[server] fix playlist methods

- deepcopy playlists in get_all_playlists

server/app/lib/playlistlib.py

@@ -1,10 +1,13 @@
 """
 This library contains all the functions related to playlists.
 """
+from progress.bar import Bar
+from app import api, instances, models, exceptions, helpers
 
-from app import api, instances, models
 from app.lib import trackslib
 
+TrackExistsInPlaylist = exceptions.TrackExistsInPlaylist
+
 
 def add_track(playlistid: str, trackid: str):
     """
@@ -13,14 +16,23 @@ def add_track(playlistid: str, trackid: str):
     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)
+            if track not in playlist.tracks:
+                playlist.tracks.append(track)
+                instances.playlist_instance.add_track_to_playlist(playlistid, track)
+                return
+            else:
+                raise TrackExistsInPlaylist("Track already in playlist.")
 
 
 def create_all_playlists():
     """
     Gets all playlists from the database.
     """
-    for playlist in instances.playlist_instance.get_all_playlists():
+    playlists = instances.playlist_instance.get_all_playlists()
+
+    _bar = Bar("Creating playlists", max=len(playlists))
+    for playlist in playlists:
         api.PLAYLISTS.append(models.Playlist(playlist))
+        _bar.next()
+    _bar.finish()