feat: Clear and manage play_next queue on playlist changes

app/services/player.py

@@ -576,6 +576,11 @@ class PlayerService:
             current_id,
         )
 
+        # Clear play_next queue when playlist changes
+        if self.state.play_next_queue:
+            logger.info("Clearing play_next queue due to playlist change")
+            self.state.play_next_queue.clear()
+
         if self.state.status != PlayerStatus.STOPPED:
             await self._stop_playback()
 
@@ -591,6 +596,9 @@ class PlayerService:
         sounds: list[Sound],
     ) -> None:
         """Handle track checking when playlist ID is the same."""
+        # Remove tracks from play_next queue that are no longer in the playlist
+        self._clean_play_next_queue(sounds)
+
         # Find the current track in the new playlist
         new_index = self._find_sound_index(previous_sound_id, sounds)
 
@@ -648,6 +656,29 @@ class PlayerService:
                 return i
         return None
 
+    def _clean_play_next_queue(self, playlist_sounds: list[Sound]) -> None:
+        """Remove tracks from play_next queue that are no longer in the playlist."""
+        if not self.state.play_next_queue:
+            return
+
+        # Get IDs of all sounds in the current playlist
+        playlist_sound_ids = {sound.id for sound in playlist_sounds}
+
+        # Filter out tracks that are no longer in the playlist
+        original_length = len(self.state.play_next_queue)
+        self.state.play_next_queue = [
+            sound
+            for sound in self.state.play_next_queue
+            if sound.id in playlist_sound_ids
+        ]
+
+        removed_count = original_length - len(self.state.play_next_queue)
+        if removed_count > 0:
+            logger.info(
+                "Removed %s track(s) from play_next queue (no longer in playlist)",
+                removed_count,
+            )
+
     def _set_first_track_as_current(self, sounds: list[Sound]) -> None:
         """Set the first track as the current track."""
         self.state.current_sound_index = 0

tests/api/v1/test_player_endpoints.py

@@ -537,6 +537,7 @@ class TestPlayerEndpoints:
                 "duration": 30000,
                 "sounds": [],
             },
+            "play_next_queue": [],
         }
         mock_player_service.get_state.return_value = mock_state