/**
 * <copyright> Copyright (c) 2006 by Know-Center, Graz, Austria </copyright>
 * 
 * This software is the confidential and proprietary information of Know-Center,
 * Graz, Austria. You shall not disclose such Confidential Information and shall
 * use it only in accordance with the terms of the license agreement you entered
 * into with Know-Center.
 * 
 * KNOW-CENTER MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
 * THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR
 * NON-INFRINGEMENT. KNOW-CENTER SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY
 * LICENSEE AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES.
 * 
 * $Id: PDFUtilities.java,v 1.3 2006/10/31 08:09:33 wprinz Exp $
 */
package at.knowcenter.wag.egov.egiz.pdf;

import java.io.ByteArrayInputStream;
import java.io.File;
import java.io.IOException;
import java.util.List;

import org.pdfbox.pdfparser.PDFParser;
import org.pdfbox.pdmodel.PDDocument;
import org.pdfbox.pdmodel.PDPage;

import at.knowcenter.wag.egov.egiz.cfg.SettingsReader;
import at.knowcenter.wag.egov.egiz.exceptions.PDFDocumentException;

import com.lowagie.text.DocumentException;

/**
 * Contains useful helpers for accessing PDF documents.
 * 
 * @author wprinz
 */
public abstract class PDFUtilities
{
  public static float calculateLastPageLength(final byte[] pdf) throws PDFDocumentException
  {
    try
    {
      ByteArrayInputStream original_bais = new ByteArrayInputStream(pdf);
      byte [] normalized_pdf = TextualSignature.normalizePDF(original_bais);
      
      ByteArrayInputStream bais = new ByteArrayInputStream(normalized_pdf);

      PDFParser parser = new PDFParser(bais);
      File temporary_dir = SettingsReader.getTemporaryDirectory();
      parser.setTempDirectory(temporary_dir);
      parser.parse();

      PDDocument pdfDocument_ = parser.getPDDocument();
      float last_page_length = calculateLastPageLength(pdfDocument_);
      pdfDocument_.close();

      return last_page_length;
    }
    catch (IOException e)
    {
      throw new PDFDocumentException(201, e);
    }
    catch (DocumentException e)
    {
      throw new PDFDocumentException(201, e);
    }
  }

  public static float calculateLastPageLength(PDDocument document) throws IOException
  {
    int last_page_id = document.getNumberOfPages();
    List allPages = document.getDocumentCatalog().getAllPages();
    PDPage last_page = (PDPage) allPages.get(last_page_id - 1);

    return calculatePageLength(last_page);
  }

  public static float calculatePageLength(PDPage page) throws IOException
  {
    // logger_.debug("Last Page id:" + last_page_id);
    // PDPage last_page = (PDPage) allPages.get(0);
    PDFPage my_page = new PDFPage();
    my_page.processStream(page, page.findResources(), page.getContents().getStream());
    return my_page.getMaxPageLength();
  }

}