Feat: Added CHANGE_USERNAME server command, registration and documentation

2026-04-15 20:49:29 +02:00
parent 497820db05
commit 190b30672a
6 changed files with 323 additions and 21 deletions
@@ -1,5 +1,8 @@
 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;
@@ -168,6 +171,15 @@ 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));
@@ -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);
+        }
+    }
+}
@@ -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"));
+    }
+}
@@ -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;
+    }
+}
@@ -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());
+    }
+}