From dbfe9927bf79392224ae57a1d8977d97acea9e4a Mon Sep 17 00:00:00 2001
From: Alexander Capehart <alex@oxycblt.org>
Date: Mon, 26 Feb 2024 16:41:31 -0700
Subject: [PATCH] playback: fix broken state restore

That didn't properly handle when the index was invalid and kept stale
song entries.

Resolves #723.
---
 .../service/PlaybackServiceFragment.kt        |  4 +++
 .../playback/state/PlaybackStateHolder.kt     |  3 +++
 .../playback/state/PlaybackStateManager.kt    | 27 +++++++++++--------
 3 files changed, 23 insertions(+), 11 deletions(-)

diff --git a/app/src/main/java/org/oxycblt/auxio/playback/service/PlaybackServiceFragment.kt b/app/src/main/java/org/oxycblt/auxio/playback/service/PlaybackServiceFragment.kt
index f30d1f727..8b06a8a78 100644
--- a/app/src/main/java/org/oxycblt/auxio/playback/service/PlaybackServiceFragment.kt
+++ b/app/src/main/java/org/oxycblt/auxio/playback/service/PlaybackServiceFragment.kt
@@ -470,6 +470,10 @@ constructor(
         ack?.let { playbackManager.ack(this, it) }
     }
 
+    override fun reset() {
+        player.setMediaItems(emptyList())
+    }
+
     // --- PLAYER OVERRIDES ---
 
     override fun onPlayWhenReadyChanged(playWhenReady: Boolean, reason: Int) {
diff --git a/app/src/main/java/org/oxycblt/auxio/playback/state/PlaybackStateHolder.kt b/app/src/main/java/org/oxycblt/auxio/playback/state/PlaybackStateHolder.kt
index 2374a421f..3cf5f44da 100644
--- a/app/src/main/java/org/oxycblt/auxio/playback/state/PlaybackStateHolder.kt
+++ b/app/src/main/java/org/oxycblt/auxio/playback/state/PlaybackStateHolder.kt
@@ -153,6 +153,9 @@ interface PlaybackStateHolder {
      *   ack.
      */
     fun applySavedState(parent: MusicParent?, rawQueue: RawQueue, ack: StateAck.NewPlayback?)
+
+    /** Reset this instance to an empty state. */
+    fun reset()
 }
 
 /**
diff --git a/app/src/main/java/org/oxycblt/auxio/playback/state/PlaybackStateManager.kt b/app/src/main/java/org/oxycblt/auxio/playback/state/PlaybackStateManager.kt
index 6e98c36e3..4dd7bb690 100644
--- a/app/src/main/java/org/oxycblt/auxio/playback/state/PlaybackStateManager.kt
+++ b/app/src/main/java/org/oxycblt/auxio/playback/state/PlaybackStateManager.kt
@@ -717,6 +717,8 @@ class PlaybackStateManagerImpl @Inject constructor() : PlaybackStateManager {
             return
         }
 
+        val stateHolder = stateHolder ?: return
+
         // The heap may not be the same if the song composition changed between state saves/reloads.
         // This also means that we must modify the shuffled mapping as well, in what it points to
         // and it's general composition.
@@ -763,27 +765,30 @@ class PlaybackStateManagerImpl @Inject constructor() : PlaybackStateManager {
             "Queue inconsistency detected: Shuffled mapping indices out of heap bounds"
         }
 
+        if (index < 0) {
+            stateHolder.reset()
+            return
+        }
+
         val rawQueue =
             RawQueue(
                 heap = heap,
                 shuffledMapping = shuffledMapping,
                 heapIndex =
                     if (shuffledMapping.isNotEmpty()) {
-                        shuffledMapping[savedState.index]
+                        shuffledMapping[index]
                     } else {
                         index
                     })
 
-        if (index > -1) {
-            // Valid state where something needs to be played, direct the stateholder to apply
-            // this new state.
-            val oldStateMirror = stateMirror
-            if (oldStateMirror.rawQueue != rawQueue) {
-                logD("Queue changed, must reload player")
-                stateHolder?.playing(false)
-                stateHolder?.applySavedState(parent, rawQueue, StateAck.NewPlayback)
-                stateHolder?.seekTo(savedState.positionMs)
-            }
+        // Valid state where something needs to be played, direct the stateholder to apply
+        // this new state.
+        val oldStateMirror = stateMirror
+        if (oldStateMirror.rawQueue != rawQueue) {
+            logD("Queue changed, must reload player")
+            stateHolder.playing(false)
+            stateHolder.applySavedState(parent, rawQueue, StateAck.NewPlayback)
+            stateHolder.seekTo(savedState.positionMs)
         }
 
         isInitialized = true