public static PLAYLIST_SONG AddSongToPlaylist(int userID, int playlistID, int songID)
{
var context = DJPlaylistContext.GetContext();
var playlist = context.PLAYLISTS.FirstOrDefault(i => i.ID == playlistID);
if (playlist == null)
{
throw new Exception("Playlist not found");
}
var song = context.SONGS.FirstOrDefault(i => i.ID == songID);
if (song == null)
{
throw new Exception("Song not found");
}
if (playlist.USER.ID != userID)
{
throw new Exception("Only owner can add songs to playlist");
}
var order = playlist.PLAYLIST_SONGS.Any() ? playlist.PLAYLIST_SONGS.Max(i => i.ORDER) + 1 : 1;
var plSong = new PLAYLIST_SONG(playlist, song, order);
context.PLAYLIST_SONGS.Add(plSong);
context.SaveChanges();
return(plSong);
}
private void ShiftSongDown(PLAYLIST_SONG plSong)
{
var songInTargetPosition = PLAYLIST_SONGS.FirstOrDefault(i => i.ORDER == plSong.ORDER + 1);
if (songInTargetPosition != null)
{
MoveSongDown(songInTargetPosition);
}
plSong.ORDER = plSong.ORDER + 1;
}
public void MoveSongUp(PLAYLIST_SONG plSong)
{
if (!PLAYLIST_SONGS.Any(i => i.ORDER < plSong.ORDER))
{
return;
}
var targetPlSong =
PLAYLIST_SONGS.Where(i => i.ORDER < plSong.ORDER).OrderByDescending(k => k.ORDER).FirstOrDefault();
int newPosition = targetPlSong.ORDER;
targetPlSong.ORDER = plSong.ORDER;
plSong.ORDER = newPosition;
}
public void MoveSongDown(PLAYLIST_SONG plSong)
{
if (!PLAYLIST_SONGS.Any(i => i.ORDER > plSong.ORDER))
{
return;
}
var songInTargetPosition = PLAYLIST_SONGS.Where(i => i.ORDER > plSong.ORDER).OrderBy(k => k.ORDER).FirstOrDefault();
var newPosition = songInTargetPosition.ORDER;
songInTargetPosition.ORDER = plSong.ORDER;
plSong.ORDER = newPosition;
}