using System;
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Threading.Tasks;
using System.Windows;
using System.Windows.Interop;
using XP.Common.GeneralForm.ViewModels;
using XP.Common.Logging.Interfaces;

namespace XP.Common.GeneralForm.Views
{
    /// <summary>
    /// 通用进度条模态窗口，支持线程安全的进度更新和关闭操作
    /// </summary>
    public partial class ProgressWindow : Window
    {
        #region Win32 API

        [DllImport("user32.dll")]
        private static extern IntPtr GetSystemMenu(IntPtr hWnd, bool bRevert);

        [DllImport("user32.dll")]
        private static extern bool EnableMenuItem(IntPtr hMenu, uint uIDEnableItem, uint uEnable);

        private const uint SC_CLOSE = 0xF060;
        private const uint MF_BYCOMMAND = 0x00000000;
        private const uint MF_GRAYED = 0x00000001;
        private const uint MF_ENABLED = 0x00000000;

        #endregion

        private readonly ProgressWindowViewModel _viewModel;
        private readonly ILoggerService? _logger;
        private bool _isClosingByCode;

        /// <summary>
        /// 构造函数
        /// </summary>
        /// <param name="title">窗口标题</param>
        /// <param name="message">提示信息</param>
        /// <param name="isCancelable">是否允许用户关闭窗口</param>
        /// <param name="logger">日志服务（可选）</param>
        public ProgressWindow(
            string title = "操作进行中",
            string message = "请稍候...",
            bool isCancelable = true,
            ILoggerService? logger = null)
        {
            // 创建 ViewModel 并设置为 DataContext
            _viewModel = new ProgressWindowViewModel(title, message, 0, isCancelable, logger);
            DataContext = _viewModel;

            // 保存日志服务引用，用于 View 层日志记录
            _logger = logger?.ForModule<ProgressWindow>();

            InitializeComponent();

            // 继承主窗口图标
            if (Application.Current?.MainWindow != null)
            {
                Icon = Application.Current.MainWindow.Icon;
            }

            // 订阅 Closing 事件，拦截用户手动关闭
            Closing += OnWindowClosing;
        }

        /// <summary>
        /// 更新进度和提示信息（线程安全，可从任意线程调用）
        /// </summary>
        /// <param name="message">提示信息文本</param>
        /// <param name="progress">进度值</param>
        public void UpdateProgress(string message, double progress)
        {
            try
            {
                if (Dispatcher.CheckAccess())
                {
                    _viewModel.UpdateProgress(message, progress);
                }
                else
                {
                    Dispatcher.Invoke(() => _viewModel.UpdateProgress(message, progress));
                }
            }
            catch (TaskCanceledException)
            {
                // 窗口已关闭时 Dispatcher 调度可能抛出此异常，静默处理
            }
            catch (Exception)
            {
                // 其他调度异常静默处理，避免影响调用方
            }
        }

        /// <summary>
        /// 线程安全关闭窗口（使用 new 关键字隐藏基类 Close 方法，因为 Window.Close() 不是虚方法）
        /// </summary>
        public new void Close()
        {
            try
            {
                _isClosingByCode = true;

                if (Dispatcher.CheckAccess())
                {
                    _logger?.Info("进度窗口正在关闭：Title={Title}", _viewModel.Title);
                    base.Close();
                }
                else
                {
                    Dispatcher.Invoke(() =>
                    {
                        _logger?.Info("进度窗口正在关闭：Title={Title}", _viewModel.Title);
                        base.Close();
                    });
                }
            }
            catch (TaskCanceledException)
            {
                // 窗口已关闭时 Dispatcher 调度可能抛出此异常，静默处理
            }
            catch (Exception)
            {
                // 其他调度异常静默处理，避免影响调用方
            }
        }

        /// <summary>
        /// 窗口源初始化时，根据 IsCancelable 控制关闭按钮状态
        /// </summary>
        protected override void OnSourceInitialized(EventArgs e)
        {
            base.OnSourceInitialized(e);

            if (!_viewModel.IsCancelable)
            {
                DisableCloseButton();
            }
        }

        /// <summary>
        /// 拦截窗口关闭事件
        /// </summary>
        private void OnWindowClosing(object? sender, CancelEventArgs e)
        {
            // 当不可取消且非程序主动关闭时，阻止关闭
            if (!_viewModel.IsCancelable && !_isClosingByCode)
            {
                e.Cancel = true;
            }
        }

        /// <summary>
        /// 通过 Win32 API 禁用窗口关闭按钮（灰色不可点击）
        /// </summary>
        private void DisableCloseButton()
        {
            var hwnd = new WindowInteropHelper(this).Handle;
            var hMenu = GetSystemMenu(hwnd, false);
            if (hMenu != IntPtr.Zero)
            {
                EnableMenuItem(hMenu, SC_CLOSE, MF_BYCOMMAND | MF_GRAYED);
            }
        }

        /// <summary>
        /// 通过 Win32 API 启用窗口关闭按钮
        /// </summary>
        private void EnableCloseButton()
        {
            var hwnd = new WindowInteropHelper(this).Handle;
            var hMenu = GetSystemMenu(hwnd, false);
            if (hMenu != IntPtr.Zero)
            {
                EnableMenuItem(hMenu, SC_CLOSE, MF_BYCOMMAND | MF_ENABLED);
            }
        }
    }
}