private Song PickSongForUser(User user)
{
// 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.
var songRankStandings = this.RavenDb
.Query<Song, Songs_RankStandings>()
.As<Songs_RankStandings.Results>()
.ToArray();
var veryPoorRankSongCount = songRankStandings.Where(s => s.Standing == CommunityRankStanding.VeryPoor).Select(s => s.Count).FirstOrDefault();
var poorRankSongCount = songRankStandings.Where(s => s.Standing == CommunityRankStanding.Poor).Select(s => s.Count).FirstOrDefault();
var normalRankSongCount = songRankStandings.Where(s => s.Standing == CommunityRankStanding.Normal).Select(s => s.Count).FirstOrDefault();
var goodRankSongCount = songRankStandings.Where(s => s.Standing == CommunityRankStanding.Good).Select(s => s.Count).FirstOrDefault();
var greatRankSongCount = songRankStandings.Where(s => s.Standing == CommunityRankStanding.Great).Select(s => s.Count).FirstOrDefault();
var bestRankSongCount = songRankStandings.Where(s => s.Standing == CommunityRankStanding.Best).Select(s => s.Count).FirstOrDefault();
var pickRankedSong = new Func<CommunityRankStanding, Func<Song>>(standing => new Func<Song>(() => PickRankedSongForUser(standing, user)));
var songPick = user.Preferences.PickSong(veryPoorRankSongCount, poorRankSongCount, normalRankSongCount, goodRankSongCount, greatRankSongCount, bestRankSongCount);
var songPicker = Match.Value(songPick)
.With(SongPick.VeryPoorRank, pickRankedSong(CommunityRankStanding.VeryPoor))
.With(SongPick.PoorRank, pickRankedSong(CommunityRankStanding.Poor))
.With(SongPick.NormalRank, pickRankedSong(CommunityRankStanding.Normal))
.With(SongPick.GoodRank, pickRankedSong(CommunityRankStanding.Good))
.With(SongPick.GreatRank, pickRankedSong(CommunityRankStanding.Great))
.With(SongPick.BestRank, pickRankedSong(CommunityRankStanding.Best))
.With(SongPick.LikedAlbum, () => PickLikedAlbumForUser(user))
.With(SongPick.LikedArtist, () => PickLikedArtistForUser(user))
.With(SongPick.LikedSong, () => PickLikedSongForUser(user))
.With(SongPick.RandomSong, PickRandomSong)
.Evaluate();
var song = songPicker();
if (song == null)
{
song = PickRandomSong();
}
return song.ToDto(user.Preferences.GetLikeStatus(song));
}
private Song PickRankedSongForUser(CommunityRankStanding rank, User user)
{
var dislikedSongIds = user.Preferences.GetDislikedSongs().Select(s => s.Name).ToArray();
return this.RavenDb.Query<Song>()
.Where(s => s.CommunityRankStanding == rank && !s.Id.In(dislikedSongIds))
.Customize(x => x.RandomOrdering())
.FirstOrDefault();
}
private Song PickLikedSongForUser(User user)
{
var randomLikedSong = user.Preferences.Songs.Where(s => s.LikeCount == 1).RandomElement();
if (randomLikedSong != null)
{
return RavenDb.Query<Song>().FirstOrDefault(s => s.Id == randomLikedSong.Name);
}
return null;
}
private Song PickLikedArtistForUser(User user)
{
var randomLikedArtist = user.Preferences.GetLikedArtists().RandomElement();
if (randomLikedArtist != null)
{
return this.RavenDb.Query<Song>()
.Where(s => s.Artist == randomLikedArtist.Name)
.Customize(c => c.RandomOrdering())
.FirstOrDefault();
}
return null;
}
private void IncrementTotalPlayed(User user)
{
user.TotalPlays += 1;
var todaysDate = DateTime.Now.Date;
var visit = this.RavenDb.Query<Visit>().FirstOrDefault(v => v.UserId == user.Id && v.DateTime == todaysDate);
if (visit != null)
{
visit.TotalPlays += 1;
}
else
{
this.RavenDb.Store(new Visit()
{
TotalPlays = 1,
UserId = user.Id,
DateTime = todaysDate
});
}
}
private User CreateUserIfNecessary(Guid clientId)
{
var user = this.RavenDb
.Query<User>()
.FirstOrDefault(u => u.ClientIdentifier == clientId);
if (user == null)
{
user = new User { ClientIdentifier = clientId };
this.RavenDb.Store(user);
}
return user;
}
