using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Windows.Forms;


namespace Back2Base
{
	static class Back2BaseProgram
	{
		static readonly string progver = "1.00";

		static readonly int screenwidth = Screen.PrimaryScreen.WorkingArea.Width;
		static readonly int screenheight = Screen.PrimaryScreen.WorkingArea.Height;

		static bool includeminimized = false;
		static bool includeanonymous = false;


		[STAThread]
		static int Main( )
		{
			Application.EnableVisualStyles( );
			Application.SetCompatibleTextRenderingDefault( false );


			#region Parse Command Line

			foreach ( string arg in Environment.CommandLine.Split( ' ' ).Skip( 1 ) )
			{
				switch ( arg.ToUpper( ) )
				{
					case "":
						break;
					case "/?":
						return ShowHelp( );
					case "/IA":
						if ( includeanonymous )
						{
							return ShowHelp( "Duplicate command line switch /IA" );
						}
						includeanonymous = true;
						break;
					case "/IM":
						if ( includeminimized )
						{
							return ShowHelp( "Duplicate command line switch /IM" );
						}
						includeminimized = true;
						break;
					default:
						return ShowHelp( "Invalid command line argument \"{0}\"", arg );
				}
			}

			#endregion Parse Command Line


			// List active windows
			GetDesktopWindowHandlesAndTitles( out windows );


			#region Restore Minimized Windows

			// First restore/maximize any minimized window(s) that should be included
			foreach ( IntPtr handle in windows.Keys )
			{
				if ( windows[handle] != "(no title)" || includeanonymous )
				{
					if ( !IsIconic( handle ) || includeminimized )
					{
						if ( IsIconic( handle ) && includeminimized )
						{
							ShowWindow( handle, SW_SHOWMAXIMIZED );
							//ShowWindow( handle, SW_SHOWMAXIMIZED );
						}
					}
				}
			}

			#endregion Restore Minimized Windows


			#region Move Windows to Primary Monitor

			// Next move the window(s) to the primary monitor
			int count = 0;

			foreach ( IntPtr handle in windows.Keys )
			{
				if ( windows[handle] != "(no title)" || includeanonymous )
				{
					if ( !IsIconic( handle ) || includeminimized )
					{
						RECT rect = new RECT( );
						if ( GetWindowRect( handle, ref rect ) )
						{
							if ( ( rect.Left > screenwidth || rect.Right < 20 || rect.Top > screenheight || rect.Bottom < 20 ) && ( rect.Left != 0 && rect.Top != 0 ) )
							{
								int width = rect.Right - rect.Left;
								int height = rect.Bottom - rect.Top;
								bool repaint = true;
								if ( MoveWindow( handle, 0, 0, width, height, repaint ) )
								{
									count += 1;
								}
							}
						}
					}
				}
			}

			#endregion Move Windows to Primary Monitor


			return count;
		}


		#region Check If Minimized

		[DllImport( "user32.dll" )]
		[return: MarshalAs( UnmanagedType.Bool )]
		static extern bool IsIconic( IntPtr hWnd ); // true if window is minimized

		#endregion Check If Minimized


		#region Get Window Size

		// Get window position and size
		// https://stackoverflow.com/a/1434577
		[DllImport( "user32.dll", SetLastError = true )]
		[return: MarshalAs( UnmanagedType.Bool )]
		static extern bool GetWindowRect( IntPtr hWnd, ref RECT lpRect );
		[StructLayout( LayoutKind.Sequential )]


		public struct RECT
		{
			public int Left;
			public int Top;
			public int Right;
			public int Bottom;
		}

		#endregion Get Window Size


		#region List Desktop Windows

		// Based on code by Rod Stephens
		// List desktop windows in C#
		// http://csharphelper.com/blog/2016/08/list-desktop-windows-in-c/

		[DllImport( "user32.dll" )]
		[return: MarshalAs( UnmanagedType.Bool )]
		private static extern bool IsWindowVisible( IntPtr hWnd );

		[DllImport( "user32.dll", EntryPoint = "GetWindowText",
		ExactSpelling = false, CharSet = CharSet.Auto, SetLastError = true )]
		private static extern int GetWindowText( IntPtr hWnd, StringBuilder lpWindowText, int nMaxCount );

		[DllImport( "user32.dll", EntryPoint = "EnumDesktopWindows",
		ExactSpelling = false, CharSet = CharSet.Auto, SetLastError = true )]
		private static extern bool EnumDesktopWindows( IntPtr hDesktop, EnumDelegate lpEnumCallbackFunction, IntPtr lParam );

		// Define the callback delegate's type.
		private delegate bool EnumDelegate( IntPtr hWnd, int lParam );

		// Save window titles and handles in Dictionary
		private static Dictionary<IntPtr, string> windows;

