#region

using System.Collections;
using System.Data;
using System.Drawing;
using System.Windows.Forms;
using CSFrameworkV5.Common;
using CSFrameworkV5.Core;
using CSFrameworkV5.Interfaces;
using DevExpress.XtraEditors;
using DevExpress.XtraGrid.Views.Grid;

#endregion

namespace CSFrameworkV5.Library.CommonClass
{
    /// <summary>
    ///     分页查询通用类(缓存分页数据)
    /// </summary>
    public class QueryByPageCache : IMyPageDataCache
    {
        private ISupportPageSearch _BusinessBLL; //业务逻辑层接口
        private int _CurrentPageNo = 1; //当前页号
        private GridView _DataView; //数据视图,如GridControl        

        private bool _IsChcheData;
        private int _PageCount; //本次搜索结果总页数
        private Hashtable _PageDataMapping; //哈希表，存储每页的数据
        private int _PageSize = 30; //预设每页返回30条记录        

        private object[] _SearchConditions; //本次查询的查询条件

        /// <summary>
        ///     构造器
        /// </summary>
        /// <param name="dataView">GridView表格</param>
        /// <param name="BLL">支持分页查询的BLL层</param>
        /// <param name="defaultPageSize">每页记录数</param>
        /// <param name="cacheData">是否缓存每页的数据（缺点：数据会过时，变成脏数据）</param>
        public QueryByPageCache(GridView dataView, ISupportPageSearch BLL,
            int defaultPageSize,
            bool cacheData = false)
        {
            _PageSize = defaultPageSize;
            _PageDataMapping = new Hashtable();
            _DataView = dataView;
            _BusinessBLL = BLL;
            _IsChcheData = cacheData;
            _DataView.GridControl.EmbeddedNavigator.ButtonClick +=
                navigator_ButtonClick;

            AddNavigatorPageButton(_DataView.GridControl.EmbeddedNavigator);
            SetPageButtonEnable(false);
        }

        /// <summary>
        ///     添加分页按钮
        /// </summary>
        /// <param name="navigator"></param>
        private void AddNavigatorPageButton(ControlNavigator navigator)
        {
            var img = new ImageList();
            img.ImageSize = new Size(40, 16);
            img.Images.Add(Globals.LoadImage("NAV_FIRST_PAGE.ico"));
            img.Images.Add(Globals.LoadImage("NAV_PRIOR_PAGE.ico"));
            img.Images.Add(Globals.LoadImage("NAV_NEXT_PAGE.ico"));
            img.Images.Add(Globals.LoadImage("NAV_LAST_PAGE.ico"));
            navigator.Buttons.ImageList = img;

            navigator.CustomButtons.Clear();

            var btnMoveFirst = new NavigatorCustomButton(0, "最前一页");
            var btnMovePrior = new NavigatorCustomButton(1, "上一页");
            var btnMoveNext1 = new NavigatorCustomButton(2, "下一页");
            var btnMoveLast1 = new NavigatorCustomButton(3, "最后一页");

            btnMoveFirst.Tag = "FIRST_PAGE";
            btnMovePrior.Tag = "PRIOR_PAGE";
            btnMoveNext1.Tag = "NEXT_PAGE";
            btnMoveLast1.Tag = "LAST_PAGE";

            navigator.CustomButtons.AddRange(new[]
                { btnMoveFirst, btnMovePrior, btnMoveNext1, btnMoveLast1 });
        }

        #region 导航按钮及事件

        public void SetPageButtonEnable(bool enable)
        {
            var navigator = _DataView.GridControl.EmbeddedNavigator;
            foreach (NavigatorCustomButton btn in navigator.Buttons
                         .CustomButtons) btn.Enabled = enable;
        }

        private void navigator_ButtonClick(object sender,
            NavigatorButtonClickEventArgs e)
        {
            if (_SearchConditions == null)
            {
                Msg.Warning("搜索器没有初始化，请先输入查询条件并查询数据！");
                return;
            }

            if (e.Button.Tag != null)
            {
                var tag = e.Button.Tag.ToStringEx().ToUpper();
                if (tag == "FIRST_PAGE") GotoFirstPage(); //第一页

                if (tag == "PRIOR_PAGE") GotoPriorPage(); //上一页

                if (tag == "NEXT_PAGE") GotoNextPage(); //下一页

                if (tag == "LAST_PAGE") GotoLastPage(); //最后页
            }
        }

        private void GotoNextPage()
        {
            _CurrentPageNo++;
            if (_CurrentPageNo > _PageCount)
            {
                _CurrentPageNo--;
                return;
            }

            var data = GetPageData(_CurrentPageNo);
            _DataView.GridControl.DataSource = data;
        }

        private void GotoPriorPage()
        {
            _CurrentPageNo--;
            if (_CurrentPageNo <= 0)
            {
                _CurrentPageNo++;
                return;
            }

            var data = GetPageData(_CurrentPageNo);
            _DataView.GridControl.DataSource = data;
        }

        private void GotoFirstPage()
        {
            _CurrentPageNo = 1;
            var data = GetPageData(_CurrentPageNo);
            _DataView.GridControl.DataSource = data;
        }

        private void GotoLastPage()
        {
            _CurrentPageNo = _PageCount;
            var data = GetPageData(_CurrentPageNo);
            _DataView.GridControl.DataSource = data;
        }

        #endregion

        #region IPageDataCache Members

        public int PageSize
        {
            get => _PageSize;
            set => _PageSize = value;
        }

        public int PageCount => _PageCount;

        public int CurrentPage => _CurrentPageNo;

        public int CachedPage => _PageDataMapping.Keys.Count;

        /// <summary>
        ///     获取指定页码的数据
        /// </summary>
        /// <param name="pageNo"></param>
        /// <returns></returns>
        public DataTable GetPageData(int pageNo)
        {
            if (pageNo <= 0) pageNo = 1;

            //不缓存每页数据，清空缓存器，程序会从数据库下载
            if (_IsChcheData == false) _PageDataMapping.Clear();

            //有缓存数据
            if (_PageDataMapping.ContainsKey(pageNo))
                return _PageDataMapping[pageNo] as DataTable; //从缓存表撷取数据

            try
            {
                Cursor.Current = Cursors.WaitCursor;

                //无缓存数据，从数据库下载然后加入缓存表
                var thisPageData =
                    _BusinessBLL.QueryByPage(_SearchConditions, pageNo,
                        _PageSize); //下载数据

                if (thisPageData != null && thisPageData.Rows.Count > 0)
                    _PageDataMapping.Add(pageNo,
                        thisPageData); //加入缓存表                

                return thisPageData; //返回数据
            }
            finally
            {
                Cursor.Current = Cursors.Default;
            }
        }

        /// <summary>
        ///     初始化缓存数据管理器
        /// </summary>
        /// <param name="searchConditions">查询条件</param>
        public void InitializeSearch(object[] searchConditions)
        {
            _PageDataMapping.Clear(); //清空哈希表            
            _SearchConditions = searchConditions;

            var firstPageData =
                _BusinessBLL.QueryByPage(searchConditions, 1, _PageSize);

            if (_BusinessBLL.TotalPages > 0)
            {
                _CurrentPageNo = 1;
                _PageDataMapping.Add(1,
                    firstPageData); //下载第一页数据，加入缓存表                
                _PageCount =
                    _BusinessBLL
                        .TotalPages; //取总页数                                
            }

            _DataView.GridControl.DataSource = firstPageData;
        }

        public void ClearCache()
        {
            _CurrentPageNo = 0;
            _PageCount = 0;
            _PageDataMapping.Clear();
        }

        #endregion
    }
}