Merge branch 'main' into 'feat/game-ui'

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

@@ -3,8 +3,25 @@ package ch.unibas.dmi.dbis.cs108.casono;
 import ch.unibas.dmi.dbis.cs108.casono.client.ClientApp;
 import ch.unibas.dmi.dbis.cs108.casono.server.ServerApp;
 
+/**
+ * Main entry point for Casono application.
+ * Handles client and server startup.
+ * <p>
+ * Standardkonstruktor für die Anwendung.
+ */
 public final class Main {
 
+    /**
+     * Standardkonstruktor.
+     */
+    public Main() {
+        // Standardkonstruktor
+    }
+
+    /**
+     * Main entry point for Casono.
+     * @param args Command line arguments
+     */
     public static void main(String[] args) {
         if (!isValid(args)) {
             printUsage();

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

@@ -1,6 +1,29 @@
 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.ui.Launcher;
+/**
+ * Entry point for the Casono client application.
+ * Handles client startup and connection parameters.
+ * <p>
+ * Standardkonstruktor für die Anwendung.
+ */
 public class ClientApp {
+
+    /**
+     * Standardkonstruktor.
+     */
+    public ClientApp() {
+        // Standardkonstruktor
+    }
+    /**
+     * 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) {
         String[] parts = arg.split(":", 2);
         if (parts.length != 2) {

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

@@ -1,22 +1,26 @@
 package ch.unibas.dmi.dbis.cs108.casono.client.ui;
 
-import ch.unibas.dmi.dbis.cs108.casono.client.ui.gameui.CasinoGameUI;
 import javafx.application.Application;
 
 /**
- * Launcher-Klasse für die Casino-Anwendung.
- *
- * Startet die JavaFX-Anwendung. Während der Entwicklung kann hier direkt
- * `Casinogameui` für Tests aufgerufen werden. Im fertigen Spiel erfolgt
- * der Aufruf von `Casinogameui` über die `Casinomainui`.
- *
- * Starte den Client über das Terminal mit:
- * {@code ./gradlew run --args="client 0.0.0.0:1234"}
+ * Launcher for the Casono main UI.
+ * <p>
+ * Standardkonstruktor für die Anwendung.
  */
 public class Launcher {
+
+    /**
+     * Standardkonstruktor.
+     */
+    public Launcher() {
+        // Standardkonstruktor
+    }
+    /**
+     * Main entry point for launching the UI.
+     * @param args Command line arguments
+     */
     public static void main(String[] args) {
-        // Application.launch(ch.unibas.dmi.dbis.cs108.casono.client.ui.lobbyui.Casinomainui.class, args);
-        Application.launch(CasinoGameUI.class, args);
+        Application.launch(ch.unibas.dmi.dbis.cs108.casono.client.ui.lobbyui.Casinomainui.class, args);
     }
 }
     

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

@@ -1,5 +1,9 @@
 package ch.unibas.dmi.dbis.cs108.casono.client.ui.lobbyui;
 
+/**
+ * Main UI application for Casono.
+ * Loads the main FXML layout and sets up the stage.
+ */
 import javafx.application.Application;
 import javafx.fxml.FXMLLoader;
 import javafx.scene.Scene;
@@ -7,8 +11,25 @@ import javafx.stage.Stage;
 
 import java.io.IOException;
 
+/**
+ * JavaFX Application class for the Casono main UI.
+ * <p>
+ * Standardkonstruktor für die Anwendung.
+ */
 public class Casinomainui extends Application {
+
+    /**
+     * Standardkonstruktor.
+     */
+    public Casinomainui() {
+        // Standardkonstruktor
+    }
     @Override
+    /**
+     * Starts the JavaFX application and loads the main UI.
+     * @param stage The primary stage for this application.
+     * @throws IOException If loading the FXML fails.
+     */
     public void start(Stage stage) throws IOException {
         FXMLLoader fxmlLoader = new FXMLLoader(getClass().getResource("/ui-structure/Casinomainui.fxml"));
         Scene scene = new Scene(fxmlLoader.load(), 1200, 800);
@@ -20,6 +41,10 @@ public class Casinomainui extends Application {
         stage.show();
     }
 
+    /**
+     * Main entry point for launching the application.
+     * @param args Command line arguments
+     */
     public static void main(String[] args) {
         launch();
     }

