using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using DevExpress.XtraGrid.Views.Grid;
namespace SystemX.Product.TRA.UIControl.Helper {
    public class MergedRowsHelper {
        List<int> _rows = new List<int>();
        GridView _gridView;
        public void Register(GridView gridView) {
            if(gridView == null) return;
            _gridView = gridView;
            gridView.FocusedRowChanged += gridView_FocusedRowChanged;
            gridView.RowStyle += gridView_RowStyle;
            gridView.GridControl.Load += GridControl_Load;
            gridView.RowCellStyle += gridView_RowCellStyle;
        }

        void GridControl_Load(object sender, EventArgs e) {
            RefreshMergedRows();
        }

        void gridView_RowStyle(object sender, RowStyleEventArgs e) {
            if (_rows.Contains(_gridView.GetDataSourceRowIndex(e.RowHandle))) {
                e.Appearance.Assign(_gridView.PaintAppearance.FocusedRow);
                e.HighPriority = true;
            }
        }

        void gridView_RowCellStyle(object sender, RowCellStyleEventArgs e)
        {
            e.Appearance.TextOptions.HAlignment = e.Column.AppearanceCell.HAlignment;
        }

        void gridView_FocusedRowChanged(object sender, DevExpress.XtraGrid.Views.Base.FocusedRowChangedEventArgs e) {
            RefreshMergedRows();

            _gridView.LayoutChanged();
        }

        void RefreshMergedRows() {
            _rows = GetMergedRows(_gridView.FocusedRowHandle);

            _gridView.RefreshData();
        }

        List<int> GetMergedRows(int rowHandle) {
            HashSet<int> mergedRows = new HashSet<int>();
            foreach(DevExpress.XtraGrid.Columns.GridColumn col in _gridView.VisibleColumns) {
                var originalCell = _gridView.GetRowCellDisplayText(rowHandle, col);
                for(int i = rowHandle; ; i--) {
                    if(!_gridView.IsValidRowHandle(i)) break;
                    var cell = _gridView.GetRowCellDisplayText(i, col);
                    if(cell == originalCell) mergedRows.Add(i);
                    else break;
                }
                for(int i = rowHandle; ; i++) {
                    if(!_gridView.IsValidRowHandle(i)) break;
                    var cell = _gridView.GetRowCellDisplayText(i, col);
                    if(cell == originalCell) mergedRows.Add(i);
                    else break;
                }
            }
            List<int> result = new List<int>();
            foreach(var item in mergedRows) {
                result.Add(_gridView.GetDataSourceRowIndex(item));
            }
            return result;
        }

    }
}