feat(llc, persistence): add support for open and close persistence via client.

Signed-off-by: xsahil03x <xdsahil@gmail.com>

packages/stream_chat/lib/src/client/channel.dart

@@ -1379,13 +1379,14 @@ class Channel {
       this.state?.updateChannelState(updatedState);
       return updatedState;
     } catch (e) {
-      if (!_client.persistenceEnabled) {
-        rethrow;
+      if (_client.persistenceEnabled) {
+        return _client.chatPersistenceClient!.getChannelStateByCid(
+          cid!,
+          messagePagination: messagesPagination,
+        );
       }
-      return _client.chatPersistenceClient!.getChannelStateByCid(
-        cid!,
-        messagePagination: messagesPagination,
-      );
+
+      rethrow;
     }
   }
 
@@ -1841,9 +1842,7 @@ class ChannelClientState {
 
   /// [isUpToDate] flag count as a stream.
   Stream<bool> get isUpToDateStream => _isUpToDateController.stream;
-
-  final BehaviorSubject<bool> _isUpToDateController =
-      BehaviorSubject.seeded(true);
+  final _isUpToDateController = BehaviorSubject.seeded(true);
 
   /// The retry queue associated to this channel.
   late final RetryQueue _retryQueue;

packages/stream_chat/lib/src/client/client.dart

@@ -125,10 +125,6 @@ class StreamChatClient {
   final _tokenManager = TokenManager();
   final _connectionIdManager = ConnectionIdManager();
 
-  set chatPersistenceClient(ChatPersistenceClient? value) {
-    _originalChatPersistenceClient = value;
-  }
-
   /// Default user agent for all requests
   static String defaultUserAgent =
       'stream-chat-dart-client-${CurrentPlatform.name}';
@@ -139,15 +135,15 @@ class StreamChatClient {
   /// The current package version
   static const packageVersion = PACKAGE_VERSION;
 
-  ChatPersistenceClient? _originalChatPersistenceClient;
-
   /// Chat persistence client
-  ChatPersistenceClient? get chatPersistenceClient => _chatPersistenceClient;
+  ChatPersistenceClient? chatPersistenceClient;
 
-  ChatPersistenceClient? _chatPersistenceClient;
-
-  /// Whether the chat persistence is available or not
-  bool get persistenceEnabled => _chatPersistenceClient != null;
+  /// Returns `True` if the [chatPersistenceClient] is available and connected.
+  /// Otherwise, returns `False`.
+  bool get persistenceEnabled {
+    final client = chatPersistenceClient;
+    return client != null && client.isConnected;
+  }
 
   late final RetryPolicy _retryPolicy;
 
@@ -324,20 +320,27 @@ class StreamChatClient {
     final ownUser = OwnUser.fromUser(user);
     state.currentUser = ownUser;
 
-    if (!connectWebSocket) return ownUser;
-
     try {
-      if (_originalChatPersistenceClient != null) {
-        _chatPersistenceClient = _originalChatPersistenceClient;
-        await _chatPersistenceClient!.connect(ownUser.id);
+      // Connect to persistence client if its set.
+      if (chatPersistenceClient != null) {
+        await openPersistenceConnection(ownUser);
       }
-      final connectedUser = await openConnection(
-        includeUserDetailsInConnectCall: true,
-      );
-      return state.currentUser = connectedUser;
+
+      // Connect to websocket if [connectWebSocket] is true.
+      //
+      // This is useful when you want to connect to websocket
+      // at a later stage or use the client in connection-less mode.
+      if (connectWebSocket) {
+        final connectedUser = await openConnection(
+          includeUserDetailsInConnectCall: true,
+        );
+        state.currentUser = connectedUser;
+      }
+
+      return state.currentUser!;
     } catch (e, stk) {
       if (e is StreamWebSocketError && e.isRetriable) {
-        final event = await _chatPersistenceClient?.getConnectionInfo();
+        final event = await chatPersistenceClient?.getConnectionInfo();
         if (event != null) return ownUser.merge(event.me);
       }
       logger.severe('error connecting user : ${ownUser.id}', e, stk);
@@ -345,6 +348,40 @@ class StreamChatClient {
     }
   }
 
