refactor: extract renegotiation logic into RenegotiationHandler

Author: SERDUN

lib/features/call/bloc/call_bloc.dart

@@ -95,6 +95,7 @@ class CallBloc extends Bloc<CallEvent, CallState> with WidgetsBindingObserver im
   Timer? _presenceInfoSyncTimer;
 
   late final PeerConnectionManager _peerConnectionManager;
+  late final RenegotiationHandler _renegotiationHandler;
 
   final _callkeepSound = WebtritCallkeepSound();
 
@@ -129,6 +130,7 @@ class CallBloc extends Bloc<CallEvent, CallState> with WidgetsBindingObserver im
   }) : super(const CallState()) {
     _signalingClientFactory = signalingClientFactory;
     _peerConnectionManager = peerConnectionManager;
+    _renegotiationHandler = RenegotiationHandler(callErrorReporter: callErrorReporter, sdpMunger: sdpMunger);
 
     on<CallStarted>(_onCallStarted, transformer: sequential());
     on<_AppLifecycleStateChanged>(_onAppLifecycleStateChanged, transformer: sequential());
@@ -2782,45 +2784,19 @@ class CallBloc extends Bloc<CallEvent, CallState> with WidgetsBindingObserver im
         onIceCandidate: (candidate) => add(_PeerConnectionEvent.iceCandidateIdentified(callId, candidate)),
         onAddStream: (stream) => add(_PeerConnectionEvent.streamAdded(callId, stream)),
         onRemoveStream: (stream) => add(_PeerConnectionEvent.streamRemoved(callId, stream)),
-        onRenegotiationNeeded: (pc) => _handleRenegotiationNeeded(callId, lineId, pc),
+        onRenegotiationNeeded: (pc) => _renegotiationHandler.handle(callId, lineId, pc, (callId, lineId, jsep) async {
+          final updateRequest = UpdateRequest(
+            transaction: WebtritSignalingClient.generateTransactionId(),
+            line: lineId,
+            callId: callId,
+            jsep: jsep.toMap(),
+          );
+          await _signalingClient?.execute(updateRequest);
+        }),
       ),
     );
   }
 
-  Future<void> _handleRenegotiationNeeded(String callId, int? lineId, RTCPeerConnection peerConnection) async {
-    final stateBeforeOffer = peerConnection.signalingState;
-    _logger.fine(() => 'onRenegotiationNeeded signalingState: $stateBeforeOffer');
-    if (stateBeforeOffer == RTCSignalingState.RTCSignalingStateStable) {
-      final localDescription = await peerConnection.createOffer({});
-      sdpMunger?.apply(localDescription);
-
-      final stateAfterOffer = peerConnection.signalingState;
-      if (stateAfterOffer != RTCSignalingState.RTCSignalingStateStable) {
-        _logger.fine(
-          () =>
-              'onRenegotiationNeeded: state changed to $stateAfterOffer after createOffer, skipping setLocalDescription',
-        );
-        return;
-      }
-
-      // According to RFC 8829 5.6 (https://datatracker.ietf.org/doc/html/rfc8829#section-5.6),
-      // localDescription should be set before sending the offer to transition into have-local-offer state.
-      await peerConnection.setLocalDescription(localDescription);
-
-      try {
-        final updateRequest = UpdateRequest(
-          transaction: WebtritSignalingClient.generateTransactionId(),
-          line: lineId,
-          callId: callId,
-          jsep: localDescription.toMap(),
-        );
-        await _signalingClient?.execute(updateRequest);
-      } catch (e, s) {
-        callErrorReporter.handle(e, s, '_createPeerConnection:onRenegotiationNeeded error');
-      }
-    }
-  }
-
   void _addToRecents(ActiveCall activeCall) {
     final number = activeCall.handle.value;
     final username = activeCall.displayName;

lib/features/call/utils/renegotiation_handler.dart

@@ -0,0 +1,49 @@
+import 'package:flutter_webrtc/flutter_webrtc.dart';
+import 'package:logging/logging.dart';
+
+import 'call_error_reporter.dart';
+import 'sdp_munger.dart';
+
+final _logger = Logger('RenegotiationHandler');
+
+typedef RenegotiationExecutor = Future<void> Function(String callId, int? lineId, RTCSessionDescription jsep);
+
+class RenegotiationHandler {
+  RenegotiationHandler({required this.callErrorReporter, this.sdpMunger});
+
+  final CallErrorReporter callErrorReporter;
+  final SDPMunger? sdpMunger;
+
+  Future<void> handle(
+    String callId,
+    int? lineId,
+    RTCPeerConnection peerConnection,
+    RenegotiationExecutor execute,
+  ) async {
+    final stateBeforeOffer = peerConnection.signalingState;
+    _logger.fine(() => 'onRenegotiationNeeded signalingState: $stateBeforeOffer');
+    if (stateBeforeOffer == RTCSignalingState.RTCSignalingStateStable) {
+      final localDescription = await peerConnection.createOffer({});
+      sdpMunger?.apply(localDescription);
+
+      final stateAfterOffer = peerConnection.signalingState;
+      if (stateAfterOffer != RTCSignalingState.RTCSignalingStateStable) {
+        _logger.fine(
+          () =>
+              'onRenegotiationNeeded: state changed to $stateAfterOffer after createOffer, skipping setLocalDescription',
+        );
+        return;
+      }
+
+      // According to RFC 8829 5.6 (https://datatracker.ietf.org/doc/html/rfc8829#section-5.6),
+      // localDescription should be set before sending the offer to transition into have-local-offer state.
+      await peerConnection.setLocalDescription(localDescription);
+
+      try {
+        await execute(callId, lineId, localDescription);
+      } catch (e, s) {
+        callErrorReporter.handle(e, s, '_createPeerConnection:onRenegotiationNeeded error');
+      }
+    }
+  }
+}

lib/features/call/utils/utils.dart

@@ -7,6 +7,7 @@ export 'ice_filter.dart';
 export 'logging_rtp_traffic_monitor_delegate.dart';
 export 'peer_connection_factory.dart';
 export 'peer_connection_manager.dart';
+export 'renegotiation_handler.dart';
 export 'peer_connection_policy_applier.dart';
 export 'rtp_traffic_monitor.dart';
 export 'sdp_mod_builder.dart';