/// <summary>
/// Returns a PLS file format for streaming playlists, used for stations like TuneIn Radio.
/// </summary>
/// <returns></returns>
public async Task <IActionResult> TuneInV3()
{
// Build the PLS file.
// PLS format is very simple: https://en.wikipedia.org/wiki/PLS_(file_format)
var plsBuilder = new StringBuilder();
plsBuilder.AppendLine("[playlist]"); // The header
var songsWithRanking = await DbSession.Query <Song, Songs_RankStandings>()
.As <Songs_RankStandings.Result>()
.ToListAsync();
var userPrefs = new UserSongPreferences();
const int totalSongCount = 25;
var songPicks = Enumerable
.Range(0, totalSongCount)
.Select(s => userPrefs.PickSong(songsWithRanking))
.ToList();
var songs = await DbSession.LoadWithoutNulls <Song>(songPicks.Select(p => p.SongId));
for (var i = 0; i < songs.Count; i++)
{
var oneBasedIndex = i + 1;
// File1=http://thefile.mp3
plsBuilder.AppendLine();
plsBuilder.Append("File");
plsBuilder.Append(oneBasedIndex);
plsBuilder.Append('=');
plsBuilder.AppendLine(songs[i].Uri.ToString());
// Title1=Shema Yisrael by Barry & Batya Segal
plsBuilder.Append("Title");
plsBuilder.Append(oneBasedIndex);
plsBuilder.Append('=');
var songName = string.IsNullOrEmpty(songs[i].HebrewName) ? songs[i].Name : songs[i].Name + " " + songs[i].HebrewName;
plsBuilder.Append(songName);
plsBuilder.Append(" by ");
plsBuilder.AppendLine(songs[i].Artist);
}
// NumberOfEntries=20
plsBuilder.AppendLine();
plsBuilder.Append("NumberOfEntries");
plsBuilder.Append('=');
plsBuilder.Append(songs.Count);
var plsBytes = Encoding.UTF8.GetBytes(plsBuilder.ToString());
return(File(plsBytes, "application/pls+xml", "ChavahTuneInStream.pls"));
}
public async Task <Song> ChooseSong()
{
// HOT PATH: This method greatly impacts the UI. The user waits for this method before ever hearing a song.
// We want to send back the next song ASAP.
var userPreferences = default(UserSongPreferences);
var songsWithRanking = default(IList <Songs_RankStandings.Result>);
// Aggressive caching for the UserSongPreferences and SongsWithRanking. These don't change often.
using (DbSession.Advanced.DocumentStore.AggressivelyCacheFor(TimeSpan.FromDays(1)))
{
var user = await GetUser();
// This is NOT an unbounded result set:
// This queries the Songs_RankStandings index, which will reduce the results. Max number of results will be the number of CommunityRankStanding enum constants.
songsWithRanking = await DbSession.Query <Song, Songs_RankStandings>()
.As <Songs_RankStandings.Result>()
.ToListAsync();
if (user != null)
{
userPreferences = await DbSession.Query <Like, Likes_SongPreferences>()
.As <UserSongPreferences>()
.FirstOrDefaultAsync(u => u.UserId == user.Id);
}
if (userPreferences == null)
{
userPreferences = new UserSongPreferences();
}
}
// Run the song picking algorithm.
var songPick = userPreferences.PickSong(songsWithRanking);
if (string.IsNullOrEmpty(songPick.SongId))
{
logger.LogWarning("Chose song but ended up with an empty Song ID.", songPick);
return(await PickRandomSong());
}
var song = await DbSession.LoadRequiredAsync <Song>(songPick.SongId);
var songLikeDislike = userPreferences.Songs.FirstOrDefault(s => s.SongId == song.Id);
var songLikeStatus = songLikeDislike?.LikeCount > 0 ?
LikeStatus.Like : songLikeDislike?.DislikeCount > 0 ?
