using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Drawing.Drawing2D;

namespace PaintDotNet.CustomControl
{
    /// <summary>
    /// 自定义的双滑块的拖动条
    /// </summary>
    public partial class DoubleSlidingTrackbar : BaseUserControl
    {
        /// <summary>
        /// 控件长度
        /// </summary>
        private int length = 0;
        /// <summary>
        /// 绘制左侧滑动块的点集合
        /// </summary>
        private List<Point> LeftPoints = new List<Point>();
        /// <summary>
        /// 绘制右侧滑动块的点集合
        /// </summary>
        private List<Point> RightPoints = new List<Point>();
        /// <summary>
        /// 鼠标按下状态
        /// </summary>
        private bool isPress = false;
        /// <summary>
        /// 鼠标按下时选中的滑块 1左 2右
        /// </summary>
        private int choise = -1;
        /// <summary>
        /// X轴的位移初始位置
        /// </summary>
        private int oldX = -1;
        /// <summary>
        /// 最大值
        /// </summary>
        public decimal maxValue = 0;
        /// <summary>
        /// 响应事件
        /// </summary>
        //private bool responseEvent = true;
        /// <summary>
        /// 左侧滑块拖动事件
        /// </summary>
        public event EventHandler LeftHandlerDrag;
        private void OnLeftHandlerDrag()
        {
            if (LeftHandlerDrag != null)
            {
                LeftHandlerDrag(this, new EventArgs());
            }
        }
        /// <summary>
        /// 右侧滑块拖动事件
        /// </summary>
        public EventHandler RightHandlerDrag;
        private void OnRightHandlerDrag()
        {
            if (RightHandlerDrag != null)
            {
                RightHandlerDrag(this, new EventArgs());
            }
        }

        /// <summary>
        /// 控件长度
        /// </summary>
        /// <param name="length"></param>
        public DoubleSlidingTrackbar(int length = 220)
        {
            SetStyle(ControlStyles.UserPaint | ControlStyles.AllPaintingInWmPaint | ControlStyles.OptimizedDoubleBuffer | ControlStyles.ResizeRedraw | ControlStyles.SupportsTransparentBackColor, true);
            this.length = length;

            InitializeComponent();

            this.Width = this.length;

            LeftPoints.Add(new Point(10, 5));
            LeftPoints.Add(new Point(16, 5));
            LeftPoints.Add(new Point(16, 20));
            LeftPoints.Add(new Point(10, 15));

            RightPoints.Add(new Point(16, 5));
            RightPoints.Add(new Point(22, 5));
            RightPoints.Add(new Point(22, 15));
            RightPoints.Add(new Point(16, 20));

            this.Paint += new PaintEventHandler(this.DoubleSlidingTrackbar_Paint);
            this.MouseDown += new MouseEventHandler(this.DoubleSlidingTrackbar_MouseDown);
            this.MouseMove += new MouseEventHandler(this.DoubleSlidingTrackbar_MouseMove);
            this.MouseUp += new MouseEventHandler(this.DoubleSlidingTrackbar_MouseUp);
        }

        private void DoubleSlidingTrackbar_MouseDown(object sender, MouseEventArgs e)
        {
            GraphicsPath leftPath = new GraphicsPath();
            leftPath.AddPolygon(LeftPoints.ToArray());
            Region leftRegion = new Region(leftPath);

            GraphicsPath rightPath = new GraphicsPath();
            rightPath.AddPolygon(RightPoints.ToArray());
            Region rightRegion = new Region(rightPath);

            if (leftRegion.IsVisible(new Point(e.X, e.Y)))
            {
                choise = 1;
                isPress = true;
                oldX = e.X;
            }

            if (rightRegion.IsVisible(new Point(e.X, e.Y)))
            {
                choise = 2;
                isPress = true;
                oldX = e.X;
            }
        }

        private void DoubleSlidingTrackbar_MouseMove(object sender, MouseEventArgs e)
        {
            if (isPress)
            {
                switch (choise)
                {
                    //左
                    case 1:
                        //if(e.X <= RightPoints[0].X)//e.X >= 10 && 
                        {
                            /*if(this.LeftPoints[1].X + e.X - oldX <= this.RightPoints[0].X 
                                && this.LeftPoints[0].X + e.X - oldX >= 10)
                            {
                                for (int i = 0; i < this.LeftPoints.Count; i++)
                                {
                                    Point point = this.LeftPoints[i];
                                    point.X += e.X - oldX;
                                    if (point.X < 10)
                                        break;
                                    else
                                        this.LeftPoints[i] = point;
                                }
                            }*/