+  /// Connects the [chatPersistenceClient] to the given [user].
+  Future<void> openPersistenceConnection(User user) async {
+    final client = chatPersistenceClient;
+    if (client == null) {
+      throw const StreamChatError('Chat persistence client is not set');
+    }
+
+    if (client.isConnected) {
+      // If the persistence client is already connected to the userId,
+      // we don't need to connect again.
+      if (client.userId == user.id) return;
+
+      throw const StreamChatError('''
+        Chat persistence client is already connected to a different user,
+        please close the connection before connecting a new one.''');
+    }
+
+    // Connect the persistence client to the userId.
+    return client.connect(user.id);
+  }
+
+  /// Disconnects the [chatPersistenceClient] from the current user.
+  Future<void> closePersistenceConnection({bool flush = false}) async {
+    final client = chatPersistenceClient;
+    // If the persistence client is never connected, we don't need to close it.
+    if (client == null || !client.isConnected) {
+      logger.info('Chat persistence client is not connected');
+      return;
+    }
+
+    // Disconnect the persistence client.
+    return client.disconnect(flush: flush);
+  }
+
   /// Creates a new WebSocket connection with the current user.
   /// If [includeUserDetailsInConnectCall] is true it will include the current
   /// user details in the connect call.
@@ -422,7 +459,7 @@ class StreamChatClient {
     final connectionId = event.connectionId;
     if (connectionId != null) {
       _connectionIdManager.setConnectionId(connectionId);
-      _chatPersistenceClient?.updateConnectionInfo(event);
+      chatPersistenceClient?.updateConnectionInfo(event);
     }
   }
 
@@ -460,9 +497,9 @@ class StreamChatClient {
         // channels are empty, assuming it's a fresh start
         // and making sure `lastSyncAt` is initialized
         if (persistenceEnabled) {
-          final lastSyncAt = await _chatPersistenceClient?.getLastSyncAt();
+          final lastSyncAt = await chatPersistenceClient?.getLastSyncAt();
           if (lastSyncAt == null) {
-            await _chatPersistenceClient?.updateLastSyncAt(DateTime.now());
+            await chatPersistenceClient?.updateLastSyncAt(DateTime.now());
           }
         }
       }
@@ -493,13 +530,12 @@ class StreamChatClient {
   /// Will automatically fetch [cids] and [lastSyncedAt] if [persistenceEnabled]
   Future<void> sync({List<String>? cids, DateTime? lastSyncAt}) {
     return synchronized(() async {
-      final channels = cids ?? await _chatPersistenceClient?.getChannelCids();
+      final channels = cids ?? await chatPersistenceClient?.getChannelCids();
       if (channels == null || channels.isEmpty) {
         return;
       }
 
-      final syncAt =
-          lastSyncAt ?? await _chatPersistenceClient?.getLastSyncAt();
+      final syncAt = lastSyncAt ?? await chatPersistenceClient?.getLastSyncAt();
       if (syncAt == null) {
         return;
       }
@@ -520,7 +556,7 @@ class StreamChatClient {
 
         final now = DateTime.now();
         _lastSyncedAt = now;
-        _chatPersistenceClient?.updateLastSyncAt(now);
+        chatPersistenceClient?.updateLastSyncAt(now);
       } catch (e, stk) {
         logger.severe('Error during sync', e, stk);
       }
@@ -679,7 +715,7 @@ class StreamChatClient {
 
     final updateData = _mapChannelStateToChannel(channels);
 
