/// <summary>
/// Generates up to maxSuggestsions song suggestions for a user based off of their song history.
/// Suggested songs are from the same artists as songs they have previously sung with a bias
/// to artists they have sung more often. Suggestions are always song they have not sung yet.
/// </summary>
/// <param name="maxSuggestions"></param>
/// <param name="mobileID"></param>
/// <param name="DJID"></param>
/// <param name="songs"></param>
/// <param name="db"></param>
/// <returns></returns>
private ExpResponse SuggestSongsNotSungByMostSungArtists(int maxSuggestions, int mobileID, int DJID, out List<Song> songs, DatabaseConnectivity db)
{
List<SongAndCount> sAc;
songs = new List<Song>();
ExpResponse r;
// Get up to 10 unique artists this user has sung, ordered by the most sung first.
r = db.MobileGetUniqueArtistsSung(mobileID, 0, 10, out sAc);
if (r.error)
return r;
// Loop through the unique artists.
// store total number of song sings in singCount
// Store the iteration singCount in tmp for each sAc.
int singCount = 0;
for (int i = 0; i < sAc.Count; i++)
{
singCount += sAc[i].count;
sAc[i].tmp = singCount;
}
// Generate a random number between 0 and the number of total sings.
// Loop through the artists, if the random number is less than the
// store singCount iteration number, choose to suggest a song based off that artist.
Random rand = new Random(DateTime.Now.Millisecond);
for (int i = 0; i < maxSuggestions; i++)
{
int rn = rand.Next(0, singCount);
for (int j = 0; j < sAc.Count; j++)
{
if (rn < sAc[j].tmp)
{
sAc[j].tmp2++;
break;
}
}
}
// For each artist, if we selected to suggest based off them, do so the number of times requested.
foreach (SongAndCount s in sAc)
{
if (s.tmp2 > 0)
{
List<int> songIDs;
r = db.MobileGetRandomSongsFromExactArtistNeverSung(s.song.artist, DJID, s.tmp2, mobileID, out songIDs);
if (r.error)
return r;
foreach (int id in songIDs)
{
Song song = new Song();
song.ID = id;
songs.Add(song);
}
}
}
return r;
}
