using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Threading;
using static ConsoleLib.NativeMethods;


namespace RobvanderWoude
{
	class Mause
	{
		static string progver = "1.06";

		const string defaultprompt = "Press any key or mouse button or wheel to continue . . .";
		const int defaulttimeout = 0;

		static IntPtr inHandle = IntPtr.Zero;
		static uint initialmode = 0;
		static string prompt = defaultprompt;
		static int timeout = defaulttimeout;
		static bool flushkeyboardbuffer = true;
		private static System.Timers.Timer timer;


		static void Main( string[] args )
		{
			foreach ( string arg in args )
			{
				if ( arg == "/?" )
				{
					ShowHelp( );
				}
				if ( arg.Length > 3 && arg.ToUpper( ).Substring( 0, 3 ) == "/T:" )
				{
					if ( timeout != defaulttimeout )
					{
						ShowHelp( "Duplicate timeout switch /T" );
					}
					try
					{
						timeout = Convert.ToInt32( arg.Substring( 3 ) );
						if ( timeout < 1 || timeout > 3600 )
						{
							ShowHelp( "Specified timeout out of 1..3600 seconds range" );
						}
					}
					catch
					{
						ShowHelp( "Invalid timeout \"{0}\"", arg );
					}
				}
				else if ( arg.ToUpper( ) == "/N" )
				{
					if ( !flushkeyboardbuffer )
					{
						ShowHelp( "Duplicate timeout switch /N" );
					}
					flushkeyboardbuffer = false;
				}
				else
				{
					if ( prompt != defaultprompt )
					{
						ShowHelp( "Too many command line arguments" );
					}
					prompt = arg;
				}
			}

			// Flush keyboard buffer unless /N switch is used
			if ( flushkeyboardbuffer )
			{
				FlushKeyboardBuffer( );
			}

			// Temporarily enable mouse input and disable Quick-Edit mode
			inHandle = GetStdHandle( STD_INPUT_HANDLE );
			GetConsoleMode( inHandle, ref initialmode );
			uint tempmode = initialmode | ENABLE_EXTENDED_FLAGS; // enable
			tempmode |= ENABLE_MOUSE_INPUT; // enable
			tempmode &= ~ENABLE_QUICK_EDIT_MODE; // disable
			tempmode &= ~ENABLE_LINE_INPUT; // disable
			tempmode &= ~ENABLE_ECHO_INPUT; // disable
			tempmode &= ~ENABLE_WINDOW_INPUT; // disable
			SetConsoleMode( inHandle, tempmode );

			// Set event listeners for keyboard and mouse input
			ConsoleLib.ConsoleListener.MouseEvent += ConsoleListener_MouseEvent;
			ConsoleLib.ConsoleListener.KeyEvent += ConsoleListener_KeyEvent;
			ConsoleLib.ConsoleListener.Start( );

			// Start timeout timer if requested
			if ( timeout > 0 )
			{
				timer = new System.Timers.Timer( );
				timer.Interval = 1000 * timeout;
				timer.Elapsed += Timer_Elapsed;
				timer.Start( );
			}

			// Show the prompt
			if ( !string.IsNullOrWhiteSpace( prompt ) )
			{
				Console.Write( prompt );
			}

			// Temporarily hide the cursor
			Console.CursorVisible = false;
		}


		static void FlushKeyboardBuffer( )
		{
			// Code to flush keyboard buffer by gandjustas
			// https://stackoverflow.com/a/3769828
			bool hidekey = true;
			while ( Console.KeyAvailable )
			{
				Console.ReadKey( hidekey );
			}
		}


		static void Quit( int rc )
		{
			// If a prompt was shown, append a newline
			if ( !string.IsNullOrWhiteSpace( prompt ) )
			{
				Console.WriteLine( );
			}
			// Stop the timeout timer, if active
			if ( timeout > 0 )
			{
				timer.Stop( );
				timer.Dispose( );
			}
			// Restore the cursor
			Console.CursorVisible = true;
			// Restore the console's initial Quick-Edit mode
			SetConsoleMode( inHandle, initialmode );
			// Exit with appropriate return code
			Environment.Exit( rc );
		}


		private static void ConsoleListener_KeyEvent( KEY_EVENT_RECORD r )
		{
			// Keyboard input
			Quit( 1 );
		}


		private static void ConsoleListener_MouseEvent( MOUSE_EVENT_RECORD r )
		{
			if ( r.dwEventFlags != 1 ) // ignore mouse movement events
			{
				// Mouse input
				Quit( 2 );
			}
		}


		private static void Timer_Elapsed( object sender, System.Timers.ElapsedEventArgs e )
		{
			// Timeout elapsed
			Quit( 3 );
		}


