public async Task<IEnumerable<SongModel>> GetSongsFromPlaylist(PlaylistModel playlist)
{
var mappings =
await _db.Table<PlaylistMapping>().Where(mapping => mapping.PlayListId == playlist.Id).ToListAsync();
HashSet<int> songIds = new HashSet<int>(mappings.Select(m => m.SongId));
return await _db.Table<SongModel>().Where(song => songIds.Contains(song.Id)).ToListAsync();
}
public async Task DeletePlaylist(PlaylistModel target)
{
var toDeleteMappings =
await _db.Table<PlaylistMapping>().Where(mapping => mapping.PlayListId == target.Id).ToListAsync();
foreach (var mapping in toDeleteMappings)
{
await _db.DeleteAsync(mapping);
}
await _db.DeleteAsync(target);
}
public async Task AddSongsToPlaylist(PlaylistModel target, IEnumerable<SongModel> songs)
{
var songsList = songs.ToList();
foreach (var song in songsList)
{
await _db.InsertAsync(new PlaylistMapping(target.Id, song.Id));
}
target.SongsCount += songsList.Count;
double newDuration = ParsePlaylistDuration(target.PlayTime).TotalSeconds +
(songsList.Sum(song => ParseSongDuration(song.Duration).TotalSeconds));
target.PlayTime = TimeSpan.FromSeconds(newDuration).ToPlaylistDuration();
}
public async Task CreateNewPlaylistAsync(string name, IEnumerable<SongModel> songs)
{
PlaylistModel newPlaylist = new PlaylistModel() { Name = name };
var songList = songs.ToList();
double totalLength = songList.Sum(song => ParseSongDuration(song.Duration).TotalSeconds);
newPlaylist.SongsCount = songList.Count;
newPlaylist.PlayTime = TimeSpan.FromSeconds(totalLength).ToPlaylistDuration();
await _db.InsertAsync(newPlaylist);
await AddSongsToPlaylist(newPlaylist, songList);
}