using System;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Shapes;
using XP.ImageProcessing.RoiControl.Models;

namespace XP.ImageProcessing.RoiControl.Controls
{
    public partial class PolygonRoiCanvas : UserControl
    {
        private bool isDragging = false;
        private Point lastMousePosition;
        private const double ZoomStep = 1.2;
        private Adorner? currentAdorner;

        public PolygonRoiCanvas()
        {
            InitializeComponent();
            Loaded += PolygonRoiCanvas_Loaded;
        }

        private void PolygonRoiCanvas_Loaded(object sender, RoutedEventArgs e)
        {
            // 监听ROI集合变化
            if (ROIItems != null)
            {
                ROIItems.CollectionChanged += ROIItems_CollectionChanged;
                foreach (var roi in ROIItems)
                {
                    roi.PropertyChanged += ROI_PropertyChanged;

                    // 如果是多边形ROI，监听Points集合变化
                    if (roi is PolygonROI polygonROI)
                    {
                        polygonROI.Points.CollectionChanged += Points_CollectionChanged;
                    }
                }
            }
        }

        private void ROIItems_CollectionChanged(object? sender, NotifyCollectionChangedEventArgs e)
        {
            if (e.NewItems != null)
            {
                foreach (ROIShape roi in e.NewItems)
                {
                    roi.PropertyChanged += ROI_PropertyChanged;

                    // 如果是多边形ROI，监听Points集合变化
                    if (roi is PolygonROI polygonROI)
                    {
                        polygonROI.Points.CollectionChanged += Points_CollectionChanged;
                    }
                }
            }
            if (e.OldItems != null)
            {
                foreach (ROIShape roi in e.OldItems)
                {
                    roi.PropertyChanged -= ROI_PropertyChanged;

                    // 取消监听Points集合变化
                    if (roi is PolygonROI polygonROI)
                    {
                        polygonROI.Points.CollectionChanged -= Points_CollectionChanged;
                    }
                }
            }
        }

        private void Points_CollectionChanged(object? sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
        {
            // 只在删除或添加顶点时更新Adorner，拖拽时的Replace操作不触发更�?
            if (e.Action == System.Collections.Specialized.NotifyCollectionChangedAction.Remove ||
                e.Action == System.Collections.Specialized.NotifyCollectionChangedAction.Add)
            {
                // Points集合变化时，如果当前选中的是多边形ROI，更新Adorner
                if (SelectedROI is PolygonROI polygonROI && sender == polygonROI.Points)
                {
                    // 使用Dispatcher延迟更新，确保UI已经处理完Points的变�?
                    Dispatcher.BeginInvoke(new Action(() =>
                    {
                        UpdateAdorner();
                    }), System.Windows.Threading.DispatcherPriority.Render);
                }
            }
            // Replace操作（拖拽时）不需要重建Adorner，只需要让现有Adorner重新布局
        }

        private void ROI_PropertyChanged(object? sender, System.ComponentModel.PropertyChangedEventArgs e)
        {
            if (e.PropertyName == nameof(ROIShape.IsSelected))
            {
                UpdateAdorner();
            }
            // 监听Points属性变化（整个集合替换的情况）
            else if (e.PropertyName == "Points" && sender is PolygonROI)
            {
                UpdateAdorner();
            }
        }

        #region Dependency Properties

        public static readonly DependencyProperty ImageSourceProperty =
            DependencyProperty.Register(nameof(ImageSource), typeof(ImageSource), typeof(PolygonRoiCanvas),
                new PropertyMetadata(null, OnImageSourceChanged));

        public ImageSource? ImageSource
        {
            get => (ImageSource?)GetValue(ImageSourceProperty);
            set => SetValue(ImageSourceProperty, value);
        }

        private static void OnImageSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var control = (PolygonRoiCanvas)d;
            if (e.NewValue is ImageSource imageSource)
            {
                control.CanvasWidth = imageSource.Width;
                control.CanvasHeight = imageSource.Height;
            }
        }

        public static readonly DependencyProperty ROIItemsProperty =
            DependencyProperty.Register(nameof(ROIItems), typeof(ObservableCollection<ROIShape>), typeof(PolygonRoiCanvas),
                new PropertyMetadata(null));

