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

namespace Tool
{

    public class PagedList<T>
    {
        public List<T> Items { get; private set; }  // 存储当前页的元素
        public int PageIndex { get; private set; }  // 当前页码（从0开始）
        public int PageSize { get; private set; }   // 每页的元素数
        public int TotalCount { get; private set; } // 总记录数
        public int TotalPages => (int)Math.Ceiling((double)TotalCount / PageSize); // 总页数

        public bool HasPreviousPage => PageIndex > 0;
        public bool HasNextPage => PageIndex + 1 < TotalPages;

        public PagedList(List<T> items, int count, int pageIndex, int pageSize)
        {
            Items = items;
            TotalCount = count;
            PageIndex = pageIndex;
            PageSize = pageSize;
        }

        // 工厂方法，用于创建分页列表
        public static PagedList<T> Create(IList<T> source, int pageIndex, int pageSize)
        {
            var count = source.Count; // 总记录数
            var items = source.Skip(pageIndex * pageSize).Take(pageSize).ToList(); // 获取当前页的元素
            return new PagedList<T>(items, count, pageIndex, pageSize);
        }
    }
}