using ErsatzTV.Core.Domain;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Metadata.Builders;

namespace ErsatzTV.Infrastructure.Data.Configurations;

public class MultiCollectionConfiguration : IEntityTypeConfiguration<MultiCollection>
{
    public void Configure(EntityTypeBuilder<MultiCollection> builder)
    {
        builder.ToTable("MultiCollection");

        builder.Property(mc => mc.Version).IsConcurrencyToken();

        builder.Property(mc => mc.Name)
            .HasMaxLength(50)
            .HasColumnType("varchar(50)");

        builder.HasIndex(mc => mc.Name)
            .IsUnique();

        // Cleanup + list-hiding of the system multi collection an auto-tune weighted channel owns (#425).
        // Nullable: null = a normal user multi collection.
        builder.HasIndex(mc => mc.OwnedByChannelId);

        builder.HasMany(m => m.Collections)
            .WithMany(m => m.MultiCollections)
            .UsingEntity<MultiCollectionItem>(
                j => j.HasOne(mci => mci.Collection)
                    .WithMany(c => c.MultiCollectionItems)
                    .HasForeignKey(mci => mci.CollectionId)
                    .OnDelete(DeleteBehavior.Cascade),
                j => j.HasOne(mci => mci.MultiCollection)
                    .WithMany(mc => mc.MultiCollectionItems)
                    .HasForeignKey(mci => mci.MultiCollectionId)
                    .OnDelete(DeleteBehavior.Cascade),
                j =>
                {
                    j.HasKey(mci => new { mci.MultiCollectionId, mci.CollectionId });

                    // default 1 = fair share (#70). Must be a DB default too, or existing rows migrate to 0 --
                    // a value that means nothing on a share-of-airtime scale. The enumerator clamps such a
                    // row to the floor, so it rotates rather than vanishing; the backfill should still be
                    // right at the source.
                    j.Property(mci => mci.Weight).HasDefaultValue(1);
                });

        builder.HasMany(m => m.SmartCollections)
            .WithMany(m => m.MultiCollections)
            .UsingEntity<MultiCollectionSmartItem>(
                j => j.HasOne(mci => mci.SmartCollection)
                    .WithMany(c => c.MultiCollectionSmartItems)
                    .HasForeignKey(mci => mci.SmartCollectionId)
                    .OnDelete(DeleteBehavior.Cascade),
                j => j.HasOne(mci => mci.MultiCollection)
                    .WithMany(mc => mc.MultiCollectionSmartItems)
                    .HasForeignKey(mci => mci.MultiCollectionId)
                    .OnDelete(DeleteBehavior.Cascade),
                j =>
                {
                    j.HasKey(mci => new { mci.MultiCollectionId, mci.SmartCollectionId });

                    // mirrors MultiCollectionItem above -- omitting it would silently un-weight
                    // every smart-collection member of a multi collection
                    j.Property(mci => mci.Weight).HasDefaultValue(1);
                });
    }
}