From 9143c6029ab383e26307b39e3dfd63d49e301929 Mon Sep 17 00:00:00 2001
From: Marcin Macierzanka <mmacierzanka@grzana.dev>
Date: Fri, 11 Sep 2026 01:29:31 +0200
Subject: [PATCH] fix: prevent overwriting saved queue with empty track lists
 in repository and music player

---
 tests/test_music_player.py           | 30 ++++++++++++++++++++++++++++
 tests/test_queue_repository.py       | 16 +++++++++++++++
 zyrarbot/music/music_player.py       | 16 +++++++--------
 zyrarbot/storage/queue_repository.py |  2 ++
 4 files changed, 56 insertions(+), 8 deletions(-)

diff --git a/tests/test_music_player.py b/tests/test_music_player.py
index fa71a18..8cd0da2 100644
--- a/tests/test_music_player.py
+++ b/tests/test_music_player.py
@@ -296,6 +296,36 @@ class MusicPlayerQueueTest(unittest.IsolatedAsyncioTestCase):
         with self.assertRaisesRegex(ValueError, "not connected"):
             await player.restore_queue(GUILD)
 
+    def test_save_queue_does_not_overwrite_with_empty_queue(self):
+        with tempfile.TemporaryDirectory() as directory:
+            player, _ = build_player()
+            player._queues = QueueRepository(directory)
+            saved = [{"id": "saved", "title": "Saved", "plays_left": 2}]
+            player._queues.save(GUILD, saved)
+
+            # Kolejka w stanie odtwarzacza jest pusta
+            player.state(GUILD).queue = []
+            player.save_queue(GUILD)
+
+            # Zapisana wcześniej kolejka powinna pozostać nienaruszona
+            self.assertEqual(player._queues.load(GUILD), saved)
+
+    def test_save_queue_does_not_save_when_all_plays_consumed(self):
+        with tempfile.TemporaryDirectory() as directory:
+            player, _ = build_player()
+            player._queues = QueueRepository(directory)
+            saved = [{"id": "saved", "title": "Saved", "plays_left": 2}]
+            player._queues.save(GUILD, saved)
+
+            # Wszystkie utwory w kolejce mają plays_left = 0
+            track = FakeTrack("consumed")
+            track.plays_left = 0
+            player.state(GUILD).queue = [track]
+            player.save_queue(GUILD)
+
+            # Zapisana wcześniej kolejka powinna pozostać nienaruszona
+            self.assertEqual(player._queues.load(GUILD), saved)
+
 
 class LoopModeTest(unittest.TestCase):
     def test_cycle_order(self):
diff --git a/tests/test_queue_repository.py b/tests/test_queue_repository.py
index 2fa3227..f1a36a1 100644
--- a/tests/test_queue_repository.py
+++ b/tests/test_queue_repository.py
@@ -20,6 +20,22 @@ class QueueRepositoryTest(unittest.TestCase):
             self.assertTrue((Path(directory) / "10.json").exists())
             self.assertTrue((Path(directory) / "20.json").exists())
 
+    def test_save_empty_tracks_does_nothing(self):
+        with tempfile.TemporaryDirectory() as directory:
+            repository = QueueRepository(directory)
+            tracks = [{"id": "first", "title": "First", "plays_left": 2}]
+
+            repository.save(10, tracks)
+            self.assertEqual(repository.load(10), tracks)
+
+            # Próba zapisania pustej listy nie powinna nadpisać poprzedniej
+            repository.save(10, [])
+            self.assertEqual(repository.load(10), tracks)
+
+            # Zapis pustej kolejki dla nowego serwera nie powinien tworzyć pliku
+            repository.save(20, [])
+            self.assertFalse(repository.exists(20))
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/zyrarbot/music/music_player.py b/zyrarbot/music/music_player.py
index 319e025..4f1bbf2 100644
--- a/zyrarbot/music/music_player.py
+++ b/zyrarbot/music/music_player.py
@@ -111,14 +111,14 @@ class MusicPlayer:
         if not self._queues:
             return
         state = self.state(guild_id)
-        self._queues.save(
-            guild_id,
-            [
-                self._track_snapshot(track)
-                for track in state.queue
-                if self.plays_left(track, guild_id) > 0
-            ],
-        )
+        tracks = [
+            self._track_snapshot(track)
+            for track in state.queue
+            if self.plays_left(track, guild_id) > 0
+        ]
+        if not tracks:
+            return
+        self._queues.save(guild_id, tracks)
 
     def finish_current(self, guild_id: int) -> None:
         """Consume one play when playback ends outside the regular callback."""
diff --git a/zyrarbot/storage/queue_repository.py b/zyrarbot/storage/queue_repository.py
index d51592b..84067ee 100644
--- a/zyrarbot/storage/queue_repository.py
+++ b/zyrarbot/storage/queue_repository.py
@@ -21,6 +21,8 @@ class QueueRepository:
         return self._stores[guild_id]
 
     def save(self, guild_id: int, tracks: list[dict[str, Any]]) -> None:
+        if not tracks:
+            return
         self._store(guild_id).set("tracks", tracks)
 
     def load(self, guild_id: int) -> list[dict[str, Any]]: