using DevExpress.Charts.Native;
using DevExpress.XtraCharts;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace IStation.WinFormUI
{
    /// <summary>
    /// 图表框选辅助类
    /// </summary>
    public class ChartBoxSelHelper
    {
        public ChartBoxSelHelper(ChartControl chart)
        {
            _chart = chart;
            _chart.CustomPaint += chartControl_CustomPaint;
            _chart.MouseDown += chartControl_MouseDown;
            _chart.MouseMove += chartControl_MouseMove;
            _chart.MouseUp += chartControl_MouseUp;
        }

        private ChartControl _chart;//图表 
        private bool _isStartBoxSelect = false;//是否开始框选
        private Point? _startPoint;//开始点
        private Rectangle? _rect;//矩形
        private Color _rectBdrColor = Color.FromArgb(0, 122, 204);//矩形边框颜色
        private Color _rectBgColor = Color.FromArgb(89, Color.FromArgb(0xbaa500));//矩形背景颜色
   
        /// <summary>
        /// 框选完成事件
        /// </summary>
        public event Action<MouseEventArgs> BoxSelCompletedEvent;

        /// <summary>
        /// 矩形边框颜色
        /// </summary>
        public Color RectBdColor { get => _rectBdrColor; set => _rectBdrColor = value; }

        /// <summary>
        /// 矩形背景颜色
        /// </summary>
        public Color RectBgColor { get => _rectBgColor; set => _rectBgColor = value; }
         
        //自定义绘制矩形
        private void chartControl_CustomPaint(object sender, CustomPaintEventArgs e)
        {
            if (!(e is DXCustomPaintEventArgs dxArgs))
                return;
            if (_rect != null)
            {
                dxArgs.Cache.DrawRectangle(_rect.Value, RectBdColor, 1);
                dxArgs.Cache.FillRectangle(RectBgColor, _rect.Value);
            }
        }

        //鼠标按下
        private void chartControl_MouseDown(object sender, MouseEventArgs e)
        {
            if (_isStartBoxSelect)
            {
                _startPoint = e.Location;
            }
        }

        //鼠标移动
        private void chartControl_MouseMove(object sender, MouseEventArgs e)
        {
            if (_isStartBoxSelect && _startPoint != null)
            {
                _rect = GetRectangle(_startPoint.Value, e.Location);
                _chart.Invalidate();
            }
        }

        private Rectangle GetRectangle(Point p1, Point p2)
        {
            int x = p1.X < p2.X ? p1.X : p2.X;
            int y = p1.Y < p2.Y ? p1.Y : p2.Y;
            int width = Math.Abs(p1.X - p2.X);
            int height = Math.Abs(p1.Y - p2.Y);
            return new Rectangle(x, y, width, height);
        }

        private RectangleF GetRectangle(PointF p1, PointF p2)
        {
            float x = p1.X < p2.X ? p1.X : p2.X;
            float y = p1.Y < p2.Y ? p1.Y : p2.Y;
            float width = Math.Abs(p1.X - p2.X);
            float height = Math.Abs(p1.Y - p2.Y);
            return new RectangleF(x, y, width, height);
        }

        //鼠标弹起
        private void chartControl_MouseUp(object sender, MouseEventArgs e)
        {
            _isStartBoxSelect = false;
            _startPoint = null;
            if (_rect != null)
            {
                this.BoxSelCompletedEvent?.Invoke(e);
            }
        }

        /// <summary>
        /// 开始框选
        /// </summary>
        public void StartBoxSel()
        { 
            _isStartBoxSelect = true;
        }

        /// <summary>
        /// 关闭框选
        /// </summary>
        public void CloseBoxSel()
        {
            _rect = null;
            _chart.Invalidate();
        }

        //计算时间选中的点
        public List<SeriesPoint> CalcuDataTimeSelSeriesPoints(List<Series> seriesList)
        {
            if (seriesList == null || seriesList.Count < 1)
                return default;
            if (_rect == null)
                return default;

            var chartStartPoint = _rect.Value.Location;
            var chartEndPoint = new Point(_rect.Value.X + _rect.Value.Width, _rect.Value.Y + _rect.Value.Height);
            var xyDiagram = _chart.Diagram as XYDiagram2D;
            var coordiStart = xyDiagram.PointToDiagram(chartStartPoint);
            var coordiEnd = xyDiagram.PointToDiagram(chartEndPoint);

            if (coordiStart.IsEmpty || coordiEnd.IsEmpty)
                return default;

            var start_time = coordiStart.DateTimeArgument;
            var start_value = coordiStart.NumericalValue;
            var end_time = coordiEnd.DateTimeArgument;
            var end_value = coordiEnd.NumericalValue;

            var list = new List<SeriesPoint>();
            foreach (Series series in seriesList)
            {
                foreach (SeriesPoint point in series.Points)
                {
                    var dataTime = point.DateTimeArgument;
                    if (dataTime >= start_time && dataTime <= end_time)
                    { 
                        var dataValue=point.Values[0];
                        if ((dataValue >= start_value && dataValue <= end_value) || (dataValue <= start_value && dataValue >= end_value))
                        {
                            list.Add(point);
                        }
                    }
                }
            }

            return list;
        }

        //计算数值选中的点
        public List<SeriesPoint> CalcuNumericalSelSeriesPoints (List<Series> seriesList)
        {
            if (seriesList == null || seriesList.Count < 1)
                return default;
            if (_rect == null)
                return default;

            var chartStartPoint = _rect.Value.Location;
            var chartEndPoint = new Point(_rect.Value.X + _rect.Value.Width, _rect.Value.Y + _rect.Value.Height);
            var xyDiagram = _chart.Diagram as XYDiagram2D;
            var coordiStart = xyDiagram.PointToDiagram(chartStartPoint);
            var coordiEnd = xyDiagram.PointToDiagram(chartEndPoint);

            if (coordiStart.IsEmpty || coordiEnd.IsEmpty)
                return default;

            PointF startPoint = new PointF((float)coordiStart.NumericalArgument, (float)coordiStart.NumericalValue);
            PointF endPoint = new PointF((float)coordiEnd.NumericalArgument, (float)coordiEnd.NumericalValue);

            var bounds = GetRectangle(startPoint, endPoint);
            var list = new List<SeriesPoint>();
            foreach (Series series in seriesList)
            {
                foreach (SeriesPoint point in series.Points)
                {
                    float x = (float)point.NumericalArgument;
                    float y = (float)point.Values[0];
                    if (bounds.Contains(x, y))
                    {
                        list.Add(point);
                    }
                }
            }

            return list;
        }
          
    }
}