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

namespace PDF_Office.Helper
{
    //全局快捷键响应
    public static class KeyEventsHelper
    {
        #region Todo 快捷键绑定解绑在其他地方使用
        //绑定：KeyEventsHelper.KeyDown += ShortCut_KeyDown;
        //解绑：KeyEventsHelper.KeyDown -= ShortCut_KeyDown;

        #endregion Todo 快捷键绑定解绑在其他地方使用

        public static event EventHandler<KeyEventArgs> KeyDown;
        private static KeyEventArgs args;
        static KeyEventsHelper()
        {
            EventManager.RegisterClassHandler(typeof(Window), UIElement.KeyDownEvent, (KeyEventHandler)onKeyDown);
            EventManager.RegisterClassHandler(typeof(ContextMenu), UIElement.KeyDownEvent, (KeyEventHandler)onKeyDown);
        }

        private static void onKeyDown(object sender, KeyEventArgs e)
        {
            if (e != null)
            {
                args = e;
                KeyDown?.Invoke(sender, e);
            }

        }

        /// <summary>
        /// 按下单一键，例如：只按下H有效；同时按下其他修饰键如ctrl等无效
        /// </summary>
        public static bool IsSingleKey(Key currentkey)
        {
            if(args == null) return false;

            if (args.Key == currentkey && args.KeyboardDevice.Modifiers == ModifierKeys.None)
            {
                return true;
            }
            return false;
        }

        /// <summary>
        /// 组合键 = 修饰键+序列键
        /// 例如：同时按下Ctrl + H 或（同时按下Ctrl + [Key=None无任何键]），同时再按下其他修饰键则无响应
        /// </summary>
        public static bool IsModifierKey(ModifierKeys modifier, Key currentkey)
        {
            if (args == null) return false;

            if (args.Key == currentkey && args.KeyboardDevice.Modifiers == modifier)
            {
                return true;
            }
            return false;
        }

        /// <summary>
        /// 例如：按下此键外，再按下其他键也响应（不常用，特殊处理）
        /// </summary>
        public static bool IsKeyDown(Key currentkey)
        {
            if (args == null) return false;

            if (Keyboard.IsKeyDown(currentkey))
            {
                return true;
            }
            return false;
        }

        /// <summary>
        /// 例如：同时按下一个或多个键外，再按下其他键也响应（不常用，特殊处理）
        /// </summary>
        public static bool IsKeyDown(List<Key> keys)
        {
            if (args == null || keys == null || keys.Count > 0) return false;

            bool result = false;
            foreach (Key key in keys)
            {
                result |= Keyboard.IsKeyDown(key);
            }

            if (result)
            {
                return true;
            }
            return false;
        }
    }
}