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

@@ -7,11 +7,17 @@ import java.io.IOException;
 import java.net.Socket;
 import java.util.ArrayList;
 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 +36,17 @@ 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 +56,6 @@ 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 +71,100 @@ 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);
+
+        boolean hasStatus = false;
+        boolean success = false;
+        List<String> lines = new ArrayList<>();
+
+        for (String rawLine : responseText.split("\\n")) {
+            String line = rawLine;
+            if (!hasStatus) {
+                if ("+OK".equals(line)) {
+                    success = true;
+                    hasStatus = true;
+                    continue;
+                }
+                if (line.startsWith("-ERR") || line.startsWith("-ERROR")) {
+                    success = false;
+                    hasStatus = true;
+                    continue;
+                }
+                continue;
+            }
+
+            if ("END".equals(line)) {
+                break;
+            }
+
+            if (line.startsWith("\t")) {
+                line = line.substring(1);
+            }
+            lines.add(line);
+        }
+
+        if (!hasStatus) {
+            if (responseText.contains("+OK")) {
+                success = true;
+                hasStatus = true;
+            } else if (responseText.contains("-ERR") || responseText.contains("-ERROR")) {
+                success = false;
+                hasStatus = true;
+            } else {
+                // best effort: treat as success
+                success = true;
+                hasStatus = true;
+            }
+        }
+
+        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);
+            }
+        }
     }
 
     /**
@@ -124,6 +230,19 @@ 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
@@ -135,74 +254,51 @@ public class ClientService {
      *     occurs.
      */
     protected List<String> processCommand(String message) {
-        List<String> response = new ArrayList<>();
+        if (offlineMode) {
-        sendRequest(
+            throw new RuntimeException("ClientService is offline");
-                () -> {
+        }
-                    try {
-                        writeToTransport(message);
-                        String responseText = clienttcptransport.read().payload();
-                        logger.info("Raw message '{}'", responseText);
 
-                        boolean hasStatus = false;
+        int reqId = idGenerator.incrementAndGet();
-                        boolean success = false;
+        ArrayBlockingQueue<ParsedResponse> q = new ArrayBlockingQueue<>(1);
-                        for (String rawLine : responseText.split("\n")) {
+        pendingResponses.put(reqId, q);
-                            String line = rawLine;
+
-                            if (!hasStatus) {
+        Future<?> writeFuture =
-                                if ("+OK".equals(line)) {
+                executor.submit(
-                                    success = true;
+                        () -> {
-                                    hasStatus = true;
+                            try {
-                                    continue;
+                                clienttcptransport.write(new RawPacket(reqId, message));
-                                }
+                            } catch (IOException e) {
-                                if (line.startsWith("-ERR") || line.startsWith("-ERROR")) {
+                                throw new RuntimeException(e);
-                                    success = false;
-                                    hasStatus = true;
-                                    continue;
-                                }
-                                // ignore any lines before the status indicator
-                                continue;
                             }
+                        });
 
-                            if ("END".equals(line)) {
+        try {
-                                break;
+            writeFuture.get();
-                            }
+        } catch (InterruptedException e) {
+            Thread.currentThread().interrupt();
+            pendingResponses.remove(reqId);
+            throw new RuntimeException(e);
+        } catch (ExecutionException e) {
+            pendingResponses.remove(reqId);
+            throw getRuntimeException(e);
+        }
 
-                            // strip a single leading tab if present (protocol formatting)
+        ParsedResponse pr;
-                            if (line.startsWith("\t")) {
+        try {
-                                line = line.substring(1);
+            pr = q.take();
-                            }
+        } catch (InterruptedException e) {
-                            response.add(line);
+            Thread.currentThread().interrupt();
-                        }
+            pendingResponses.remove(reqId);
+            throw new RuntimeException(e);
+        } finally {
+            pendingResponses.remove(reqId);
+        }
 
-                        if (!hasStatus) {
+        if (pr.success) {
-                            // Fallback for servers that do not place the status on a
+            return pr.lines;
-                            // dedicated line: try to detect status markers anywhere
+        }
-                            // in the payload to remain compatible with older servers.
-                            if (responseText.contains("+OK")) {
-                                success = true;
-                                hasStatus = true;
-                            } else if (responseText.contains("-ERR")
-                                    || responseText.contains("-ERROR")) {
-                                success = false;
-                                hasStatus = true;
-                            } else {
-                                throw new RuntimeException(
-                                        "No status line in response for '"
-                                                + message
-                                                + "': "
-                                                + responseText);
-                            }
-                        }
 
-                        if (success) {
+        throw new RuntimeException("Error in " + message + ": " + pr.lines);
-                            return;
-                        }
-
-                        throw new RuntimeException("Error in " + message + ": " + response);
-                    } catch (Exception e) {
-                        throw getRuntimeException(e);
-                    }
-                });
-        return response;
     }
 
