namespace HrynCo.DAL.EF.Core;

using HrynCo.Common;
using HrynCo.DAL.Abstract.Entities;
using HrynCo.DAL.EF.Converters;
using HrynCo.DAL.EF.Exceptions;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.ChangeTracking;
using Microsoft.EntityFrameworkCore.Metadata;

public abstract class BaseDbContext : DbContext
{
    private readonly IClock _clock;

    protected BaseDbContext(DbContextOptions options, IClock clock)
        : base(options)
    {
        _clock = clock;
    }

    public override int SaveChanges()
    {
        ApplyTimestamps();
        return base.SaveChanges();
    }

    public override async Task<int> SaveChangesAsync(CancellationToken cancellationToken = default)
    {
        ApplyTimestamps();
        return await base.SaveChangesAsync(cancellationToken);
    }

    private void ApplyTimestamps()
    {
        DateTimeOffset now = _clock.UtcNow;

        foreach (EntityEntry<IEntity> entry in ChangeTracker.Entries<IEntity>())
        {
            switch (entry.State)
            {
                case EntityState.Added:
                    entry.Entity.Created = now;
                    break;
                case EntityState.Modified:
                    entry.Entity.Updated = now;
                    break;
                case EntityState.Detached:
                case EntityState.Unchanged:
                case EntityState.Deleted:
                    break;
                default:
                    throw new UnexpectedEntityStateException(entry.State);
            }
        }
    }

    protected override void ConfigureConventions(ModelConfigurationBuilder configurationBuilder)
    {
        configurationBuilder.Properties<DateTime>().HaveConversion<UtcValueConverter>();
    }

    protected override void OnModelCreating(ModelBuilder modelBuilder)
    {
        foreach (IMutableForeignKey relationship in modelBuilder.Model.GetEntityTypes()
                     .SelectMany(e => e.GetForeignKeys()))
        {
            relationship.DeleteBehavior = DeleteBehavior.Restrict;
        }

        modelBuilder.ApplyConfigurationsFromAssembly(GetType().Assembly);

        base.OnModelCreating(modelBuilder);
    }
}