using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows.Input;
using GummingCommon;

namespace Gumming
{
    public class PagerControlViewModule: ViewModelBase
    {
        public PagerControlView View { get; set; }

        public delegate void PagerHandler(int currentpagenumber, int currentrows);
        public event PagerHandler OnPager;

        private ViewProperty<int> _CurrentPageIndex = new ViewProperty<int>(1);
        public int CurrentPageIndex
        {
            get { return _CurrentPageIndex.Value; }
            set { if (_CurrentPageIndex.Value != value) _CurrentPageIndex.Value = value; this.OnPropertyChanged("CurrentPageIndex"); }
        }
        private int _TotalPages = 1;
        public int TotalPages
        {
            get { return _TotalPages; }
            set { if (_TotalPages != value) _TotalPages = value; this.OnPropertyChanged("TotalPages"); }
        }
        private int records = 0;
        private int counts = 0;
        public ICommand FirstCommand { get; set; }
        public ICommand PreviousCommand { get; set; }
        public ICommand NextCommand { get; set; }
        public ICommand LastCommand { get; set; }
        private bool _FirstIsEnabled = false;
        public bool FirstIsEnabled
        {
            get { return _FirstIsEnabled; }
            set { if (_FirstIsEnabled != value) _FirstIsEnabled = value; this.OnPropertyChanged("FirstIsEnabled"); }
        }
        private bool _PreviousIsEnabled = false;
        public bool PreviousIsEnabled
        {
            get { return _PreviousIsEnabled; }
            set { if (_PreviousIsEnabled != value) _PreviousIsEnabled = value; this.OnPropertyChanged("PreviousIsEnabled"); }
        }
        private bool _NextIsEnabled = false;
        public bool NextIsEnabled
        {
            get { return _NextIsEnabled; }
            set { if (_NextIsEnabled != value) _NextIsEnabled = value; this.OnPropertyChanged("NextIsEnabled"); }
        }
        private bool _LastIsEnabled = false;
        public bool LastIsEnabled
        {
            get { return _LastIsEnabled; }
            set { if (_LastIsEnabled != value) _LastIsEnabled = value; this.OnPropertyChanged("LastIsEnabled"); }
        }
        private bool _PageIsEnabled = false;
        public bool PageIsEnabled
        {
            get { return _PageIsEnabled; }
            set { if (_PageIsEnabled != value) _PageIsEnabled = value; this.OnPropertyChanged("PageIsEnabled"); }
        }
        private string _PagerInfo1;
        public string PagerInfo1
        {
            get { return _PagerInfo1; }
            set { if (_PagerInfo1 != value) _PagerInfo1 = value; this.OnPropertyChanged("PagerInfo1"); }
        }
        private string _TotalInfo;
        public string TotalInfo
        {
            get { return _TotalInfo; }
            set { if (_TotalInfo != value) _TotalInfo = value; this.OnPropertyChanged("TotalInfo"); }
        }

        public IEnumerable<int> PagerRows
        {
            get;
            set;
        }

        private ViewProperty<int> _CurrentPagerRows = new ViewProperty<int>();
        public int CurrentPagerRows
        {
            get { return _CurrentPagerRows.Value; }
            set
            {
                if (_CurrentPagerRows.Value == value)
                    return;
                _CurrentPagerRows.Value = value;

                OnPropertyChanged("CurrentPagerRows");
            }
        }

        public PagerControlViewModule()
        {
            View = new PagerControlView();
            View.DataContext = this;
            PageIsEnabled = false;
            IList<int> pagerNumbers = new List<int>() { 10, 20, 50, 100 };
            PagerRows = pagerNumbers;
            FirstCommand = new DelegateCommand(OnFirstCommand);
            PreviousCommand = new DelegateCommand(OnPreviousCommand);
            NextCommand = new DelegateCommand(OnNextCommand);
            LastCommand = new DelegateCommand(OnLastCommand);
            _CurrentPagerRows.ValueChanged += new Action(_CurrentPagerRows_ValueChanged);
            _CurrentPageIndex.ValueChanged += new Action(_CurrentPageIndex_ValueChanged);
        }

        private void _CurrentPageIndex_ValueChanged()
        {
            if (OnPager != null)
            {
                OnPager(CurrentPageIndex, CurrentPagerRows);
            }
        }

        private void _CurrentPagerRows_ValueChanged()
        {            
            if (CurrentPageIndex == 1)
            {
                if (OnPager != null)
                {
                    OnPager(CurrentPageIndex, CurrentPagerRows);
                }
            }
            else
            {
                CurrentPageIndex = 1;
            }
        }


        public void SetPager(int _rows, int _pagenumber, int _pagecount, int _counts , int _records)
        {
            CurrentPagerRows = _rows;
            if (!PagerRows.Contains(_rows))
            { 
                IList<int> pagerNumbers = PagerRows.ToList();
                pagerNumbers.Add(_rows);
                PagerRows = pagerNumbers;
                OnPropertyChanged("PagerRows");
            }
            CurrentPageIndex = _pagenumber;
            TotalPages = _pagecount;
            records = _records;
            counts = _counts;
            SetStatus();
            PageIsEnabled = true;
        }

        private void OnFirstCommand(object sender)
        {
            CurrentPageIndex = 1;
            SetStatus();            
        }
        private void OnPreviousCommand(object sender)
        {
            CurrentPageIndex = CurrentPageIndex - 1;
            SetStatus();
        }
        private void OnNextCommand(object sender)
        {
            CurrentPageIndex = CurrentPageIndex + 1;
            SetStatus();            
        }
        private void OnLastCommand(object sender)
        {
            CurrentPageIndex = TotalPages;
            SetStatus();
        }

        private void SetStatus()
        {
            if (CurrentPageIndex <= 1)
            {
                FirstIsEnabled = false;
                PreviousIsEnabled = false;
            }
            else
            {
                FirstIsEnabled = true;
                PreviousIsEnabled = true;
            }

            if (CurrentPageIndex >= TotalPages)
            {
                NextIsEnabled = false;
                LastIsEnabled = false;
            }
            else
            {
                NextIsEnabled = true;
                LastIsEnabled = true;
            }
           
            TotalInfo = string.Format("当前页面记录{0}/共{1}条记录", counts, records);
        }
    }
}