graph TB
  entrypoint[A new track is added]-->check_album_name
  check_album_name{{Check its album name}}-- If empty -->unknown_albums["Handle unknown albums"]
  check_album_name-- If provided -->if_not_empty
  if_not_empty{{Is the new track in the same folder and with the same title as the previously analyzed track?}} -- Yes -->return_last_candidate[Return the previously selected album]
  if_not_empty-- No -->get_candidates
  get_candidates[Fetch all album with the same title]-->for_each["Album selection mainloop"]

graph TB
  if_empty{{"Is there an album artist provided for this track?"}}-- Yes -->use_album_artist_unknown_album["Use the 
album artist's unknown album"]
  if_empty-- No -->check_track_artist_unknown_album
  check_track_artist_unknown_album["Is there an artist provided for this track?"]-- Yes -->use_track_artist_unknown_album["Use the track artist's unknown album"]
  check_track_artist_unknown_album-- No -->use_unknown["Use unknown artist's unknown album"]

graph TB
  for_each[For each album candidate]-->check_new_track_album_artist
  check_new_track_album_artist[Does the new track have an album artist]-- Yes --> compare_album_artist
  compare_album_artist["Does the album artist differ from the candidate album?"]-- Yes -->discard_candidate
  compare_album_artist-- No -->check_multi_disc
  check_new_track_album_artist-- No -->check_multi_disc
  check_multi_disc["Is the album tagged as multi disc?"] -- No -->check_different_folder
  check_multi_disc -- Yes --> accept_candidate
  check_different_folder["Is the new track in the same folder as the candidate album?"]-- Yes -->accept_candidate
  check_different_folder-- No -->check_multi_artists
  check_multi_artists["Are there multiple artists in the candidate album?"]-- No -->check_date
  check_multi_artists-- Yes -->discard_candidate
  check_date["Are all of the candidate album tracks released on the same date?"]-- Yes -->accept_candidate
  check_date-- No -->discard_candidate
  discard_candidate[Discard this candidate]
  accept_candidate[Accept this candidate]

graph LR
  candidate_list[Remaining candidates after filtering]-->choose_candidate
  choose_candidate{{"How many candidates are there left?"}}-- 0 -->create_album["Create a new album"]
  choose_candidate-- 1 -->select_candidate["Select that candidate"]
  choose_candidate-- 2+ -->select_first_candidate["Warn and select the 1st candidate"]