using System.ComponentModel;

namespace AntDesignWPF.Controls;

public enum NotificationPlacement
{
    TopRight,
    TopLeft,
    BottomRight,
    BottomLeft
}

//public static class NotificationManager
//{
//    private static readonly Dictionary<NotificationPlacement, List<NotificationView>> _activeNotifications = new Dictionary<NotificationPlacement, List<NotificationView>>
//    {
//        { NotificationPlacement.TopRight, new List<NotificationView>() },
//        { NotificationPlacement.TopLeft, new List<NotificationView>() },
//        { NotificationPlacement.BottomRight, new List<NotificationView>() },
//        { NotificationPlacement.BottomLeft, new List<NotificationView>() }
//    };

//    private static readonly object _lock = new object();

//    public static void Show(string title, string message, NotificationType type = NotificationType.Info, NotificationPlacement placement = NotificationPlacement.TopRight, int durationSeconds = 3)
//    {
//        var duration = TimeSpan.FromSeconds(durationSeconds);

//        Application.Current.Dispatcher.Invoke(() =>
//        {
//            var notificationWindow = new NotificationView(title, message, type, duration);
//            notificationWindow.Closed += (s, e) =>
//            {
//                lock (_lock)
//                {
//                    _activeNotifications[placement].Remove(notificationWindow);
//                    Reposition(placement);
//                }
//            };

//            lock (_lock)
//            {
//                _activeNotifications[placement].Add(notificationWindow);
//                Reposition(placement);
//            }

//            notificationWindow.Show();
//        });
//    }

//    private static void Reposition(NotificationPlacement placement)
//    {
//        var workArea = SystemParameters.WorkArea;
//        var notifications = _activeNotifications[placement];
//        double currentTop = workArea.Top + 10;
//        double currentBottom = workArea.Bottom - 10;

//        foreach (var window in notifications)
//        {
//            // 如果窗口尚未加载，先在屏幕外显示以获取其实际尺寸
//            if (!window.IsLoaded)
//            {
//                window.WindowStartupLocation = WindowStartupLocation.Manual;
//                window.Left = -9999;
//                window.Top = -9999;
//                // 调用Show()会使窗口加载并经过布局计算
//                // 对于非模态窗口，这不会阻塞代码执行
//                window.Show();
//            }

//            // 经过Show()之后，ActualHeight和ActualWidth就已经是准确的了
//            if (placement == NotificationPlacement.TopRight || placement == NotificationPlacement.TopLeft)
//            {
//                window.Top = currentTop;
//                currentTop += window.ActualHeight + 10;
//            }
//            else // BottomRight or BottomLeft
//            {
//                window.Top = currentBottom - window.ActualHeight;
//                currentBottom -= (window.ActualHeight + 10);
//            }

//            if (placement == NotificationPlacement.TopRight || placement == NotificationPlacement.BottomRight)
//            {
//                // 在这里应该使用ActualWidth，特别是当窗口宽度为"Auto"时
//                window.Left = workArea.Right - window.ActualWidth - 10;
//            }
//            else // TopLeft or BottomLeft
//            {
//                window.Left = workArea.Left + 10;
//            }
//        }
//    }
//}
public static class NotificationManager
{
    // 使用 ConditionalWeakTable 来将通知列表与父窗口关联。
    // 这有助于自动处理内存，当父窗口被垃圾回收时，关联的通知列表也会被回收，避免了内存泄漏。
    private static readonly System.Runtime.CompilerServices.ConditionalWeakTable<Window, Dictionary<NotificationPlacement, List<NotificationView>>> _windowNotifications =
        new System.Runtime.CompilerServices.ConditionalWeakTable<Window, Dictionary<NotificationPlacement, List<NotificationView>>>();

    // 保留一个用于全局通知的静态字典（当 owner 为 null 时使用）
    private static readonly Dictionary<NotificationPlacement, List<NotificationView>> _globalNotifications =
        new Dictionary<NotificationPlacement, List<NotificationView>>
        {
                { NotificationPlacement.TopRight, new List<NotificationView>() },
                { NotificationPlacement.TopLeft, new List<NotificationView>() },
                { NotificationPlacement.BottomRight, new List<NotificationView>() },
                { NotificationPlacement.BottomLeft, new List<NotificationView>() }
        };

    private static readonly object _lock = new object();

    /// <summary>
    /// 显示一个通知。
    /// </summary>
    /// <param name="owner">通知要附着到的父窗口。如果为 null，则显示为全局通知。</param>
    /// <param name="title">标题</param>
    /// <param name="message">消息</param>
    /// <param name="type">类型</param>
    /// <param name="placement">位置</param>
    /// <param name="durationSeconds">显示时长（秒）</param>
    public static void Show(Window owner, string title, string message, NotificationType type = NotificationType.Info, NotificationPlacement placement = NotificationPlacement.TopRight, int durationSeconds = 3)
    {
        var duration = TimeSpan.FromSeconds(durationSeconds);

        // 必须在UI线程上执行
        Application.Current.Dispatcher.Invoke(() =>
        {
            var notificationWindow = new NotificationView(title, message, type, duration);
            notificationWindow.Owner = owner; // 设置所有者

            // 获取或创建与此窗口关联的通知列表
            var activeNotifications = GetNotificationListForOwner(owner);

            notificationWindow.Closed += (s, e) =>
            {
                lock (_lock)
                {
                    activeNotifications[placement].Remove(notificationWindow);
                    // 如果这是父窗口的最后一个通知，则取消事件订阅
                    if (owner != null && !HasActiveNotifications(owner))
                    {
                        UnsubscribeFromOwnerEvents(owner);
                    }
                    Reposition(owner, placement);
                }
            };

            lock (_lock)
            {
                // 如果是第一个为该窗口创建的通知，则订阅事件
                if (owner != null && !HasActiveNotifications(owner))
                {
                    SubscribeToOwnerEvents(owner);
                }
                activeNotifications[placement].Add(notificationWindow);
                Reposition(owner, placement);
            }

