using Furion;
using Furion.DatabaseAccessor;
using Furion.DistributedIDGenerator;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.ChangeTracking;
using Microsoft.EntityFrameworkCore.Diagnostics;
using Microsoft.EntityFrameworkCore.Metadata.Builders;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Text;
using System.Threading.Tasks;

namespace FlexJobApi.Core
{
    public static class DbUtils
    {
        /// <summary>
        /// 生成实体注释
        /// </summary>
        /// <param name="modelBuilder"></param>
        /// <param name="dbContextLocator"></param>
        /// <returns></returns>
        public static async Task BuildEntityComment(ModelBuilder modelBuilder, Type dbContextLocator = null)
        {
            var xmlDoc = await XmlDocUtils.GetXmlDocAsync();
            var entityTypes = App.Assemblies
                .Where(it => it.FullName.Contains("FlexJob"))
                .SelectMany(it => it.GetTypes())
                .Where(it =>
                    it.IsClass
                    && !it.IsAbstract
                    && typeof(IPrivateEntity).IsAssignableFrom(it)
                    && (dbContextLocator == null
                    ? it.BaseType == typeof(CommonEntity)
                    : it.BaseType.GenericTypeArguments.Any(it => it == dbContextLocator)))
                .ToList();
            foreach (var entityType in entityTypes)
            {
                Console.WriteLine($"正在生成表：{entityType.Name}");
                // 获取实体类的XML注释，并设置为表注释
                var entityBuilder = modelBuilder.Entity(entityType);
                string typeComment = (await entityType.GetXmlDocMemberAsync(xmlDoc))?.Summary;
                if (!string.IsNullOrEmpty(typeComment))
                {
                    Console.WriteLine($"正在生成表注释：{entityType.Name}-{typeComment}");
                    entityBuilder.ToTable(it => it.HasComment(typeComment));
                }
                // 获取实体属性的XML注释，并设置为列注释
                var properties = entityType.GetProperties()
                    .Where(p =>
                        p.CanRead
                        && p.CanWrite
                        && !typeof(System.Collections.ICollection).IsAssignableFrom(p.PropertyType)
                        && (p.PropertyType.IsClass ? p.PropertyType.FullName.Contains("System.") : true));
                foreach (var property in properties)
                {
                    string propComment = (await property.GetXmlDocMemberAsync(xmlDoc))?.Summary;
                    if (!string.IsNullOrEmpty(propComment))
                    {
                        Console.WriteLine($"正在生成属性注释：{property.Name}-{propComment}");
                        entityBuilder.Property(property.Name).HasComment(propComment);
                    }
                }
            }
        }

        public static void SavingChangesEvent(DbContextEventData eventData, InterceptionResult<int> result)
        {
            // 获取当前事件对应上下文
            var dbContext = eventData.Context;

            // 强制重新检查一边实体更改信息
            // dbContext.ChangeTracker.DetectChanges();

            // 获取所有更改，删除，新增的实体
            var dbAuditLogIgnoreType = typeof(IDbAuditLogIgnore);
            var physicalDeletionType = typeof(IPhysicalDeletion);
            var entities = dbContext.ChangeTracker.Entries()
                .Where(u =>
                    u.GetType() != typeof(DbAuditLog)
                    && (u.State == EntityState.Modified
                    || u.State == EntityState.Deleted
                    || u.State == EntityState.Added))
                .ToList();

            // 通过请求中获取当前操作人
            var logier = JwtUtils.GetCurrentLogier();

            // 获取所有已更改的实体
            foreach (var entity in entities)
            {
                // 获取实体类型
                var entityType = entity.Entity.GetType();

                if (entity.State == EntityState.Added)
                {
                    // 赋值创建日期
                    var prop = entity.Property(nameof(CommonEntity.CreatedTime));
                    if (prop != null && prop.CurrentValue?.ToDateTime() == null)
                    {
                        prop.CurrentValue = DateTimeOffset.Now;
                    }

