Fix bug where a new Tidal playlist was created everytime sync.py run with --uri argument

I was passing (playlist, None) in the case where the --uri argument was used,
and None means create a new playlist.

I've fixed it to look for the Tidal playlist if it exists like the other
code paths do, and only pass None when it doesn't exist.

Unfortunately this will mean that your Tidal collection might have been polluted with
duplicate playlists. I've added a delete playlist function to tidalapi_patch to help
with deleting these programmatically, which some people might find useful.

Fixes #8

sync.py

@@ -98,7 +98,10 @@ def tidal_search(spotify_track_and_cache, tidal_session):
 def get_tidal_playlists_dict(tidal_session):
     # a dictionary of name --> playlist
     tidal_playlists = tidal_session.get_user_playlists(tidal_session.user.id)
-    return {playlist.name: playlist for playlist in tidal_playlists}
+    output = {}
+    for playlist in tidal_playlists:
+        output[playlist.name] = playlist
+    return output 
 
 def repeat_on_exception(function, *args, remaining=5, **kwargs):
     # utility to repeat calling the function up to 5 times if an exception is thrown
@@ -222,17 +225,22 @@ def sync_list(spotify_session, tidal_session, playlists, config):
     results.append(tidal_id)
   return results
 
+def pick_tidal_playlist_for_spotify_playlist(spotify_playlist, tidal_playlists):
+    if spotify_playlist['name'] in tidal_playlists:
+      # if there's an existing tidal playlist with the name of the current playlist then use that
+      tidal_playlist = tidal_playlists[spotify_playlist['name']]
+      return (spotify_playlist['id'], tidal_playlist.id)
+    else:
+      print(f"No playlist found on Tidal corresponding to Spotify playlist: '{spotify_playlist['name']}', creating new playlist")
+      return (spotify_playlist['id'], None)
+    
+
 def get_user_playlist_mappings(spotify_session, tidal_session, config):
   results = []
   spotify_playlists = get_playlists_from_spotify(spotify_session, config)
   tidal_playlists = get_tidal_playlists_dict(tidal_session)
   for spotify_playlist in spotify_playlists:
-    if spotify_playlist['name'] in tidal_playlists:
-      # if there's an existing tidal playlist with the name of the current playlist then use that
-      tidal_playlist = tidal_playlists[spotify_playlist['name']]
-      results.append((spotify_playlist['id'], tidal_playlist.id))
-    else:
-      results.append((spotify_playlist['id'], None))
+      results.append( pick_tidal_playlist_for_spotify_playlist(spotify_playlist, tidal_playlists) )
   return results
 
 def get_playlists_from_spotify(spotify_session, config):
@@ -269,7 +277,9 @@ if __name__ == '__main__':
         sys.exit("Could not connect to Tidal")
     if args.uri:
         # if a playlist ID is explicitly provided as a command line argument then use that
-        sync_list(spotify_session, tidal_session, [(args.uri, None)], config)
+        tidal_playlists = get_tidal_playlists_dict(tidal_session)
+        tidal_playlist = pick_tidal_playlist_for_spotify_playlist(spotify_playlist, tidal_playlists)
+        sync_list(spotify_session, tidal_session, [tidal_playlist], config)
     elif config.get('sync_playlists', None):
         # if the config contains a sync_playlists list of mappings then use that
         sync_list(spotify_session, tidal_session, get_playlists_from_config(config), config)

tidalapi_patch.py

@@ -70,4 +70,7 @@ def create_tidal_playlist(session, name):
     result = session.request('POST','users/%s/playlists' % session.user.id ,data={'title': name})
     return session.get_playlist(result.json()['uuid'])
 
-
+def delete_tidal_playlist(session, playlist):
+    etag = session.request('GET','playlists/%s' % playlist.id).headers['ETag']
+    headers = {'if-none-match' : etag}
+    session.request('DELETE','playlists/%s' % playlist.id, headers=headers)