From 2b97b81b6ea0cd0ad26c8af7a41fdc8fb51c0d3a Mon Sep 17 00:00:00 2001
From: David Zhao <david@davidzhao.com>
Date: Tue, 26 Oct 2021 13:12:23 -0700
Subject: [PATCH] Fix restartTrack for audio in Safari

On Safari we need to stop the current audio device prior to acquiring the new one. Fixes #63
---
 src/room/events.ts                       |  3 +++
 src/room/participant/LocalParticipant.ts |  2 +-
 src/room/track/LocalAudioTrack.ts        |  5 ++---
 src/room/track/LocalTrack.ts             | 26 ++++++++++++++++--------
 4 files changed, 23 insertions(+), 13 deletions(-)

diff --git a/src/room/events.ts b/src/room/events.ts
index 0479cdc6ea..ca27157035 100644
--- a/src/room/events.ts
+++ b/src/room/events.ts
@@ -104,6 +104,8 @@ export enum RoomEvent {
 
   /**
    * A track was published successfully
+   *
+   * args: ([[LocalTrackPublication]], [[LocalParticipant]])
    */
   LocalTrackPublished = 'localTrackPublished',
 
@@ -188,6 +190,7 @@ export enum TrackEvent {
   Message = 'message',
   Muted = 'muted',
   Unmuted = 'unmuted',
+  Ended = 'ended',
   /** @internal */
   UpdateSettings = 'updateSettings',
   /** @internal */
diff --git a/src/room/participant/LocalParticipant.ts b/src/room/participant/LocalParticipant.ts
index e6202a3931..41acf765d3 100644
--- a/src/room/participant/LocalParticipant.ts
+++ b/src/room/participant/LocalParticipant.ts
@@ -179,7 +179,7 @@ export default class LocalParticipant extends Participant {
     // handle track actions
     track.on(TrackEvent.Muted, this.onTrackMuted);
     track.on(TrackEvent.Unmuted, this.onTrackUnmuted);
-    track.mediaStreamTrack.addEventListener('ended', () => {
+    track.on(TrackEvent.Ended, () => {
       this.unpublishTrack(track);
     });
 
diff --git a/src/room/track/LocalAudioTrack.ts b/src/room/track/LocalAudioTrack.ts
index 998e514468..1611b308d9 100644
--- a/src/room/track/LocalAudioTrack.ts
+++ b/src/room/track/LocalAudioTrack.ts
@@ -18,9 +18,8 @@ export default class LocalAudioTrack extends LocalTrack {
       return;
     }
     this.constraints.deviceId = deviceId;
-    await this.restartTrack();
-    if (this.isMuted) {
-      this.mediaStreamTrack.enabled = false;
+    if (!this.isMuted) {
+      await this.restartTrack();
     }
   }
 
diff --git a/src/room/track/LocalTrack.ts b/src/room/track/LocalTrack.ts
index d9182be902..22d6d3fcbb 100644
--- a/src/room/track/LocalTrack.ts
+++ b/src/room/track/LocalTrack.ts
@@ -15,6 +15,7 @@ export default class LocalTrack extends Track {
   protected constructor(mediaTrack: MediaStreamTrack, kind: Track.Kind,
     name?: string, constraints?: MediaTrackConstraints) {
     super(mediaTrack, kind, name);
+    this.mediaStreamTrack.addEventListener('ended', this.handleEnded);
     this.constraints = constraints ?? mediaTrack.getConstraints();
   }
 
@@ -129,19 +130,22 @@ export default class LocalTrack extends Track {
       streamConstraints.audio = constraints;
     }
 
-    // TODO: for safari, there is a bug that might cause this to be wonky
-    // _workaroundWebKitBug1208516
-    const mediaStream = await navigator.mediaDevices.getUserMedia(streamConstraints);
-    const newTrack = mediaStream.getTracks()[0];
-    log.info('re-acquired MediaStreamTrack');
-
-    // detach and reattach
-    this.mediaStreamTrack.stop();
+    // detach
     this.attachedElements.forEach((el) => {
       detachTrack(this.mediaStreamTrack, el);
     });
+    this.mediaStreamTrack.removeEventListener('ended', this.handleEnded);
+    // on Safari, the old audio track must be stopped before attempting to acquire
+    // the new track, otherwise the new track will stop with
+    // 'A MediaStreamTrack ended due to a capture failure`
+    this.mediaStreamTrack.stop();
+
+    // create new track and attach
+    const mediaStream = await navigator.mediaDevices.getUserMedia(streamConstraints);
+    const newTrack = mediaStream.getTracks()[0];
+    newTrack.addEventListener('ended', this.handleEnded);
+    log.debug('re-acquired MediaStreamTrack');
 
-    newTrack.enabled = this.mediaStreamTrack.enabled;
     await this.sender.replaceTrack(newTrack);
     this.mediaStreamTrack = newTrack;
 
@@ -162,4 +166,8 @@ export default class LocalTrack extends Track {
     this.mediaStreamTrack.enabled = !muted;
     this.emit(muted ? TrackEvent.Muted : TrackEvent.Unmuted, this);
   }
+
+  private handleEnded = () => {
+    this.emit(TrackEvent.Ended);
+  };
 }