public ActionResult MoveTrackToHistory(long id)
{
var tracks = playlistManager.ReadPlaylist(id).PlaylistTracks;
if (tracks.Count == 0) return new HttpStatusCodeResult(400);
var track = tracks.OrderByDescending(p => p.Votes.Sum(v => v.Score)).First(t => t.PlayedAt == null);
playlistManager.MarkTrackAsPlayed(track.Id, id);
return new HttpStatusCodeResult(200);
}