using Prism.Commands;
using Prism.Mvvm;
using Prism.Regions;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows;

namespace DM_Weight.Components.pagination
{
    public class PaginationViewModel: BindableBase, IRegionMemberLifetime
    {
        public static readonly DependencyProperty PageSizeProperty = DependencyProperty
        .Register("CurrentPage",
                typeof(int),
                typeof(Pagination),
                new FrameworkPropertyMetadata(10));

        // 每页条数
        private int _pageSize = 10;
        // 当前页码
        private int _currentPage = 1;
        // 总条数
        private int _totalPages = 0;
        
        public int PageSize { get=> _pageSize;  set => SetProperty(ref _pageSize, value); }
        public int CurrentPage { get => _currentPage; set => SetProperty(ref _currentPage, value); }
        public int TotalPages { get => _totalPages; set => SetProperty(ref _totalPages, value); }
        // 总页数 
        public int PageCount
        {
            get => (int)Math.Ceiling((double)TotalPages/ PageSize);
        }

        public string InfoText
        {
            get => ((CurrentPage - 1) * PageSize + 1) + "-" + (CurrentPage * PageSize > TotalPages ? TotalPages : CurrentPage * PageSize) + "/" + TotalPages;
        }

        public bool KeepAlive => false;


        public DelegateCommand ToFirst
        {
            get => new(() =>
            {
                CurrentPage = 1;
            });
        }



        public DelegateCommand ToPrve
        {
            get => new(() =>
            {
                CurrentPage -= 1;
            });
        }

        public DelegateCommand ToNext
        {
            get => new(() =>
            {
                CurrentPage += 1;
            });
        }

        public DelegateCommand ToEnd
        {
            get => new(() =>
            {
                CurrentPage = PageCount;
            });
        }


    }
}