using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Windows.Forms.VisualStyles;

namespace TemuKJD.UserComponent
{
    /// <summary>
    /// 带表头全选的选择框列
    /// </summary>
    public class DataGridViewCheckBoxColumnSelectAll : DataGridViewCheckBoxColumn
    {
        private DatagridViewCheckBoxHeaderCell headerCell;
        private bool loaded;

        public event CheckBoxClickedHandler OnCheckBoxClicked;
        int TotalCheckedCheckBoxes = 0;
        bool IsHeaderCheckBoxClicked = false;

        public DataGridViewCheckBoxColumnSelectAll()
        {
            this.headerCell = new DatagridViewCheckBoxHeaderCell();
            base.HeaderCell = this.headerCell;

            this.headerCell.OnCheckBoxClicked += new CheckBoxClickedHandler(this.headerCell_OnCheckBoxClicked);
            this.loaded = false;

        }

        public DataGridViewCheckBoxColumnSelectAll(bool threeState)
            : base(threeState)
        {
            this.headerCell = new DatagridViewCheckBoxHeaderCell();
            base.HeaderCell = this.headerCell;
        }

        /// <summary>
        /// 在DataGridView改变时进行事件的绑定
        /// </summary>
        protected override void OnDataGridViewChanged()
        {
            if (this.DataGridView != null)
            {
                this.DataGridView.CellValueChanged -= DataGridView_CellValueChanged;
                this.DataGridView.CellValueChanged += DataGridView_CellValueChanged;
                this.DataGridView.CurrentCellDirtyStateChanged -= DataGridView_CurrentCellDirtyStateChanged;
                this.DataGridView.CurrentCellDirtyStateChanged += DataGridView_CurrentCellDirtyStateChanged;
            }
        }

        /// <summary>
        /// 在复选的时候进行判断.
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        void DataGridView_CellValueChanged(object sender, DataGridViewCellEventArgs e)
        {
            if (e.RowIndex >= 0 && e.ColumnIndex >= 0)
            {
                if (!IsHeaderCheckBoxClicked)
                    RowCheckBoxClick((DataGridViewCheckBoxCell)this.DataGridView[e.ColumnIndex, e.RowIndex]);
            }

        }

        /// <summary>
        /// 在复选框被选中的时候触发该事件, 该事件用于触发ValueChanged事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void DataGridView_CurrentCellDirtyStateChanged(object sender, EventArgs e)
        {
            if (this.DataGridView.CurrentCell is DataGridViewCheckBoxCell)
                this.DataGridView.CommitEdit(DataGridViewDataErrorContexts.Commit);
        }

        /// <summary>
        /// 复选框被点击时所需要做的操作
        /// </summary>
        /// <param name="checkBox"></param>
        private void RowCheckBoxClick(DataGridViewCheckBoxCell checkBox)
        {
            var head = this.headerCell as DatagridViewCheckBoxHeaderCell;
            if (checkBox != null)
            {
                //计算所有被选中的行的数量 
                if ((bool)checkBox.Value && TotalCheckedCheckBoxes < this.DataGridView.RowCount)
                    TotalCheckedCheckBoxes++;
                else if (TotalCheckedCheckBoxes > 0)
                    TotalCheckedCheckBoxes--;

                //当所有复选框都被选中的时候,列的头上的复选框被选中, 反之则不被选中.
                if (TotalCheckedCheckBoxes < this.DataGridView.RowCount)
                    head.IsChecked = false;
                else if (TotalCheckedCheckBoxes == this.DataGridView.RowCount)
                    head.IsChecked = true;
                //强制repained
                head.DataGridView.InvalidateCell(head);
            }
        }

