using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Controls;
using System.Windows.Media;
using System.Windows;
using System.ComponentModel;

namespace HMI.UI
{
    public class TreeViewHelper
    {
        public static bool GetAutoExpand(TreeView treeView)
        {
            return (bool)treeView.GetValue(AutoExpandProperty);
        }

        public static void SetAutoExpand(TreeView treeView, bool value)
        {
            treeView.SetValue(AutoExpandProperty, value);
        }

        public static readonly DependencyProperty AutoExpandProperty =
            DependencyProperty.RegisterAttached("AutoExpand", typeof(bool), typeof(TreeViewHelper),
            new PropertyMetadata(false, (d, e) =>
            {
                if (!(d is TreeView treeView)) return;
                if ((bool)e.NewValue)
                {
                    var dpd = DependencyPropertyDescriptor.FromProperty(ItemsControl.ItemsSourceProperty, typeof(DataGrid));
                    dpd?.AddValueChanged(treeView, TreeView_ItemSourceChanged);
                }
                else
                {
                    var dpd = DependencyPropertyDescriptor.FromProperty(ItemsControl.ItemsSourceProperty, typeof(DataGrid));
                    dpd?.RemoveValueChanged(treeView, TreeView_ItemSourceChanged);
                }
            }));

        private static void TreeView_ItemSourceChanged(object sender, EventArgs e)
        {
            TreeView tree = sender as TreeView;
            if (!tree.IsLoaded)
            {
                tree.Loaded += Tree_Loaded;
            }
            else
            {
                ExpandAll(tree);
            }
        }

        private static void Tree_Loaded(object sender, RoutedEventArgs e)
        {
            TreeView tree = sender as TreeView;
            ExpandAll(tree);
            tree.Loaded -= Tree_Loaded;
        }

        public static void ExpandAll(TreeView treeView)
        {
            foreach (var item in treeView.Items)
            {
                var temp = treeView.ItemContainerGenerator.ContainerFromItem(item);
                if (temp is TreeViewItem treeViewItem)
                {
                    ExpandTreeViewItem(treeViewItem);
                }
            }
        }
        public static void ExpandTreeViewItem(TreeViewItem item)
        {
            item.IsExpanded = true;
            // 确保子项已经生成
            item.ApplyTemplate();
            if (item.Items.Count > 0)
            {
                foreach (var subItem in item.Items)
                {
                    if (item.ItemContainerGenerator.ContainerFromItem(subItem) is TreeViewItem childItem)
                    {
                        ExpandTreeViewItem(childItem);
                    }
                }
            }
        }
    }
}