		#region Error handling

		static void ShowHelp( params string[] errmsg )
		{
			#region Error Message

			if ( errmsg.Length > 0 )
			{
				List<string> errargs = new List<string>( errmsg );
				errargs.RemoveAt( 0 );
				Console.Error.WriteLine( );
				Console.ForegroundColor = ConsoleColor.Red;
				Console.Error.Write( "ERROR:\t" );
				Console.ForegroundColor = ConsoleColor.White;
				Console.Error.WriteLine( errmsg[0], errargs.ToArray( ) );
				Console.ResetColor( );
			}

			#endregion Error Message


			#region Help Text

			/*
			Mause.exe,  Version 1.06
			Mouse enabled pAUSE command
 
			Usage:    Mause.exe  [ prompt ]  [ /T:seconds ]  [ /N ]
 
			Where:    prompt      is the prompt to be displayed (default: "Press any key
			                      or mouse button or wheel to continue . . ."; use "" to
			                      show no prompt)
			          /N          do Not flush the keyboard buffer
			                      (default: flush keyboard buffer when program is started)
			          /T:seconds  timeout in seconds (1..3600; default: wait forever)

			Notes:    Return code 1 for key, 2 for mouse, 3 for timeout or -1 for errors.
			          While Mause is running, the console's Quick-Edit mode will be
			          temporarily disabled; before exiting, the console's initial
			          Quick-Edit state will be restored.

			Credits:  ConsoleListener class by SWdV on StackOverflow.com
			          https://stackoverflow.com/a/29971246
			          Code to flush keyboard buffer by gandjustas on StackOverflow.com
			          https://stackoverflow.com/a/3769828
 
			Written by Rob van der Woude
			https://www.robvanderwoude.com
			*/

			#endregion Help Text


			#region Display Help Text

			Console.Error.WriteLine( );

			Console.Error.WriteLine( "Mause.exe,  Version {0}", progver );

			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "M" );
			Console.ResetColor( );
			Console.Error.Write( "ouse enabled p" );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "AUSE" );
			Console.ResetColor( );
			Console.Error.WriteLine( " command" );

			Console.Error.WriteLine( );

			Console.Error.Write( "Usage:    " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.WriteLine( "Mause.exe  [ prompt ]  [ /T:timeout ]  [ /N ]" );
			Console.ResetColor( );

			Console.Error.WriteLine( );

			Console.Error.Write( "Where:    " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "prompt" );
			Console.ResetColor( );
			Console.Error.WriteLine( "      is the prompt to be displayed (default: \"Press any key" );

			Console.Error.WriteLine( "                      or mouse button or wheel to continue . . .\"; use \"\" to" );

			Console.Error.WriteLine( "                      show no prompt)" );

			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "          /N" );
			Console.ResetColor( );
			Console.Error.Write( "          do " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "N" );
			Console.ResetColor( );
			Console.Error.WriteLine( "ot flush the keyboard buffer" );

			Console.Error.WriteLine( "                      (default: flush keyboard buffer when program is started)" );

			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "          /T:seconds" );
			Console.ResetColor( );
			Console.Error.WriteLine( "  timeout in seconds (1..3600; default: wait forever)" );

			Console.Error.WriteLine( );

			Console.Error.WriteLine( "Notes:    Return code 1 for key, 2 for mouse, 3 for timeout or -1 for errors." );

			Console.Error.WriteLine( "          While Mause is running, the console's Quick-Edit mode will be" );

			Console.Error.WriteLine( "          temporarily disabled; before exiting, the console's initial" );

			Console.Error.WriteLine( "          Quick-Edit state will be restored." );

