using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls.Primitives;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Shapes;

namespace XP.ImageProcessing.RoiControl
{
    /// <summary>
    /// 多边形装饰器，用于编辑多边形顶点
    /// </summary>
    public class PolygonAdorner : Adorner
    {
        private List<ControlThumb> vertexThumbs = new List<ControlThumb>();  // 顶点控制�?
        private VisualCollection visualChildren;
        private double scaleFactor = 1;
        private Models.PolygonROI? polygonROI;

        public PolygonAdorner(UIElement adornedElement, double scaleFactor = 1, Models.PolygonROI? roiModel = null)
            : base(adornedElement)
        {
            visualChildren = new VisualCollection(this);
            this.scaleFactor = scaleFactor;
            this.polygonROI = roiModel;

            // 使用ROI模型的Points数量而不是Polygon的Points
            int pointCount = polygonROI?.Points.Count ?? 0;

            // 创建顶点控制�?
            for (int i = 0; i < pointCount; i++)
            {
                var thumb = new ControlThumb();
                thumb.DragDelta += HandleDrag;
                thumb.DragCompleted += HandleDragCompleted;
                thumb.MouseRightButtonDown += HandleRightClick;
                thumb.Tag = i;
                thumb.Cursor = Cursors.Hand;
                vertexThumbs.Add(thumb);
                visualChildren.Add(thumb);
            }

            // 不再创建边中点控制点 - 使用智能插入算法代替
            // 用户可以直接点击画布，系统会自动找到最近的边并插入顶点
        }

        private void HandleDrag(object sender, DragDeltaEventArgs args)
        {
            Thumb? hitThumb = sender as Thumb;
            if (hitThumb == null || polygonROI == null) return;

            int index = (int)hitThumb.Tag;

            // 直接修改ROI模型的Points
            if (index < polygonROI.Points.Count)
            {
                Point currentPoint = polygonROI.Points[index];
                Point newPoint = new Point(
                    currentPoint.X + args.HorizontalChange,
                    currentPoint.Y + args.VerticalChange
                );

                // 使用索引器修改ObservableCollection中的元素
                polygonROI.Points[index] = newPoint;
            }

            // 强制重新布局
            InvalidateArrange();
        }

        private void HandleDragCompleted(object sender, DragCompletedEventArgs args)
        {
            // 拖拽完成后通知模型更新
            if (polygonROI != null)
            {
                polygonROI.OnPropertyChanged(nameof(polygonROI.Points));
            }
        }

        private void HandleRightClick(object sender, MouseButtonEventArgs e)
        {
            // 右键删除顶点（至少保�?个顶点）
            if (polygonROI != null && polygonROI.Points.Count > 3)
            {
                Thumb? hitThumb = sender as Thumb;
                if (hitThumb != null)
                {
                    int index = (int)hitThumb.Tag;

                    // 删除顶点 - ObservableCollection会自动触发CollectionChanged事件
                    // PolygonRoiCanvas会监听到这个变化并自动更新Adorner
                    polygonROI.Points.RemoveAt(index);

                    e.Handled = true;
                }
            }
        }

        protected override Size ArrangeOverride(Size finalSize)
        {
            // 使用ROI模型的Points而不是Polygon的Points
            if (polygonROI != null)
            {
                double thumbSize = 12 * scaleFactor;

                // 布局顶点控制�?
                for (int i = 0; i < vertexThumbs.Count && i < polygonROI.Points.Count; i++)
                {
                    vertexThumbs[i].Arrange(new Rect(
                        polygonROI.Points[i].X - (thumbSize / 2),
                        polygonROI.Points[i].Y - (thumbSize / 2),
                        thumbSize,
                        thumbSize));
                }
            }
            else
            {
                // 备用方案：使用Polygon的Points
                Polygon poly = (Polygon)AdornedElement;
                double thumbSize = 12 * scaleFactor;

                for (int i = 0; i < vertexThumbs.Count && i < poly.Points.Count; i++)
                {
                    vertexThumbs[i].Arrange(new Rect(
                        poly.Points[i].X - (thumbSize / 2),
                        poly.Points[i].Y - (thumbSize / 2),
                        thumbSize,
                        thumbSize));
                }
            }

            return finalSize;
        }

        protected override int VisualChildrenCount
        { get { return visualChildren.Count; } }

        protected override Visual GetVisualChild(int index)
        { return visualChildren[index]; }
    }
}