting session's user.
+ */
+public class PlayerCallRequest extends Request {
+    private final Integer gameId;
+
+    /**
+     * Creates a new {@code PlayerCallRequest}.
+     *
+     * @param context the request context
+     * @param gameId optional game id of the targeted lobby (may be {@code null})
+     */
+    public PlayerCallRequest(RequestContext context, Integer gameId) {
+        super(context);
+        this.gameId = gameId;
+    }
+
+    /**
+     * Returns the optional target game id.
+     *
+     * @return the game id or {@code null} if not provided
+     */
+    public Integer getGameId() {
+        return gameId;
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/fold/PlayerFoldHandler.java

@@ -0,0 +1,90 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.fold;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.app.checks.GameLobbyExistsCheck;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.checks.UserLoggedInCheck;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.GameController;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.player.PlayerId;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.Lobby;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyId;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyManager;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.User;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.UserRegistry;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.ErrorResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.OkResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.dispatcher.ResponseDispatcher;
+import java.util.Optional;
+
+/**
+ * Handler for the `FOLD` command.
+ *
+ * <p>This handler validates the session, resolves the lobby (by `GAME_ID` when provided or by
+ * session username otherwise), checks for a running game and forwards the fold action to the {@code
+ * GameController}.
+ */
+public class PlayerFoldHandler extends CommandHandler<PlayerFoldRequest> {
+    private final UserRegistry userRegistry;
+    private final LobbyManager lobbyManager;
+
+    /**
+     * Creates a new {@code PlayerFoldHandler}.
+     *
+     * @param responseDispatcher dispatcher used to send responses back to the client
+     * @param userRegistry registry to resolve users from session ids
+     * @param lobbyManager manager used to lookup lobbies and their game controllers
+     */
+    public PlayerFoldHandler(
+            ResponseDispatcher responseDispatcher,
+            UserRegistry userRegistry,
+            LobbyManager lobbyManager) {
+        super(responseDispatcher);
+        this.userRegistry = userRegistry;
+        this.lobbyManager = lobbyManager;
+        addCheck(new UserLoggedInCheck(userRegistry));
+        addCheck(new GameLobbyExistsCheck(userRegistry, lobbyManager));
+    }
+
+    /**
+     * Execute the fold request: resolve lobby by `GAME_ID` if present, otherwise by session user,
+     * verify game is running, and forward the fold to the game controller.
+     *
+     * @param request the parsed {@link PlayerFoldRequest}
+     */
+    @Override
+    public void execute(PlayerFoldRequest request) {
+        Optional<User> opt = userRegistry.getBySessionId(request.getSessionId());
+        if (opt.isEmpty()) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(request.getContext(), "NOT_LOGGED_IN", "User not logged in"));
+            return;
+        }
+
+        String username = opt.get().getName();
+
+        Integer gameId = request.getGameId();
+        Lobby lobby;
+        if (gameId != null) {
+            lobby = lobbyManager.getLobby(LobbyId.of(gameId));
+        } else {
+            lobby = lobbyManager.getLobbyByUsername(username);
+        }
+
+        GameController game = lobby.getGameController();
+        if (game == null) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(
+                            request.getContext(), "GAME_NOT_STARTED", "Game not started"));
+            return;
+        }
+
+        try {
+            game.playerFold(PlayerId.of(username));
+        } catch (RuntimeException e) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(request.getContext(), "GAME_ACTION_FAILED", e.getMessage()));
+            return;
+        }
+
+        responseDispatcher.dispatch(new OkResponse(request.getContext()));
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/fold/PlayerFoldParser.java

@@ -0,0 +1,28 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.fold;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.parsing.CommandParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.PrimitiveRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.accessor.RequestParameterAccessor;
+
+/**
+ * Parser for the `FOLD` command.
+ *
+ * <p>Accepts an optional `GAME_ID` parameter. If provided, the handler will target the specified
+ * lobby; otherwise the server resolves the lobby by the requesting session's user.
+ */
+public class PlayerFoldParser implements CommandParser<PlayerFoldRequest> {
+    @Override
+    public PlayerFoldRequest parse(PrimitiveRequest primitiveRequest) {
+        RequestParameterAccessor accessor =
+                new RequestParameterAccessor(primitiveRequest.parameters());
+
+        Integer gameId = null;
+        try {
+            gameId = accessor.optional("GAME_ID", null, Integer::parseInt);
+        } catch (Exception e) {
+            // parse handled by framework
+        }
+
+        return new PlayerFoldRequest(primitiveRequest.context(), gameId);
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/fold/PlayerFoldRequest.java

