using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Collections.Specialized;
using System.Windows;
using System.Windows.Input;
using HandyControl.Data;

namespace HandyControl.Tools;

public class GlobalShortcut
{
    private static ObservableCollection<KeyBinding> KeyBindingCollection;

    private static readonly Dictionary<string, KeyBinding> CommandDic = new();

    private static void KeyboardHook_KeyDown(object sender, KeyboardHookEventArgs e) => HitTest(e.Key);

    static GlobalShortcut()
    {
        KeyboardHook.KeyDown += KeyboardHook_KeyDown;
    }

    private static void HitTest(Key key)
    {
        if (IsModifierKey(key)) return;

        var modifierKeys = Keyboard.Modifiers;
        var keyStr = modifierKeys != ModifierKeys.None ? $"{modifierKeys.ToString()}, {key.ToString()}" : key.ToString();
        ExecuteCommand(keyStr);
    }

    private static void ExecuteCommand(string key)
    {
        if (string.IsNullOrEmpty(key)) return;
        if (CommandDic.ContainsKey(key))
        {
            var keyBinding = CommandDic[key];
            var command = keyBinding.Command;
            if (command != null && command.CanExecute(keyBinding.CommandParameter))
            {
                command.Execute(keyBinding.CommandParameter);
            }
        }
    }

    private static bool IsModifierKey(Key key)
    {
        return key == Key.LeftCtrl || key == Key.LeftAlt || key == Key.LeftShift || key == Key.LWin ||
               key == Key.RightCtrl || key == Key.RightAlt || key == Key.RightShift || key == Key.RWin;
    }

    public static void Init(List<KeyBinding> list)
    {
        CommandDic.Clear();

        if (list == null) return;
        KeyBindingCollection = new ObservableCollection<KeyBinding>(list);
        if (KeyBindingCollection.Count == 0) return;

        AddKeyBindings(KeyBindingCollection);
        KeyboardHook.Start();
    }

    private static void AddKeyBindings(IEnumerable<KeyBinding> keyBindings)
    {
        foreach (var item in keyBindings)
        {
            if (item.Key == Key.None) continue;

            if (item.Modifiers == ModifierKeys.None)
            {
                CommandDic[item.Key.ToString()] = item;
            }
            else
            {
                var keyStr = $"{item.Modifiers.ToString()}, {item.Key.ToString()}";
                CommandDic[keyStr] = item;
            }
        }
    }

    public static readonly DependencyProperty HostProperty = DependencyProperty.RegisterAttached(
        "Host", typeof(bool), typeof(GlobalShortcut), new PropertyMetadata(ValueBoxes.FalseBox, OnHostChanged));

    private static void OnHostChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
    {
        if (DesignerHelper.IsInDesignMode) return;

        if (KeyBindingCollection != null)
        {
            KeyBindingCollection.CollectionChanged -= KeyBindingCollection_CollectionChanged;
        }
        KeyBindingCollection = GetKeyBindings(d);
        if (KeyBindingCollection != null)
        {
            KeyBindingCollection.CollectionChanged += KeyBindingCollection_CollectionChanged;
        }
    }

    private static void KeyBindingCollection_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
    {
        AddKeyBindings(KeyBindingCollection);
        KeyboardHook.Start();
    }

    public static void SetHost(DependencyObject element, bool value)
        => element.SetValue(HostProperty, ValueBoxes.BooleanBox(value));

    public static bool GetHost(DependencyObject element)
        => (bool) element.GetValue(HostProperty);

    public static readonly DependencyProperty KeyBindingsProperty = DependencyProperty.RegisterAttached(
        "KeyBindings", typeof(ObservableCollection<KeyBinding>), typeof(GlobalShortcut), new PropertyMetadata(new ObservableCollection<KeyBinding>()));

    public static void SetKeyBindings(DependencyObject element, ObservableCollection<KeyBinding> value)
        => element.SetValue(KeyBindingsProperty, value);

    public static ObservableCollection<KeyBinding> GetKeyBindings(DependencyObject element)
        => (ObservableCollection<KeyBinding>) element.GetValue(KeyBindingsProperty);
}