using PaintDotNet.Annotation.Enum;
using PaintDotNet.Base.CommTool;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Windows.Forms;

/*
 * 视场,
 * 全部图形构成基于点阵(Points)拟合.
 * 图形变换,对外属性均依赖于点阵的换算.
 * 点阵集合继承DrawObject 的 pointArrayList 字段
 * 全部接口数值皆为原始数值并未进行缩放处理.
 */
namespace PaintDotNet.Annotation.FieldView
{
    public abstract class ViewBase : DrawObject
    {
        /// <summary>
        /// 鼠标形状
        /// </summary>
        public static Cursor m_rotateCursor = new Cursor(PdnResources.GetResourceStream("Cursors.AnnotationRotateHandle.cur"));
        public static Cursor m_resizeCursor = new Cursor(PdnResources.GetResourceStream("Cursors.AnnotationResizeHandle.cur"));

        public override double Width
        {
            get => Rectangle.Width;
            set
            {

            }
        }

        public override double Height
        {
            get => Rectangle.Height;
            set
            {
            }
        }


        #region Points
        public virtual List<PointF> Points
        {
            get
            {
                if (pointArrayList == null)
                    pointArrayList = new List<PointF>();
                return pointArrayList;
            }
            set
            {
                pointArrayList = new List<PointF>();
                foreach (var p in value)
                {
                    pointArrayList.Add(p);
                }
            }
        }

        public void AddPoint(int x, int y)
        {
            AddPoint(new PointF(x, y));
        }

        protected void AddPoint(PointF point)
        {
            Points.Add(point);
        }

        public override List<PointF> GetPoints()
        {
            return Points;
        }
        #endregion

        #region Bounding Rectangle
        public override RectangleF Rectangle
        {
            get
            {
                return GetBoundingBox();
            }
        }

        /// <summary>
        /// 外接矩形
        /// </summary>
        public override RectangleF GetBoundingBox()
        {
            float minx = 0, maxx = 0, miny = 0, maxy = 0;
            for (int i = 0; i < Points.Count; i++)
            {
                if (i == 0)
                {
                    minx = maxx = Points[i].X;
                    miny = maxy = Points[i].Y;
                }
                else
                {
                    if (Points[i].X > maxx) maxx = Points[i].X;
                    if (Points[i].X < minx) minx = Points[i].X;
                    if (Points[i].Y > maxy) maxy = Points[i].Y;
                    if (Points[i].Y < miny) miny = Points[i].Y;
                }
            }

            return new RectangleF(minx, miny, maxx - minx, maxy - miny);
        }
        #endregion

        #region Draw
        /// <summary>
        /// 指定如何组合不同的剪辑区域
        /// 用于存储是合并视场、还是剪切视场
        /// </summary>
        public CombineMode combineMode;

        /// <summary>
        /// Draw rectangle
        /// </summary>
        /// <param name="g"></param>
        public override void Draw(Graphics g)
        {
            Region reg = g.Clip;
            ViewBase view = null;
            for (int i = ISurfaceBox.GraphicsList.Count - 1; ;)
            {

                if (ISurfaceBox.GraphicsList[i].objectType == DrawClass.View)
                {
                    view = (ViewBase)ISurfaceBox.GraphicsList[i];
                    if (view.combineMode == CombineMode.Union)
                    {
                        break;
                    }
                }
                i--;
                if (i < 0)
                {
                    view.combineMode = CombineMode.Union;
                    break;
                }
            }

            //获取所有合并的视场
            Region union = GetUnionOrDeleteView(CombineMode.Union);
            //获取所有删除的视场
            Region delete = GetUnionOrDeleteView(CombineMode.Complement);

            if (union != null)
            {
                reg.Xor(union);
            }

            if (delete != null)
            {
                reg.Union(delete);
            }

            SolidBrush sb = new SolidBrush(Color.FromArgb(180, 0, 0, 0));
            g.FillRegion(sb, reg);
        }

