documents/docs/networking/commands/protocol-document.md

@@ -1111,4 +1111,58 @@ GET_LOBBY_STATUS ID=1
   CODE=LOBBY_NOT_FOUND
   MESSAGE=Lobby not found
 END
+```
+
+## CREATE_LOBBY command
+
+The `CREATE_LOBBY` command requests the server to create a new lobby and return its identifier.
+
+### Required pre-execution checks
+
+None.
+
+### Request Parameters
+
+No parameters.
+
+### Implementation notes
+
+- Parser: CreateLobbyParser — constructs a CreateLobbyRequest from the incoming PrimitiveRequest context (no parameters are read).
+- Handler: CreateLobbyHandler — calls LobbyManager.createNewLobby(null).
+  - If the returned LobbyId is null, the handler dispatches an ErrorResponse with code `LOBBIES_FULL` and message "Maximum number of 8 lobbies reached".
+  - On success, the handler dispatches a CreateLobbyResponse containing the new lobby id.
+
+### Success Response
+
+| Field     | Type | Description |
+| :-------- | :--- | :---------- |
+| `LOBBY_ID`| `int`| Numeric id of the newly created lobby |
+
+### Error Response
+
+| Code        | Description                                                            |
+| :---------- | :--------------------------------------------------------------------- |
+| `LOBBIES_FULL` | The server cannot create a new lobby because the maximum number of lobbies has been reached |
+
+### Example Request
+
+```
+CREATE_LOBBY
+```
+
+### Example Success Response
+
+```
++OK
+  LOBBY_ID=1
+END
+```
+
+### Example Error Response
+
+```
+-ERR
+  CODE=LOBBIES_FULL
+  MESSAGE=Maximum number of 8 lobbies reached
+END
 ```

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

@@ -41,8 +41,25 @@ 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);
     }
 
     /**

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

@@ -239,6 +239,20 @@ public class ServerApp {
                                 .get_lobby_status.GetLobbyStatusHandler(
                                 responseDispatcher, lobbyManager, userRegistry));
 
+        // CREATE_LOBBY registration
+        parserDispatcher.register(
+                "CREATE_LOBBY",
+                new ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.create_lobby
+                        .CreateLobbyParser());
+        commandRouter.register(
+                ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.create_lobby
+                        .CreateLobbyRequest.class,
+                (ch.unibas.dmi.dbis.cs108.casono.server.network.command.execution.CommandHandler<
+                                ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby
+                                        .create_lobby.CreateLobbyRequest>)
+                        new ch.unibas.dmi.dbis.cs108.casono.server.app.commands.lobby.create_lobby
+                                .CreateLobbyHandler(responseDispatcher, lobbyManager));
+
         // JOIN_LOBBY registration
         parserDispatcher.register(
                 "JOIN_LOBBY",

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

@@ -0,0 +1,32 @@
+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.response.ErrorResponse;
+import ch.unibas.dmi.dbis.cs108.casono.server.network.protocol.response.dispatcher.ResponseDispatcher;
+
+public class CreateLobbyHandler extends CommandHandler<CreateLobbyRequest> {
+    private final LobbyManager lobbyManager;
+
+    public CreateLobbyHandler(ResponseDispatcher responseDispatcher, LobbyManager lobbyManager) {
+        super(responseDispatcher);
+        this.lobbyManager = lobbyManager;
+    }
+
+    @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()));
+    }
+}

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());
+    }
+}