@@ -0,0 +1,34 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.fold;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.Request;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+
+/**
+ * Request for the `FOLD` command.
+ *
+ * <p>Contains an optional `gameId` when the client targets a specific lobby, otherwise the server
+ * will resolve the lobby from the requesting session's user.
+ */
+public class PlayerFoldRequest extends Request {
+    private final Integer gameId;
+
+    /**
+     * Creates a new {@code PlayerFoldRequest}.
+     *
+     * @param context the request context
+     * @param gameId optional game id of the targeted lobby (may be {@code null})
+     */
+    public PlayerFoldRequest(RequestContext context, Integer gameId) {
+        super(context);
+        this.gameId = gameId;
+    }
+
+    /**
+     * Returns the optional target game id.
+     *
+     * @return the game id or {@code null} if not provided
+     */
+    public Integer getGameId() {
+        return gameId;
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/get_game_state/GetGameStateHandler.java

@@ -0,0 +1,126 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.get_game_state;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.app.checks.UserLoggedInCheck;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.state.GamePhase;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.Lobby;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyId;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyManager;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.User;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.UserRegistry;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.ErrorResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.dispatcher.ResponseDispatcher;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.TimeUnit;
+import java.util.logging.Level;
+import java.util.logging.Logger;
+
+/** Handler for GET_GAME_STATE: returns pot, phase, community cards and per-player info. */
+public class GetGameStateHandler extends CommandHandler<GetGameStateRequest> {
+    private static final Logger LOGGER = Logger.getLogger(GetGameStateHandler.class.getName());
+    private static final int FINISHED_CLEANUP_DELAY_SECONDS = 2;
+
+    private final LobbyManager lobbyManager;
+    private final UserRegistry userRegistry;
+
+    public GetGameStateHandler(
+            ResponseDispatcher responseDispatcher,
+            LobbyManager lobbyManager,
+            UserRegistry userRegistry) {
+        super(responseDispatcher);
+        this.lobbyManager = lobbyManager;
+        this.userRegistry = userRegistry;
+        addCheck(new UserLoggedInCheck(userRegistry));
+    }
+
+    @Override
+    public void execute(GetGameStateRequest request) {
+        Integer gameId = request.getGameId();
+        String username = resolveUsername(request);
+
+        Lobby lobby;
+        LobbyId lobbyId;
+        if (gameId != null) {
+            lobbyId = LobbyId.of(gameId);
+            lobby = lobbyManager.getLobby(lobbyId);
+            if (lobby == null) {
+                responseDispatcher.dispatch(
+                        new ErrorResponse(
+                                request.getContext(), "LOBBY_NOT_FOUND", "Lobby not found"));
+                return;
+            }
+        } else {
+            if (username == null) {
+                var maybeUser = userRegistry.getBySessionId(request.getSessionId());
+                if (maybeUser.isEmpty()) {
+                    responseDispatcher.dispatch(
+                            new ErrorResponse(
+                                    request.getContext(), "NOT_LOGGED_IN", "User not logged in"));
+                    return;
+                }
+                User u = maybeUser.get();
+                username = u.getName();
+            }
+
+            lobby = lobbyManager.getLobbyByUsername(username);
+            if (lobby == null) {
+                responseDispatcher.dispatch(
+                        new ErrorResponse(
+                                request.getContext(), "NOT_IN_LOBBY", "User not in a lobby"));
+                return;
+            }
+            lobbyId = lobby.getId();
+        }
+
+        var game = lobby.getGameController();
+        if (game == null) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(
+                            request.getContext(), "GAME_NOT_STARTED", "Game not started"));
+            return;
+        }
+
+        responseDispatcher.dispatch(new GetGameStateResponse(request.getContext(), game, username));
+
+        if (game.getState().getPhase() == GamePhase.FINISHED) {
+            CompletableFuture.delayedExecutor(FINISHED_CLEANUP_DELAY_SECONDS, TimeUnit.SECONDS)
+                    .execute(() -> cleanupLobby(lobby, lobbyId));
+        }
+    }
+
+    /**
+     * Cleans up a lobby by removing all players and resetting the game controller. This is called
+     * when the game reaches FINISHED phase.
+     */
+    private void cleanupLobby(Lobby lobby, LobbyId lobbyId) {
+        if (lobby == null || lobbyId == null) {
+            return;
+        }
+
+        try {
+            for (String playerName : lobby.getPlayerNames()) {
+                lobbyManager.removePlayer(playerName);
+            }
+            lobby.initGame(null);
+        } catch (RuntimeException e) {
+            LOGGER.log(
+                    Level.WARNING,
+                    "Failed to cleanup lobby " + lobbyId + " during FINISHED state",
+                    e);
+        }
+    }
+
+    private String resolveUsername(GetGameStateRequest request) {
+        String username = request.getUsername();
+        if (username != null && !username.isBlank()) {
+            return username.trim();
+        }
+
+        return userRegistry
+                .getBySessionId(request.getSessionId())
+                .map(User::getName)
+                .map(String::trim)
+                .filter(name -> !name.isEmpty())
+                .orElse(null);
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/get_game_state/GetGameStateParser.java

