From bf46c46fc09509e94845a5a1a6fde92dd7b2052d Mon Sep 17 00:00:00 2001
From: ronaldheft <ron@ronaldheft.com>
Date: Thu, 18 Aug 2022 19:31:32 -0400
Subject: [PATCH] Fix race conditions on first launch

---
 ios/App/App/plugins/AbsAudioPlayer.swift | 15 +++++++++++----
 ios/App/App/plugins/AbsDatabase.swift    |  4 ++++
 ios/App/Shared/player/AudioPlayer.swift  |  6 ++++++
 ios/App/Shared/util/PlayerEvents.swift   |  1 +
 4 files changed, 22 insertions(+), 4 deletions(-)

diff --git a/ios/App/App/plugins/AbsAudioPlayer.swift b/ios/App/App/plugins/AbsAudioPlayer.swift
index 814f39a6..9ffa975e 100644
--- a/ios/App/App/plugins/AbsAudioPlayer.swift
+++ b/ios/App/App/plugins/AbsAudioPlayer.swift
@@ -12,6 +12,7 @@ import RealmSwift
 @objc(AbsAudioPlayer)
 public class AbsAudioPlayer: CAPPlugin {
     private var initialPlayWhenReady = false
+    private var isUIReady = false
     
     override public func load() {
         NotificationCenter.default.addObserver(self, selector: #selector(sendMetadata), name: NSNotification.Name(PlayerEvents.update.rawValue), object: nil)
@@ -22,15 +23,21 @@ public class AbsAudioPlayer: CAPPlugin {
         NotificationCenter.default.addObserver(self, selector: #selector(sendSleepTimerEnded), name: NSNotification.Name(PlayerEvents.sleepEnded.rawValue), object: nil)
         NotificationCenter.default.addObserver(self, selector: #selector(onPlaybackFailed), name: NSNotification.Name(PlayerEvents.failed.rawValue), object: nil)
         NotificationCenter.default.addObserver(self, selector: #selector(onLocalMediaProgressUpdate), name: NSNotification.Name(PlayerEvents.localProgress.rawValue), object: nil)
-        
-        // Restore the playack session when plugin loads
-        Timer.scheduledTimer(timeInterval: 1, target: self, selector: #selector(restorePlaybackSession), userInfo: nil, repeats: false)
+        NotificationCenter.default.addObserver(self, selector: #selector(userInterfaceReady), name: NSNotification.Name(PlayerEvents.playerUserInterfaceReady.rawValue), object: nil)
         
         self.bridge?.webView?.allowsBackForwardNavigationGestures = true;
         
     }
     
-    @objc func restorePlaybackSession() {
+    @objc func userInterfaceReady() {
+        if !self.isUIReady {
+            NSLog("User interface is ready. Performing state restore...")
+            self.restorePlaybackSession()
+            self.isUIReady = true
+        }
+    }
+    
+    func restorePlaybackSession() {
         // We don't need to restore if we have an active session
         guard PlayerHandler.getPlaybackSession() == nil else { return }
         
diff --git a/ios/App/App/plugins/AbsDatabase.swift b/ios/App/App/plugins/AbsDatabase.swift
index a78619df..4c5cf2a4 100644
--- a/ios/App/App/plugins/AbsDatabase.swift
+++ b/ios/App/App/plugins/AbsDatabase.swift
@@ -155,6 +155,10 @@ public class AbsDatabase: CAPPlugin {
                 call.reject("Failed to report synced media progress")
             }
         }
+        
+        // If we're syncing progress with the server, we also have the UI ready
+        // This will restore the player to the last playback session
+        NotificationCenter.default.post(name: NSNotification.Name(PlayerEvents.playerUserInterfaceReady.rawValue), object: nil)
     }
     
     @objc func syncServerMediaProgressWithLocalMediaProgress(_ call: CAPPluginCall) {
diff --git a/ios/App/Shared/player/AudioPlayer.swift b/ios/App/Shared/player/AudioPlayer.swift
index 3ba2da62..857fa140 100644
--- a/ios/App/Shared/player/AudioPlayer.swift
+++ b/ios/App/Shared/player/AudioPlayer.swift
@@ -261,6 +261,12 @@ class AudioPlayer: NSObject {
     }
     
     public func setPlaybackRate(_ rate: Float, observed: Bool = false) {
+        // Handle a race condition on first launch
+        guard self.status != -1 else {
+            NSLog("Did not set playback rate as player is not initialized")
+            return
+        }
+        
         if self.audioPlayer.rate != rate {
             NSLog("setPlaybakRate rate changed from \(self.audioPlayer.rate) to \(rate)")
             self.audioPlayer.rate = rate
diff --git a/ios/App/Shared/util/PlayerEvents.swift b/ios/App/Shared/util/PlayerEvents.swift
index 4b225a9e..d8bfa0d1 100644
--- a/ios/App/Shared/util/PlayerEvents.swift
+++ b/ios/App/Shared/util/PlayerEvents.swift
@@ -14,4 +14,5 @@ enum PlayerEvents: String {
     case sleepEnded = "com.audiobookshelf.app.player.sleep.ended"
     case failed = "com.audiobookshelf.app.player.failed"
     case localProgress = "com.audiobookshelf.app.player.localProgress"
+    case playerUserInterfaceReady = "com.audiobookshelf.app.player.playerUserInterfaceReady"
 }