same for background mode

app/src/main/java/com/github/libretube/Globals.kt

@@ -18,5 +18,5 @@ object Globals {
     var SELECTED_PLAYLIST_ID: String? = null
 
     // history of played videos in the current lifecycle
-    val videoIds = mutableListOf<String>()
+    val playingQueue = mutableListOf<String>()
 }

app/src/main/java/com/github/libretube/dialogs/VideoOptionsDialog.kt

@@ -83,7 +83,7 @@ class VideoOptionsDialog(
                         shareDialog.show(parentFragmentManager, ShareDialog::class.java.name)
                     }
                     context?.getString(R.string.add_to_queue) -> {
-                        Globals.videoIds += videoId
+                        Globals.playingQueue += videoId
                     }
                 }
             }

app/src/main/java/com/github/libretube/fragments/PlayerFragment.kt

@@ -201,6 +201,9 @@ class PlayerFragment : BaseFragment() {
         super.onViewCreated(view, savedInstanceState)
         context?.hideKeyboard(view)
 
+        // clear the playing queue
+        Globals.playingQueue.clear()
+
         setUserPrefs()
 
         if (autoplayEnabled) playerBinding.autoplayIV.setImageResource(R.drawable.ic_toggle_on)
@@ -748,7 +751,7 @@ class PlayerFragment : BaseFragment() {
                     }
                 }
             }
-            Globals.videoIds += videoId!!
+            Globals.playingQueue += videoId!!
         }
         run()
     }
@@ -1053,13 +1056,13 @@ class PlayerFragment : BaseFragment() {
 
         // next and previous buttons
         playerBinding.skipPrev.visibility = if (
-            skipButtonsEnabled && Globals.videoIds.indexOf(videoId!!) != 0
+            skipButtonsEnabled && Globals.playingQueue.indexOf(videoId!!) != 0
         ) View.VISIBLE else View.INVISIBLE
         playerBinding.skipNext.visibility = if (skipButtonsEnabled) View.VISIBLE else View.INVISIBLE
 
         playerBinding.skipPrev.setOnClickListener {
-            val index = Globals.videoIds.indexOf(videoId!!) - 1
+            val index = Globals.playingQueue.indexOf(videoId!!) - 1
-            videoId = Globals.videoIds[index]
+            videoId = Globals.playingQueue[index]
             playVideo()
         }
 

app/src/main/java/com/github/libretube/services/BackgroundMode.kt

@@ -12,6 +12,7 @@ import android.os.Looper
 import android.widget.Toast
 import com.fasterxml.jackson.databind.ObjectMapper
 import com.github.libretube.BACKGROUND_CHANNEL_ID
+import com.github.libretube.Globals
 import com.github.libretube.PLAYER_NOTIFICATION_ID
 import com.github.libretube.R
 import com.github.libretube.obj.Segment
@@ -78,7 +79,7 @@ class BackgroundMode : Service() {
     /**
      * The [videoId] of the next stream for autoplay
      */
-    private lateinit var nextStreamId: String
+    private var nextStreamId: String? = null
 
     /**
      * Helper for finding the next video in the playlist
@@ -111,6 +112,9 @@ class BackgroundMode : Service() {
      */
     override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
         try {
+            // clear the playing queue
+            Globals.playingQueue.clear()
+
             // get the intent arguments
             videoId = intent?.getStringExtra("videoId")!!
             playlistId = intent.getStringExtra("playlistId")
@@ -135,6 +139,8 @@ class BackgroundMode : Service() {
         videoId: String,
         seekToPosition: Long = 0
     ) {
+        // append the video to the playing queue
+        Globals.playingQueue += videoId
         runBlocking {
             val job = launch {
                 streams = RetrofitInstance.api.getStreams(videoId)
@@ -217,8 +223,7 @@ class BackgroundMode : Service() {
         if (!this::autoPlayHelper.isInitialized) autoPlayHelper = AutoPlayHelper(playlistId!!)
         // search for the next videoId in the playlist
         CoroutineScope(Dispatchers.IO).launch {
-            val nextId = autoPlayHelper.getNextVideoId(videoId)
+            nextStreamId = autoPlayHelper.getNextVideoId(videoId, streams!!.relatedStreams!!)
-            if (nextId != null) nextStreamId = nextId
         }
     }
 
@@ -226,10 +231,10 @@ class BackgroundMode : Service() {
      * Plays the first related video to the current (used when the playback of the current video ended)
      */
     private fun playNextVideo() {
-        if (!this::nextStreamId.isInitialized || nextStreamId == videoId) return
+        if (nextStreamId == null || nextStreamId == videoId) return
 
         // play new video on background
-        this.videoId = nextStreamId
+        this.videoId = nextStreamId!!
         this.segmentData = null
         playAudio(videoId)
     }

app/src/main/java/com/github/libretube/util/AutoPlayHelper.kt

@@ -17,9 +17,9 @@ class AutoPlayHelper(
         currentVideoId: String,
         relatedStreams: List<StreamItem>
     ): String? {
-        val currentVideoIndex = Globals.videoIds.indexOf(currentVideoId)
+        val currentVideoIndex = Globals.playingQueue.indexOf(currentVideoId)
-        return if (Globals.videoIds.size > currentVideoIndex + 1) {
+        return if (Globals.playingQueue.size > currentVideoIndex + 1) {
-            Globals.videoIds[currentVideoIndex + 1]
+            Globals.playingQueue[currentVideoIndex + 1]
         } else if (playlistId == null) getNextTrendingVideoId(
             currentVideoId,
             relatedStreams
@@ -36,8 +36,8 @@ class AutoPlayHelper(
         var nextStreamId: String? = null
         while (nextStreamId == null ||
             (
-                Globals.videoIds.contains(nextStreamId) &&
+                Globals.playingQueue.contains(nextStreamId) &&
-                    Globals.videoIds.indexOf(videoId) > Globals.videoIds.indexOf(
+                    Globals.playingQueue.indexOf(videoId) > Globals.playingQueue.indexOf(
                         nextStreamId
                     )
                 )