@@ -0,0 +1,16 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.get_game_state;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.parsing.CommandParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.PrimitiveRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.accessor.RequestParameterAccessor;
+
+public class GetGameStateParser implements CommandParser<GetGameStateRequest> {
+    @Override
+    public GetGameStateRequest parse(PrimitiveRequest primitiveRequest) {
+        RequestParameterAccessor accessor =
+                new RequestParameterAccessor(primitiveRequest.parameters());
+        Integer gameId = accessor.optional("GAME_ID", null, Integer::parseInt);
+        String username = accessor.optional("USERNAME", null);
+        return new GetGameStateRequest(primitiveRequest.context(), username, gameId);
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/get_game_state/GetGameStateRequest.java

@@ -0,0 +1,31 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.get_game_state;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.Request;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+
+/**
+ * Request object for `GET_GAME_STATE`.
+ *
+ * <p>Either `USERNAME` or `GAME_ID` may be provided by the client. If both are omitted the handler
+ * will resolve the username from the session.
+ */
+public class GetGameStateRequest extends Request {
+    private final String username;
+    private final Integer gameId;
+
+    public GetGameStateRequest(RequestContext context, String username, Integer gameId) {
+        super(context);
+        this.username = username;
+        this.gameId = gameId;
+    }
+
+    /** Returns the optional username provided in the request. */
+    public String getUsername() {
+        return username;
+    }
+
+    /** Returns the optional game id provided in the request. */
+    public Integer getGameId() {
+        return gameId;
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/get_game_state/GetGameStateResponse.java

