using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Drawing;
using System.Windows.Forms;

namespace TibisMathematicsSuite.KeyboardIO
{
    public class KeyShortcutBox : TextBox
    {
        #region Variables
        private KeyMessageFilter keyFilter = new KeyMessageFilter();
        private MyKey currentKey = new MyKey();
        private bool inputFinished = false;
        #endregion

        #region Properties
        public MyKey Key
        {
            get {
                return MyKey.Parse(this.Text);
            }
        }

        #endregion

        #region Constructor
        public KeyShortcutBox() : base() 
        {
            this.ReadOnly = true;
            this.BackColor = SystemColors.Window;

            Application.AddMessageFilter(keyFilter);

            keyFilter.KeyDown += new EventHandler<KeyEventArgs>(keyFilter_KeyDown);
            keyFilter.KeyUp += new EventHandler<KeyEventArgs>(keyFilter_KeyUp);
        }
        #endregion

        #region Key updating
        private void keyFilter_KeyUp(object sender, KeyEventArgs e)
        {
            switch (e.KeyCode)
            {
                case Keys.LMenu:
                case Keys.RMenu:
                case Keys.Menu: currentKey.Mods &= ~MyKey.Modifiers.Alt; break;

                case Keys.LShiftKey:
                case Keys.RShiftKey:
                case Keys.ShiftKey: currentKey.Mods &= ~MyKey.Modifiers.Shift; break;

                case Keys.LControlKey:
                case Keys.RControlKey:
                case Keys.ControlKey: currentKey.Mods &= ~MyKey.Modifiers.Ctrl; break;

                case Keys.LWin:
                case Keys.RWin: currentKey.Mods &= ~MyKey.Modifiers.Win; break;

                default:
                    inputFinished = true;
                    currentKey.Key = Keys.None; 
                    break;
            }

            updateKey();
        }

        private void keyFilter_KeyDown(object sender, KeyEventArgs e)
        {
            switch (e.KeyCode)
            {
                case Keys.LMenu:
                case Keys.RMenu:
                case Keys.Menu: currentKey.Mods |= MyKey.Modifiers.Alt; break;

                case Keys.LShiftKey:
                case Keys.RShiftKey:
                case Keys.ShiftKey: currentKey.Mods |= MyKey.Modifiers.Shift; break;

                case Keys.LControlKey:
                case Keys.RControlKey:
                case Keys.ControlKey: currentKey.Mods |= MyKey.Modifiers.Ctrl; break;

                case Keys.LWin:
                case Keys.RWin: currentKey.Mods |= MyKey.Modifiers.Win; break;

                default: currentKey.Key = e.KeyCode; break;
            }

            inputFinished = false;
            updateKey();
        }

        private void updateKey()
        {
            if (!inputFinished && this.Focused && this.Enabled)
                this.Text = currentKey.ToString();
        }
        #endregion

        #region Reset
        public void Reset()
        {
            this.Text = "";
            this.inputFinished = false;
        }
        #endregion
    }
}