organize the cleanUp chain

lib/src/core/engine.dart

@@ -88,9 +88,9 @@ class Engine extends Disposable with EventsEmittable<EngineEvent> {
     _setUpSignalListeners();
 
     onDispose(() async {
+      await cleanUp();
       await events.dispose();
       await delays.dispose();
-      await close();
       await _signalListener.dispose();
     });
   }
@@ -137,27 +137,22 @@ class Engine extends Disposable with EventsEmittable<EngineEvent> {
     }
   }
 
-  /// Close connection between the server.
-  Future<void> close() async {
-    logger.fine('${runtimeType}.close()');
-    if (_connectionState == ConnectionState.disconnected) {
-      logger.warning('${runtimeType}.close() already disconnected');
-    }
-    // _statsTimer.cancel();
+  // resets internal state to a re-usable state
+  Future<void> cleanUp() async {
+    logger.fine('[${objectId}] cleanUp()');
+
     // cancel all ongoing delays
     await delays.cancelAll();
 
-    // PCTransport is responsible for disposing RTCPeerConnection
     await publisher?.dispose();
     publisher = null;
 
     await subscriber?.dispose();
     subscriber = null;
 
-    await signalClient.disconnect();
+    await signalClient.cleanUp();
 
     _updateConnectionState(ConnectionState.disconnected);
-    // notifyListeners();
   }
 
   @internal
@@ -647,7 +642,7 @@ class Engine extends Disposable with EventsEmittable<EngineEvent> {
             '[Signal] Received Leave while engine is reconnecting, ignoring...');
         return;
       }
-      await close();
+      await cleanUp();
     })
     ..on<SignalMuteTrackEvent>(
         (event) => events.emit(EngineRemoteMuteChangedEvent(

lib/src/core/room.dart

@@ -91,6 +91,8 @@ class Room extends DisposableChangeNotifier with EventsEmittable<RoomEvent> {
     });
 
     onDispose(() async {
+      // clean up routine
+      await _cleanUp();
       // dispose events
       await events.dispose();
       // dispose local participant
@@ -489,24 +491,28 @@ class Room extends DisposableChangeNotifier with EventsEmittable<RoomEvent> {
 extension RoomPrivateMethods on Room {
   // resets internal state to a re-usable state
   Future<void> _cleanUp() async {
-    logger.fine('[$objectId] _handleClose()');
-    if (connectionState == ConnectionState.disconnected) {
-      logger.warning('[$objectId]: close() already disconnected');
-    }
+    logger.fine('[${objectId}] cleanUp()');
 
     // clean up RemoteParticipants
-    for (final _ in _participants.values.toList()) {
+    for (final participant in _participants.values) {
       // RemoteParticipant is responsible for disposing resources
-      await _.dispose();
+      await participant.dispose();
     }
     _participants.clear();
 
     // clean up LocalParticipant
     await localParticipant?.unpublishAllTracks();
 
-    // clean up engine
-    await engine.close();
-
     _activeSpeakers.clear();
+
+    // clean up engine
+    await engine.cleanUp();
+
+    // reset params
+    _name = null;
+    _sid = null;
+    _metadata = null;
+    _serverVersion = null;
+    _serverRegion = null;
   }
 }

lib/src/core/signal_client.dart

@@ -36,8 +36,8 @@ class SignalClient extends Disposable with EventsEmittable<SignalEvent> {
     });
 
     onDispose(() async {
-      await events.dispose();
       await cleanUp();
+      await events.dispose();
     });
   }
 
@@ -106,19 +106,16 @@ class SignalClient extends Disposable with EventsEmittable<SignalEvent> {
     }
   }
 
+  // resets internal state to a re-usable state
   @internal
   Future<void> cleanUp() async {
+    logger.fine('[${objectId}] cleanUp()');
+
     await _ws?.dispose();
     _ws = null;
     _queue.clear();
   }
 
-  @internal
-  Future<void> disconnect() async {
-    logger.fine('SignalClient disconnect');
-    await cleanUp();
-  }
-
   void _sendRequest(
     lk_rtc.SignalRequest req, {
     bool enqueueIfReconnecting = true,