                            if (this.LeftPoints[0].X + e.X - oldX >= 10)
                            {
                                if (this.LeftPoints[1].X + e.X - oldX <= this.RightPoints[0].X)
                                {
                                    for (int i = 0; i < this.LeftPoints.Count; i++)
                                    {
                                        Point point = this.LeftPoints[i];
                                        point.X += e.X - oldX;
                                        if (point.X < 10)
                                        {
                                            break;
                                        }
                                        else
                                        {
                                            this.LeftPoints[i] = point;
                                        }
                                    }
                                }
                                else
                                {
                                    LeftPoints.Clear();
                                    LeftPoints.Add(new Point(RightPoints[0].X - 6, 5));
                                    LeftPoints.Add(new Point(RightPoints[0].X, 5));
                                    LeftPoints.Add(new Point(RightPoints[0].X, 20));
                                    LeftPoints.Add(new Point(RightPoints[0].X - 6, 15));
                                }
                                OnLeftHandlerDrag();
                            }
                        }
                        break;
                    //右
                    case 2:
                        //if (e.X > LeftPoints[1].X)//e.X <= 210 && 
                        {
                            /*if (this.RightPoints[1].X + e.X - oldX <= 210
                                && this.RightPoints[0].X + e.X - oldX>= LeftPoints[1].X)
                            {
                                for (int i = 0; i < this.RightPoints.Count; i++)
                                {
                                    Point point = this.RightPoints[i];
                                    point.X += e.X - oldX;
                                    if (point.X > 210)
                                        break;
                                    else
                                        this.RightPoints[i] = point;
                                }
                            }*/
                            if (this.RightPoints[1].X + e.X - oldX <= this.length - 10)
                            {
                                if (this.RightPoints[0].X + e.X - oldX >= LeftPoints[1].X)
                                {
                                    for (int i = 0; i < this.RightPoints.Count; i++)
                                    {
                                        Point point = this.RightPoints[i];
                                        point.X += e.X - oldX;

                                        if (point.X > 210)
                                        {
                                            break;
                                        }
                                        else
                                        {
                                            this.RightPoints[i] = point;
                                        }
                                    }
                                }
                                else
                                {
                                    RightPoints.Clear();
                                    RightPoints.Add(new Point(LeftPoints[1].X, 5));
                                    RightPoints.Add(new Point(LeftPoints[1].X + 6, 5));
                                    RightPoints.Add(new Point(LeftPoints[1].X + 6, 15));
                                    RightPoints.Add(new Point(LeftPoints[1].X, 20));
                                }
                                OnRightHandlerDrag();
                            }
                        }
                        break;
                }
                oldX = e.X;
                this.Refresh();
            }
        }

        private void DoubleSlidingTrackbar_MouseUp(object sender, MouseEventArgs e)
        {
            oldX = -1;
            isPress = false;
        }

        private void DoubleSlidingTrackbar_Paint(object sender, PaintEventArgs e)
        {
            //绘制横线
            e.Graphics.FillRectangle(new SolidBrush(Color.FromArgb(214,214,214)), new Rectangle(16, 9, this.length - 32, 3));
            //绘制第一个滑块
            e.Graphics.FillPolygon(new SolidBrush(Color.FromArgb(0, 120, 215)), this.LeftPoints.ToArray());
            //e.Graphics.FillRectangle(new SolidBrush(Color.Blue), new Rectangle(10, 5, 6, 10));
            //绘制第二个滑块
            e.Graphics.FillPolygon(new SolidBrush(Color.FromArgb(36, 171, 242)), this.RightPoints.ToArray());
            //e.Graphics.FillRectangle(new SolidBrush(Color.Yellow), new Rectangle(16, 5, 6, 10));
        }

        public double GetLeftSliderValue()
        {
            decimal unitLenght = this.maxValue / (this.length - 32);
            return (double)((LeftPoints[1].X-16) * unitLenght);
        }

        public double GetRightSliderValue()
        {
            decimal unitLenght = this.maxValue / (this.length - 32);
            return (double)((RightPoints[0].X - 16) * unitLenght);
        }

        public void SetLeftSliderPos(double left)
        {
            if (!isPress)
            {
                decimal unitLenght = (this.length - 32) / this.maxValue;
                int pos = (int)(left * (double)unitLenght);
                LeftPoints.Clear();
                LeftPoints.Add(new Point(10 + pos, 5));
                LeftPoints.Add(new Point(16 + pos, 5));
                LeftPoints.Add(new Point(16 + pos, 20));
                LeftPoints.Add(new Point(10 + pos, 15));
                this.Refresh();
            }
        }

        public void SetRightSliderPos(double right)
        {
            if(!isPress)
            {
                decimal unitLenght =  (this.length - 32) / this.maxValue;
                int pos = (int)(right * (double)unitLenght);
                RightPoints.Clear();
                RightPoints.Add(new Point(16+pos, 5));
                RightPoints.Add(new Point(22+pos, 5));
                RightPoints.Add(new Point(22+pos, 15));
                RightPoints.Add(new Point(16+pos, 20));
                this.Refresh();
            }
        }

        public void InitLeftRightPoints()
        {
            LeftPoints.Clear();
            LeftPoints.Add(new Point(10, 5));
            LeftPoints.Add(new Point(16, 5));
            LeftPoints.Add(new Point(16, 20));
            LeftPoints.Add(new Point(10, 15));

            RightPoints.Clear();
            RightPoints.Add(new Point(16, 5));
            RightPoints.Add(new Point(22, 5));
            RightPoints.Add(new Point(22, 15));
            RightPoints.Add(new Point(16, 20));

            this.Refresh();
        }
    }
}