        public ObservableCollection<ROIShape>? ROIItems
        {
            get => (ObservableCollection<ROIShape>?)GetValue(ROIItemsProperty);
            set => SetValue(ROIItemsProperty, value);
        }

        public static readonly DependencyProperty ZoomScaleProperty =
            DependencyProperty.Register(nameof(ZoomScale), typeof(double), typeof(PolygonRoiCanvas),
                new PropertyMetadata(1.0, OnZoomScaleChanged));

        public double ZoomScale
        {
            get => (double)GetValue(ZoomScaleProperty);
            set => SetValue(ZoomScaleProperty, Math.Max(0.1, Math.Min(10.0, value)));
        }

        private static void OnZoomScaleChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var control = (PolygonRoiCanvas)d;
            // 缩放变化时更新Adorner以调整控制点大小
            control.UpdateAdorner();
        }

        public static readonly DependencyProperty PanOffsetXProperty =
            DependencyProperty.Register(nameof(PanOffsetX), typeof(double), typeof(PolygonRoiCanvas),
                new PropertyMetadata(0.0, OnPanOffsetChanged));

        public double PanOffsetX
        {
            get => (double)GetValue(PanOffsetXProperty);
            set => SetValue(PanOffsetXProperty, value);
        }

        public static readonly DependencyProperty PanOffsetYProperty =
            DependencyProperty.Register(nameof(PanOffsetY), typeof(double), typeof(PolygonRoiCanvas),
                new PropertyMetadata(0.0, OnPanOffsetChanged));

        public double PanOffsetY
        {
            get => (double)GetValue(PanOffsetYProperty);
            set => SetValue(PanOffsetYProperty, value);
        }

        private static void OnPanOffsetChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var control = (PolygonRoiCanvas)d;

            // 平移时重建Adorner，确保控制点位置正确
            if (control.SelectedROI != null && control.SelectedROI.IsSelected)
            {
                control.UpdateAdorner();
            }
        }

        public static readonly DependencyProperty CanvasWidthProperty =
            DependencyProperty.Register(nameof(CanvasWidth), typeof(double), typeof(PolygonRoiCanvas),
                new PropertyMetadata(800.0));

        public double CanvasWidth
        {
            get => (double)GetValue(CanvasWidthProperty);
            set => SetValue(CanvasWidthProperty, value);
        }

        public static readonly DependencyProperty CanvasHeightProperty =
            DependencyProperty.Register(nameof(CanvasHeight), typeof(double), typeof(PolygonRoiCanvas),
                new PropertyMetadata(600.0));

        public double CanvasHeight
        {
            get => (double)GetValue(CanvasHeightProperty);
            set => SetValue(CanvasHeightProperty, value);
        }

        public static readonly DependencyProperty SelectedROIProperty =
            DependencyProperty.Register(nameof(SelectedROI), typeof(ROIShape), typeof(PolygonRoiCanvas),
                new PropertyMetadata(null, OnSelectedROIChanged));

        public ROIShape? SelectedROI
        {
            get => (ROIShape?)GetValue(SelectedROIProperty);
            set => SetValue(SelectedROIProperty, value);
        }

        private static void OnSelectedROIChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            var control = (PolygonRoiCanvas)d;

            // 更新IsSelected状�?
            if (e.OldValue is ROIShape oldROI)
            {
                oldROI.IsSelected = false;
            }
            if (e.NewValue is ROIShape newROI)
            {
                newROI.IsSelected = true;
            }

            control.UpdateAdorner();
        }

        #endregion Dependency Properties

        #region Adorner Management

        private void UpdateAdorner()
        {
            // 移除旧的Adorner
            if (currentAdorner != null)
            {
                var adornerLayer = AdornerLayer.GetAdornerLayer(mainCanvas);
                if (adornerLayer != null)
                {
                    adornerLayer.Remove(currentAdorner);
                }
                currentAdorner = null;
            }

