using System.Collections.Generic;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Input;
using System.Windows.Media;

namespace Sinvo.EplanHpD.Plugin.WPFUI.Utils
{
    public static class ScrollSynchronizer
    {
        // 附加属性定义
        public static readonly DependencyProperty SynchronizeWithParentProperty =
            DependencyProperty.RegisterAttached(
                "SynchronizeWithParent",
                typeof(bool),
                typeof(ScrollSynchronizer),
                new PropertyMetadata(false, OnSynchronizeWithParentChanged));
        // 为 ListBox 添加自动寻找内部 DataGrid 的附加属性
        public static readonly DependencyProperty AutoSynchronizeChildrenProperty =
            DependencyProperty.RegisterAttached(
                "AutoSynchronizeChildren",
                typeof(bool),
                typeof(ScrollSynchronizer),
                new PropertyMetadata(false, OnAutoSynchronizeChildrenChanged));

        // Getter 和 Setter
        public static bool GetSynchronizeWithParent(DependencyObject obj)
        {
            return (bool)obj.GetValue(SynchronizeWithParentProperty);
        }

        public static void SetSynchronizeWithParent(DependencyObject obj, bool value)
        {
            obj.SetValue(SynchronizeWithParentProperty, value);
        }

        /// <summary>
        /// 当属性值改变时触发
        /// </summary>
        /// <param name="d"></param>
        /// <param name="e"></param>
        private static void OnSynchronizeWithParentChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            if (d is UIElement element)
            {
                if ((bool)e.NewValue)
                {
                    // 添加事件处理
                    element.PreviewMouseWheel += Element_PreviewMouseWheel;
                }
                else
                {
                    // 移除事件处理
                    element.PreviewMouseWheel -= Element_PreviewMouseWheel;
                }
            }
        }

        /// <summary>
        /// 处理滚动事件
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private static void Element_PreviewMouseWheel(object sender, MouseWheelEventArgs e)
        {
            if (sender is UIElement element)
            {
                // 向上查找父级 ListBox
                var listBox = FindParentListBox(element);
                if (listBox != null)
                {
                    // 直接获取 ListBox 的 ScrollViewer
                    ScrollViewer scrollViewer = GetScrollViewer(listBox);
                    if (scrollViewer != null)
                    {
                        // 直接控制滚动位置
                        if (e.Delta < 0)
                        {
                            scrollViewer.LineDown();
                        }
                        else
                        {
                            scrollViewer.LineUp();
                        }

                        // 标记事件已处理
                        e.Handled = true;
                    }
                    else
                    {
                        // 如果找不到 ScrollViewer，回退到事件传递
                        var eventArg = new MouseWheelEventArgs(e.MouseDevice, e.Timestamp, e.Delta);
                        eventArg.RoutedEvent = UIElement.MouseWheelEvent;
                        eventArg.Source = sender;
                        listBox.RaiseEvent(eventArg);
                        e.Handled = true;
                    }
                }
            }
        }
        /// <summary>
        /// 添加获取 ScrollViewer 的辅助方法
        /// </summary>
        /// <param name="element"></param>
        /// <returns></returns>
        private static ScrollViewer GetScrollViewer(DependencyObject element)
        {
            if (element is ScrollViewer scrollViewer)
                return scrollViewer;

            // 尝试从控件模板中查找 ScrollViewer
            ScrollViewer result = null;
            for (int i = 0; i < VisualTreeHelper.GetChildrenCount(element) && result == null; i++)
            {
                var child = VisualTreeHelper.GetChild(element, i);
                result = GetScrollViewer(child);  // 递归查找
            }

            return result;
        }

        /// <summary>
        /// 查找父级 ListBox
        /// </summary>
        /// <param name="child"></param>
        /// <returns></returns>
        private static ListBox FindParentListBox(DependencyObject child)
        {
            var parent = VisualTreeHelper.GetParent(child);
            while (parent != null && !(parent is ListBox))
            {
                parent = VisualTreeHelper.GetParent(parent);
            }
            return parent as ListBox;
        }

        public static bool GetAutoSynchronizeChildren(DependencyObject obj)
        {
            return (bool)obj.GetValue(AutoSynchronizeChildrenProperty);
        }

        public static void SetAutoSynchronizeChildren(DependencyObject obj, bool value)
        {
            obj.SetValue(AutoSynchronizeChildrenProperty, value);
        }

        private static void OnAutoSynchronizeChildrenChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            if (d is ListBox listBox && (bool)e.NewValue)
            {
                // 监听 ListBox 的 Loaded 事件
                listBox.Loaded += ListBox_Loaded;
                // 监听 ItemContainerGenerator 状态变化，处理动态加载的项
                listBox.ItemContainerGenerator.StatusChanged += (s, args) =>
                {
                    if (listBox.ItemContainerGenerator.Status == System.Windows.Controls.Primitives.GeneratorStatus.ContainersGenerated)
                    {
                        AttachToAllDataGrids(listBox);
                    }
                };
            }
        }

        private static void ListBox_Loaded(object sender, RoutedEventArgs e)
        {
            if (sender is ListBox listBox)
            {
                AttachToAllDataGrids(listBox);
            }
        }

        private static void AttachToAllDataGrids(ListBox listBox)
        {
            var dataGrids = FindVisualChildren<DataGrid>(listBox);
            foreach (var dataGrid in dataGrids)
            {
                SetSynchronizeWithParent(dataGrid, true);
            }
        }

        /// 查找所有指定类型的可视化子元素
        private static IEnumerable<T> FindVisualChildren<T>(DependencyObject obj) where T : DependencyObject
        {
            if (obj != null)
            {
                for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
                {
                    DependencyObject child = VisualTreeHelper.GetChild(obj, i);
                    if (child != null && child is T)
                    {
                        yield return (T)child;
                    }

                    foreach (T childOfChild in FindVisualChildren<T>(child))
                    {
                        yield return childOfChild;
                    }
                }
            }
        }
    }
}