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

@@ -1,22 +1,21 @@
 package ch.unibas.dmi.dbis.cs108.casono.client.ui.lobbyui;
-import javafx.application.Platform;
-import javafx.fxml.FXML;
-import javafx.scene.control.Label;
-import javafx.scene.layout.AnchorPane;
-import javafx.scene.control.Button;
-import javafx.scene.image.ImageView;
-import javafx.scene.shape.Rectangle;
-import javafx.application.Platform;
-import javafx.fxml.FXML;
-import javafx.scene.control.Label;
-import javafx.scene.control.TextField;
-import javafx.scene.input.KeyCode;
-import javafx.scene.input.KeyEvent;
-import javafx.scene.input.MouseEvent;
-import javafx.scene.layout.HBox;
-import javafx.scene.layout.AnchorPane;
 
+import javafx.application.Platform;
+import javafx.fxml.FXML;
+import javafx.scene.control.Label;
+import javafx.scene.control.Button;
+import javafx.scene.image.Image;
+import javafx.scene.image.ImageView;
+import javafx.scene.layout.AnchorPane;
+import javafx.scene.layout.VBox;
+import javafx.scene.shape.Rectangle;
+
+/**
+ * Controller for the Casono main UI lobby.
+ * Handles UI initialization and user actions.
+ */
 public class CasinomainuiController {
+
     @FXML
     private AnchorPane rootPane;
     @FXML
@@ -24,26 +23,63 @@ public class CasinomainuiController {
     @FXML
     private Label subtitleLabel;
     @FXML
-    private javafx.scene.image.ImageView logoView;
+    private ImageView logoView;
     @FXML
-    private javafx.scene.shape.Rectangle greenBox;
+    private Rectangle greenBox;
     @FXML
     private Button exitbutton;
-    
-    
+    @FXML
+    private VBox casinoTable;
 
+    private LobbyButtonTranslationManager translationManager;
+    private LobbyButtonGridManager gridManager;
+    private int nextButtonId = 1;
 
+    public CasinomainuiController() {
+        // Default constructor
+    }
+
+    /**
+     * Initializes the UI components and sets default values.
+     */
+    @FXML
     public void initialize() {
         titleLabel.setText("Casono");
         subtitleLabel.setText("Texas Hold'em Poker");
-        // Logo laden
-        logoView.setImage(new javafx.scene.image.Image(getClass().getResource("/images/logo.png").toExternalForm()));
+        logoView.setImage(new Image(getClass().getResource("/images/logo.png").toExternalForm()));
+
+        translationManager = new LobbyButtonTranslationManager();
+        gridManager = new LobbyButtonGridManager(new javafx.scene.layout.GridPane(), translationManager);
+        casinoTable.getChildren().clear();
+        casinoTable.getChildren().add(gridManager.getGridPane());
+        gridManager.renderLobbyButtons();
     }
 
+    /**
+     * Handles the exit button action to close the application.
+     */
     @FXML
     public void handleexitbutton() {
         Platform.exit();
     }
 
+    /**
+     * Handles creation of a new lobby button.
+     */
+    @FXML
+    public void handleCreateLobbyButton() {
+        if (translationManager.isFull()) {
+            System.out.println("Grid voll! Keine weiteren Lobbys moeglich.");
+            return;
+        }
+        int buttonId = nextButtonId++;
+        int lobbyId = gridManager.createLobby();
+        try {
+            translationManager.addLobbyButton(buttonId, lobbyId);
+            System.out.println("ButtonID: " + buttonId + ", LobbyID: " + lobbyId);
+            gridManager.renderLobbyButtons();
+        } catch (Exception e) {
+            System.out.println("Fehler beim Hinzufügen: " + e.getMessage());
+        }
+    }
 }
-

