using JSMachine.WMS.Domain.IRepository;
using JSMachine.WMS.Domain.Repository;
using System.Collections.Generic;

namespace JSMachine.WMS.Domain.Entity
{
    /// <summary>
    /// 通用分页查询结果，封装分页统计信息和当前页数据。
    /// </summary>
    /// <typeparam name="T">页数据的元素类型。</typeparam>
    public class PagedResult<T>
    {
        public static readonly PagedResult<T> EmptyPagedResult = new PagedResult<T>(0, 0, 0, 0, null);

        #region Public Properties
        /// <summary>
        /// 总记录数
        /// </summary>
        public int TotalRecords { get; set; }

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

        /// <summary>
        /// 每页的记录数
        /// </summary>
        public int PageSize { get; set; }

        /// <summary>
        /// 当前页码
        /// </summary>
        public int PageNumber { get; set; }

        /// <summary>
        /// 获取或设置当前页码的记录
        /// </summary>
        public List<T> PageData { get; set; }

        #endregion


        /// <summary>
        /// 创建空的分页结果，页数据初始化为空集合。
        /// </summary>
        public PagedResult()
        {
            this.PageData = new List<T>();
        }

        /// <summary>
        /// 使用完整分页统计信息创建结果。
        /// </summary>
        /// <param name="totalRecords">符合条件的总记录数。</param>
        /// <param name="totalPages">总页数。</param>
        /// <param name="pageSize">每页记录数。</param>
        /// <param name="pageNumber">当前页码。</param>
        /// <param name="data">当前页数据。</param>
        public PagedResult(int totalRecords, int totalPages, int pageSize, int pageNumber, List<T> data)
        {
            this.TotalPages = totalPages;
            this.TotalRecords = totalRecords;
            this.PageSize = pageSize;
            this.PageNumber = pageNumber;
            this.PageData = data;
        }

        /// <summary>
        /// 根据总记录数和分页参数计算总页数并创建结果。
        /// </summary>
        /// <param name="totalRecords">符合条件的总记录数。</param>
        /// <param name="pageSize">每页记录数。</param>
        /// <param name="pageNumber">当前页码。</param>
        /// <param name="data">当前页数据。</param>
        public PagedResult(int totalRecords, int pageSize, int pageNumber, List<T> data)
        {
            if (pageSize > 0)
            {
                this.TotalPages = totalRecords % pageSize == 0 ? totalRecords / pageSize : totalRecords / pageSize + 1;
            }

            this.TotalRecords = totalRecords;
            this.PageSize = pageSize;
            this.PageNumber = pageNumber;
            this.PageData = data;
        }
    }
}