using System;
using System.Net;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Ink;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Animation;
using System.Windows.Shapes;
using System.Windows.Browser;
using System.Collections.Generic;
using System.Linq;

namespace YouAppNamespace
{
public partial class App : Application
{
    public static HotKeyHandler GlobalHotKeyHandler { get; private set; }
    internal static Dictionary< Key,int> KeyCodeLookUp = new Dictionary<Key,int>();
    static App()
    {
        //start thread here to process this from backend
        
        GlobalHotKeyHandler = new HotKeyHandler();
            
        //  KeyCodeLookUp.Add(Key.D1,49);
        //Digits
        for (int i = (int)Key.D0; i <= (int)Key.D9;i++ )
            KeyCodeLookUp.Add((Key)i, i+28);
        //Chars
        for (int i = (int)Key.A; i <= (int)Key.Z; i++)
            KeyCodeLookUp.Add((Key)i, i + 35);

        //functional Key
        for (int i = (int)Key.F1; i <= (int)Key.F12; i++)
            KeyCodeLookUp.Add((Key)i, i + 65);

        KeyCodeLookUp.Add(Key.Escape, 1);
        //return;
    }
}

public class EventArgsKeyUp : EventArgs
{
    object[] data ;
    public object[] Data {get{return data;}}
    public EventArgsKeyUp(object[] data)
    {
        this.data = data;
    }
}

public delegate void KeyUpHandler(object sender, EventArgsKeyUp e);
public sealed class HotKeyHandler
{
       
    private List<Shortcut> shortcuts = new List<Shortcut>();
    public HotKeyHandler() {  }
    private bool isRegistered = false;
    public void Register()
    {
        //return;
        if (this.isRegistered == false)
        {
            try
            {
                App.Current.RootVisual.KeyUp += new System.Windows.Input.KeyEventHandler(RootVisual_KeyUp);
                HtmlDocument document = HtmlPage.Document;
                EventHandler<HtmlEventArgs> KeyDownHandler;
                KeyDownHandler = new EventHandler<HtmlEventArgs>(OnBodyKeyUp);
                bool b = document.AttachEvent("onkeyup", KeyDownHandler);
            }
            catch (Exception ex) { }              
            finally
            {
                this.isRegistered = true;
            }
        }
    }

    public void Unregister()
    {
        if (this.isRegistered)
        {
            try
            {
                App.Current.RootVisual.KeyUp -= RootVisual_KeyUp;
                HtmlDocument document = HtmlPage.Document;
                EventHandler<HtmlEventArgs> KeyDownHandler;
                KeyDownHandler = new EventHandler<HtmlEventArgs>(OnBodyKeyUp);
                document.DetachEvent("onkeyup", KeyDownHandler);
            }
            catch (Exception ex) { } 
            finally
            {
                this.isRegistered = false;
            }
        }
    }

    private void RaiseOnKeyUp(ModifierKeys modKey,int keyCode,System.Windows.Input.KeyEventArgs ke,HtmlEventArgs he)
    {
        var handlers = (from h in this.shortcuts
                        where h.ModKeys == modKey && 
                        (ke!= null? h.Key == ke.Key : h.KeyCode==he.KeyCode)
                        select h);
        foreach (Shortcut s in handlers)
        {
            s.Handler(this,new EventArgsKeyUp(s.Data));
            if(ke!=null)ke.Handled = true;
            if (he != null) he.StopPropagation();
        }
    }

    internal Shortcut RegisterShortcut(ModifierKeys ModKeys, Key key, KeyUpHandler handler, params object[] data)
    {
       Shortcut shortcut = RegisterShortcut(ModKeys, key, handler);
        shortcut.Data = data;
        return shortcut;
    }

    internal Shortcut RegisterShortcut(ModifierKeys ModKeys, Key key, KeyUpHandler handler)
    {
        var shortAlready = from s in shortcuts
                            where s.ModKeys == ModKeys &&
                            s.Key == key && s.Handler.Method.Equals(handler.Method)
                            select s;
        if (shortAlready.Count() == 0)
        {
            Shortcut shortcut = new Shortcut { ModKeys = ModKeys, Key = key, Handler = handler };
            shortcuts.Add(shortcut);
            return shortcut;
        }
        else
        {
            return shortAlready.FirstOrDefault();
        }
    }

    private void OnBodyKeyUp(object sender, HtmlEventArgs e)
    {
        RaiseOnKeyUp(GetModKey(e), e.KeyCode,null,e);
           
    }

       
    private ModifierKeys GetModKey(HtmlEventArgs e)
    {
        ModifierKeys modKey = ModifierKeys.None;
        if (e.CtrlKey) modKey = modKey | ModifierKeys.Control;
        if (e.AltKey) modKey = modKey | ModifierKeys.Alt;
        if (e.ShiftKey) modKey = modKey | ModifierKeys.Shift;

        return modKey;
    }

    void RootVisual_KeyUp(object sender, System.Windows.Input.KeyEventArgs e)
    {

        RaiseOnKeyUp(Keyboard.Modifiers,e.PlatformKeyCode,e,null);
    }

    internal class Shortcut
    {
        public KeyUpHandler Handler { get; set; }
        public ModifierKeys ModKeys { get; set; }
        Key key;
        public object[] Data;
        public Key Key
        {
            get { return key; }
            set {key=value;
                KeyCode = App.KeyCodeLookUp[value]; }
        }
        public int KeyCode { get; set; }
    }
}
}