refact: playlist as str, fix prev and init

src/aura_engine/scheduling/domain.py

@@ -165,6 +165,19 @@ class Playlist:
         item.playlist = self
         self.items.append(item)
 
+    def __str__(self) -> str:
+        """
+        String representation.
+
+        Returns:
+            str: Playlist as String.
+
+        """
+        s = f"ID#{self.id} | {self.get_duration()}seconds"
+        if self.desc:
+            s += f" ({self.desc})"
+        return s
+
 
 Playlists = NamedTuple(
     "Playlists", [("timeslot", Playlist), ("schedule", Playlist), ("show", Playlist)]
@@ -256,7 +269,7 @@ class Timeslot:
         self.end = end
         self.show = show
         self.episode = episode
-        self.playlist = None
+        self.playlist = Playlists(None, None, None)
 
     def get_id(self) -> int:
         """
@@ -478,6 +491,8 @@ class PlaylistItem:
         self.volume = volume
         self.metadata = metadata
 
+        self.play_queue_state = PlaylistItem.QueueState.OKAY
+
     def get_playlist(self) -> Playlist:
         """
         Get the playlist of this item.
@@ -563,7 +578,7 @@ class PlaylistItem:
         prev = self.get_prev()
         if prev:
             all_prev = prev.get_all_prev()
-            all_prev.append(self)
+            all_prev.append(prev)
             return all_prev
         return []