feat(xep): Add cache and roomstate to MUC implementation.

Signed-off-by: Ikjot Singh Dhody <ikjotsd@gmail.com>

packages/moxxmpp/lib/src/xeps/xep_0045/types.dart

@@ -32,3 +32,14 @@ class RoomInformation {
   /// The name or title of the Multi-User Chat (MUC) room.
   final String name;
 }
+
+class RoomState {
+  RoomState({
+    required this.roomJid,
+    required this.roomInformation,
+    this.nick,
+  });
+  final JID roomJid;
+  final RoomInformation roomInformation;
+  String? nick;
+}

packages/moxxmpp/lib/src/xeps/xep_0045/xep_0045.dart

@@ -11,6 +11,7 @@ import 'package:moxxmpp/src/xeps/xep_0030/types.dart';
 import 'package:moxxmpp/src/xeps/xep_0030/xep_0030.dart';
 import 'package:moxxmpp/src/xeps/xep_0045/errors.dart';
 import 'package:moxxmpp/src/xeps/xep_0045/types.dart';
+import 'package:synchronized/synchronized.dart';
 
 enum ConversationType { chat, groupchat, groupchatprivate }
 
@@ -25,6 +26,12 @@ class MUCManager extends XmppManagerBase {
   @override
   Future<bool> isSupported() async => true;
 
+  /// Map full JID to RoomState
+  final Map<JID, RoomState> _mucRoomCache = {};
+
+  /// Cache lock
+  final Lock _cacheLock = Lock();
+
   Future<Result<RoomInformation, MUCError>> queryRoomInformation(
     JID roomJID,
   ) async {
@@ -38,6 +45,14 @@ class MUCManager extends XmppManagerBase {
       final roomInformation = RoomInformation.fromDiscoInfo(
         discoInfo: result.get<DiscoInfo>(),
       );
+      await _cacheLock.synchronized(
+        () async {
+          _mucRoomCache[roomJID] = RoomState(
+            roomJid: roomJID,
+            roomInformation: roomInformation,
+          );
+        },
+      );
       return Result(roomInformation);
     } catch (e) {
       return Result(InvalidDiscoInfoResponse);
@@ -64,23 +79,39 @@ class MUCManager extends XmppManagerBase {
         ),
       ),
     );
+    await _cacheLock.synchronized(
+      () async {
+        _mucRoomCache[roomJID]!.nick = nick;
+      },
+    );
     return const Result(true);
   }
 
   Future<Result<bool, MUCError>> leaveRoom(
-    JID roomJIDWithNickname,
+    JID roomJID,
   ) async {
-    if (roomJIDWithNickname.resource.isEmpty) {
+    String? nick;
+    await _cacheLock.synchronized(
+      () async {
+        nick = _mucRoomCache[roomJID]!.nick;
+      },
+    );
+    if (nick!.isEmpty) {
       return Result(NoNicknameSpecified());
     }
     await getAttributes().sendStanza(
       StanzaDetails(
         Stanza.presence(
-          to: roomJIDWithNickname.toString(),
+          to: roomJID.withResource(nick!).toString(),
           type: 'unavailable',
         ),
       ),
     );
+    await _cacheLock.synchronized(
+      () async {
+        _mucRoomCache.remove(roomJID);
+      },
+    );
     return const Result(true);
   }
 }