			Console.Error.WriteLine( );

			Console.Error.WriteLine( "Credits:  ConsoleListener class by SWdV on StackOverflow.com" );

			Console.ForegroundColor = ConsoleColor.DarkGray;
			Console.Error.WriteLine( "          https://stackoverflow.com/a/29971246" );
			Console.ResetColor( );

			Console.Error.WriteLine( "          Code to flush keyboard buffer by gandjustas on StackOverflow.com" );

			Console.ForegroundColor = ConsoleColor.DarkGray;
			Console.Error.WriteLine( "          https://stackoverflow.com/a/3769828" );
			Console.ResetColor( );

			Console.Error.WriteLine( );

			Console.Error.WriteLine( "Written by Rob van der Woude" );

			Console.Error.WriteLine( "https://www.robvanderwoude.com" );

			#endregion Display Help Text


			Environment.Exit( -1 );
		}

		#endregion Error handling
	}
}



// ConsoleListener class by SWdV on StackOverflow.com
// https://stackoverflow.com/a/29971246
namespace ConsoleLib
{
	public static class ConsoleListener
	{
		public static event ConsoleMouseEvent MouseEvent;

		public static event ConsoleKeyEvent KeyEvent;

		public static event ConsoleWindowBufferSizeEvent WindowBufferSizeEvent;

		private static bool Run = false;


		public static void Start( )
		{
			if ( !Run )
			{
				Run = true;
				IntPtr handleIn = GetStdHandle( STD_INPUT_HANDLE );
				new Thread( ( ) =>
				{
					while ( true )
					{
						uint numRead = 0;
						INPUT_RECORD[] record = new INPUT_RECORD[1];
						record[0] = new INPUT_RECORD( );
						ReadConsoleInput( handleIn, record, 1, ref numRead );
						if ( Run )
							switch ( record[0].EventType )
							{
								case INPUT_RECORD.MOUSE_EVENT:
									MouseEvent?.Invoke( record[0].MouseEvent );
									break;
								case INPUT_RECORD.KEY_EVENT:
									KeyEvent?.Invoke( record[0].KeyEvent );
									break;
								case INPUT_RECORD.WINDOW_BUFFER_SIZE_EVENT:
									WindowBufferSizeEvent?.Invoke( record[0].WindowBufferSizeEvent );
									break;
							}
						else
						{
							uint numWritten = 0;
							WriteConsoleInput( handleIn, record, 1, ref numWritten );
							return;
						}
					}
				} ).Start( );
			}
		}


		public static void Stop( ) => Run = false;


		public delegate void ConsoleMouseEvent( MOUSE_EVENT_RECORD r );


		public delegate void ConsoleKeyEvent( KEY_EVENT_RECORD r );


		public delegate void ConsoleWindowBufferSizeEvent( WINDOW_BUFFER_SIZE_RECORD r );
	}


	public static class NativeMethods
	{
		public struct COORD
		{
			public short X;
			public short Y;


			public COORD( short x, short y )
			{
				X = x;
				Y = y;
			}
		}


		[StructLayout( LayoutKind.Explicit )]
		public struct INPUT_RECORD
		{
			public const ushort KEY_EVENT = 0x0001,
				MOUSE_EVENT = 0x0002,
				WINDOW_BUFFER_SIZE_EVENT = 0x0004; //more

			[FieldOffset( 0 )]
			public ushort EventType;

			[FieldOffset( 4 )]
			public KEY_EVENT_RECORD KeyEvent;

			[FieldOffset( 4 )]
			public MOUSE_EVENT_RECORD MouseEvent;