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

@@ -0,0 +1,101 @@
+package ch.unibas.dmi.dbis.cs108.casono.client.ui.lobbyui;
+
+/**
+ * Manages the grid for lobby buttons and rendering.
+ * Uses LobbyButtonTranslationManager for mapping ButtonID to LobbyID.
+ */
+
+import javafx.scene.control.Button;
+import javafx.scene.image.Image;
+import javafx.scene.image.ImageView;
+import javafx.scene.layout.GridPane;
+import java.util.Map;
+
+/**
+ * Manages the grid for lobby buttons and rendering.
+ * Uses LobbyButtonTranslationManager for mapping ButtonID to LobbyID.
+ */
+public class LobbyButtonGridManager {
+
+    /** GridPane for the button grid. */
+    private final GridPane gridPane;
+    /** Manager for mapping ButtonID to LobbyID. */
+    private final LobbyButtonTranslationManager translationManager;
+    /** Number of rows in the grid. */
+    private final int rows = 2;
+    /** Number of columns in the grid. */
+    private final int cols = 4;
+    /** Path to the button image. */
+    private final String buttonImagePath = "/images/logo.png";
+
+    /**
+     * Constructor for the GridManager.
+     * 
+     * @param gridPane           the GridPane for rendering
+     * @param translationManager the manager for mapping ButtonID to LobbyID
+     */
+    public LobbyButtonGridManager(GridPane gridPane, LobbyButtonTranslationManager translationManager) {
+        this.gridPane = gridPane;
+        this.translationManager = translationManager;
+    }
+
+    /**
+     * Renders all lobby buttons in the grid.
+     * Creates a button for each mapping with image and event handler.
+     */
+    public void renderLobbyButtons() {
+        gridPane.getChildren().clear();
+        int index = 0;
+        Map<Integer, Integer> mapping = translationManager.getButtonIdToLobbyId();
+        if (mapping.isEmpty()) {
+            // No buttons to render
+            return;
+        }
+        for (Map.Entry<Integer, Integer> entry : mapping.entrySet()) {
+            int buttonId = entry.getKey();
+            Button btn = new Button();
+            btn.setId("lobbyBtn-" + buttonId);
+            btn.setGraphic(new ImageView(new Image(getClass().getResourceAsStream(buttonImagePath))));
+            btn.setOnAction(e -> {
+                Integer lobbyId = translationManager.getLobbyIdForButton(buttonId);
+                if (lobbyId != null)
+                    joinLobby(lobbyId);
+            });
+            int row = index / cols;
+            int col = index % cols;
+            gridPane.add(btn, col, row);
+            index++;
+        }
+    }
+
+    /**
+     * Placeholder for lobby creation logic. Returns a generated lobbyId.
+     * 
+     * @return The generated lobbyId
+     */
+    public int createLobby() {
+        // TODO: Replace with actual lobby creation logic
+        int lobbyId = (int) (Math.random() * 10000 + 1);
+        System.out.println("Lobby created: " + lobbyId);
+        return lobbyId;
+    }
+
+    /**
+     * Placeholder for joining a lobby.
+     * 
+     * @param lobbyId The lobbyId to join
+     */
+    public void joinLobby(int lobbyId) {
+        // TODO: Replace with actual join logic
+        System.out.println("Joining lobby: " + lobbyId);
+    }
+
+    /**
+     * Getter for the GridPane.
+     * 
+     * @return The GridPane for the button grid
+     */
+    public javafx.scene.layout.GridPane getGridPane() {
+        return gridPane;
+    }
+}

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

@@ -0,0 +1,66 @@
+package ch.unibas.dmi.dbis.cs108.casono.client.ui.lobbyui;
+
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * Verwaltet das Mapping zwischen Button-IDs und Lobby-IDs rein im Speicher.
+ * Keine Dateioperationen, nur Laufzeitdatenstruktur.
+ */
+public class LobbyButtonTranslationManager {
+    /** Maximale Anzahl an Buttons/Lobbys */
+    private static final int MAX_BUTTONS = 8;
+    /** Zuordnung ButtonID → LobbyID */
+    private final Map<Integer, Integer> buttonIdToLobbyId = new HashMap<>();
+
+    /**
+     * Konstruktor: initialisiert die Zuordnung leer.
+     */
+    public LobbyButtonTranslationManager() {
+        // Zuordnung bleibt leer beim Start
+    }
+
+    /**
+     * Prüft, ob das Grid voll ist (MAX_BUTTONS erreicht).
+     * @return true, wenn Grid voll; sonst false
+     */
+    public boolean isFull() {
+        return buttonIdToLobbyId.size() >= MAX_BUTTONS;
+    }
+
+    /**
+     * Fügt eine Zuordnung ButtonID → LobbyID hinzu.
+     * @param buttonId Die ID des Buttons
+     * @param lobbyId Die ID der Lobby
+     * @throws Exception wenn das Grid voll ist
+     */
+    public void addLobbyButton(int buttonId, int lobbyId) throws Exception {
+        if (isFull()) throw new Exception("Grid is full!");
+        buttonIdToLobbyId.put(buttonId, lobbyId);
+    }
+
+    /**
+     * Entfernt eine Zuordnung für die gegebene ButtonID.
+     * @param buttonId Die ID des zu entfernenden Buttons
+     */
+    public void removeLobbyButton(int buttonId) {
+        buttonIdToLobbyId.remove(buttonId);
+    }
+
+    /**
+     * Gibt die LobbyID für eine gegebene ButtonID zurück.
+     * @param buttonId Die ButtonID
+     * @return Die zugehoerige LobbyID oder null, falls nicht vorhanden
+     */
+    public Integer getLobbyIdForButton(int buttonId) {
+        return buttonIdToLobbyId.get(buttonId);
+    }
+
+    /**
+     * Gibt die gesamte Zuordnung ButtonID → LobbyID zurück.
+     * @return Map aller Zuordnungen
+     */
+    public Map<Integer, Integer> getButtonIdToLobbyId() {
+        return buttonIdToLobbyId;
+    }
+}

