using System;
using System.Linq;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.ChangeTracking;
using Microsoft.EntityFrameworkCore.Metadata.Builders;
using Microsoft.EntityFrameworkCore.Storage.ValueConversion;
using TakeoutSaaS.Domain.Identity.Entities;

namespace TakeoutSaaS.Infrastructure.Identity.Persistence;

/// <summary>
/// 身份认证 DbContext。
/// </summary>
public sealed class IdentityDbContext : DbContext
{
    public IdentityDbContext(DbContextOptions<IdentityDbContext> options)
        : base(options)
    {
    }

    public DbSet<IdentityUser> IdentityUsers => Set<IdentityUser>();
    public DbSet<MiniUser> MiniUsers => Set<MiniUser>();

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        ConfigureIdentityUser(modelBuilder.Entity<IdentityUser>());
        ConfigureMiniUser(modelBuilder.Entity<MiniUser>());
    }

    private static void ConfigureIdentityUser(EntityTypeBuilder<IdentityUser> builder)
    {
        builder.ToTable("identity_users");
        builder.HasKey(x => x.Id);
        builder.Property(x => x.Account).HasMaxLength(64).IsRequired();
        builder.Property(x => x.DisplayName).HasMaxLength(64).IsRequired();
        builder.Property(x => x.PasswordHash).HasMaxLength(256).IsRequired();
        builder.Property(x => x.Avatar).HasMaxLength(256);

        var converter = new ValueConverter<string[], string>(
            v => string.Join(',', v ?? Array.Empty<string>()),
            v => string.IsNullOrWhiteSpace(v) ? Array.Empty<string>() : v.Split(',', StringSplitOptions.RemoveEmptyEntries));

        var comparer = new ValueComparer<string[]>(
            (l, r) => l!.SequenceEqual(r!),
            v => v.Aggregate(0, (current, item) => HashCode.Combine(current, item.GetHashCode())),
            v => v.ToArray());

        builder.Property(x => x.Roles)
            .HasConversion(converter)
            .Metadata.SetValueComparer(comparer);

        builder.Property(x => x.Permissions)
            .HasConversion(converter)
            .Metadata.SetValueComparer(comparer);

        builder.HasIndex(x => x.Account).IsUnique();
    }

    private static void ConfigureMiniUser(EntityTypeBuilder<MiniUser> builder)
    {
        builder.ToTable("mini_users");
        builder.HasKey(x => x.Id);
        builder.Property(x => x.OpenId).HasMaxLength(128).IsRequired();
        builder.Property(x => x.UnionId).HasMaxLength(128);
        builder.Property(x => x.Nickname).HasMaxLength(64).IsRequired();
        builder.Property(x => x.Avatar).HasMaxLength(256);

        builder.HasIndex(x => x.OpenId).IsUnique();
    }
}