using System;
using System.Collections.Generic;
using System.Windows.Forms;

namespace SafeMobileLib
{
    public class KeyInterceptor
    {

        private GlobalKeyboardHook _globalKeyboardHook;
        private EventHandler<GlobalKeyboardHookEventArgs> callbackKeyboardHook;
        public enum KeyState { UP, DOWN, UNKNOWN};
        private Dictionary<int, KeyState> keyStates;

        private enum TriggerState { TRIGGERED, NOT_TRIGGERED };
        private TriggerState triggeredState = TriggerState.NOT_TRIGGERED;

        private Keys searchedKey;
        private Keys specialKey;
        private int specKey = 164;
        private int searKey = 65;

        public KeyInterceptor(Keys searchedKey, Keys specialKey)
        {
            keyStates = new Dictionary<int, KeyState>();

            this.searchedKey = searchedKey;
            this.specialKey = specialKey;

            searKey = (int)searchedKey;
            specKey = specialKey == Keys.Alt ? 164 : (specialKey == Keys.ShiftKey ? 160 : 162);

            keyStates.Add(searKey, KeyState.UNKNOWN);
            keyStates.Add(specKey, KeyState.UNKNOWN);
            keyStates.Add(0x73, KeyState.UNKNOWN);


            _globalKeyboardHook = new GlobalKeyboardHook();
            callbackKeyboardHook = new EventHandler<GlobalKeyboardHookEventArgs>(OnKeyPressed);
            _globalKeyboardHook.KeyboardPressed += callbackKeyboardHook;
        }


        private void OnKeyPressed(object sender, GlobalKeyboardHookEventArgs e)
        {
            if (!keyStates.ContainsKey(e.KeyboardData.VirtualCode))
                keyStates.Add(e.KeyboardData.VirtualCode, KeyState.UNKNOWN);

            keyStates[e.KeyboardData.VirtualCode] = (e.KeyboardState.ToString().ToLower().Contains("down") ? KeyState.DOWN : KeyState.UP);

            if (keyStates[164] == KeyState.DOWN && keyStates[0x73] == KeyState.DOWN)
            {
                Utils.WriteLine("Alt+F4 pressed", ConsoleColor.Green);
            }

            if (keyStates[specKey] == KeyState.DOWN && keyStates[searKey] == KeyState.DOWN)
            {
                if (triggeredState == TriggerState.NOT_TRIGGERED)
                {
                    OnKeyPressedStateChanged?.Invoke((Keys)searKey, specKey == 164 ? Keys.Alt : (specKey == 160 ? Keys.ShiftKey : Keys.ControlKey), KeyState.DOWN);
                    triggeredState = TriggerState.TRIGGERED;
                }
            }
            else
            {
                if (triggeredState == TriggerState.TRIGGERED)
                {
                    OnKeyPressedStateChanged?.Invoke((Keys)searKey, specKey == 164 ? Keys.Alt : (specKey == 160 ? Keys.ShiftKey : Keys.ControlKey), KeyState.UP);
                    triggeredState = TriggerState.NOT_TRIGGERED;
                }
            }

            if (e.KeyboardData.VirtualCode != GlobalKeyboardHook.VkSnapshot)
                return;
            

            if (e.KeyboardState == GlobalKeyboardHook.KeyboardState.KeyDown)
            {
                Utils.WriteLine("Print Screen", ConsoleColor.Red);
                e.Handled = true;
            }
        }

        public void Dispose()
        {
            _globalKeyboardHook?.Dispose();
        }



        public delegate void KeyStateChanged(Keys searchedKEy, Keys specialKey, KeyState state);
        public event KeyStateChanged OnKeyPressedStateChanged;
    }

}