                    // 生成Id
                    prop = entity.Property(nameof(CommonEntity.Id));
                    var defaultValue = Activator.CreateInstance(prop.Metadata.ClrType);
                    if (prop != null && (prop.CurrentValue == null || prop.CurrentValue.Equals(defaultValue)))
                    {
                        prop.CurrentValue = IDGen.NextID();
                    }

                    // 赋值用户信息Id
                    prop = entity.Property(nameof(CommonEntity.CreatedUserInfoId));
                    if (prop != null && prop.CurrentValue == null)
                    {
                        prop.CurrentValue = logier?.UserInfoId;
                    }
                }
                else
                {
                    // 赋值修改日期
                    var prop = entity.Property(nameof(CommonEntity.UpdatedTime));
                    if (prop != null && prop.CurrentValue?.ToDateTime() == null)
                    {
                        prop.CurrentValue = DateTimeOffset.Now;
                    }

                    // 赋值用户信息Id
                    prop = entity.Property(nameof(CommonEntity.UpdatedUserInfoId));
                    if (prop != null && prop.CurrentValue == null)
                    {
                        prop.CurrentValue = logier?.UserInfoId;
                    }

                    // 赋值跟踪Id
                    prop = entity.Property(nameof(CommonEntity.TraceId));
                    if (prop != null && prop.CurrentValue == null)
                    {
                        prop.CurrentValue = App.GetTraceId();
                    }

                    // 软删除
                    if (entity.State == EntityState.Deleted && !physicalDeletionType.IsAssignableFrom(entityType))
                    {
                        entity.State = EntityState.Modified;

                        prop = entity.Property(nameof(CommonEntity.IsDeleted));
                        if (prop != null && prop.CurrentValue == null)
                        {
                            prop.CurrentValue = true;
                        }
                    }
                }

                if (dbAuditLogIgnoreType.IsAssignableFrom(entityType))
                {
                    continue;
                }

                Db.GetRepository<DbAuditLog, LogDbContextLocator>().InsertNow(new DbAuditLog
                {
                    Id = IDGen.NextID(),
                    TableName = entityType.Name,
                    PrimaryKey = (Guid)entity.Property("Id").CurrentValue,
                    NewValues = entity.State == EntityState.Added || entity.State == EntityState.Modified
                        ? GetPropertyValuesAsJson(entity)
                        : null,
                    OldValues = entity.State == EntityState.Deleted || entity.State == EntityState.Modified
                        ? GetPropertyValuesAsJson(entity, entity.State == EntityState.Modified)
                        : null,
                    Operate = entity.State == EntityState.Added
                        ? EnumDbAuditOperate.Added
                        : entity.State == EntityState.Modified
                        ? EnumDbAuditOperate.Modified
                        : EnumDbAuditOperate.Deleted,
                    TraceId = App.GetTraceId(),
                    CreatedTime = DateTime.Now,
                    CreatedUserInfoId = logier?.UserInfoId,
                });
            }
        }

        private static string GetPropertyValuesAsJson(EntityEntry entry, bool getOldValues = false)
        {
            var properties = entry.Properties
                .Where(p => getOldValues ? p.IsModified : true)
                .ToDictionary(p => p.Metadata.Name, p => getOldValues ? p.OriginalValue : p.CurrentValue);

            return JsonConvert.SerializeObject(properties);
        }

        public static void OnCreating(ModelBuilder modelBuilder, EntityTypeBuilder entityBuilder, DbContext dbContext, Type dbContextLocator)
        {
            var metadata = entityBuilder.Metadata;

            var parameter = Expression.Parameter(metadata.ClrType, "e");
            var property = Expression.Property(parameter, nameof(CommonEntity.IsDeleted));
            var falseConstant = Expression.Constant(false, typeof(bool));
            var fakeDeleteQueryFilterExpression = Expression.Lambda(
                Expression.Equal(property, falseConstant),
                parameter
            );
            if (fakeDeleteQueryFilterExpression == null) return;
            entityBuilder.HasQueryFilter(fakeDeleteQueryFilterExpression);
        }
    }
}