            // 为选中的ROI添加Adorner
            if (SelectedROI != null && SelectedROI.IsSelected)
            {
                // 查找对应的UI元素
                var container = FindROIVisual(SelectedROI);
                if (container != null)
                {
                    var adornerLayer = AdornerLayer.GetAdornerLayer(mainCanvas);
                    if (adornerLayer != null)
                    {
                        double scaleFactor = 1.0 / ZoomScale;

                        if (SelectedROI is PolygonROI polygonROI)
                        {
                            currentAdorner = new PolygonAdorner(container, scaleFactor, polygonROI);
                        }

                        if (currentAdorner != null)
                        {
                            adornerLayer.Add(currentAdorner);
                        }
                    }
                }
            }
        }

        private UIElement? FindROIVisual(ROIShape roi)
        {
            // 在ItemsControl中查找对应的视觉元素
            var itemsControl = FindVisualChild<ItemsControl>(mainCanvas);
            if (itemsControl != null)
            {
                for (int i = 0; i < itemsControl.Items.Count; i++)
                {
                    if (itemsControl.Items[i] == roi)
                    {
                        // 尝试获取容器
                        var container = itemsControl.ItemContainerGenerator.ContainerFromIndex(i) as ContentPresenter;

                        // 如果容器还没生成，尝试强制生�?
                        if (container == null)
                        {
                            // 强制生成容器
                            itemsControl.UpdateLayout();
                            container = itemsControl.ItemContainerGenerator.ContainerFromIndex(i) as ContentPresenter;
                        }

                        if (container != null)
                        {
                            // 查找实际的形状元素（只支持多边形�?
                            if (roi is PolygonROI)
                            {
                                return FindVisualChild<Polygon>(container);
                            }
                        }
                    }
                }
            }
            return null;
        }

        private T? FindVisualChild<T>(DependencyObject parent) where T : DependencyObject
        {
            for (int i = 0; i < VisualTreeHelper.GetChildrenCount(parent); i++)
            {
                var child = VisualTreeHelper.GetChild(parent, i);
                if (child is T result)
                {
                    return result;
                }
                var childOfChild = FindVisualChild<T>(child);
                if (childOfChild != null)
                {
                    return childOfChild;
                }
            }
            return null;
        }

        #endregion Adorner Management

        #region Mouse Events

        private void Canvas_MouseWheel(object sender, MouseWheelEventArgs e)
        {
            // 获取鼠标�?imageDisplayGrid 中的位置
            Point mousePos = e.GetPosition(imageDisplayGrid);

            // 获取鼠标�?Canvas 中的位置（缩放前�?
            Point mousePosOnCanvas = e.GetPosition(mainCanvas);

            double oldZoom = ZoomScale;
            double newZoom = oldZoom;

            if (e.Delta > 0)
            {
                newZoom = oldZoom * ZoomStep;
            }
            else
            {
                newZoom = oldZoom / ZoomStep;
            }

            // 限制缩放范围
            newZoom = Math.Max(0.1, Math.Min(10.0, newZoom));

            if (Math.Abs(newZoom - oldZoom) > 0.001)
            {
                // 计算缩放比例变化
                double scale = newZoom / oldZoom;

                // 更新缩放
                ZoomScale = newZoom;

                // 调整平移偏移，使鼠标位置保持不变
                // 新的偏移 = 旧偏�?+ 鼠标位置 - 鼠标位置 * 缩放比例
                PanOffsetX = mousePos.X - (mousePos.X - PanOffsetX) * scale;
                PanOffsetY = mousePos.Y - (mousePos.Y - PanOffsetY) * scale;
            }

            e.Handled = true;
        }

        private void Canvas_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            lastMousePosition = e.GetPosition(imageDisplayGrid);
            isDragging = false;
            mainCanvas.CaptureMouse();
        }

        private void Canvas_MouseMove(object sender, MouseEventArgs e)
        {
            if (e.LeftButton == MouseButtonState.Pressed && mainCanvas.IsMouseCaptured)
            {
                Point currentPosition = e.GetPosition(imageDisplayGrid);
                Vector delta = currentPosition - lastMousePosition;

                if (delta.Length > 5)
                {
                    isDragging = true;
                    PanOffsetX += delta.X;
                    PanOffsetY += delta.Y;
                    lastMousePosition = currentPosition;
                }
            }
        }

