/// <summary>
/// Form the initial population from all the genres and albums that can be reached from the specified initial set of genres
/// </summary>
/// <param name="startingGenres"></param>
public void AddAllReachableGenres(IEnumerable <string> startingGenres)
{
List <string> newGenres = null;
List <Album> newAlbums = null;
int expansionCount = 0;
// Start with the initial genres
List <string> currentGenres = startingGenres.ToList();
do
{
// Are there any genres that have not been seen before
newGenres = currentGenres.Where(gen => GenresAlreadyIncluded.Add(gen) == true).ToList();
if (newGenres.Count > 0)
{
// Are there any albums associated with these genres that have not been seen before
newAlbums = GetAlbumsFromGenres(newGenres);
if (newAlbums.Count > 0)
{
// Get all the genres associated with these new albums
currentGenres = newAlbums.SelectMany(alb => alb.Genre.Split(';')).ToList();
}
}
}while ((newGenres.Count > 0) && (newAlbums.Count > 0) && ((FastSpreadLimit == 0) || (++expansionCount < FastSpreadLimit)));
// Unload the genres and albums from the HashSets and use to generate the first population
Populations.Add(new Population(GenrePopulations.CreatePopulation(Id, Populations.Count, GenresAlreadyIncluded.ToList()),
GenresAlreadyIncluded.ToList(), Albums.AlbumCollection.Where(alb => AlbumsAlreadyIncluded.Contains(alb.Id))));
}
/// <summary>
/// Add the genres and their associated albums either to the next or a new population
/// </summary>
/// <param name="populationIndex"></param>
/// <param name="genres"></param>
public void AddToPopulation(int populationIndex, IEnumerable <string> genres)
{
// Make sure that there are some genres and albums that have not been seen before
// Use a List here as having the GenresAlreadyIncluded modifier in the .where seems to cause problems with Linq lazy evaluation
List <string> newGenres = genres.Where(gen => GenresAlreadyIncluded.Add(gen) == true).ToList();
if (newGenres.Count > 0)
{
// Are there any albums associated with these genres that have not been seen before
List <Album> newAlbums = GetAlbumsFromGenres(newGenres);
if (newAlbums.Count > 0)
{
// Add these entries to the next population to the one just used. If the one just used was the last one then create a new population
if (populationIndex == (Populations.Count - 1))
{
// A new population is required
Populations.Add(new Population(GenrePopulations.CreatePopulation(Id, Populations.Count, newGenres), newGenres, newAlbums));
}
else
{
// Add the genres and albums to the existing Population
Populations[populationIndex + 1].Add(newGenres, newAlbums);
}
}
}
}
/// <summary>
/// Clear the Population and SeedGenres entries
/// </summary>
public void Clear()
{
foreach (Population population in Populations)
{
GenrePopulations.RemovePopulation(population.SeedPopulation);
}
if (SeedGenres != null)
{
GenrePopulations.RemovePopulation(SeedGenres);
SeedGenres = null;
}
Populations.Clear();
GenresAlreadyIncluded.Clear();
AlbumsAlreadyIncluded.Clear();
}
/// <summary>
/// Intialise the Population list from the GenrePopulation records
/// </summary>
public void InitialisePopulations()
{
// Get all the GenrePopulation records associated with this Autoplay and order by the population index
IEnumerable <GenrePopulation> genrePopulations = GenrePopulations.GenrePopulationCollection.Where(gp => gp.AutoplayId == Id).OrderBy(gp => gp.Index);
// Create a Population for each GenrePopulation and add it to the list
foreach (GenrePopulation population in genrePopulations)
{
// If this is the original set of genres then save it separately
if (population.Index == -1)
{
SeedGenres = population;
}
else
{
// Get all the new genres and albums
List <string> populationGenres = population.Genres.Where(gen => GenresAlreadyIncluded.Add(gen) == true).ToList();
IEnumerable <Album> populationAlbums = GetAlbumsFromGenres(populationGenres);
Populations.Add(new Population(population, populationGenres, populationAlbums));
}
}
}