LikeStatus.Dislike : LikeStatus.None;
return(song.ToDto(songLikeStatus, songPick));
}
public async Task <List <string> > GetPrefsDebug(string email)
{
var stopWatch = new System.Diagnostics.Stopwatch();
stopWatch.Start();
var userId = "AppUsers/" + email;
var userPreferences = await DbSession.Query <Like, Likes_SongPreferences>()
.As <UserSongPreferences>()
.FirstOrDefaultAsync(u => u.UserId == userId);
var userPrefsTime = stopWatch.Elapsed;
stopWatch.Restart();
if (userPreferences == null)
{
userPreferences = new UserSongPreferences();
}
var songsWithRanking = await DbSession.Query <Song, Songs_RankStandings>()
.As <Songs_RankStandings.Result>()
.ToListAsync();
var rankingTime = stopWatch.Elapsed;
stopWatch.Restart();
var table = userPreferences.BuildSongWeightsTable(songsWithRanking);
var tableTime = stopWatch.Elapsed;
stopWatch.Stop();
var songsOrderedByWeight = table
.Select(s => (SongId: s.Key, s.Value.Weight, s.Value.ArtistMultiplier, s.Value.AlbumMultiplier, SongMultipler: s.Value.SongMultiplier, s.Value.TagMultiplier, RankMultiplier: s.Value.CommunityRankMultiplier, s.Value.AgeMultiplier))
.OrderByDescending(s => s.Weight)
.Select(s => $"Song ID {s.SongId}, Weight {s.Weight}, Artist multiplier: {s.ArtistMultiplier}, Album multipler: {s.AlbumMultiplier}, Song multiplier: {s.SongMultipler}, Tag multiplier {s.TagMultiplier}, Rank multiplier: {s.RankMultiplier}, Age multiplier: {s.AgeMultiplier}")
.ToList();
songsOrderedByWeight.Insert(0, $"Performance statistics: Total query time {tableTime + rankingTime + userPrefsTime}. Querying user prefs {userPrefsTime}, querying ranking {rankingTime}, building table {tableTime}");
return(songsOrderedByWeight);
}
public async Task <ActionResult> GetNextSong()
{
var userPreferences = new UserSongPreferences();
var songsWithRanking = default(IList <Songs_RankStandings.Result>);
// Aggressive caching for the UserSongPreferences and SongsWithRanking. These don't change often.
using (var cache = DbSession.Advanced.DocumentStore.AggressivelyCacheFor(TimeSpan.FromDays(1)))
{
// This is NOT an unbounded result set:
// This queries the Songs_RankStandings index, which will reduce the results. Max number of results will be the number of CommunityRankStanding enum constants.
songsWithRanking = await DbSession.Query <Song, Songs_RankStandings>()
.As <Songs_RankStandings.Result>()
.ToListAsync();
}
var songPick = userPreferences.PickSong(songsWithRanking);
var song = await DbSession.LoadRequiredAsync <Song>(songPick.SongId);
return(Redirect(song.Uri.ToString()));
}
public async Task <List <Song> > ChooseSongBatch()
{
const int songsInBatch = 5;
var userPreferences = default(UserSongPreferences);
var songsWithRanking = default(IList <Songs_RankStandings.Result>);
// Aggressive caching for the UserSongPreferences and SongsWithRanking. These don't change often.
using (var cache = DbSession.Advanced.DocumentStore.AggressivelyCacheFor(TimeSpan.FromDays(1)))
{
var user = await GetUser();
// This is NOT an unbounded result set:
// This queries the Songs_RankStandings index, which will reduce the results. Max number of results will be the number of CommunityRankStanding enum constants.
songsWithRanking = await DbSession.Query <Song, Songs_RankStandings>()
.As <Songs_RankStandings.Result>()
.ToListAsync();
if (user != null)
{
userPreferences = await DbSession.Query <Like, Likes_SongPreferences>()
.As <UserSongPreferences>()
.FirstOrDefaultAsync(u => u.UserId == user.Id);
}
if (userPreferences == null)
{
userPreferences = new UserSongPreferences();
}
}
// Run the song picking algorithm.
var batch = new List <Song>(songsInBatch);
var pickedSongs = Enumerable.Range(0, songsInBatch)
.Select(_ => userPreferences.PickSong(songsWithRanking))
.ToList();
if (pickedSongs.Any(s => string.IsNullOrEmpty(s.SongId)))
{
logger.LogWarning("Picked songs for batch, but returned one or more empty song IDs {pickedSongs}", pickedSongs);
}
// Make a single trip to the database to load all the picked songs.
var pickedSongIds = pickedSongs
.Select(s => s.SongId)
.ToList();
var songs = await DbSession
.LoadWithoutNulls <Song>(pickedSongIds);
var songDtos = new List <Song>(songs.Count);
for (var i = 0; i < songs.Count; i++)
{
var song = songs[i];
if (song != null)
{
var pickReasons = pickedSongs[i];
var songLikeDislike = userPreferences.Songs.FirstOrDefault(s => s.SongId == song.Id);
var songLikeStatus = songLikeDislike?.LikeCount > 0 ?
LikeStatus.Like : songLikeDislike?.DislikeCount > 0 ?
LikeStatus.Dislike : LikeStatus.None;
var dto = song.ToDto(songLikeStatus, pickReasons);
songDtos.Add(dto);
}
}
return(songDtos);
}