        private void Canvas_MouseLeftButtonUp(object sender, MouseButtonEventArgs e)
        {
            mainCanvas.ReleaseMouseCapture();

            if (!isDragging)
            {
                // 处理点击事件
                Point clickPosition = e.GetPosition(mainCanvas);
                OnCanvasClicked(clickPosition);
            }

            isDragging = false;
        }

        private void Canvas_MouseRightButtonDown(object sender, MouseButtonEventArgs e)
        {
            // 右键点击完成多边�?
            OnRightClick();
            e.Handled = true;
        }

        private void ROI_MouseLeftButtonDown(object sender, MouseButtonEventArgs e)
        {
            // 选择ROI
            if (sender is FrameworkElement element && element.DataContext is ROIShape roi)
            {
                SelectedROI = roi;
                e.Handled = true;
            }
        }

        #endregion Mouse Events

        #region Public Methods

        public void ResetView()
        {
            // 自动适应显示窗口 (类似 PictureBox SizeMode.Zoom)
            ZoomScale = 1.0;
            PanOffsetX = 0;
            PanOffsetY = 0;

            if (imageDisplayGrid != null && CanvasWidth > 0 && CanvasHeight > 0)
            {
                // 使用 Dispatcher 延迟执行，确保布局已完�?
                Dispatcher.BeginInvoke(new Action(() =>
                {
                    // 获取图像显示区域的实际尺�?
                    double viewportWidth = imageDisplayGrid.ActualWidth;
                    double viewportHeight = imageDisplayGrid.ActualHeight;

                    if (viewportWidth > 0 && viewportHeight > 0)
                    {
                        // 计算宽度和高度的缩放比例
                        double scaleX = viewportWidth / CanvasWidth;
                        double scaleY = viewportHeight / CanvasHeight;

                        // 选择较小的缩放比例，确保图像完全显示在窗口内（保持宽高比�?
                        ZoomScale = Math.Min(scaleX, scaleY);

                        // 居中显示�?Grid �?HorizontalAlignment �?VerticalAlignment 自动处理
                        PanOffsetX = 0;
                        PanOffsetY = 0;
                    }
                }), System.Windows.Threading.DispatcherPriority.Loaded);
            }
        }

        private void BtnZoomIn_Click(object sender, RoutedEventArgs e)
        {
            double newZoom = ZoomScale * 1.2;
            if (newZoom <= 10.0)
            {
                ZoomScale = newZoom;
            }
        }

        private void BtnZoomOut_Click(object sender, RoutedEventArgs e)
        {
            double newZoom = ZoomScale / 1.2;
            if (newZoom >= 0.1)
            {
                ZoomScale = newZoom;
            }
        }

        private void BtnReset_Click(object sender, RoutedEventArgs e)
        {
            ResetView();
        }

        #endregion Public Methods

        #region Events

        public static readonly RoutedEvent CanvasClickedEvent =
            EventManager.RegisterRoutedEvent(nameof(CanvasClicked), RoutingStrategy.Bubble,
                typeof(RoutedEventHandler), typeof(PolygonRoiCanvas));

        public event RoutedEventHandler CanvasClicked
        {
            add { AddHandler(CanvasClickedEvent, value); }
            remove { RemoveHandler(CanvasClickedEvent, value); }
        }

        protected virtual void OnCanvasClicked(Point position)
        {
            var args = new CanvasClickedEventArgs(CanvasClickedEvent, position);
            RaiseEvent(args);
        }

        public static readonly RoutedEvent RightClickEvent =
            EventManager.RegisterRoutedEvent(nameof(RightClick), RoutingStrategy.Bubble,
                typeof(RoutedEventHandler), typeof(PolygonRoiCanvas));

        public event RoutedEventHandler RightClick
        {
            add { AddHandler(RightClickEvent, value); }
            remove { RemoveHandler(RightClickEvent, value); }
        }

        protected virtual void OnRightClick()
        {
            RaiseEvent(new RoutedEventArgs(RightClickEvent));
        }

        #endregion Events
    }
}