			[FieldOffset( 4 )]
			public WINDOW_BUFFER_SIZE_RECORD WindowBufferSizeEvent;
			/*
            and:
             MENU_EVENT_RECORD MenuEvent;
             FOCUS_EVENT_RECORD FocusEvent;
             */
		}


		public struct MOUSE_EVENT_RECORD
		{
			public COORD dwMousePosition;

			public const uint FROM_LEFT_1ST_BUTTON_PRESSED = 0x0001,
				FROM_LEFT_2ND_BUTTON_PRESSED = 0x0004,
				FROM_LEFT_3RD_BUTTON_PRESSED = 0x0008,
				FROM_LEFT_4TH_BUTTON_PRESSED = 0x0010,
				RIGHTMOST_BUTTON_PRESSED = 0x0002;

			public uint dwButtonState;

			public const int CAPSLOCK_ON = 0x0080,
				ENHANCED_KEY = 0x0100,
				LEFT_ALT_PRESSED = 0x0002,
				LEFT_CTRL_PRESSED = 0x0008,
				NUMLOCK_ON = 0x0020,
				RIGHT_ALT_PRESSED = 0x0001,
				RIGHT_CTRL_PRESSED = 0x0004,
				SCROLLLOCK_ON = 0x0040,
				SHIFT_PRESSED = 0x0010;

			public uint dwControlKeyState;

			public const int DOUBLE_CLICK = 0x0002,
				MOUSE_HWHEELED = 0x0008,
				MOUSE_MOVED = 0x0001,
				MOUSE_WHEELED = 0x0004;

			public uint dwEventFlags;
		}

		[StructLayout( LayoutKind.Explicit, CharSet = CharSet.Unicode )]
		public struct KEY_EVENT_RECORD
		{
			[FieldOffset( 0 )]
			public bool bKeyDown;

			[FieldOffset( 4 )]
			public ushort wRepeatCount;

			[FieldOffset( 6 )]
			public ushort wVirtualKeyCode;

			[FieldOffset( 8 )]
			public ushort wVirtualScanCode;

			[FieldOffset( 10 )]
			public char UnicodeChar;

			[FieldOffset( 10 )]
			public byte AsciiChar;

			public const int CAPSLOCK_ON = 0x0080,
				ENHANCED_KEY = 0x0100,
				LEFT_ALT_PRESSED = 0x0002,
				LEFT_CTRL_PRESSED = 0x0008,
				NUMLOCK_ON = 0x0020,
				RIGHT_ALT_PRESSED = 0x0001,
				RIGHT_CTRL_PRESSED = 0x0004,
				SCROLLLOCK_ON = 0x0040,
				SHIFT_PRESSED = 0x0010;

			[FieldOffset( 12 )]
			public uint dwControlKeyState;
		}

		public struct WINDOW_BUFFER_SIZE_RECORD
		{
			public COORD dwSize;
		}

		public const uint STD_INPUT_HANDLE = unchecked((uint) -10),
			STD_OUTPUT_HANDLE = unchecked((uint) -11),
			STD_ERROR_HANDLE = unchecked((uint) -12);

		[DllImport( "kernel32.dll" )]
		public static extern IntPtr GetStdHandle( uint nStdHandle );

		public const uint ENABLE_MOUSE_INPUT = 0x0010,
			ENABLE_QUICK_EDIT_MODE = 0x0040,
			ENABLE_EXTENDED_FLAGS = 0x0080,
			ENABLE_ECHO_INPUT = 0x0004,
			ENABLE_WINDOW_INPUT = 0x0008,
			ENABLE_INSERT_MODE = 0x0020,
			ENABLE_LINE_INPUT = 0x0002,
			ENABLE_PROCESSED_INPUT = 0x0001,
			ENABLE_VIRTUAL_TERMINAL_INPUT = 0x0200;

		[DllImportAttribute( "kernel32.dll" )]
		public static extern bool GetConsoleMode( IntPtr hConsoleInput, ref uint lpMode );

		[DllImportAttribute( "kernel32.dll" )]
		public static extern bool SetConsoleMode( IntPtr hConsoleInput, uint dwMode );

		[DllImportAttribute( "kernel32.dll", CharSet = CharSet.Unicode )]
		public static extern bool ReadConsoleInput( IntPtr hConsoleInput, [Out] INPUT_RECORD[] lpBuffer, uint nLength, ref uint lpNumberOfEventsRead );

		[DllImportAttribute( "kernel32.dll", CharSet = CharSet.Unicode )]
		public static extern bool WriteConsoleInput( IntPtr hConsoleInput, INPUT_RECORD[] lpBuffer, uint nLength, ref uint lpNumberOfEventsWritten );
	}
}