        /// <summary>
        /// 获取所有合并或删除的视场
        /// </summary>
        /// <returns></returns>
        private Region GetUnionOrDeleteView(CombineMode combineMode)
        {
            Region region = null;
            if (ISurfaceBox.GraphicsList != null && ISurfaceBox.GraphicsList.Count > 0)
            {
                for (int i = 0; i < ISurfaceBox.GraphicsList.Count; i++)
                {
                    if (ISurfaceBox.GraphicsList[i].objectType == DrawClass.View)
                    {
                        ViewBase view = (ViewBase)ISurfaceBox.GraphicsList[i];
                        GraphicsPath path = new GraphicsPath();
                        switch (view.drawToolType)
                        {
                            case DrawToolType.ViewOval:
                                path.AddClosedCurve(ISurfaceBox.GraphicsList[i].GetPoints().ToArray());
                                break;
                            case DrawToolType.ViewCircle:
                                path.AddEllipse(ISurfaceBox.GraphicsList[i].Rectangle);
                                break;
                            case DrawToolType.ViewSquare:
                            case DrawToolType.ViewRectangle:
                            case DrawToolType.ViewTriangle:
                            case DrawToolType.ViewPolygon:
                            case DrawToolType.ViewTriangleEx:
                            case DrawToolType.ViewRectangleEx:
                                if ((ISurfaceBox.GraphicsList[i]).GetPoints().Count > 2)
                                {
                                    path.AddPolygon((ISurfaceBox.GraphicsList[i]).GetPoints().ToArray());
                                }
                                break;
                        }

                        if (view.combineMode == combineMode)
                        {
                            if (region == null)
                                region = new Region(path);
                            else
                                region.Union(path);
                        }
                    }
                }
            }

            return region;
        }

        public override void DrawTracker(Graphics g)
        {
            if (!Selected)
                return;

            SolidBrush brush = new SolidBrush(Color.FromArgb(184, Color.Black));
            var pen = new Pen(Color.FromArgb(0, 148, 255));
            switch (drawToolType)
            {
                case DrawToolType.ViewOval:
                    g.DrawClosedCurve(pen, GetPoints().ToArray());
                    break;
                case DrawToolType.ViewCircle:
                    g.DrawEllipse(pen, Rectangle);
                    break;
                case DrawToolType.ViewSquare:
                case DrawToolType.ViewRectangle:
                case DrawToolType.ViewTriangle:
                case DrawToolType.ViewPolygon:
                case DrawToolType.ViewTriangleEx:
                case DrawToolType.ViewRectangleEx:
                    if (GetPoints().Count > 2)
                    {
                        g.DrawPolygon(pen, GetPoints().ToArray());
                    }
                    break;
            }
            if (Rotatable && Points.Count > 2)
            {
                for (int i = 1; i <= HandleCount - 1; i++)
                {
                    g.FillRectangle(brush, GetHandleRectangle(i));
                    g.DrawRectangle(pen, GetHandleRectangle(i));
                }
                brush = new SolidBrush(Color.Red);
                g.FillEllipse(brush, GetHandleRectangle(HandleCount));
                brush.Dispose();
            }
            else
            {
                for (int i = 1; i <= HandleCount; i++)
                {
                    g.FillRectangle(brush, GetHandleRectangle(i));
                    g.DrawRectangle(pen, GetHandleRectangle(i));
                }
            }
        }
        #endregion 

        #region Rotate
        protected PointF _lastPoint;
        protected PointF _lastCenter;
        protected bool _isRotating;

        /// <summary>
        /// 设置可旋转性,用于显示旋转Handle
        /// </summary>
        public bool Rotatable = false;

