using System;
using System.Text;
using AutoHotkey.Interop;
using System.Threading.Tasks;

namespace ConsoleApplication
{
    class Program
    {
        private static void Main(string[] args)
        {
            var keyboardSimulator = new KeyboardSimulator();
            keyboardSimulator.PressButton("a"); // нажать кнопку a
        }
    }

    class KeyboardSimulator : IDisposable
    {
        private AutoHotkey.Interop.AutoHotkeyEngine _ahk;

        public void Dispose()
        {
            _ahk = null;
        }

        public KeyboardSimulator()
        {
            _ahk = new AutoHotkeyEngine();
        }

        public void PressButton(string key)
        {
            StringBuilder sb = new StringBuilder();
            sb.Append("sendinput, {").Append(GetAhkVk(key)).Append('}');

            _ahk.ExecRaw(sb.ToString());
        }

        public async void AsyncPressButton(string key)
        {
            await Task.Run(new Action(delegate
            {
                PressButton(key);
            }));
        }

        private string GetAhkVk(string key)
        {
            var _key = key.ToLower();

            for (int i = 0; i < _ahkButtons.Length; i++)
            {
                if (_key == _normalButtons[i])
                    return _ahkButtons[i];
            }

            return "";
        }

        private readonly string[] _ahkButtons = new string[]
        {
            "sc1","sc3B","sc3C","sc3D","sc3E","sc3F","sc40","sc41","sc42","sc43","sc44","sc57","sc58", // esc f1 f2 f3 f4 f5 f6 f7 f8 f9 f10 f11 f12
            "sc29","sc2","sc3","sc4","sc5","sc6","sc7","sc8","sc9","scA","scB","scC","scD","scE", // ` 1 2 3 4 5 6 7 8 9 0 - = backspace
            "scF","sc10","sc11","sc12","sc13","sc14","sc15","sc16","sc17","sc18","sc19","sc1A","sc1B","sc1C", // tab q w e r t y u i o p [ ] enter
            "sc3A","sc1E","sc1F","sc20","sc21","sc22","sc23","sc24","sc25","sc26","sc27","sc28","sc2B",// caps a s d f g h j k l ; ' \
            "sc2A","sc2C","sc2D","sc2E","sc2F","sc30","sc31","sc32","sc33","sc34","sc35","sc36", // lshift z x c v b n m , . / rshift
            "sc1D","sc15B","sc38","sc39", "sc36"  // ctrl win alt space shift
        };

        private readonly string[] _normalButtons = new[]
        {
            "esc","f1","f2","f3","f4","f5","f6","f7","f8","f9","f10","f11","f12",
            "`","1","2","3","4","5","6","7","8","9","0","-","=","backspace",
            "tab","q","w","e","r","t","y","u","i","o","p","[","]","enter",
            "caps","a","s","d","f","g","h","j","k","l",";","'","\\",
            "lshift","z","x","c","v","b","n","m",",",".","/","rshift",
            "ctrl","win","alt","space", "shift"
        };
    }
}