/**
  * Hook into post deletion and remove associated episode.
  *
  * @param int $post_id
  */
 public function delete_trashed_episodes($post_id)
 {
     $episode = Model\Episode::find_one_by_post_id($post_id);
     if (!$episode) {
         return;
     }
     if ($media_files = Model\MediaFile::find_all_by_episode_id($episode->id)) {
         foreach ($media_files as $media_file) {
             $media_file->delete();
         }
     }
     $episode->delete();
 }