private static ICollection <TrackPlaylist> ArrangePlaylist(PlaylistConfigDTO playlistConfigDTO, ICollection <TrackPlaylist> trackPlaylist)
{
if (playlistConfigDTO.UseTopTracks)
{
trackPlaylist = trackPlaylist.OrderBy(t => t.Track.Rank).ToList();
}
else
{
trackPlaylist = trackPlaylist.OrderByDescending(t => t.Track.Rank).ToList();
}
return(trackPlaylist);
}
private async Task <IReadOnlyCollection <Track> > RandomTracksByGenreConfig(PlaylistConfigDTO playlistConfigDTO, string genreName)
{
var genreNames = playlistConfigDTO.GenreConfigs
.Where(g => g.IsChecked == true)
.Select(g => g.Name);
var tracks = await _appDbContext.Tracks
.AsNoTracking()
.Where(t => t.IsDeleted == false)
.Include(g => g.Genre)
.Where(t => genreNames.Contains(t.Genre.Name) && t.Genre.Name.Equals(genreName))
.OrderBy(t => Guid.NewGuid())
.ToListAsync();
return(tracks);
}
public async Task <PlaylistDTO> GeneratePlaylist(string from, string to, PlaylistConfigDTO playlistConfigDTO, Guid userId)
{
var travelDuration = await GetTravelDurationAsync(from, to);
if (travelDuration <= 0 || playlistConfigDTO == null)
{
return(null);
}
int totalDuration = 0;
var genres = playlistConfigDTO.GenreConfigs
.Where(x => x.IsChecked == true); // Get only checked genres
int genresCount = genres.Count();
if (genresCount <= 0)
{
return(null);
}
int avgMinPerGenre = 300 / genresCount; // Get Average additional minute per genre ( 5min MAX )
//Initialize playlist
var playlist = new Playlist()
{
CreatedOn = DateTime.Now,
Title = playlistConfigDTO.Title,
UserId = userId,
};
ICollection <TrackPlaylist> trackPlaylist = new List <TrackPlaylist>();
foreach (var genre in genres)
{
int durationPerGenre = 0;
int genreDuration = 0;
var genreTracks = await RandomTracksByGenreConfig(playlistConfigDTO, genre.Name);
if (genre.Percentage <= 0 && playlistConfigDTO.IsAdvanced == false)
{
double genrePercent = 100 / genresCount;
durationPerGenre = (int)Math.Floor(travelDuration * genrePercent) / 100;
}
else
{
durationPerGenre = (travelDuration * genre.Percentage) / 100;
}
int count = 0;
while (true)
{
if (count >= genreTracks.Count())
{
break;
}
//Gets Element at index
var track = genreTracks.ElementAt(count);
//Break if next track will surpass Max duation per genre
if (genreDuration + track.Duration > durationPerGenre + avgMinPerGenre)
{
break;
}
totalDuration += track.Duration;
genreDuration += track.Duration;
trackPlaylist.Add(new TrackPlaylist()
{
CreatedOn = DateTime.Now,
PlaylistId = playlist.Id,
Playlist = playlist,
TrackId = track.Id,
Track = _mapper.Map <Track>(track),
});
count++;
}
}
trackPlaylist = ArrangePlaylist(playlistConfigDTO, trackPlaylist);
playlist.Rank = (int)trackPlaylist.Average(t => t.Track.Rank);
playlist.Duration = totalDuration;
var trackPlaylistDB = trackPlaylist
.Select(x => new TrackPlaylist()
{
PlaylistId = x.PlaylistId,
TrackId = x.TrackId,
})
.ToList();
playlist.TrackPlaylists = trackPlaylistDB;
await _appDbContext.Playlists.AddAsync(playlist);
await _appDbContext.SaveChangesAsync();
playlist.TrackPlaylists = trackPlaylist;
var playlistDTO = _mapper.Map <PlaylistDTO>(playlist);
return(playlistDTO);
}