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

@@ -1,8 +1,22 @@
 package ch.unibas.dmi.dbis.cs108.casono.server;
 
+import ch.unibas.dmi.dbis.cs108.casono.server.network.NetworkManager;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.events.DisconnectEvent;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.events.EventBus;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.sessions.SessionManager;
+
+/**
+ * Application class for starting the server.
+ */
 public class ServerApp {
     public static void start(String arg) {
         int port = Integer.parseInt(arg);
         System.out.println("You've selected the server. It will accept connections at port " + port);
+
+        EventBus eventBus = new EventBus();
+        SessionManager sessionManager = new SessionManager();
+        eventBus.subscribe(DisconnectEvent.class, event -> sessionManager.removeSession(event.sessionId()));
+        NetworkManager networkManager = new NetworkManager(port, sessionManager, eventBus);
+        networkManager.start();
     }
 }

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

@@ -0,0 +1,81 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.network;
+
+import java.io.IOException;
+import java.net.ServerSocket;
+import java.net.Socket;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.events.DisconnectEvent;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.events.EventBus;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.sessions.Session;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.sessions.SessionManager;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.transport.TcpTransport;
+
+/**
+ * Creates and manages the server socket. Accepts new incoming connections and creates sessions.
+ */
+public class NetworkManager implements Runnable {
+    private Integer port;
+    private Logger logger;
+    private Thread thread;
+    private Boolean running;
+    private SessionManager sessionManager;
+    private EventBus eventBus;
+
+    /**
+     * Creates a new NetworkManager with the given port, session manager, and event bus.
+     *
+     * @param port           the port to listen on
+     * @param sessionManager the session manager to use
+     * @param eventBus       the event bus for events
+     */
+    public NetworkManager(Integer port, SessionManager sessionManager, EventBus eventBus) {
+        this.port = port;
+        this.logger = LogManager.getLogger(NetworkManager.class);
+        this.thread = new Thread(this, "networkManager");
+        this.running = true;
+        this.sessionManager = sessionManager;
+        this.eventBus = eventBus;
+        this.eventBus.subscribe(DisconnectEvent.class, event -> clientDisconnected(event));
+    }
+
+    /**
+     * Starts the internal thread to accept new connections.
+     */
+    public void start() {
+        logger.debug("Starting server at port " + port);
+        thread.start();
+    }
+
+    /**
+     * Handles client disconnection events.
+     *
+     * @param event the disconnect event
+     */
+    public void clientDisconnected(DisconnectEvent event) {
+        logger.info("Session " + event.sessionId().value() + " disconnected adhasghd");
+    }
+
+    /**
+     * Runs the network manager loop, accepting connections.
+     */
+    @Override
+    public void run() {
+        try (ServerSocket serverSocket = new ServerSocket(port)) {
+            while (running) {
+                Socket clientSocket = serverSocket.accept();
+                
+                System.out.println("Accepted connection from " + clientSocket.getRemoteSocketAddress());
+
+                Session session = new Session(new TcpTransport(clientSocket), eventBus);
+                sessionManager.addSession(session);
+                session.start();
+            }
+
+        } catch (IOException e) {
+            logger.fatal(e);
+        }
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/network/events/DisconnectEvent.java

