fix: make audio player safe with other app audio/music session

Mastodon/Scene/Share/ViewModel/VideoPlayerViewModel.swift

@@ -69,7 +69,8 @@ final class VideoPlayerViewModel {
                 case .gif:
                     break
                 case .video:
-                    try? AVAudioSession.sharedInstance().setCategory(.soloAmbient, mode: .default)
+                    break
+//                    try? AVAudioSession.sharedInstance().setCategory(.soloAmbient, mode: .default)
                 }
             }
             .store(in: &disposeBag)
@@ -107,7 +108,8 @@ extension VideoPlayerViewModel {
         case .gif:
             break
         case .video:
-            try? AVAudioSession.sharedInstance().setCategory(.soloAmbient, mode: .default)
+            break
+//            try? AVAudioSession.sharedInstance().setCategory(.soloAmbient, mode: .default)
         }
 
         player.play()

Mastodon/Service/AudioPlaybackService.swift

@@ -23,7 +23,6 @@ final class AudioPlaybackService: NSObject {
     var statusObserver: Any?
     var attachment: Attachment?
 
-    let session = AVAudioSession.sharedInstance()
     let playbackState = CurrentValueSubject<PlaybackState, Never>(PlaybackState.unknown)
 
     let currentTimeSubject = CurrentValueSubject<TimeInterval, Never>(0)
@@ -31,6 +30,23 @@ final class AudioPlaybackService: NSObject {
     override init() {
         super.init()
         addObserver()
+
+        playbackState
+            .receive(on: RunLoop.main)
+            .sink { status in
+                os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s: audio status: %s", ((#file as NSString).lastPathComponent), #line, #function, status.description)
+                switch status {
+                case .unknown, .buffering, .readyToPlay:
+                    break
+                case .playing:
+                    try? AVAudioSession.sharedInstance().setCategory(.soloAmbient)
+                    try? AVAudioSession.sharedInstance().setActive(true)
+                case .paused, .stopped, .failed:
+                    try? AVAudioSession.sharedInstance().setCategory(.ambient)
+                    try? AVAudioSession.sharedInstance().setActive(false, options: .notifyOthersOnDeactivation)
+                }
+            }
+            .store(in: &disposeBag)
     }
 }
 
@@ -39,12 +55,6 @@ extension AudioPlaybackService {
         guard let url = URL(string: audioAttachment.url) else {
             return
         }
-        do {
-            try session.setCategory(.playback)
-        } catch {
-            print(error)
-            return
-        }
 
         notifyWillPlayAudioNotification()
         if audioAttachment == attachment {
@@ -64,27 +74,6 @@ extension AudioPlaybackService {
     }
 
     func addObserver() {
-        UIDevice.current.isProximityMonitoringEnabled = true
-        NotificationCenter.default.publisher(for: UIDevice.proximityStateDidChangeNotification, object: nil)
-            .sink { [weak self] _ in
-                guard let self = self else { return }
-                if UIDevice.current.proximityState == true {
-                    do {
-                        try self.session.setCategory(.playAndRecord)
-                    } catch {
-                        print(error)
-                        return
-                    }
-                } else {
-                    do {
-                        try self.session.setCategory(.playback)
-                    } catch {
-                        print(error)
-                        return
-                    }
-                }
-            }
-            .store(in: &disposeBag)
         NotificationCenter.default.publisher(for: VideoPlayerViewModel.appWillPlayVideoNotification)
             .sink { [weak self] _ in
                 guard let self = self else { return }
@@ -96,7 +85,7 @@ extension AudioPlaybackService {
             guard let self = self else { return }
             self.currentTimeSubject.value = time.seconds
         })
-        player.publisher(for: \.status, options: .new)
+        player.publisher(for: \.status, options: [.initial, .new])
             .sink(receiveValue: { [weak self] status in
                 guard let self = self else { return }
                 switch status {

Mastodon/Service/PlaybackState.swift

@@ -23,3 +23,21 @@ public enum PlaybackState : Int {
 
     case failed = 6
 }
+
+// MARK: - CustomStringConvertible
+extension PlaybackState: CustomStringConvertible {
+    public var description: String {
+        switch self {
+        case .unknown: return "unknown"
+        case .buffering: return "buffering"
+        case .readyToPlay: return "readyToPlay"
+        case .playing: return "playing"
+        case .paused: return "paused"
+        case .stopped: return "stopped"
+        case .failed: return "failed"
+        default:
+            assertionFailure()
+            return "<nil>"
+        }
+    }
+}

Mastodon/Service/VideoPlaybackService.swift

@@ -40,7 +40,7 @@ extension VideoPlaybackService {
             } else {
                 if latestPlayingVideoPlayerViewModel === playerViewModel {
                     latestPlayingVideoPlayerViewModel = nil
-                    try? AVAudioSession.sharedInstance().setCategory(.soloAmbient, mode: .default)
+//                    try? AVAudioSession.sharedInstance().setCategory(.soloAmbient, mode: .default)
                 }
             }
         }
@@ -111,7 +111,7 @@ extension VideoPlaybackService {
         os_log(.info, log: .debug, "%{public}s[%{public}ld], %{public}s", (#file as NSString).lastPathComponent, #line, #function)
         
         // note: do not retain view controller
-        // pause all player when view disppear exclude full screen player and other transitioning scene
+        // pause all player when view disappear exclude full screen player and other transitioning scene
         for viewModel in viewPlayerViewModelDict.values {
             guard !viewModel.isTransitioning else {
                 viewModel.isTransitioning = false