using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using Microsoft.Win32;


namespace RobvanderWoude
{
	internal class QuickEditMode
	{
		static readonly string progver = "1.01";

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

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


		static int Main( string[] args )
		{
			#region Command Line Parsing

			bool consoledefault = false;
			bool currentconsole = false;
			string quickedit = "get";
			foreach ( string arg in args )
			{
				if ( arg == "0" )
				{
					if ( quickedit != "get" )
					{
						return ShowHelp( "Duplicate new value on command line" );
					}
					quickedit = "off";
				}
				else if ( arg == "1" )
				{
					if ( quickedit != "get" )
					{
						return ShowHelp( "Duplicate new value on command line" );
					}
					quickedit = "on";
				}
				else if ( arg.ToUpper( ) == "/C" )
				{
					if ( currentconsole )
					{
						return ShowHelp( "Duplicate command line switch /C" );
					}
					currentconsole = true;
				}
				else if ( arg.ToUpper( ) == "/D" )
				{
					if ( consoledefault )
					{
						return ShowHelp( "Duplicate command line switch /D" );
					}
					consoledefault = true;
				}
				else if ( arg == "/?" )
				{
					return ShowHelp( );
				}
				else
				{
					return ShowHelp( "Invalid command line argument \"{0}\"", arg );
				}
			}
			if ( !consoledefault )
			{
				currentconsole = true;
			}
			if ( quickedit == "get" && consoledefault && currentconsole )
			{
				return ShowHelp( "Use either /C or /D, not both, when reading the current status" );
			}

			#endregion Command Line Parsing


			#region Get or Set Current Console

			int currentstatus = 0;
			if ( currentconsole )
			{
				currentstatus = CurrentConsole( quickedit );
				if ( currentstatus == -1 )
				{
					if ( quickedit == "get" )
					{
						return ShowHelp( "Failed to get current console's Quick-Edit mode" );
					}
					else
					{
						return ShowHelp( "Failed to set current console's Quick-Edit mode" );
					}
				}
			}


			#endregion Get or Set Current Console


			#region Get or Set Console Default

			int defaultstatus = 0;
			if ( consoledefault )
			{
				defaultstatus = ConsoleDefault( quickedit );
				if ( defaultstatus == -1 )
				{
					if ( quickedit == "get" )
					{
						return ShowHelp( "Failed to get default Quick-Edit mode" );
					}
					else
					{
						return ShowHelp( "Failed to set default Quick-Edit mode" );
					}
				}
			}

			#endregion Get or Set Console Default


			return currentstatus + defaultstatus;
		}


		static int ConsoleDefault( string quickeditcommand )
		{
			if ( quickeditcommand == "get" )
			{
				return (int)Registry.GetValue( "HKEY_CURRENT_USER\\Console", "QuickEdit", -1 );
			}
			else
			{
				int newvalue = 0; // disable
				if ( quickeditcommand == "on" )
				{
					newvalue = 1; // enable
				}
				Registry.SetValue( "HKEY_CURRENT_USER\\Console", "QuickEdit", newvalue, RegistryValueKind.DWord );
				if ( (int)Registry.GetValue( "HKEY_CURRENT_USER\\Console", "QuickEdit", -1 ) == newvalue )
				{
					return 0; // success
				}
			}
			return -1; // failure
		}


		static int CurrentConsole( string quickeditcommand )
		{
			IntPtr handle = GetStdHandle( STD_INPUT_HANDLE );
			if ( handle != IntPtr.Zero )
			{
				uint mode = 0;
				if ( GetConsoleMode( handle, ref mode ) )
				{
					if ( quickeditcommand == "get" )
					{
						if ( ( mode & ENABLE_QUICK_EDIT_MODE ) == 0 )
						{
							return 0; // not set
						}
						else
						{
							return 1; // set
						}
					}
					else
					{
						mode |= ENABLE_EXTENDED_FLAGS; // enable, required to change Quick-Edit mode
						if ( quickeditcommand == "on" )
						{
							mode |= ENABLE_QUICK_EDIT_MODE; // enable
						}
						else
						{
							mode &= ~ENABLE_QUICK_EDIT_MODE; // disable
						}
						if ( SetConsoleMode( handle, mode ) )
						{
							return 0; // success
						}
					}
				}
			}
			return -1; // failure
		}

