using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
using System.IO;


namespace RobvanderWoude
{
	class RotateImage
	{
		static string progver = "1.02";


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

			if ( args.Length < 2 || args.Length > 4 )
			{
				return ShowHelp( );
			}

			string imagepath = String.Empty;
			string outputfile = String.Empty;
			string fileextout = String.Empty;
			int maxwidth = 0;
			int maxheight = 0;
			int rotateby = 90;

			foreach ( string arg in args )
			{
				if ( arg[0] == '/' )
				{
					if ( arg.Length > 3 && arg[2] == ':' )
					{
						switch ( arg.ToUpper( )[1] )
						{
							case 'M':
								if ( maxwidth != 0 )
								{
									return ShowHelp( "Duplicate command line switch /M" );
								}
								try
								{
									if ( arg.Substring( 3 ).ToLower( ).IndexOf( 'x' ) > 1 )
									{
										maxwidth = Convert.ToInt32( arg.Substring( 3, arg.ToLower( ).IndexOf( 'x' ) - 3 ) );
										maxheight = Convert.ToInt32( arg.Substring( arg.ToLower( ).IndexOf( 'x' ) + 1 ) );
									}
									else
									{
										maxwidth = Convert.ToInt32( arg.Substring( 3 ) );
										maxheight = maxwidth;
									}
								}
								catch
								{
									return ShowHelp( "size must be integer" );
								}
								if ( maxwidth < 50 || maxwidth > 10000 )
								{
									return ShowHelp( "size must be an integer between 50 and 10000" );
								}
								break;
							case 'R':
								if ( rotateby != 90 )
								{
									return ShowHelp( "Duplicate command line switch /R" );
								}
								try
								{
									rotateby = Convert.ToInt32( arg.Substring( 3 ) );
								}
								catch
								{
									return ShowHelp( "deg must be integer" );
								}
								if ( ( rotateby % 90 ) != 0 )
								{
									return ShowHelp( "deg must be a multiple of 90 degrees" );
								}
								break;
							default:
								return ShowHelp( "Invalid command line argument: \"{0}\"", arg );
						}
					}
					else
					{
						return ShowHelp( "Invalid command line argument: \"{0}\"", arg );
					}
				}
				else
				{
					if ( String.IsNullOrEmpty( imagepath ) )
					{
						imagepath = arg;
						if ( !File.Exists( imagepath ) )
						{
							return ShowHelp( "Image file not found: \"{0}\"", imagepath );
						}
					}
					else if ( String.IsNullOrEmpty( outputfile ) )
					{
						outputfile = arg;
						if ( !Directory.Exists( Directory.GetParent( outputfile ).FullName ) )
						{
							return ShowHelp( "Directory for output file not found: \"{0}\"", Directory.GetParent( outputfile ).FullName );
						}
						fileextout = Path.GetExtension( outputfile ).ToLower( );
					}
					else
					{
						return ShowHelp( "Invalid command line argument: \"{0}\"", arg );
					}
				}
			}

			#endregion Parse Command Line

			#region Validate Command Line

			string fileextin = Path.GetExtension( imagepath ).ToLower( );
			if ( String.IsNullOrEmpty( fileextout ) )
			{
				fileextout = fileextin;
			}
			string filenamein = Path.GetFileNameWithoutExtension( imagepath );
			string parentfolderin = Directory.GetParent( imagepath ).FullName;
			if ( String.IsNullOrEmpty( outputfile ) )
			{
				outputfile = Path.Combine( parentfolderin, filenamein + "_rotated" + ( ( rotateby + 720 ) % 360 ).ToString( ) );
			}
			ImageFormat formatout;
			switch ( fileextout )
			{
				case ".bmp":
					formatout = ImageFormat.Bmp;
					break;
				case ".gif":
					formatout = ImageFormat.Gif;
					break;
				case ".jpg":
				case ".jpeg":
					formatout = ImageFormat.Jpeg;
					break;
				case ".png":
					formatout = ImageFormat.Png;
					break;
				case ".tif":
				case ".tiff":
					formatout = ImageFormat.Tiff;
					break;
				default:
					return -1;
			}

			#endregion Validate Command Line

			Bitmap bitmap = new Bitmap( imagepath );
			int imagewidth = bitmap.Width;
			int imageheight = bitmap.Height;
			int rc = imagewidth; // Return code = image width before rotation
			if ( maxwidth > 0 )
			{
				float aspectratio = (float) imagewidth / (float) imageheight;
				if ( imagewidth > maxwidth || imageheight > maxheight )
				{
					float scale = Math.Min( (float) maxwidth / (float) imagewidth, (float) maxheight / (float) imageheight );
					int newwidth = (int) ( (float) imagewidth * scale );
					int newheight = (int) ( (float) imageheight * scale );
					rc = newwidth;
					Bitmap resized = new Bitmap( newwidth, newheight ); // Return code = resized image width before rotation
					// Based on blog entry by DeltaWolf7
					// http://www.deltasblog.co.uk/code-snippets/c-resizing-a-bitmap-image/
					using ( Graphics graph = Graphics.FromImage( resized ) )
					{
						graph.DrawImage( bitmap, 0, 0, newwidth, newheight );
					}
					bitmap = resized;
				}
			}
			switch ( ( rotateby + 720 ) % 360 )
			{
				case 90:
					bitmap.RotateFlip( RotateFlipType.Rotate90FlipNone );
					break;
				case 180:
					bitmap.RotateFlip( RotateFlipType.Rotate180FlipNone );
					break;
				case 270:
					bitmap.RotateFlip( RotateFlipType.Rotate270FlipNone );
					break;
				default:
					// rotation 0 or invalid: do nothing
					break;
			}