        /// <summary>
        /// 图形斜率,用于旋转
        /// </summary>
        public double K
        {
            get;
            set;
        } = 0;

        public virtual void SetK() { }

        public virtual PointF Center
        {
            get
            {
                var centerX = Rectangle.X + Math.Abs(Rectangle.Width / 2);
                var centerY = Rectangle.Y + Math.Abs(Rectangle.Height / 2);
                return new PointF(centerX, centerY);
            }
            set { }
        }

        protected virtual void StartRotate()
        {
            _isRotating = true;
            _lastCenter = Center;
        }

        protected virtual void EndRotate()
        {
            _isRotating = false;
            SetK();
        }

        protected virtual void MoveRotate(PointF point)
        {
            if (!_isRotating)
            {
                StartRotate();
                _lastPoint = point;
            }
            double angle = BasicCalculationHelper.CalculateAngle(_lastCenter.X, _lastCenter.Y, _lastPoint.X, _lastPoint.Y, point.X, point.Y);
            _lastPoint = point;
            for (int i = 0; i < Points.Count; i++)
            {
                Points[i] = BasicCalculationHelper.GetAnglePoint(Points[i], _lastCenter, angle);
            }
        }

        /// <summary>
        /// 标准化外接矩形
        /// </summary>
        public override void Normalize()
        {
            Console.WriteLine("Normalize");
            if (_isRotating)
                EndRotate();
        }
        #endregion

        #region Select
        /// <summary>
        /// Hit test.
        /// Return value: -1 - no hit
        ///                0 - hit anywhere
        ///                > 1 - handle number
        /// </summary>
        /// <param name="pointscroll"></param>
        /// <returns></returns>
        public override int HitTest(Point point)
        {
            if (Selected)
            {
                for (int i = 1; i <= HandleCount; i++)
                {
                    if (GetHandleRectangle(i).Contains(point))
                        return i;
                }
            }

            if (PointInObject(point))
                return 0;

            return -1;
        }
        protected override bool PointInObject(Point point)
        {
            int counter = 0;
            int i;
            double xinters;
            PointF p1, p2;
            int pointCount = Points.Count;
            p1 = Points[0];
            for (i = 1; i <= pointCount; i++)
            {
                p2 = Points[i % pointCount];
                if (point.Y > Math.Min(p1.Y, p2.Y)//校验点的Y大于线段端点的最小Y
                    && point.Y <= Math.Max(p1.Y, p2.Y))//校验点的Y小于线段端点的最大Y
                {
                    if (point.X <= Math.Max(p1.X, p2.X))//校验点的X小于等线段端点的最大X(使用校验点的左射线判断).
                    {
                        if (p1.Y != p2.Y)//线段不平行于X轴
                        {
                            xinters = (point.Y - p1.Y) * (p2.X - p1.X) / (p2.Y - p1.Y) + p1.X;
                            if (p1.X == p2.X || point.X <= xinters)
                            {
                                counter++;
                            }
                        }
                    }

                }
                p1 = p2;
            }
            return counter % 2 != 0;
        }

        public override bool IntersectsWith(Rectangle rectangle)
        {
            return Rectangle.IntersectsWith(rectangle);
        }
        #endregion

        public override void Move(int x, int y)
        {
            for (int i = 0; i < Points.Count; i++)
            {
                PointF p = Points[i];
                p.X += x;
                p.Y += y;
                Points[i] = p;
            }
            OnPropertyChanged();
        }

        /// <summary>
        /// 获取视场面积
        /// </summary>
        /// <returns></returns>
        public virtual double Getacreage()
        {
            var count = Points.Count;
            double area0 = 0;
            double area1 = 0;
            for (int i = 0; i < count; i++)
            {
                var x = Points[i].X;
                var y = i + 1 < count ? Points[i + 1].Y : Points[0].Y;
                area0 += x * y;

                x = Points[i].Y;
                y = i + 1 < count ? Points[i + 1].X : Points[0].X;
                area1 += x * y;
            }
            return Math.Abs(0.5 * (area0 - area1));
        }

    }
}