Advanced chat management via UI

frontend/lib/backend.dart

@@ -3,6 +3,13 @@ import 'dart:html';
 import 'dart:convert';
 import 'dart:async'; // Import for handling Completers
 
+class ChatInfo {
+  int id;
+  String name;
+
+  ChatInfo({required this.id, required this.name});
+}
+
 class Backend {
   static WebSocket? _socket;
   static String? _url;
@@ -10,6 +17,9 @@ class Backend {
   static Map<int, StreamController<Map<String, dynamic>>> _chatControllers = {};
   static int _nextNonce = 0; // Tracking nonce for each action
   static StreamController<Map<String, dynamic>> _packetStreamController = StreamController.broadcast();
+
+  // Cached Data
+  static List<ChatInfo>? _chats;
   
   // Authentication
   static ({String username, String password})? _credentials;
@@ -36,6 +46,8 @@ class Backend {
     _socket = WebSocket(_url!);
     _socket!.onOpen.listen((event) {
       print('Connected to the WebSocket server');
+      Backend.invalidateCache(chat: true);
+
       print('Logging in...');
       if (_credentials != null) {
         _socket!.send(json.encode({'username': _credentials!.username, 'password': _credentials!.password}));
@@ -128,6 +140,33 @@ class Backend {
     }
   }
 
+  static Future<List<ChatInfo>> getChats () async {
+    if (_chats == null) {
+      final response = await Backend.sendAction("get-chats", {});
+      List<dynamic> chatObjects = response['chats'];
+      _chats = chatObjects
+          .map((msg) => ChatInfo(
+                id: msg['id'],
+                name: msg['name']?.isNotEmpty == true ? msg['name'] : '[Chat ${msg['id']}]',
+              ))
+          .toList();
+    }
+    return _chats!;
+  }
+
+  static Future<ChatInfo?> getChat (int chatId) async {
+    final chats = await getChats();
+    try {
+      return chats.firstWhere((chat) => chat.id == chatId);
+    } on StateError {
+      return null;
+    }
+  }
+
+  static void invalidateCache ({bool chat = false}) {
+    if (chat) { _chats = null; }
+  }
+
   static void ping() {
     if (_socket!= null && _socket!.readyState == WebSocket.OPEN) {
       final data = json.encode({'path': 'ping'});