            // Show() 必须在 Reposition 之后调用，以确保初始位置正确
            notificationWindow.Show();
        });
    }

    // 重载一个 Show 方法以保持与旧 API 的兼容性（全局通知）
    public static void Show(string title, string message, NotificationType type = NotificationType.Info, NotificationPlacement placement = NotificationPlacement.TopRight, int durationSeconds = 3)
    {
        Show(null, title, message, type, placement, durationSeconds);
    }

    private static Dictionary<NotificationPlacement, List<NotificationView>> GetNotificationListForOwner(Window owner)
    {
        if (owner == null)
        {
            return _globalNotifications;
        }

        lock (_lock)
        {
            return _windowNotifications.GetValue(owner, key =>
            {
                // 当 ConditionalWeakTable 中没有找到该窗口的条目时，此工厂方法被调用
                return new Dictionary<NotificationPlacement, List<NotificationView>>
                    {
                        { NotificationPlacement.TopRight, new List<NotificationView>() },
                        { NotificationPlacement.TopLeft, new List<NotificationView>() },
                        { NotificationPlacement.BottomRight, new List<NotificationView>() },
                        { NotificationPlacement.BottomLeft, new List<NotificationView>() }
                    };
            });
        }
    }

    private static bool HasActiveNotifications(Window owner)
    {
        if (owner == null) return false;

        var lists = GetNotificationListForOwner(owner);
        foreach (var list in lists.Values)
        {
            if (list.Count > 0) return true;
        }
        return false;
    }


    private static void SubscribeToOwnerEvents(Window owner)
    {
        owner.LocationChanged += OnOwnerMoved;
        owner.SizeChanged += OnOwnerMoved;
        owner.StateChanged += OnOwnerStateChanged;
        owner.Closing += OnOwnerClosing; // 确保在父窗口关闭时清理
    }

    private static void UnsubscribeFromOwnerEvents(Window owner)
    {
        owner.LocationChanged -= OnOwnerMoved;
        owner.SizeChanged -= OnOwnerMoved;
        owner.StateChanged -= OnOwnerStateChanged;
        owner.Closing -= OnOwnerClosing;
    }

    private static void OnOwnerClosing(object sender, CancelEventArgs e)
    {
        if (sender is Window owner)
        {
            // 不需要手动关闭通知，因为设置了Owner会自动关闭
            // 但需要取消订阅
            UnsubscribeFromOwnerEvents(owner);
        }
    }

    private static void OnOwnerStateChanged(object sender, EventArgs e)
    {
        if (sender is Window owner)
        {
            var notifications = GetNotificationListForOwner(owner);
            var visibility = (owner.WindowState == WindowState.Minimized) ? Visibility.Collapsed : Visibility.Visible;

            foreach (var list in notifications.Values)
            {
                foreach (var notificationView in list)
                {
                    notificationView.Visibility = visibility;
                }
            }

            // 恢复时重新定位
            if (visibility == Visibility.Visible)
            {
                RepositionAll(owner);
            }
        }
    }

    private static void OnOwnerMoved(object sender, EventArgs e)
    {
        if (sender is Window owner)
        {
            RepositionAll(owner);
        }
    }

    private static void RepositionAll(Window owner)
    {
        Reposition(owner, NotificationPlacement.TopRight);
        Reposition(owner, NotificationPlacement.TopLeft);
        Reposition(owner, NotificationPlacement.BottomRight);
        Reposition(owner, NotificationPlacement.BottomLeft);
    }

    private static void Reposition(Window owner, NotificationPlacement placement)
    {
        var activeNotifications = GetNotificationListForOwner(owner);
        var notifications = activeNotifications[placement];
        if (notifications.Count == 0) return;

        // 获取定位基准区域
        Rect workArea;
        if (owner != null && owner.IsLoaded)
        {
            // 如果父窗口最小化，则不进行重定位
            if (owner.WindowState == WindowState.Minimized) return;
            workArea = new Rect(owner.Left, owner.Top, owner.ActualWidth, owner.ActualHeight);
        }
        else
        {
            workArea = SystemParameters.WorkArea;
        }

        double currentTop = workArea.Top + 10;
        double currentBottom = workArea.Bottom - 10;

        foreach (var window in notifications)
        {
            // 确保窗口已加载以获取其实际尺寸
            if (!window.IsLoaded)
            {
                window.WindowStartupLocation = WindowStartupLocation.Manual;
                window.Left = -9999;
                window.Top = -9999;
                window.Show();
                window.Activate(); // 激活以确保尺寸计算完成
            }

            if (placement == NotificationPlacement.TopRight || placement == NotificationPlacement.TopLeft)
            {
                window.Top = currentTop;
                currentTop += window.ActualHeight + 10;
            }
            else // BottomRight or BottomLeft
            {
                window.Top = currentBottom - window.ActualHeight;
                currentBottom -= (window.ActualHeight + 10);
            }

            if (placement == NotificationPlacement.TopRight || placement == NotificationPlacement.BottomRight)
            {
                window.Left = workArea.Right - window.ActualWidth - 10;
            }
            else // TopLeft or BottomLeft
            {
                window.Left = workArea.Left + 10;
            }
        }
    }
}