create the lib module

server/app/lib/playlistlib.py

@@ -0,0 +1,24 @@
+from app import api, instances, models
+from app.lib import trackslib
+
+
+def add_track(playlistid: str, trackid: str):
+    """
+    Adds a track to a playlist in the api.PLAYLISTS dict and to the database.
+    """
+    for playlist in api.PLAYLISTS:
+        if playlist.playlistid == playlistid:
+            track = trackslib.get_track_by_id(trackid)
+            playlist.tracks.append(track)
+
+            instances.playlist_instance.add_track_to_playlist(playlistid, track)
+
+
+
+
+def create_all_playlists():
+    """
+    Gets all playlists from the database.
+    """
+    for playlist in instances.playlist_instance.get_all_playlists():
+        api.PLAYLISTS.append(models.Playlist(playlist))