using SqlSugar;
using System;
using System.Collections.Generic;
using System.Text;
using System.Threading.Tasks;

namespace Utility
{
    public class SqlSugarPagedList
    {
        /// <summary>
        /// 总条数
        /// </summary>
        public int Total { get; set; }

        /// <summary>
        /// 总页数
        /// </summary>
        public int TotalPages { get; set; }

        /// <summary>
        /// 当前页集合
        /// </summary>
        public object Items { get; set; }
    }
    /// <summary>
    /// 分页拓展类
    /// </summary>
    public static class SqlSugarPagedExtensions
    {
        /// <summary>
        /// 分页拓展
        /// </summary>
        /// <param name="query"><see cref="ISugarQueryable{TEntity}"/>对象</param>
        /// <param name="pageIndex">当前页码，从1开始</param>
        /// <param name="pageSize">页码容量</param>
        /// <returns></returns>
        public static async Task<SqlSugarPagedList> ToPagedListAsync<TEntity>(this ISugarQueryable<TEntity> query, int pageIndex, int pageSize)
            where TEntity : new()
        {
            RefAsync<int> total = 0;
            var items = await query.ToPageListAsync(pageIndex, pageSize, total);
            var totalPages = pageSize > 0 ? (int)Math.Ceiling(total / (double)pageSize) : 0;
            return new SqlSugarPagedList
            {
                Items = items,
                Total = total,
                TotalPages = totalPages,
            };
        }
    }
}