		// Return a list of the desktop windows' handles and titles.
		public static void GetDesktopWindowHandlesAndTitles( out Dictionary<IntPtr, string> windowslist )
		{
			windowslist = new Dictionary<IntPtr, string>( );

			if ( !EnumDesktopWindows( IntPtr.Zero, FilterCallback, IntPtr.Zero ) )
			{
				windowslist = null;
			}
			else
			{
				windowslist = windows;
			}
		}


		// We use this function to filter windows
		// This version selects visible windows that aren't minimized
		private static bool FilterCallback( IntPtr hWnd, int lParam )
		{
			// Get the window's title
			StringBuilder sb_title = new StringBuilder( 1024 );
			int _ = GetWindowText( hWnd, sb_title, sb_title.Capacity );
			string title = sb_title.ToString( );

			// If the window is visible and has a title, save it.
			if ( IsWindowVisible( hWnd ) )
			{
				if ( string.IsNullOrEmpty( title ) )
				{
					title = "(no title)";
				}
				windows.Add( hWnd, title );
			}

			// Return true to indicate that we should continue enumerating windows
			return true;
		}

		#endregion List Desktop Windows


		#region Move Window

		// Based on code by Roberto Luis Bisb\u00E9
		// Moving windows programatically with Windows API, the path to WinResize
		// https://rlbisbe.net/2013/11/19/moving-windows-programatically-with-windows-api-the-path-to-winresize/

		[DllImport( "user32.dll" )]
		public static extern bool MoveWindow( IntPtr hWnd, int X, int Y, int nWidth, int nHeight, bool bRepaint );

		#endregion Move Window


		#region Restore Window

		// private const int SW_SHOWNORMAL = 1;
		// private const int SW_SHOWMINIMIZED = 2;
		private const int SW_SHOWMAXIMIZED = 3;


		[DllImport( "user32.dll" )]
		private static extern bool ShowWindow( IntPtr hWnd, int nCmdShow );


		[DllImport( "user32.dll" )]
		private static extern bool ShowWindowAsync( IntPtr hWnd, int nCmdShow );

		#endregion Restore Window


		#region Error handling

		public static int ShowHelp( params string[] errmsg )
		{
			string helptext = string.Empty;
			string title = "Back2Base,  Version " + progver;
			MessageBoxIcon icon = MessageBoxIcon.Information;

			#region Error Message

			if ( errmsg.Length > 0 )
			{
				List<string> errargs = new List<string>( errmsg );
				errargs.RemoveAt( 0 );
				helptext += "\nERROR:\t" + string.Format( errmsg[0], errargs.ToArray( ) ) + "\n\n";
				title = "Error";
				icon = MessageBoxIcon.Error;
			}

			#endregion Error Message


			#region Help Text

			/*
			Back2Base.exe,  Version 1.00
			Move out-of-sight windows back to the primary screen
 
			Usage:   Back2Base  [ /IA ]  [ /IM ]
 
			Options: /IA	Include Anonymous windows, i.e. those without title
			         /IM    Include Minimized windows
 
			Credits:
			Get window position and size
			https://stackoverflow.com/a/1434577

			List desktop windows based on code by Rod Stephens
			http://csharphelper.com/blog/2016/08/list-desktop-windows-in-c/

			Moving windows based on code by Roberto Luis Bisb\u00E9
			https://rlbisbe.net/2013/11/19/moving-windows-programatically-with-windows-api-the-path-to-winresize/

			Notes:
			This is a GUI version of CatchStrayWindows.exe; the only visible output will be error messages.
			Return code equals number of moved windows, or -1 in case of errors.

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

			#endregion Help Text


			#region Display Help Text

			helptext += "Back2Base.exe,  Version " + progver;
			helptext += "\nMove out-of-sight windows back to the primary screen";
			helptext += "\n\nOptions:\n======\n\n/IA\tInclude Anonymous windows, i.e. those without title";
			helptext += "\n/IM\tInclude Minimized windows";
			helptext += "\n\nCredits:\n=====\n\nGet window position and size:";
			helptext += "\nhttps://stackoverflow.com/a/1434577";
			helptext += "\n\nList desktop windows based on code by Rod Stephens:";
			helptext += "\nhttp://csharphelper.com/blog/2016/08/list-desktop-windows-in-c/";
			helptext += "\n\nMoving windows based on code by Roberto Luis Bisb\u00E9:";
			helptext += "\nhttps://rlbisbe.net/2013/11/19/moving-windows-programatically-with-windows-api-the-path-to-winresize/";
			helptext += "\n\nNotes:\n====\n\nThis is a GUI version of CatchStrayWindows.exe; the only visible output will be error messages.";
			helptext += "\n\nReturn code equals number of moved windows, or -1 in case of errors.";
			helptext += "\n\nWritten by Rob van der Woude";
			helptext += "\nhttps://www.robvanderwoude.com";

			MessageBox.Show( helptext, title, MessageBoxButtons.OK, icon, MessageBoxDefaultButton.Button1, MessageBoxOptions.DefaultDesktopOnly | MessageBoxOptions.ServiceNotification );

			#endregion Display Help Text

			return -1;
		}

		#endregion Error handling
	}
}