/**
 * <copyright> Copyright 2006 by Know-Center, Graz, Austria </copyright>
 * PDF-AS has been contracted by the E-Government Innovation Center EGIZ, a
 * joint initiative of the Federal Chancellery Austria and Graz University of
 * Technology.
 *
 * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by
 * the European Commission - subsequent versions of the EUPL (the "Licence");
 * You may not use this work except in compliance with the Licence.
 * You may obtain a copy of the Licence at:
 * http://www.osor.eu/eupl/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the Licence is distributed on an "AS IS" basis,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Licence for the specific language governing permissions and
 * limitations under the Licence.
 *
 * This product combines work with different licenses. See the "NOTICE" text
 * file for details on the various modules and licenses.
 * The "NOTICE" text file is part of the distribution. Any derivative works
 * that you distribute must include a readable copy of the "NOTICE" text file.
 *
 * $Id: ParseDocument.java,v 1.1 2006/08/25 17:00:59 wprinz Exp $
 */
package at.knowcenter.wag.exactparser;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import at.knowcenter.wag.exactparser.parsing.PDFUtils;
import at.knowcenter.wag.exactparser.parsing.results.DictionaryParseResult;
import at.knowcenter.wag.exactparser.parsing.results.FooterParseResult;
import at.knowcenter.wag.exactparser.parsing.results.IndirectObjectReferenceParseResult;
import at.knowcenter.wag.exactparser.parsing.results.NameParseResult;
import at.knowcenter.wag.exactparser.parsing.results.NumberParseResult;
import at.knowcenter.wag.exactparser.parsing.results.ObjectParseResult;
import at.knowcenter.wag.exactparser.parsing.results.StartXRefParseResult;
import at.knowcenter.wag.exactparser.parsing.results.TrailerParseResult;
import at.knowcenter.wag.exactparser.parsing.results.XRefSectionParseResult;


/**
 * Test class.
 * @author wprinz
 */
public class ParseDocument
{

  public static final String DOCUMENT = "C:/wprinz/temp.pdf";

  public static final byte[] EGIZ_DICT_NAME = { 'E', 'G', 'I', 'Z', 'S', 'i',
      'g', 'D', 'i', 'c', 't' };

  public static final byte[] EGIZ_ODS_NAME = { 'O', 'D', 'S' };

  public static final byte[] EGIZ_XOBJ_NAME = { 'S', 'i', 'g', 'X', 'O', 'b',
      'j', 'e', 'c', 't' };

  /**
   * @param args
   */
  public static void main(String[] args)
  {

    try
    {
      File in = new File(DOCUMENT);
      FileInputStream fis = new FileInputStream(in);
      byte[] pdf = new byte[(int) in.length()];
      fis.read(pdf);
      fis.close();
      fis = null;

      List blocks = parseDocument(pdf);

      Iterator it = blocks.iterator();
      while (it.hasNext())
      {
        FooterParseResult bpr = (FooterParseResult) it.next();
        
        System.out.print("block from " + bpr.start_index + " to " + bpr.next_index);

        if (bpr.tpr.root != null)
        {
          int root_index = PDFUtils.getObjectOffsetFromXRefByIndirectObjectReference(bpr.xpr, bpr.tpr.root.ior);
          ObjectParseResult root_opr = PDFUtils.parseObject(pdf, root_index);
          DictionaryParseResult root_dpr = (DictionaryParseResult) root_opr.object;

          int egiz_index = PDFUtils.indexOfName(pdf, root_dpr.names, EGIZ_DICT_NAME);
          if (egiz_index >= 0)
          {
            System.out.print(" == EGIZDict");
          }
        }

        System.out.println();
      }

    }
    catch (IOException e)
    {
      e.printStackTrace();
    }
  }

  public static List parseDocument(final byte[] pdf) throws IOException
  {
    //HeaderParseResult hpr = PDFUtils.parseHeader(pdf, 0);
    //System.out.println("PDF-version = " + hpr.major + "." + hpr.minor);
    
    List blocks = new ArrayList();

    int last_start_xref = PDFUtils.findLastStartXRef(pdf);
    StartXRefParseResult last_sxpr = PDFUtils.parseStartXRef(pdf, last_start_xref);
    int xref_index = last_sxpr.xref_index;

    for (;;)
    {
      FooterParseResult fpr = PDFUtils.parseFooter(pdf, xref_index);
      blocks.add(0, fpr);

      //System.out.println("tpr.has_predecessor = " + fpr.tpr.has_predecessor);
      if (!fpr.tpr.has_predecessor)
      {
        // eventually parse the PDF header here.
        break;
      }