@@ -0,0 +1,235 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.get_game_state;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.GameController;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.deck.Card;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.deck.Rank;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.deck.Suit;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.player.Player;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.player.PlayerId;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.state.GamePhase;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.state.GameState;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.highscore.HighscoreService;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.SuccessResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.builder.ResponseBody;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.builder.ResponseBodyBuilder;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * Response carrying a snapshot of the current game state using the project's wire format.
+ *
+ * <p>Wire format (relevant parts):
+ *
+ * <p>+OK PHASE=... POT=... CURRENT_BET=... DEALER=... ACTIVE_PLAYER=... CARD VALUE=... SUIT=... END
+ * PLAYER NAME=... CHIPS=... BET=... STATE=... CARD (only for requesting user) VALUE=... SUIT=...
+ * END END END
+ *
+ * <p>Notes: - Community cards are always emitted at top-level (0..5). If none exist (e.g. PREFLOP),
+ * none are emitted. - Hole cards are only emitted for the requesting player (privacy).
+ */
+public class GetGameStateResponse extends SuccessResponse {
+
+    public GetGameStateResponse(
+            RequestContext context, GameController game, String requestingUsername) {
+        super(
+                context,
+                buildBody(
+                        game,
+                        Objects.requireNonNull(game, "game must not be null").getState(),
+                        requestingUsername));
+    }
+
+    private static ResponseBody buildBody(
+            GameController game, GameState state, String requestingUsername) {
+        Objects.requireNonNull(state, "state must not be null");
+
+        ResponseBodyBuilder builder = ResponseBody.builder();
+
+        builder.param("PHASE", state.getPhase() == null ? "UNKNOWN" : state.getPhase().name());
+        builder.param("POT", state.getPot() == null ? 0 : state.getPot().getAmount());
+        builder.param("CURRENT_BET", computeGlobalCurrentBet(state));
+        builder.param("DEALER", state.getDealerIndex());
+        builder.param("ACTIVE_PLAYER", state.getCurrentPlayerIndex());
+        int winnerIndex = computeWinnerIndex(state, game);
+        builder.param("WINNER", winnerIndex);
+
+        appendWinnerToHighscoresIfFinished(state, winnerIndex);
+        appendHighscoreEntries(builder);
+
+        appendCommunityCards(builder, state);
+
+        appendPlayers(builder, state, requestingUsername);
+
+        return builder.build();
+    }
+
+    private static void appendWinnerToHighscoresIfFinished(GameState state, int winnerIndex) {
+        if (winnerIndex < 0 || state.getPhase() != GamePhase.FINISHED) {
+            return;
+        }
+
+        if (!state.tryMarkWinnerPersistedForHand()) {
+            return;
+        }
+
+        Player winner = findPlayerByIndex(state, winnerIndex);
+        if (winner == null || winner.getId() == null || winner.getId().value() == null) {
+            return;
+        }
+
+        HighscoreService.getInstance().appendWinner(winner.getId().value());
+    }
+
+    private static Player findPlayerByIndex(GameState state, int winnerIndex) {
+        int currentIndex = 0;
+        for (Player player : state.getPlayers()) {
+            if (currentIndex == winnerIndex) {
+                return player;
+            }
+            currentIndex++;
+        }
+        return null;
+    }
+
+    private static void appendHighscoreEntries(ResponseBodyBuilder builder) {
+        for (String entry : HighscoreService.getInstance().readFormattedEntries()) {
+            builder.param("HIGHSCORE", entry);
+        }
+    }
+
+    private static int computeWinnerIndex(GameState state, GameController game) {
+        GamePhase phase = state.getPhase();
+        if (phase != GamePhase.SHOWDOWN && phase != GamePhase.FINISHED) {
+            return -1;
+        }
+
+        PlayerId winnerId = game.determineWinner();
+        if (winnerId == null) {
+            return -1;
+        }
+
+        int index = 0;
+        for (Player p : state.getPlayers()) {
+            if (p != null && winnerId.equals(p.getId())) {
+                return index;
+            }
+            index++;
+        }
+
+        return -1;
+    }
+
+    private static int computeGlobalCurrentBet(GameState state) {
+        int globalCurrentBet = 0;
+        for (Player p : state.getPlayers()) {
+            if (p == null) {
+                continue;
+            }
+
+            int b = state.getCurrentBet(p.getId());
+            if (b > globalCurrentBet) {
+                globalCurrentBet = b;
+            }
+        }
+        return globalCurrentBet;
+    }
+
+    private static void appendCommunityCards(ResponseBodyBuilder builder, GameState state) {
+        List<Card> community = state.getCommunityCards();
+
+        if (community == null || community.isEmpty()) {
+            return;
+        }
+
+        for (Card c : community) {
+            if (c == null) {
+                continue;
+            }
+
+            builder.block(
+                    "CARD",
+                    card -> {
+                        card.param("VALUE", rankToWire(c.getRank()));
+                        card.param("SUIT", suitToWire(c.getSuit()));
+                    });
+        }
+    }
+
+    private static void appendPlayers(
+            ResponseBodyBuilder builder, GameState state, String requestingUsername) {
+        String req = (requestingUsername == null) ? null : requestingUsername.trim();
+
+        for (Player p : state.getPlayers()) {
+            if (p == null) {
+                continue;
+            }
+
+            PlayerId pid = p.getId();
+            String name = (pid == null || pid.value() == null) ? "" : pid.value().trim();
+
+            builder.block(
+                    "PLAYER",
+                    pblock -> {
+                        pblock.param("NAME", name);
+                        pblock.param("CHIPS", p.getChips());
+                        pblock.param("BET", pid == null ? 0 : state.getCurrentBet(pid));
+                        pblock.param("STATE", p.isFolded() ? "FOLDED" : "ACTIVE");
+
+                        if (req != null && pid != null && req.equals(name)) {
+                            List<Card> hole = state.getHoleCards(pid);
+
+                            if (hole != null) {
+                                for (Card hc : hole) {
+                                    if (hc == null) {
+                                        continue;
+                                    }
+
+                                    pblock.block(
+                                            "CARD",
+                                            cblock -> {
+                                                cblock.param("VALUE", rankToWire(hc.getRank()));
+                                                cblock.param("SUIT", suitToWire(hc.getSuit()));
+                                            });
+                                }
+                            }
+                        }
+                    });
+        }
+    }
+
+    private static String rankToWire(Rank r) {
+        if (r == null) {
+            return "";
+        }
+
+        return switch (r) {
+            case TWO -> "2";
+            case THREE -> "3";
+            case FOUR -> "4";
+            case FIVE -> "5";
+            case SIX -> "6";
+            case SEVEN -> "7";
+            case EIGHT -> "8";
+            case NINE -> "9";
+            case TEN -> "10";
+            case JACK -> "J";
+            case QUEEN -> "Q";
+            case KING -> "K";
+            case ACE -> "A";
+        };
+    }
+
+    private static String suitToWire(Suit s) {
+        if (s == null) {
+            return "";
+        }
+
+        return switch (s) {
+            case HEARTS -> "H";
+            case DIAMONDS -> "D";
+            case CLUBS -> "C";
+            case SPADES -> "S";
+        };
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/raise/PlayerRaiseHandler.java