@@ -0,0 +1,8 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.network.events;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.sessions.SessionId;
+
+/**
+ * Represents a disconnect event for a session.
+ */
+public record DisconnectEvent(SessionId sessionId) implements Event {}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/network/events/Event.java

@@ -0,0 +1,6 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.network.events;
+
+/**
+ * Marker interface for events in the event bus system.
+ */
+interface Event {}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/network/events/EventBus.java

@@ -0,0 +1,40 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.network.events;
+
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.function.Consumer;
+
+/**
+ * A simple event bus for publishing and subscribing to events.
+ */
+public class EventBus {
+    private final Map<Class<?>, List<Consumer<Object>>> handlers = new ConcurrentHashMap<>();
+
+    /**
+     * Subscribes a handler to a specific event type.
+     *
+     * @param eventType the class of the event to subscribe to
+     * @param handler   the consumer to handle the event
+     */
+    @SuppressWarnings("unchecked") // This cast is safe, because handlers only get passed the type they subscribed to
+    public <T extends Event> void subscribe(Class<T> eventType, Consumer<T> handler) {
+        handlers.computeIfAbsent(eventType, k -> new CopyOnWriteArrayList<>())
+                .add((Consumer<Object>) (Consumer<?>) handler);
+    }
+
+    /**
+     * Publishes an event to all subscribed handlers.
+     *
+     * @param event the event to publish
+     */
+    public <T extends Event> void publish(T event) {
+        Objects.requireNonNull(event, "event must not be null");
+        List<Consumer<Object>> subscribers = handlers.get(event.getClass());
+        if (subscribers != null) {
+            subscribers.forEach(h -> h.accept(event));
+        }
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/network/sessions/Session.java

@@ -0,0 +1,85 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.network.sessions;
+
+import java.io.EOFException;
+import java.io.IOException;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import ch.unibas.dmi.dbis.cs108.casono.server.network.events.DisconnectEvent;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.events.EventBus;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.transport.TransportLayer;
+
+/**
+ * Represents a client session in the network server.
+ */
+public class Session implements Runnable {
+    private SessionId id;
+    private Thread thread;
+    private TransportLayer transport;
+    private Logger logger;
+    private Boolean running;
+    private EventBus eventBus;
+    
+    /**
+     * Creates a new Session with the given transport and event bus.
+     *
+     * @param transport the transport layer for communication
+     * @param eventBus  the event bus for publishing events
+     * @throws IOException if an I/O error occurs during initialization
+     */
+    public Session(TransportLayer transport, EventBus eventBus) throws IOException {
+        this.id = new SessionId();
+        this.thread = new Thread(this, "session-" + this.id.value());
+        this.transport = transport;
+        this.running = true;
+        this.eventBus = eventBus;
+
+        this.logger = LogManager.getLogger(Session.class.toString() + id.value());
+        this.logger.info("Created new session");
+    }
+
+    /**
+     * Returns the ID of this session.
+     *
+     * @return the session ID
+     */
+    public SessionId getId() {
+        return this.id;
+    }
+
+    /**
+     * Starts the session thread.
+     */
+    public void start() {
+        thread.start();
+    }
+
+    /**
+     * Closes the session and its transport.
+     *
+     * @throws IOException if an I/O error occurs
+     */
+    public void close() throws IOException {
+        transport.close();
+        this.running = false;
+    }
+
+    /**
+     * Runs the session loop, reading from the transport.
+     */
+    @Override
+    public void run() {
+        while (running) {
+            try {
+                System.out.println("Recieved: " + transport.read());
+            } catch (EOFException e) {
+                logger.info("Client disconnected");
+                eventBus.publish(new DisconnectEvent(id));
+                break;
+            } catch (IOException e) {
+                e.printStackTrace();
+                break;
+            }
+        }
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/network/sessions/SessionId.java

@@ -0,0 +1,35 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.network.sessions;
+
+import java.util.UUID;
+
+/**
+ * Represents a unique identifier for a session.
+ */
+public class SessionId {
+    private final UUID value;
+
+    /**
+     * Creates a new SessionId with a randomly generated UUID.
+     */
+    public SessionId() {
+        this.value = UUID.randomUUID();
+    }
+
+    /**
+     * Creates a new SessionId with the specified UUID.
+     *
+     * @param UUID to use for this SessionId
+     */
+    public SessionId(UUID value) {
+        this.value = value;
+    }
+
+    /**
+     * Returns the UUID value of this SessionId.
+     *
+     * @return the UUID value
+     */
+    public UUID value() {
+        return value;
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/network/sessions/SessionManager.java