-    await _chatPersistenceClient?.updateChannelQueries(
+    await chatPersistenceClient?.updateChannelQueries(
       filter,
       channels.map((c) => c.channel!.cid).toList(),
       clearQueryCache: paginationParams.offset == 0,
@@ -698,7 +734,7 @@ class StreamChatClient {
     List<SortOption<ChannelState>>? channelStateSort,
     PaginationParams paginationParams = const PaginationParams(),
   }) async {
-    final offlineChannels = (await _chatPersistenceClient?.getChannelStates(
+    final offlineChannels = (await chatPersistenceClient?.getChannelStates(
           filter: filter,
           // ignore: deprecated_member_use_from_same_package
           sort: sort,
@@ -1362,7 +1398,7 @@ class StreamChatClient {
     final response =
         await _chatApi.message.deleteMessage(messageId, hard: hard);
     if (hard == true) {
-      await _chatPersistenceClient?.deleteMessageById(messageId);
+      await chatPersistenceClient?.deleteMessageById(messageId);
     }
     return response;
   }
@@ -1468,34 +1504,33 @@ class StreamChatClient {
   Future<void> disconnectUser({bool flushChatPersistence = false}) async {
     logger.info('Disconnecting user : ${state.currentUser?.id}');
 
-    // resetting state
+    // resetting state.
     state.dispose();
     state = ClientState(this);
     _lastSyncedAt = null;
 
-    // resetting credentials
+    // resetting credentials.
     _tokenManager.reset();
     _connectionIdManager.reset();
 
-    // disconnecting persistence client
-    await _chatPersistenceClient?.disconnect(flush: flushChatPersistence);
-    _chatPersistenceClient = null;
+    // closing persistence connection.
+    await closePersistenceConnection(flush: flushChatPersistence);
 
     // closing web-socket connection
-    closeConnection();
+    return closeConnection();
   }
 
   /// Call this function to dispose the client
   Future<void> dispose() async {
     logger.info('Disposing new StreamChatClient');
 
-    // disposing state
+    // disposing state.
     state.dispose();
 
-    // disconnecting persistence client
-    await _chatPersistenceClient?.disconnect();
+    // closing persistence connection.
+    await closePersistenceConnection();
 
-    // closing web-socket connection
+    // closing web-socket connection.
     closeConnection();
 
     await _eventController.close();

packages/stream_chat/lib/src/db/chat_persistence_client.dart

@@ -17,6 +17,11 @@ abstract class ChatPersistenceClient {
   /// Whether the connection is established.
   bool get isConnected;
 
+  /// The current user id to which the client is connected.
+  ///
+  /// Returns `null` if the client is not connected.
+  String? get userId;
+
   /// Creates a new connection to the client
   Future<void> connect(String userId);
 

packages/stream_chat/test/src/db/chat_persistence_client_test.dart

@@ -15,6 +15,9 @@ class TestPersistenceClient extends ChatPersistenceClient {
   @override
   bool get isConnected => throw UnimplementedError();
 
+  @override
+  String? get userId => throw UnimplementedError();
+
   @override
   Future<void> connect(String userId) => throw UnimplementedError();
 

packages/stream_chat/test/src/mocks.dart

@@ -64,11 +64,16 @@ class MockAttachmentFileUploader extends Mock
     implements AttachmentFileUploader {}
 
 class MockPersistenceClient extends Mock implements ChatPersistenceClient {
-  @override
-  Future<void> connect(String userId) => Future.value();
+  bool _isConnected = false;
 
   @override
-  Future<void> disconnect({bool flush = false}) => Future.value();
+  bool get isConnected => _isConnected;
+
+  @override
+  Future<void> connect(String userId) async => _isConnected = true;
+
+  @override
+  Future<void> disconnect({bool flush = false}) async => _isConnected = false;
 }
 
 class MockStreamChatClient extends Mock implements StreamChatClient {

packages/stream_chat_persistence/lib/src/stream_chat_persistence_client.dart

@@ -82,6 +82,9 @@ class StreamChatPersistenceClient extends ChatPersistenceClient {
   @override
   bool get isConnected => db != null;
 
+  @override
+  String? get userId => db?.userId;
+
   @override
   Future<void> connect(
     String userId, {