@@ -0,0 +1,104 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.raise;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.app.checks.GameLobbyExistsCheck;
+import ch.unibas.dmi.dbis.cs108.casono.server.app.checks.UserLoggedInCheck;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.GameController;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.game.player.PlayerId;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.Lobby;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyId;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyManager;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.User;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.UserRegistry;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.ErrorResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.OkResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.dispatcher.ResponseDispatcher;
+import java.util.Optional;
+
+/**
+ * Handler for the `RAISE` command.
+ *
+ * <p>This handler validates the request (amount >= 0), resolves the user and target lobby (by
+ * `GAME_ID` when provided or by session username otherwise), checks that a game is running and then
+ * forwards the action to the {@code GameController}.
+ *
+ * <p>On failure the handler dispatches an {@link ErrorResponse} with an appropriate error code
+ * (e.g. {@code INVALID_AMOUNT}, {@code NOT_IN_LOBBY}, {@code LOBBY_NOT_FOUND}, {@code
+ * GAME_NOT_STARTED}, {@code GAME_ACTION_FAILED}). On success it dispatches an {@link OkResponse}.
+ */
+public class PlayerRaiseHandler extends CommandHandler<PlayerRaiseRequest> {
+    private final UserRegistry userRegistry;
+    private final LobbyManager lobbyManager;
+
+    /**
+     * Creates a new {@code PlayerRaiseHandler}.
+     *
+     * @param responseDispatcher dispatcher used to send responses back to the client
+     * @param userRegistry registry to resolve users from session ids
+     * @param lobbyManager manager used to lookup lobbies and their game controllers
+     */
+    public PlayerRaiseHandler(
+            ResponseDispatcher responseDispatcher,
+            UserRegistry userRegistry,
+            LobbyManager lobbyManager) {
+        super(responseDispatcher);
+        this.userRegistry = userRegistry;
+        this.lobbyManager = lobbyManager;
+        addCheck(new UserLoggedInCheck(userRegistry));
+        addCheck(new GameLobbyExistsCheck(userRegistry, lobbyManager));
+    }
+
+    /**
+     * Execute the raise request: validate parameters, resolve lobby and game, and forward the raise
+     * action to the game controller. Sends an {@link ErrorResponse} on failure or an {@link
+     * OkResponse} on success.
+     *
+     * @param request the parsed {@link PlayerRaiseRequest}
+     */
+    @Override
+    public void execute(PlayerRaiseRequest request) {
+        int amount = request.getAmount();
+
+        if (amount < 0) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(
+                            request.getContext(), "INVALID_AMOUNT", "Amount must be non-negative"));
+            return;
+        }
+
+        Optional<User> opt = userRegistry.getBySessionId(request.getSessionId());
+        if (opt.isEmpty()) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(request.getContext(), "NOT_LOGGED_IN", "User not logged in"));
+            return;
+        }
+
+        String username = opt.get().getName();
+
+        Integer gameId = request.getGameId();
+        Lobby lobby;
+        if (gameId != null) {
+            lobby = lobbyManager.getLobby(LobbyId.of(gameId));
+        } else {
+            lobby = lobbyManager.getLobbyByUsername(username);
+        }
+
+        GameController game = lobby.getGameController();
+        if (game == null) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(
+                            request.getContext(), "GAME_NOT_STARTED", "Game not started"));
+            return;
+        }
+
+        try {
+            game.playerRaise(PlayerId.of(username), amount);
+        } catch (RuntimeException e) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(request.getContext(), "GAME_ACTION_FAILED", e.getMessage()));
+            return;
+        }
+
+        responseDispatcher.dispatch(new OkResponse(request.getContext()));
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/raise/PlayerRaiseParser.java

@@ -0,0 +1,34 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.raise;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.parsing.CommandParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.PrimitiveRequest;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.accessor.RequestParameterAccessor;
+
+/**
+ * Parser for the `RAISE` command.
+ *
+ * <p>Parses the request parameters and builds a {@link PlayerRaiseRequest}. Expected parameters:
+ *
+ * <ul>
+ *   <li>`GAME_ID` (optional) - numeric id of the lobby/game to target
+ *   <li>`AMOUNT` (required) - amount to raise
+ * </ul>
+ */
+public class PlayerRaiseParser implements CommandParser<PlayerRaiseRequest> {
+    @Override
+    public PlayerRaiseRequest parse(PrimitiveRequest primitiveRequest) {
+        RequestParameterAccessor accessor =
+                new RequestParameterAccessor(primitiveRequest.parameters());
+
+        Integer gameId = null;
+        try {
+            gameId = accessor.optional("GAME_ID", null, Integer::parseInt);
+        } catch (Exception e) {
+            // parse handled by framework
+        }
+
+        int amount = accessor.require("AMOUNT", Integer::parseInt);
+
+        return new PlayerRaiseRequest(primitiveRequest.context(), gameId, amount);
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/game/raise/PlayerRaiseRequest.java

