/***************************************************************************
 *   Copyright (C) 2006 by Dominik Seichter                                *
 *   domseichter@web.de                                                    *
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program is distributed in the hope that it will be useful,       *
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
 *   GNU General Public License for more details.                          *
 *                                                                         *
 *   You should have received a copy of the GNU General Public License     *
 *   along with this program; if not, write to the                         *
 *   Free Software Foundation, Inc.,                                       *
 *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
 ***************************************************************************/


/*
 * Include the standard headers for cout to write
 * some output to the console.
 */
#include <iostream>

/*
 * Now include all podofo header files, to have access
 * to all functions of podofo and so that you do not have
 * to care about the order of includes.
 *
 * You should always use podofo.h and not try to include
 * the required headers on your own.
 */
#include <podofo/podofo.h>

/*
 * All podofo classes are member of the PoDoFo namespace.
 */
using namespace PoDoFo;

void PrintHelp()
{
    std::cout << "This is a example application for the PoDoFo PDF library." << std::endl
              << "It creates a small PDF file containing the text >Hello World!<" << std::endl
              << "Please see http://podofo.sf.net for more information" << std::endl << std::endl;
    std::cout << "Usage:" << std::endl;
    std::cout << "  examplehelloworld [outputfile.pdf]" << std::endl << std::endl;
}

void HelloWorld( const char* pszFilename ) 
{
    /*
     * PdfStreamedDocument is the class that can actually write a PDF file.
     * PdfStreamedDocument is much faster than PdfDocument, but it is only
     * suitable for creating/drawing PDF files and cannot modify existing
     * PDF documents.
     *
     * The document is written directly to pszFilename while being created.
     */
    PdfStreamedDocument document( pszFilename );

	/*
     * PdfPainter is the class which is able to draw text and graphics
     * directly on a PdfPage object.
     */
    PdfPainter painter;

	/*
     * This pointer will hold the page object later. 
     * PdfSimpleWriter can write several PdfPage's to a PDF file.
     */
    PdfPage* pPage;

	/*
     * A PdfFont object is required to draw text on a PdfPage using a PdfPainter.
     * PoDoFo will find the font using fontconfig on your system and embedd truetype
     * fonts automatically in the PDF file.
     */     
    PdfFont* pFont;

	try {
		/*
		 * The PdfDocument object can be used to create new PdfPage objects.
		 * The PdfPage object is owned by the PdfDocument will also be deleted automatically
		 * by the PdfDocument object.
		 *
		 * You have to pass only one argument, i.e. the page size of the page to create.
		 * There are predefined enums for some common page sizes.
		 */
		pPage = document.CreatePage( PdfPage::CreateStandardPageSize( ePdfPageSize_A4 ) );

		/*
		 * If the page cannot be created because of an error (e.g. ePdfError_OutOfMemory )
		 * a NULL pointer is returned.
		 * We check for a NULL pointer here and throw an exception using the RAISE_ERROR macro.
		 * The raise error macro initializes a PdfError object with a given error code and
		 * the location in the file in which the error ocurred and throws it as an exception.
		 */
		if( !pPage ) 
		{
			PODOFO_RAISE_ERROR( ePdfError_InvalidHandle );
		}

		/*
		 * Set the page as drawing target for the PdfPainter.
		 * Before the painter can draw, a page has to be set first.
		 */
		painter.SetPage( pPage );

		/*
		 * Create a PdfFont object using the font "Arial".
		 * The font is found on the system using fontconfig and embedded into the
		 * PDF file. If Arial is not available, a default font will be used.
		 *
		 * The created PdfFont will be deleted by the PdfDocument.
		 */
		pFont = document.CreateFont( "Arial" );
	    
		/*
		 * If the PdfFont object cannot be allocated return an error.
		 */
		if( !pFont )
		{
			PODOFO_RAISE_ERROR( ePdfError_InvalidHandle );
		}

		/*
		 * Set the font size
		 */
		pFont->SetFontSize( 18.0 );

		/*
		 * Set the font as default font for drawing.
		 * A font has to be set before you can draw text on
		 * a PdfPainter.
		 */
		painter.SetFont( pFont );

		/*
		 * You could set a different color than black to draw
		 * the text.
		 *
		 * SAFE_OP( painter.SetColor( 1.0, 0.0, 0.0 ) );
		 */

		/*
		 * Actually draw the line "Hello World!" on to the PdfPage at
		 * the position 2cm,2cm from the top left corner. 
		 * Please remember that PDF files have their origin at the 
		 * bottom left corner. Therefore we substract the y coordinate 
		 * from the page height.
		 * 
		 * The position specifies the start of the baseline of the text.
		 *
		 * All coordinates in PoDoFo are in PDF units.
		 * You can also use PdfPainterMM which takes coordinates in 1/1000th mm.
		 *
		 */
		painter.DrawText( 56.69, pPage->GetPageSize().GetHeight() - 56.69, "Hello World!" );

		/*
		 * Tell PoDoFo that the page has been drawn completely.
		 * This required to optimize drawing operations inside in PoDoFo
		 * and has to be done whenever you are done with drawing a page.
		 */
		painter.FinishPage();

		/*
		 * Set some additional information on the PDF file.
		 */
		document.GetInfo()->SetCreator ( PdfString("examplahelloworld - A PoDoFo test application") );
		document.GetInfo()->SetAuthor  ( PdfString("Dominik Seichter") );
		document.GetInfo()->SetTitle   ( PdfString("Hello World") );
		document.GetInfo()->SetSubject ( PdfString("Testing the PoDoFo PDF Library") );
		document.GetInfo()->SetKeywords( PdfString("Test;PDF;Hello World;") );

		/*
		 * The last step is to close the document.
		 */
		document.Close();
	} catch ( const PdfError & e ) {
		/*
		 * All PoDoFo methods may throw exceptions
		 * make sure that painter.FinishPage() is called
		 * or who will get an assert in its destructor
		 */
		try {
			painter.FinishPage();
		} catch( ... ) {
			/*
			 * Ignore errors this time
			 */
		}

		throw e;
	}
}

int main( int argc, char* argv[] )
{
    /*
     * Check if a filename was passed as commandline argument.
     * If more than 1 argument or no argument is passed,
     * a help message is displayed and the example application
     * will quit.
     */
    if( argc != 2 )
    {
        PrintHelp();
        return -1;
    }

    /*
     * All podofo functions will throw an exception in case of an error.
     *
     * You should catch the exception to either fix it or report
     * back to the user.
     *
     * All exceptions podofo throws are objects of the class PdfError.
     * Thats why we simply catch PdfError objects.
     */
    try {
        /*
         * Call the drawing routing which will create a PDF file
         * with the filename of the output file as argument.
         */
         HelloWorld( argv[1] );
    } catch( const PdfError & eCode ) {
        /*
         * We have to check if an error has occurred.
         * If yes, we return and print an error message
         * to the commandline.
         */
        eCode.PrintErrorMsg();
        return eCode.GetError();
    }


    /**
     * Free global memory allocated by PoDoFo.
     * This is normally not necessary.
     */
    PdfEncodingFactory::FreeGlobalEncodingInstances();

    /*
     * The PDF was created sucessfully.
     */
    std::cout << std::endl
              << "Created a PDF file containing the line \"Hello World!\": " << argv[1] << std::endl << std::endl;
    
    return 0;
}