		#region Error handling

		static int 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

			/*
			QuickEditMode.exe,  Version 1.01
			Get or set Quick-Edit mode for consoles
 
			Usage:    QuickEditMode.exe  [ /C | /D ]
 
			   or:    QuickEditMode.exe  [ 0 | 1 ]  [ /C ]  [ /D ]
 
			Where:    0    disables Quick-Edit mode
			          1    enables Quick-Edit mode
			          /C   for current console
			          /D   default for all consoles

			Notes:    Without command line argument 0 or 1 (get mode), return code 0
			          indicates Quick-Edit mode was not set, return code 1 indicates
			          it was set.
			          With command line argument 0 or 1 (set mode), return code 0
			          indicates Quick-Edit mode was changed successfully.
			          Return code -1 always indicates an error occurred.
			          Without command line switches, only the setting for the current
			          console is read or changed.
			          With command line switch /D the default setting for all consoles
			          is read or changed.
			          Use both /C and /D if you want to change the default as well as the
			          current console; when reading the current status do not use both.
			          Besides this help, the program does not generate any screen output.

			Written by Rob van der Woude
			https://www.robvanderwoude.com
			*/

			#endregion Help Text


			#region Display Help Text

			Console.Error.WriteLine( );

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

			Console.Error.WriteLine( "Get or set the current console's Quick-Edit mode" );

			Console.Error.WriteLine( );

			Console.Error.Write( "Usage:    " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.WriteLine( "QuickEditMode.exe  [ /C | /D ]" );
			Console.ResetColor( );

			Console.Error.WriteLine( );

			Console.Error.Write( "   or:    " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.WriteLine( "QuickEditMode.exe  [ 0 | 1 ]  [ /C ]  [ /D ]" );
			Console.ResetColor( );

			Console.Error.WriteLine( );

			Console.Error.Write( "Where:    " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "0" );
			Console.ResetColor( );
			Console.Error.WriteLine( "    disables Quick-Edit mode" );

			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "          1" );
			Console.ResetColor( );
			Console.Error.WriteLine( "    enables Quick-Edit mode" );


			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "          /C" );
			Console.ResetColor( );
			Console.Error.WriteLine( "   for current console" );


			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "          /D" );
			Console.ResetColor( );
			Console.Error.WriteLine( "   default for all consoles" );


			Console.Error.WriteLine( );

			Console.Error.WriteLine( "Notes:    Without command line argument 0 or 1 (get mode), return code 0" );

			Console.Error.WriteLine( "          indicates Quick-Edit mode was not set, return code 1 indicates" );

			Console.Error.WriteLine( "          it was set." );

			Console.Error.WriteLine( "          With command line argument 0 or 1 (set mode), return code 0" );

			Console.Error.WriteLine( "          indicates Quick-Edit mode was changed successfully." );

			Console.Error.WriteLine( "          Return code -1 always indicates an error occurred." );

			Console.Error.WriteLine( "          Without command line switches, only the setting for the current" );

			Console.Error.WriteLine( "          console is read or changed." );

			Console.Error.WriteLine( "          With command line switch /D the default setting for all consoles" );

			Console.Error.WriteLine( "          is read or changed." );

			Console.Error.Write( "          Use both /C and /D if you want to " );
			Console.ForegroundColor = ConsoleColor.Yellow;
			Console.Error.Write( "change" );
			Console.ResetColor( );
			Console.Error.WriteLine( " the default as well as the" );

			Console.Error.Write( "          current console; when " );
			Console.ForegroundColor = ConsoleColor.Yellow;
			Console.Error.Write( "reading" );
			Console.ResetColor( );
			Console.Error.Write( " the current status do " );
			Console.ForegroundColor = ConsoleColor.Yellow;
			Console.Error.Write( "not" );
			Console.ResetColor( );
			Console.Error.WriteLine( " use both." );

			Console.Error.WriteLine( "          Besides this help, the program does not generate any screen output." );

			Console.Error.WriteLine( );

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

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

			#endregion Display Help Text


			return -1;
		}

		#endregion Error handling


		#region DLL Imports

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


		[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 );


		#endregion DLL Imports
	}
}