@@ -0,0 +1,45 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.game.raise;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.Request;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+
+/**
+ * Request for the `RAISE` command.
+ *
+ * <p>Contains the optional target `gameId` and the `amount` the player wants to raise.
+ */
+public class PlayerRaiseRequest extends Request {
+    private final Integer gameId;
+    private final int amount;
+
+    /**
+     * Creates a new {@code PlayerRaiseRequest}.
+     *
+     * @param context the request context
+     * @param gameId optional game id of the targeted lobby (may be {@code null})
+     * @param amount the raise amount (non-negative)
+     */
+    public PlayerRaiseRequest(RequestContext context, Integer gameId, int amount) {
+        super(context);
+        this.gameId = gameId;
+        this.amount = amount;
+    }
+
+    /**
+     * Returns the optional target game id.
+     *
+     * @return the game id or {@code null} if not provided
+     */
+    public Integer getGameId() {
+        return gameId;
+    }
+
+    /**
+     * Returns the requested raise amount.
+     *
+     * @return the raise amount
+     */
+    public int getAmount() {
+        return amount;
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/highscore/clear_highscores/ClearHighscoresHandler.java

@@ -0,0 +1,22 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.highscore.clear_highscores;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.highscore.HighscoreService;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.OkResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.dispatcher.ResponseDispatcher;
+
+/** Handler for CLEAR_HIGHSCORES. */
+public class ClearHighscoresHandler extends CommandHandler<ClearHighscoresRequest> {
+    private final HighscoreService highscoreService;
+
+    public ClearHighscoresHandler(ResponseDispatcher responseDispatcher) {
+        super(responseDispatcher);
+        this.highscoreService = HighscoreService.getInstance();
+    }
+
+    @Override
+    public void execute(ClearHighscoresRequest request) {
+        highscoreService.clearAll();
+        responseDispatcher.dispatch(new OkResponse(request.getContext()));
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/highscore/clear_highscores/ClearHighscoresParser.java

@@ -0,0 +1,12 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.highscore.clear_highscores;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.parsing.CommandParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.PrimitiveRequest;
+
+/** Parser for CLEAR_HIGHSCORES. */
+public class ClearHighscoresParser implements CommandParser<ClearHighscoresRequest> {
+    @Override
+    public ClearHighscoresRequest parse(PrimitiveRequest primitiveRequest) {
+        return new ClearHighscoresRequest(primitiveRequest.context());
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/highscore/clear_highscores/ClearHighscoresRequest.java

@@ -0,0 +1,11 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.highscore.clear_highscores;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.Request;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+
+/** Request object for CLEAR_HIGHSCORES. */
+public class ClearHighscoresRequest extends Request {
+    public ClearHighscoresRequest(RequestContext context) {
+        super(context);
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/highscore/get_highscores/GetHighscoresHandler.java

@@ -0,0 +1,22 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.highscore.get_highscores;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.highscore.HighscoreService;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.dispatcher.ResponseDispatcher;
+
+/** Handler for GET_HIGHSCORES. */
+public class GetHighscoresHandler extends CommandHandler<GetHighscoresRequest> {
+    private final HighscoreService highscoreService;
+
+    public GetHighscoresHandler(ResponseDispatcher responseDispatcher) {
+        super(responseDispatcher);
+        this.highscoreService = HighscoreService.getInstance();
+    }
+
+    @Override
+    public void execute(GetHighscoresRequest request) {
+        responseDispatcher.dispatch(
+                new GetHighscoresResponse(
+                        request.getContext(), highscoreService.readFormattedEntries()));
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/highscore/get_highscores/GetHighscoresParser.java

@@ -0,0 +1,12 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.highscore.get_highscores;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.parsing.CommandParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.PrimitiveRequest;
+
+/** Parser for GET_HIGHSCORES. */
+public class GetHighscoresParser implements CommandParser<GetHighscoresRequest> {
+    @Override
+    public GetHighscoresRequest parse(PrimitiveRequest primitiveRequest) {
+        return new GetHighscoresRequest(primitiveRequest.context());
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/highscore/get_highscores/GetHighscoresRequest.java

@@ -0,0 +1,11 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.highscore.get_highscores;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.Request;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+
+/** Request object for GET_HIGHSCORES. */
+public class GetHighscoresRequest extends Request {
+    public GetHighscoresRequest(RequestContext context) {
+        super(context);
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/highscore/get_highscores/GetHighscoresResponse.java

@@ -0,0 +1,23 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.highscore.get_highscores;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.SuccessResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.builder.ResponseBody;
+import java.util.List;
+
+/** Success response containing repeated HIGHSCORE parameters. */
+public class GetHighscoresResponse extends SuccessResponse {
+    public GetHighscoresResponse(RequestContext context, List<String> entries) {
+        super(
+                context,
+                ResponseBody.builder()
+                        .block(
+                                "HIGHSCORES",
+                                block -> {
+                                    for (String entry : entries) {
+                                        block.param("HIGHSCORE", entry);
+                                    }
+                                })
+                        .build());
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/lobby/create_lobby/CreateLobbyHandler.java

