using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.Linq;
using Infrastructure.Domain;
using Infrastructure.Extensions;
using Microsoft.AspNetCore.Http;
using Microsoft.EntityFrameworkCore;

namespace Infrastructure.Data
{
    public class EfDbContext : DbContext
    {
        private readonly IHttpContextAccessor _httpContext;

        public EfDbContext(DbContextOptions options, IHttpContextAccessor httpContext) : base(options)
        {
            this._httpContext = httpContext;
        }

        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        {
            optionsBuilder.EnableSensitiveDataLogging();
            base.OnConfiguring(optionsBuilder);
        }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            base.OnModelCreating(modelBuilder);
            modelBuilder.RemovePluralizingTableNameConvention();
            OnModelCreatingAction(modelBuilder);
            foreach (var entity in modelBuilder.Model.GetEntityTypes())
            {
                if (entity.GetProperties().Any(o => o.Name == "Id"))
                {
                    modelBuilder.Entity(entity.Name).HasKey("Id");
                }
                if (entity.GetProperties().Any(o => o.Name == "RowVersion"))
                {
                    modelBuilder.Entity(entity.Name).Property("RowVersion")?.IsConcurrencyToken().ValueGeneratedNever();
                }
            }
        }

        public override int SaveChanges()
        {
            this.ChangeTracker.DetectChanges();
            var entries = this.ChangeTracker.Entries().Where(o => o.State == EntityState.Added ||
            o.State == EntityState.Modified || o.State == EntityState.Deleted).ToList();
            foreach (var entry in entries)
            {
                var entity = entry.Entity as BaseEntity;
                if (entity is IValidatableObject)
                {
                    var validationResults = new List<ValidationResult>();
                    if (!Validator.TryValidateObject(entry.Entity, new ValidationContext(entity, null, null), validationResults, true))
                    {
                        throw new EntityInvalidException(validationResults, $"{entity.GetType().FullName} 实体验证失败");
                    }
                }
                var now = DateTimeOffset.Now;
                var rowVersion = Guid.NewGuid().ToString();
                var userName = this._httpContext?.HttpContext?.User?.Identity?.Name ?? "admin";
                if (entity is Entity)
                {
                    (entity as Entity).RowVersion = rowVersion;
                }
                if (entry.State == EntityState.Added)
                {
                    entity.UpdatedOn = now;
                }
                else if (entry.State == EntityState.Modified)
                {
                    if (entity is IDisableUpdate || entity.IsReadOnly)
                    {
                        throw new Exception("当前实体不可修改");
                    }
                    entity.UpdatedOn = now;
                }
                else if (entry.State == EntityState.Deleted || entity.IsReadOnly)
                {
                    if (entity is IDisableDelete || entity.IsReadOnly)
                    {
                        throw new Exception("当前实体不可删除");
                    }
                }
                Console.WriteLine($"{entity.GetType().Name}:{entry.State.ToString()}:{entry.OriginalValues.ToObject().ToJson()}/{entry.CurrentValues.ToObject().ToJson()}");
            }
            try
            {
                return base.SaveChanges();
            }
            catch (Exception ex)
            {
                ex.PrintStack();
                var list = entries.Select(o => o.Entity).ToList();
                Console.WriteLine(list.ToJson());
                throw new Exception(ex.Message, ex);
            }
        }

        public static Action<ModelBuilder> OnModelCreatingAction;
    }
}