@@ -0,0 +1,59 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.network.sessions;
+
+import java.util.Map;
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * Manages active sessions in the server.
+ */
+public class SessionManager {
+    private Map<SessionId, Session> sessions;
+
+    /**
+     * Constructs a new SessionManager.
+     */
+    public SessionManager() {
+        this.sessions = new ConcurrentHashMap<>();
+    }
+
+    /**
+     * Adds a session to the manager.
+     *
+     * @param session the session to add
+     */
+    public void addSession(Session session) {
+        sessions.put(session.getId(), session);
+        System.out.println("Added session " + session.getId().value() + " to session manager");
+    }
+
+    /**
+     * Removes a session by its ID.
+     *
+     * @param id the ID of the session to remove
+     * @return the removed session, or null if not found
+     */
+    public Session removeSession(SessionId id) {
+        System.out.println("Removed session " + id.value() + " from session manager");
+        return sessions.remove(id);
+    }
+
+    /**
+     * Removes the specified session.
+     *
+     * @param session the session to remove
+     * @return the removed session, or null if not found
+     */
+    public Session removeSession(Session session) {
+        return sessions.remove(session.getId());
+    }
+
+    /**
+     * Retrieves a session by its ID.
+     *
+     * @param id the ID of the session to retrieve
+     * @return the session with the specified ID, or null if not found
+     */
+    public Session getSessionById(SessionId id) {
+        return sessions.get(id);
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/network/transport/TcpTransport.java

@@ -0,0 +1,63 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.network.transport;
+
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.IOException;
+import java.net.Socket;
+import java.nio.charset.StandardCharsets;
+
+/**
+ * Implements TCP-based transport layer for network communication.
+ */
+public class TcpTransport implements TransportLayer {
+    private Socket socket;
+    private DataInputStream in;
+    private DataOutputStream out;
+
+    /**
+     * Creates a new TcpTransport with the given socket.
+     *
+     * @param socket the socket to use for communication
+     * @throws IOException if an I/O error occurs
+     */
+    public TcpTransport(Socket socket) throws IOException {
+        this.socket = socket;
+        this.in = new DataInputStream(socket.getInputStream());
+        this.out = new DataOutputStream(socket.getOutputStream());
+    }
+
+    /**
+     * Reads a string from the socket.
+     *
+     * @return the read string
+     * @throws IOException if an I/O error occurs
+     */
+    public String read() throws IOException {
+        int length = in.readInt();
+        byte[] payload = new byte[length];
+        in.readFully(payload);
+        return new String(payload, StandardCharsets.UTF_8);
+    }
+
+    /**
+     * Writes a string to the socket.
+     *
+     * @param payload the string to write
+     * @throws IOException if an I/O error occurs
+     */
+    public void write(String payload) throws IOException {
+        byte[] rawPayload = payload.getBytes(StandardCharsets.UTF_8);
+        out.writeInt(rawPayload.length);
+        out.write(rawPayload);
+        out.flush();    
+    }
+
+    /**
+     * Closes the socket.
+     *
+     * @throws IOException if an I/O error occurs
+     */
+    public void close() throws IOException {
+        socket.close();
+    }
+}

src/main/java/ch/unibas/dmi/dbis/cs108/casono/server/network/transport/TransportLayer.java

@@ -0,0 +1,31 @@
+package ch.unibas.dmi.dbis.cs108.casono.server.network.transport;
+
+import java.io.IOException;
+
+/**
+ * Interface for transport layer implementations.
+ */
+public interface TransportLayer {
+    /**
+     * Reads data from the transport layer.
+     *
+     * @return the read data as a string
+     * @throws IOException if an I/O error occurs
+     */
+    String read() throws IOException;
+
+    /**
+     * Writes data to the transport layer.
+     *
+     * @param data the data to write
+     * @throws IOException if an I/O error occurs
+     */
+    void write(String data) throws IOException;
+
+    /**
+     * Closes the transport layer.
+     *
+     * @throws IOException if an I/O error occurs
+     */
+    void close() throws IOException;
+}