@@ -0,0 +1,56 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.create_lobby;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyId;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyManager;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.ErrorResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.SuccessResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.builder.ResponseBody;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.dispatcher.ResponseDispatcher;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.sessions.Session;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.sessions.SessionManager;
+
+public class CreateLobbyHandler extends CommandHandler<CreateLobbyRequest> {
+    private final LobbyManager lobbyManager;
+    private final SessionManager sessionManager;
+
+    public CreateLobbyHandler(
+            ResponseDispatcher responseDispatcher,
+            LobbyManager lobbyManager,
+            SessionManager sessionManager) {
+        super(responseDispatcher);
+        this.lobbyManager = lobbyManager;
+        this.sessionManager = sessionManager;
+    }
+
+    @Override
+    public void execute(CreateLobbyRequest request) {
+        LobbyId id = lobbyManager.createNewLobby(null);
+
+        if (id == null) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(
+                            request.getContext(),
+                            "LOBBIES_FULL",
+                            "Maximum number of 8 lobbies reached"));
+            return;
+        }
+
+        responseDispatcher.dispatch(new CreateLobbyResponse(request.getContext(), id.value()));
+
+        // broadcast LOBBY_CREATED event to all connected sessions (requestId=0)
+        for (Session s : sessionManager.getAllSessions()) {
+            RequestContext ctx = new RequestContext(s.getId(), 0);
+            SuccessResponse ev =
+                    new SuccessResponse(
+                            ctx,
+                            ResponseBody.builder()
+                                    .param("EVENT", "LOBBY_CREATED")
+                                    .param("LOBBY_ID", id.value())
+                                    .build()) {};
+
+            responseDispatcher.dispatch(ev);
+        }
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/lobby/create_lobby/CreateLobbyParser.java

@@ -0,0 +1,11 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.create_lobby;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.parsing.CommandParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.PrimitiveRequest;
+
+public class CreateLobbyParser implements CommandParser<CreateLobbyRequest> {
+    @Override
+    public CreateLobbyRequest parse(PrimitiveRequest primitiveRequest) {
+        return new CreateLobbyRequest(primitiveRequest.context());
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/lobby/create_lobby/CreateLobbyRequest.java

@@ -0,0 +1,10 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.create_lobby;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.Request;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+
+public class CreateLobbyRequest extends Request {
+    public CreateLobbyRequest(RequestContext context) {
+        super(context);
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/lobby/create_lobby/CreateLobbyResponse.java

@@ -0,0 +1,14 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.create_lobby;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.SuccessResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.builder.ResponseBodyBuilder;
+
+/** Sends ID of newly created lobby back to client. */
+public class CreateLobbyResponse extends SuccessResponse {
+    public CreateLobbyResponse(RequestContext context, int lobbyId) {
+        super(
+                context,
+                new ResponseBodyBuilder().param("LOBBY_ID", String.valueOf(lobbyId)).build());
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/lobby/get_lobby_list/GetLobbyListHandler.java

@@ -0,0 +1,28 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.get_lobby_list;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.Lobby;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyManager;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.dispatcher.ResponseDispatcher;
+import java.util.Collection;
+
+/**
+ * Handler for the `GET_LOBBY_LIST` command.
+ *
+ * <p>Queries the {@link LobbyManager} for all available lobbies and dispatches a {@link
+ * GetLobbyListResponse} containing basic metadata for each lobby (`ID`, `NAME`, `PLAYER_COUNT`).
+ */
+public class GetLobbyListHandler extends CommandHandler<GetLobbyListRequest> {
+    private final LobbyManager lobbyManager;
+
+    public GetLobbyListHandler(ResponseDispatcher responseDispatcher, LobbyManager lobbyManager) {
+        super(responseDispatcher);
+        this.lobbyManager = lobbyManager;
+    }
+
+    @Override
+    public void execute(GetLobbyListRequest request) {
+        Collection<Lobby> l = lobbyManager.getAllLobbies();
+        responseDispatcher.dispatch(new GetLobbyListResponse(request.getContext(), l));
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/lobby/get_lobby_list/GetLobbyListParser.java

@@ -0,0 +1,17 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.get_lobby_list;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.parsing.CommandParser;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.PrimitiveRequest;
+
+/**
+ * Parser for the `GET_LOBBY_LIST` command.
+ *
+ * <p>Parses the incoming primitive request and produces a {@link GetLobbyListRequest}. This command
+ * takes no parameters.
+ */
+public class GetLobbyListParser implements CommandParser<GetLobbyListRequest> {
+    @Override
+    public GetLobbyListRequest parse(PrimitiveRequest primitiveRequest) {
+        return new GetLobbyListRequest(primitiveRequest.context());
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/lobby/get_lobby_list/GetLobbyListRequest.java

