using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Interop;

namespace WpfAppTest.Behavior
{
    public static class WindowBehavior
    {
        // 这是我们的附加属性，用于启用自定义窗口行为
        public static readonly DependencyProperty EnableCustomWindowBehaviorProperty =
            DependencyProperty.RegisterAttached(
                "EnableCustomWindowBehavior",
                typeof(bool),
                typeof(WindowBehavior),
                new PropertyMetadata(false, OnEnableCustomWindowBehaviorChanged));

        public static bool GetEnableCustomWindowBehavior(DependencyObject obj)
        {
            return (bool)obj.GetValue(EnableCustomWindowBehaviorProperty);
        }

        public static void SetEnableCustomWindowBehavior(DependencyObject obj, bool value)
        {
            obj.SetValue(EnableCustomWindowBehaviorProperty, value);
        }

        // 当 EnableCustomWindowBehavior 属性值改变时触发
        private static void OnEnableCustomWindowBehaviorChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            if (d is Window window)
            {
                if ((bool)e.NewValue)
                {
                    // 当启用行为时，在窗口加载后查找并绑定元素
                    window.Loaded += Window_Loaded;
                }
                else
                {
                    // 当禁用行为时，解除绑定（如果需要更彻底的清理，可以做更多操作）
                    window.Loaded -= Window_Loaded;
                }
            }
        }

        // 窗口加载后执行，此时 ControlTemplate 已经被应用
        private static void Window_Loaded(object sender, RoutedEventArgs e)
        {
            if (sender is Window window)
            {
                // *** 关键：通过 FindName 在 ControlTemplate 中查找元素 ***
                // 这些元素的 x:Name 必须与你的 Window 样式模板中的名称一致！
                Button minimizeButton = window.Template.FindName("MinimizeButton", window) as Button;
                Button maximizeRestoreButton = window.Template.FindName("MaximizeRestoreButton", window) as Button;
                Button closeButton = window.Template.FindName("CloseButton", window) as Button;
                Border titleBarDragArea = window.Template.FindName("WindowBorder", window) as Border; // 或者你的标题栏 Border 的 x:Name
                Border resizeGrip = window.Template.FindName("PART_ResizeGrip", window) as Border; // 调整大小手柄

                // --- 绑定按钮点击事件 ---
                if (minimizeButton != null)
                {
                    minimizeButton.Click += (s, ev) => window.WindowState = WindowState.Minimized;
                }

                if (maximizeRestoreButton != null)
                {
                    maximizeRestoreButton.Click += (s, ev) =>
                    {
                        if (window.WindowState == WindowState.Normal)
                            window.WindowState = WindowState.Maximized;
                        else
                            window.WindowState = WindowState.Normal;
                    };
                }

                if (closeButton != null)
                {
                    closeButton.Click += (s, ev) => window.Close();
                }

                // --- 绑定标题栏拖拽和双击最大化事件 ---
                if (titleBarDragArea != null)
                {
                    // 单击并拖动以移动窗口
                    titleBarDragArea.MouseLeftButtonDown += (s, ev) =>
                    {
                        if (ev.ClickCount == 1 && window.WindowState == WindowState.Normal)
                        {
                            window.DragMove(); // WPF 内置的拖动方法
                        }
                    };

                    // 双击标题栏最大化/还原窗口
                    titleBarDragArea.MouseLeftButtonDown += (s, ev) =>
                    {
                        if (ev.ClickCount == 2)
                        {
                            if (window.WindowState == WindowState.Normal)
                                window.WindowState = WindowState.Maximized;
                            else
                                window.WindowState = WindowState.Normal;
                        }
                    };
                }

                // --- 处理调整大小手柄 ---
                if (resizeGrip != null)
                {
                    resizeGrip.PreviewMouseLeftButtonDown += (s, ev) =>
                    {
                        if (window.WindowState == WindowState.Normal)
                        {
                            // 调用 Win32 API 来启动窗口调整大小
                            IntPtr handle = new WindowInteropHelper(window).Handle;
                            SendMessage(handle, 0x0112, (IntPtr)0xF008, IntPtr.Zero); // WM_SYSCOMMAND, SC_SIZE (bottom-right)
                            ev.Handled = true; // 阻止事件冒泡，避免与窗口拖动冲突
                        }
                    };
                }
            }
        }

        // --- P/Invoke: 调用 Windows API 的 SendMessage 函数 ---
        [DllImport("user32.dll", CharSet = CharSet.Auto)]
        private static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, IntPtr wParam, IntPtr lParam);
    }
}