        /// <summary>
        /// 头被选中时触发OnCheckBoxClicked事件.
        /// </summary>
        /// <param name="state"></param>
        private void headerCell_OnCheckBoxClicked(bool state)
        {
            if (this.OnCheckBoxClicked != null)
            {
                this.OnCheckBoxClicked(state);
            }
        }

        public delegate void CheckBoxClickedHandler(bool state);

        internal class DatagridViewCheckBoxHeaderCell : DataGridViewColumnHeaderCell
        {
            private CheckBoxState _cbState = CheckBoxState.UncheckedNormal;
            private Point _cellLocation = new Point();
            private bool _checked;
            private Point checkBoxLocation;
            private Size checkBoxSize;

            public bool IsChecked
            {
                get
                {
                    return _checked;
                }

                set
                {
                    _checked = value;
                    if (this._checked)
                    {
                        this._cbState = CheckBoxState.CheckedNormal;
                    }
                    else
                    {
                        this._cbState = CheckBoxState.UncheckedNormal;
                    }
                }
            }

            public event CheckBoxClickedHandler OnCheckBoxClicked;

            /// <summary>
            /// 点击列头的时候触发的事件,这里有个判断, 如果点击的位置是复选框则触发OnCheckBoxClicked事件.
            /// </summary>
            /// <param name="e"></param>
            protected override void OnMouseClick(DataGridViewCellMouseEventArgs e)
            {
                Point point = new Point(e.X + this._cellLocation.X, e.Y + this._cellLocation.Y);
                if (((point.X >= this.checkBoxLocation.X) && (point.X <= (this.checkBoxLocation.X + this.checkBoxSize.Width))) && ((point.Y >= this.checkBoxLocation.Y) && (point.Y <= (this.checkBoxLocation.Y + this.checkBoxSize.Height))))
                {
                    this._checked = !this._checked;
                    bool temp = this._checked;
                    if (this.OnCheckBoxClicked != null)
                    {
                        this.OnCheckBoxClicked(this._checked);
                        base.DataGridView.InvalidateCell(this);
                    }
                    foreach (DataGridViewRow row in base.DataGridView.Rows)
                    {
                        ((DataGridViewCheckBoxCell)row.Cells[e.ColumnIndex]).Value = temp;
                    }
                    base.DataGridView.RefreshEdit();
                }
                base.OnMouseClick(e);
            }

            /// <summary>
            /// 绘制一个CheckBox
            /// </summary>
            protected override void Paint(Graphics graphics, Rectangle clipBounds, Rectangle cellBounds, int rowIndex, DataGridViewElementStates dataGridViewElementState, object value, object formattedValue, string errorText, DataGridViewCellStyle cellStyle, DataGridViewAdvancedBorderStyle advancedBorderStyle, DataGridViewPaintParts paintParts)
            {
                base.Paint(graphics, clipBounds, cellBounds, rowIndex, dataGridViewElementState, value, formattedValue, errorText, cellStyle, advancedBorderStyle, paintParts);
                Point point = new Point();
                Size glyphSize = CheckBoxRenderer.GetGlyphSize(graphics, CheckBoxState.UncheckedNormal);
                point.X = (cellBounds.Location.X + (cellBounds.Width / 2)) - (glyphSize.Width / 2) - 1; // x位置补偿一个像素(否则在win11中偏右)
                point.Y = (cellBounds.Location.Y + (cellBounds.Height / 2)) - (glyphSize.Height / 2);
                //point.X = cellBounds.Location.X + (cellBounds.Width - glyphSize.Width) / 2; // 放一块以后除以2会有抖动
                //point.Y = cellBounds.Location.Y + (cellBounds.Height - glyphSize.Height) / 2;
                this._cellLocation = cellBounds.Location;
                this.checkBoxLocation = point;
                this.checkBoxSize = glyphSize;
                if (this._checked)
                {
                    this._cbState = CheckBoxState.CheckedNormal;
                }
                else
                {
                    this._cbState = CheckBoxState.UncheckedNormal;
                }
                CheckBoxRenderer.DrawCheckBox(graphics, this.checkBoxLocation, this._cbState);
            }
        }
    }
}