using DW5S.DTO;
using DW5S.Entity;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.ChangeTracking;
using Microsoft.EntityFrameworkCore.Query;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Linq.Expressions;
using System.Text;
using System.Threading.Tasks;

namespace DW5S.Repostory
{
    public interface IRepository<T, IDType> where T : BaseEntity<IDType>
    {
        IQueryable<T> AsQueryable();
        Task<T> GetByIdAsync(object id);
        Task<IEnumerable<T>> GetAllAsync();
        Task<IEnumerable<T>> GetAllAsync<TKey>(Expression<Func<T, TKey>> keySelector = null, bool asc = true);
        Task<IEnumerable<T>> FindAsync(Expression<Func<T, bool>> predicate);
        Task<IEnumerable<T>> FindAsync<TKey>(Expression<Func<T, bool>> predicate, Expression<Func<T, TKey>> keySelector = null, bool asc = true);
        Task<IEnumerable<Res>> GetDistinctAsync<Res>(Expression<Func<T, Res>> selector);

        Task<T> FirstOrDefaultAsync(Expression<Func<T, bool>> predicate = null);
        Task<T> AddOrUpdateAsync(T entity);
        Task AddOrUpdateAsync(IEnumerable<T> entitis);

        /// <summary>
        /// 修改某些字段
        /// expression  s => s.SetProperty(b => b.Enable, true)
        /// </summary>
        /// <param name="predicate"></param>
        /// <param name="expression">ddd</param>
        /// <returns></returns>
        Task<int> UpdatePropAsync(Expression<Func<T, bool>> predicate, Expression<Func<SetPropertyCalls<T>, SetPropertyCalls<T>>> expression);

        Task<int> DeleteAsync(T entity);
        Task<int> DeleteAsync(IEnumerable<T> entitis);

        Task<int> DeleteAsync(Expression<Func<T, bool>> predicate = null);

        Task<bool> AnyAsync(Expression<Func<T, bool>> predicate = null);

        T MaxBy<TResult>(Expression<Func<T, TResult>> selector, Expression<Func<T, bool>> predicate = null);

        Task<PageData<T>> GetPageData(PageQueryDto dto, IQueryable<T> queryable);

    }

    public class Repository<T, IDType> : IRepository<T, IDType> where T : BaseEntity<IDType>
    {
        protected readonly OracleContext ctx;
        protected readonly DbSet<T> dbSet;

        public Repository(OracleContext ctx)
        {
            this.ctx = ctx;
            this.dbSet = ctx.Set<T>();
        }
        public IQueryable<T> AsQueryable()
        {
            return dbSet.AsQueryable();
        }
        public async Task<T> GetByIdAsync(object id)
        {
            return await dbSet.FindAsync(id);
        }
        public async Task<IEnumerable<T>> GetAllAsync()
        {
            return await dbSet.ToListAsync();
        }
        public async Task<PageData<T>> GetPageData(PageQueryDto dto, IQueryable<T> queryable)
        {
            if (dto.Page < 1) dto.Page = 1;
            var count = await queryable.LongCountAsync();
            if (count == 0)
            {
                return new PageData<T>()
                {
                    CountPerPage = dto.CountPerPage,
                    Data = new List<T>(),
                    Page = 1,
                    TotalCount = 0,
                };
            }
            PageData<T> pageData = new PageData<T>()
            {
                CountPerPage = dto.CountPerPage,
                TotalCount = count,
            };
            if (pageData.TotalPage < dto.Page)
            {
                dto.Page = pageData.TotalPage;//没有这么多页就查询最后一页数据
            }
            int skip = dto.CountPerPage * (dto.Page - 1);
            queryable = queryable.Skip(skip).Take(dto.CountPerPage);
            var data = await queryable.ToListAsync();
            pageData.Page = dto.Page;
            pageData.Data = data;
            return pageData;

        }

        public async Task<IEnumerable<T>> GetAllAsync<TKey>(Expression<Func<T, TKey>> keySelector = null, bool asc = true)
        {
            if (keySelector == null)
            {
                return await dbSet.ToListAsync();
            }
            else
            {
                if (asc)
                    return await dbSet.OrderBy(keySelector).ToListAsync();
                else
                    return await dbSet.OrderByDescending(keySelector).ToListAsync();

            }
        }

        public async Task<IEnumerable<T>> FindAsync(Expression<Func<T, bool>> predicate)
        {
            return await dbSet.Where(predicate).ToListAsync();
        }
        public async Task<IEnumerable<T>> FindAsync<TKey>(Expression<Func<T, bool>> predicate, Expression<Func<T, TKey>> keySelector = null, bool asc = true)
        {
            if (keySelector == null)
            {
                return await dbSet.Where(predicate).ToListAsync();
            }
            else
            {
                if (asc)
                    return await dbSet.Where(predicate).OrderBy(keySelector).ToListAsync();
                else
                    return await dbSet.Where(predicate).OrderByDescending(keySelector).ToListAsync();

            }
        }
        public async Task<T> FirstOrDefaultAsync(Expression<Func<T, bool>> predicate = null)
        {
            if (predicate != null)
                return await dbSet.Where(predicate).FirstOrDefaultAsync();
            return await dbSet.FirstOrDefaultAsync();
        }

        public async Task<IEnumerable<Res>> GetDistinctAsync<Res>(Expression<Func<T, Res>> selector)
        {
            var res = await dbSet.Select(selector).Distinct().ToListAsync();
            return res;
        }

        public async Task AddOrUpdateAsync(IEnumerable<T> entity)
        {
            if (entity.First().Id.Equals(0))
            {
                foreach (var item in entity)
                {
                    item.CreateTime = DateTime.Now;
                    item.UpdateTime = DateTime.Now;
                }
                await dbSet.AddRangeAsync(entity);
            }
            else
            {
                foreach (var item in entity)
                {
                    item.UpdateTime = DateTime.Now;
                }
                dbSet.UpdateRange(entity);
            }
        }

        public async Task<T> AddOrUpdateAsync(T entity)
        {
            if (entity.Id.Equals(0))
            {
                entity.CreateTime = DateTime.Now;
                entity.UpdateTime = DateTime.Now;
                var res = await dbSet.AddAsync(entity);
                return res.Entity;
            }
            else
            {
                entity.UpdateTime = DateTime.Now;
                var res = dbSet.Update(entity);
                return res.Entity;
            }
        }

        public async Task<int> DeleteAsync(T entity)
        {
            return await dbSet.Where(p => p.Id.Equals(entity.Id)).ExecuteDeleteAsync();
        }

        public async Task<int> DeleteAsync(IEnumerable<T> entities)
        {
            var ids = entities.Select(p => p.Id);
            return await DeleteAsync(p => ids.Contains(p.Id));
        }

        public async Task<int> DeleteAsync(Expression<Func<T, bool>> predicate = null)
        {
            return await dbSet.Where(predicate).ExecuteDeleteAsync();
        }

        public async Task<bool> AnyAsync(Expression<Func<T, bool>> predicate = null)
        {
            return await dbSet.AnyAsync(predicate);
        }

        public T MaxBy<TResult>(Expression<Func<T, TResult>> selector, Expression<Func<T, bool>> predicate = null)
        {
            if (predicate == null)
                return dbSet.MaxBy(selector);
            else
                return dbSet.Where(predicate).MaxBy(selector);
        }


        public async Task<int> UpdatePropAsync(Expression<Func<T, bool>> predicate, Expression<Func<SetPropertyCalls<T>, SetPropertyCalls<T>>> expression)
        {
            return await dbSet.Where(predicate)
                .ExecuteUpdateAsync(expression);
        }
    }
}