@@ -0,0 +1,15 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.get_lobby_list;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.Request;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+
+/**
+ * Request object for the `GET_LOBBY_LIST` command.
+ *
+ * <p>Contains only the request context; this command does not require parameters.
+ */
+public class GetLobbyListRequest extends Request {
+    public GetLobbyListRequest(RequestContext context) {
+        super(context);
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/lobby/get_lobby_list/GetLobbyListResponse.java

@@ -0,0 +1,37 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.get_lobby_list;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.Lobby;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.request.RequestContext;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.SuccessResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.builder.ResponseBody;
+import java.util.Collection;
+
+/**
+ * Success response for `GET_LOBBY_LIST`.
+ *
+ * <p>Builds a `LOBBIES` collection with repeated `LOBBY` blocks containing `ID`, `NAME` and
+ * `PLAYER_COUNT`.
+ */
+public class GetLobbyListResponse extends SuccessResponse {
+    public GetLobbyListResponse(RequestContext context, Collection<Lobby> lobbies) {
+        super(
+                context,
+                ResponseBody.builder()
+                        .block(
+                                "LOBBIES",
+                                lobbies_block -> {
+                                    for (Lobby lobby : lobbies) {
+                                        lobbies_block.block(
+                                                "LOBBY",
+                                                lb -> {
+                                                    lb.param("ID", lobby.getId().value());
+                                                    lb.param("NAME", lobby.getName());
+                                                    lb.param(
+                                                            "PLAYER_COUNT",
+                                                            lobby.getPlayerNames().size());
+                                                });
+                                    }
+                                })
+                        .build());
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/app/commands/lobby/get_lobby_status/GetLobbyStatusHandler.java

@@ -0,0 +1,81 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.get_lobby_status;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyId;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.lobby.LobbyManager;
+import ch.unibas.dmi.dbis.cs108.casono.server.domain.user.UserRegistry;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandHandler;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.ErrorResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.dispatcher.ResponseDispatcher;
+import java.util.Optional;
+
+/**
+ * Handler for the `GET_LOBBY_STATUS` command.
+ *
+ * <p>Resolves the target lobby either by the optional `ID` parameter or by `USERNAME`. If both are
+ * omitted the handler requires the session to be associated with a logged-in user (see the inline
+ * pre-execution check). On success a {@link GetLobbyStatusResponse} is dispatched, otherwise an
+ * {@link ErrorResponse} with code `LOBBY_NOT_FOUND` is sent.
+ */
+public class GetLobbyStatusHandler extends CommandHandler<GetLobbyStatusRequest> {
+    private final LobbyManager lobbyManager;
+    private final UserRegistry userRegistry;
+
+    public GetLobbyStatusHandler(
+            ResponseDispatcher responseDispatcher,
+            LobbyManager lobbyManager,
+            UserRegistry userRegistry) {
+        super(responseDispatcher);
+        this.lobbyManager = lobbyManager;
+        this.userRegistry = userRegistry;
+
+        // Only require logged-in session if the request does not provide an explicit ID
+        // or USERNAME
+        addCheck(
+                request -> {
+                    if (!(request instanceof GetLobbyStatusRequest)) {
+                        return Optional.empty();
+                    }
+                    GetLobbyStatusRequest r = (GetLobbyStatusRequest) request;
+                    if (r.getId() != null || r.getUsername() != null) {
+                        return Optional.empty();
+                    }
+                    var maybeUser = userRegistry.getBySessionId(r.getSessionId());
+                    if (maybeUser.isPresent()) {
+                        return Optional.empty();
+                    }
+                    return Optional.of(
+                            new ErrorResponse(
+                                    r.getContext(),
+                                    "USER_NOT_LOGGED_IN",
+                                    "Request requires an associated logged-in user"));
+                });
+    }
+
+    @Override
+    public void execute(GetLobbyStatusRequest request) {
+        // Resolve username from request or session when no explicit ID/USERNAME
+        // provided
+        String targetUsername = request.getUsername();
+        if (targetUsername == null) {
+            var maybeUser = userRegistry.getBySessionId(request.getSessionId());
+            if (maybeUser.isPresent()) {
+                targetUsername = maybeUser.get().getName();
+            }
+        }
+
+        var lobby =
+                (request.getId() != null)
+                        ? lobbyManager.getLobby(LobbyId.of(request.getId()))
+                        : (targetUsername != null
+                                ? lobbyManager.getLobbyByUsername(targetUsername)
+                                : null);
+
+        if (lobby == null) {
+            responseDispatcher.dispatch(
+                    new ErrorResponse(request.getContext(), "LOBBY_NOT_FOUND", "Lobby not found"));
+            return;
+        }
+
+        responseDispatcher.dispatch(new GetLobbyStatusResponse(request.getContext(), lobby));
+    }
+}