      //System.out.println("tpr.prev = " + fpr.tpr.getPrev());

      xref_index = fpr.tpr.getPrev();
    }

    return blocks;
  }

  // public static void parseEGIZ()
  // {
  //
  // int root_index =
  // PDFUtils.getObjectOffsetFromXRefByIndirectObjectReference(bpr.xpr,
  // bpr.tpr.root.ior);
  // ObjectParseResult root_opr = PDFUtils.parseObject(pdf, root_index);
  // DictionaryParseResult root_dpr = (DictionaryParseResult) root_opr.object;
  //
  // int egiz_index = PDFUtils.indexOfName(pdf, root_dpr.names, EGIZ_DICT_NAME);
  // if (egiz_index >= 0)
  // {
  // IndirectObjectReferenceParseResult egiz_iorpr =
  // (IndirectObjectReferenceParseResult) root_dpr.values.get(egiz_index);
  // System.out.println("EGIZ signature info at = " + egiz_iorpr);
  //
  // int egiz_dict_index =
  // PDFUtils.getObjectOffsetFromXRefByIndirectObjectReference(bpr.xpr,
  // egiz_iorpr.ior);
  // ObjectParseResult opr = PDFUtils.parseObject(pdf, egiz_dict_index);
  // DictionaryParseResult egiz_dict = (DictionaryParseResult) opr.object;
  //
  // for (int i = 0; i < egiz_dict.names.size(); i++)
  // {
  // NameParseResult npr = egiz_dict.names.get(i);
  // int len = npr.next_index - npr.name_start_index;
  // byte[] name = new byte[len];
  // System.arraycopy(pdf, npr.name_start_index, name, 0, len);
  // System.out.print(" " + new String(name, "US-ASCII") + " = ");
  //
  // System.out.println(egiz_dict.values.get(i));
  // }
  //
  // // int key = PDFUtils.indexOfName(pdf, egiz_dict.names, new byte [] { 'K',
  // // 'e', 'y'});
  // // IndirectObjectReferenceParseResult key_iorpr =
  // // (IndirectObjectReferenceParseResult) egiz_dict.values.get(key);
  // // int key_offset =
  // // PDFUtils.getObjectOffsetFromXRefByIndirectObjectReference(xpr,
  // // key_iorpr.ior);
  // // ObjectParseResult key_opr = PDFUtils.parseObject(pdf, key_offset);
  // // StreamParseResult spr = (StreamParseResult) key_opr.object;
  // // System.out.println(" key stream from " + spr.content_start_index + " to
  // // " + spr.content_end_index);
  // //
  // // int data_len = spr.content_end_index - spr.content_start_index;
  // // byte [] data = new byte[data_len];
  // // System.arraycopy(pdf, spr.content_start_index, data, 0, data_len);
  // // System.out.println(new String(data, "US-ASCII"));
  //
  // }
  // else
  // {
  // System.out.println("No EGIZ block found.");
  // }
  //
  // }

  public static byte[] getOriginalDocument(final File file_name) throws IOException
  {
    FileInputStream fis = new FileInputStream(file_name);
    byte[] pdf = new byte[(int) file_name.length()];
    fis.read(pdf);
    fis.close();
    fis = null;

    int last_start_xref = PDFUtils.findLastStartXRef(pdf);

    StartXRefParseResult sxpr = PDFUtils.parseStartXRef(pdf, last_start_xref);

    XRefSectionParseResult xpr = PDFUtils.parseXRefSection(pdf, sxpr.xref_index);

    TrailerParseResult tpr = PDFUtils.parseTrailer(pdf, xpr.next_index);

    System.out.println("tpr.info = " + tpr.info);
    System.out.println("tpr.root = " + tpr.root);
    System.out.println("tpr.size = " + tpr.size);

    System.out.println("tpr.has_predecessor = " + tpr.has_predecessor);
    if (tpr.has_predecessor)
    {
      System.out.println("tpr.prev = " + tpr.getPrev());
    }

    int root_index = PDFUtils.getObjectOffsetFromXRefByIndirectObjectReference(xpr, tpr.root.ior);
    ObjectParseResult root_opr = PDFUtils.parseObject(pdf, root_index);
    DictionaryParseResult root_dpr = (DictionaryParseResult) root_opr.object;

    byte[] EGIZ_TYPE = new String("EGIZSigDict").getBytes("US-ASCII");
    int egiz_index = PDFUtils.indexOfName(pdf, root_dpr.names, EGIZ_TYPE);
    if (egiz_index >= 0)
    {
      System.out.println("The document is EGIZ-signed. ==> extract original document");

      IndirectObjectReferenceParseResult egiz_iorpr = (IndirectObjectReferenceParseResult) root_dpr.values.get(egiz_index);
      System.out.println("EGIZ signature info at = " + egiz_iorpr);

      int egiz_dict_index = PDFUtils.getObjectOffsetFromXRefByIndirectObjectReference(xpr, egiz_iorpr.ior);
      ObjectParseResult opr = PDFUtils.parseObject(pdf, egiz_dict_index);
      DictionaryParseResult egiz_dict = (DictionaryParseResult) opr.object;

      for (int i = 0; i < egiz_dict.names.size(); i++)
      {
        NameParseResult npr = (NameParseResult) egiz_dict.names.get(i);
        int len = npr.next_index - npr.name_start_index;
        byte[] name = new byte[len];
        System.arraycopy(pdf, npr.name_start_index, name, 0, len);
        System.out.print("  " + new String(name, "US-ASCII") + " = ");

        System.out.println(egiz_dict.values.get(i));
      }

      // Original document size
      int key = PDFUtils.indexOfName(pdf, egiz_dict.names, new byte[] { 'O',
          'D', 'S' });
      NumberParseResult ods = (NumberParseResult) egiz_dict.values.get(key);

      int original_document_size = ods.number;
      System.out.println("Original Document Size = " + original_document_size);

      byte[] original = new byte[original_document_size];
      System.arraycopy(pdf, 0, original, 0, original_document_size);

      return original;
    }

    System.out.println("No EGIZ block found. ==> the whold document is the original document");
    return pdf;
  }

}