			bitmap.Save( outputfile, formatout );

			return rc;
		}


		#region Error handling

		public 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

			/*
			RotateImage.exe,  Version 1.02
			Rotate a bitmap by a multiple of 90 degrees
 
			Usage:   ROTATEIMAGE  image  [ output ]  [ options ]
 
			Where:   image        input image file (bmp, gif, jpg, png or tif)
			         output       output file name and type (default: image_rotateddeg,
			                      same type as input image)
 			
			Options: /M:size      Maximum dimension of rotated image in pixels, either as
			                      (original) width x (original) height (e.g. /M:1024x768)
			                      or as a single number for the largest dimension (e.g.
			                      /M:1024, equivalent to /M:1024x1024); if image does not
			                      fit within the specified dimensions, it will be resized
			                      while preserving its original aspect ratio
			         /R:deg       Rotation in degrees (90, 180 or 270)

			Notes:   Unless an output file name is specified, the rotated output file name
			         is the input image file name with "_rotated" and the amount of degrees
			         appended, e.g. image_rotated90.gif; if no output file is specified,
			         the file types of input and output file are identical.
			         Return code ("errorlevel") equals the width of the (resized) output
			         image before rotation, or -1 in case of errors
 
			Written by Rob van der Woude
			http://www.robvanderwoude.com
			*/

			Console.Error.WriteLine( );

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

			Console.Error.WriteLine( "Rotate a bitmap by a multiple of 90 degrees" );

			Console.Error.WriteLine( );

			Console.Error.Write( "Usage:   " );

			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.WriteLine( "ROTATEIMAGE  image  [ output ]  [ options ]" );
			Console.ResetColor( );

			Console.Error.WriteLine( );

			Console.Error.Write( "Where:   " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "image" );
			Console.ResetColor( );
			Console.Error.WriteLine( "        input image file (bmp, gif, jpg, png or tif)" );

			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "         output" );
			Console.ResetColor( );
			Console.Error.Write( "       output file name and type (default: " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "image" );
			Console.ResetColor( );
			Console.Error.Write( "_rotated" );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "deg" );
			Console.ResetColor( );
			Console.Error.WriteLine( ",)" );

			Console.Error.WriteLine( "                      same type as input image)" );

			Console.Error.WriteLine( );

			Console.Error.Write( "Options: " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "/M:size      M" );
			Console.ResetColor( );
			Console.Error.WriteLine( "aximum dimension of rotated image in pixels, either as" );

			Console.Error.Write( "                      (original) " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "width x" );
			Console.ResetColor( );
			Console.Error.Write( " (original) " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "height" );
			Console.ResetColor( );
			Console.Error.Write( " (e.g. " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "/M:1024x768" );
			Console.ResetColor( );
			Console.Error.WriteLine( ")" );

			Console.Error.WriteLine( "                      or as a single number for the largest dimension (e.g." );

			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "                      /M:1024" );
			Console.ResetColor( );
			Console.Error.Write( ", equivalent to " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "/M:1024x1024" );
			Console.ResetColor( );
			Console.Error.WriteLine( "); if image does not" );

			Console.Error.WriteLine( "                      fit within the specified dimensions, it will be resized" );

			Console.Error.WriteLine( "                      while preserving its original aspect ratio" );

			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "         /R:deg       R" );
			Console.ResetColor( );
			Console.Error.Write( "otation in " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "deg" );
			Console.ResetColor( );
			Console.Error.WriteLine( "rees (90, 180 or 270; default: 0)" );

			Console.Error.WriteLine( );

			Console.Error.WriteLine( "Notes:   Unless an output file name is specified, the rotated output file name" );

			Console.Error.WriteLine( "         is the input image file name with \"_rotated\" and the amount of degrees" );

			Console.Error.Write( "         appended, e.g. " );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "image" );
			Console.ResetColor( );
			Console.Error.Write( "_rotated" );
			Console.ForegroundColor = ConsoleColor.White;
			Console.Error.Write( "90" );
			Console.ResetColor( );
			Console.Error.WriteLine( ".gif; if no output file is specified," );

			Console.Error.WriteLine( "         the file types of input and output file are identical." );

			Console.Error.WriteLine( "         Return code (\"errorlevel\") equals the width of the (resized) output" );

			Console.Error.WriteLine( "         image before rotation, or -1 in case of errors" );

			Console.Error.WriteLine( );

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

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

			#endregion Help Text

			return -1;
		}

		#endregion Error handling
	}
}