     /**
@@ -250,7 +346,17 @@ 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");
@@ -259,16 +365,9 @@ public class ClientService {
         }
     }
 
-    /**
+    // removed unused helper writeToTransport; write is done via processCommand()
-     * Method to write with the tcp transport to the server
+    // which
-     *
+    // manages request ids and response matching
-     * @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));
-    }
 
     public void ping() {
         processCommand("PING");

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

@@ -32,7 +32,25 @@ 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;
     }
 
     /**
@@ -68,8 +86,15 @@ 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();
+        List<String> lines = client.processCommand("GET_LOBBY_ID");
-        return Integer.parseInt(response);
+        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);
+        }
     }
 
     /**

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

@@ -2,6 +2,7 @@ package ch.unibas.dmi.dbis.cs108.casono.client.ui.lobbyui;
 
 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.server.network.command.parsing.RequestParameter;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -53,7 +54,7 @@ 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 +63,43 @@ public class LobbyButtonGridManager {
             ClientService clientService) {
 
         this(gridPane, translationManager, new LobbyClient(clientService));
+
+        // Subscribe to server-initiated events so closed lobbies are removed
+        // immediately
+        clientService.addEventListener(
+                lines -> {
+                    List<RequestParameter> params = ClientService.convertToRequestParameters(lines);
+                    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();
+                        }
+                    }
+                    if (evt != null && "LOBBY_CLOSED".equalsIgnoreCase(evt) && lidStr != null) {
+                        int lid;
+                        try {
+                            lid = Integer.parseInt(lidStr);
+                        } catch (NumberFormatException ex) {
+                            return;
+                        }
+                        // 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) {
+                            translationManager.removeLobbyButton(toRemove);
+                            javafx.application.Platform.runLater(this::renderLobbyButtons);
+                        }
+                    }
+                });
     }
 
     private void startPeriodicRefresh(long initialDelay, long period) {
@@ -80,7 +118,11 @@ public class LobbyButtonGridManager {
 
         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(
                             () -> {
@@ -97,8 +139,7 @@ public class LobbyButtonGridManager {
                                 if (status == null) {
                                     translationManager.removeLobbyButton(buttonId);
 
-                                    javafx.application.Platform.runLater(
+                                    javafx.application.Platform.runLater(this::renderLobbyButtons);
-                                            this::updateLobbyButtonImages);
                                 }
                             });
         }
@@ -118,7 +159,11 @@ 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);
 
@@ -253,7 +298,11 @@ 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(
                             () -> {
@@ -361,8 +410,4 @@ public class LobbyButtonGridManager {
     public LobbyClient getLobbyClient() {
         return lobbyClient;
     }
-
-    public void refreshNow() {
-        refreshMappings();
-    }
 }

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

@@ -33,7 +33,11 @@ import ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandR
 import ch.unibas.dmi.dbis.cs108.casono.server.network.command.parsing.CommandParserDispatcher;
 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.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.dispatcher.ResponseDispatcher;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.sessions.Session;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.sessions.SessionDisconnectJob;
 import ch.unibas.dmi.dbis.cs108.casono.server.network.sessions.SessionManager;
 import java.time.Duration;
@@ -51,6 +55,9 @@ public class ServerApp {
     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 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);
@@ -89,6 +96,41 @@ public class ServerApp {
         LobbyManager lobbyManager = new LobbyManager();
         registerCommands(dispatcher, router, responseDispatcher, userRegistry, lobbyManager);
 
+        // Periodic cleanup: remove empty lobbies older than 30s and notify affected
+        // users
+        scheduler.scheduleAtFixedRate(
+                () -> {
+                    try {
+                        var expired =
+                                lobbyManager.findEmptyLobbiesOlderThan(
+                                        Duration.ofSeconds(LOBBY_EXPIRY_SECONDS));
+                        for (var lid : expired) {
+                            // remove lobby from manager first
+                            lobbyManager.removeLobby(lid);
+
+                            // broadcast LOBBY_CLOSED 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_CLOSED")
+                                                        .param("LOBBY_ID", lid.value())
+                                                        .build()) {};
+
+                                responseDispatcher.dispatch(ev);
+                            }
+                        }
+                    } catch (Exception e) {
+                        logger.warn("Lobby expiry job failed", e);
+                    }
+                },
+                LOBBY_CLEANUP_INITIAL_DELAY_SECONDS,
+                LOBBY_CLEANUP_PERIOD_SECONDS,
+                TimeUnit.SECONDS);
+
         NetworkManager networkManager = new NetworkManager(port, sessionManager, router);
         networkManager.start();
     }

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

@@ -22,6 +22,7 @@ public class GetLobbyStatusResponse extends SuccessResponse {
         super(
                 context,
                 ResponseBody.builder()
+                        .param("STATUS", lobby.getGameController() != null ? "RUNNING" : "CREATED")
                         .block(
                                 "LOBBY",
                                 lb -> {