/**
 * <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: BinarySignator_1_0_0.java,v 1.1 2006/08/25 17:07:35 wprinz Exp $
 */
package at.knowcenter.wag.egov.egiz.framework.signators;

import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import at.gv.egiz.pdfas.framework.input.DataSource;
import at.gv.egiz.pdfas.framework.input.PdfDataSource;
import at.gv.egiz.pdfas.impl.input.CompoundPdfDataSourceImpl;
import at.gv.egiz.pdfas.impl.signator.IncrementalUpdateHelper;
import at.knowcenter.wag.egov.egiz.PdfAS;
import at.knowcenter.wag.egov.egiz.PdfASID;
import at.knowcenter.wag.egov.egiz.exceptions.PDFDocumentException;
import at.knowcenter.wag.egov.egiz.exceptions.PresentableException;
import at.knowcenter.wag.egov.egiz.framework.SignResult;
import at.knowcenter.wag.egov.egiz.framework.Signator;
import at.knowcenter.wag.egov.egiz.framework.SignatorFactory;
import at.knowcenter.wag.egov.egiz.pdf.BinarySignature;
import at.knowcenter.wag.egov.egiz.pdf.IncrementalUpdateInformation;
import at.knowcenter.wag.egov.egiz.pdf.PositioningInstruction;
import at.knowcenter.wag.egov.egiz.pdf.ReplaceInfo;
import at.knowcenter.wag.egov.egiz.pdf.StringInfo;
import at.knowcenter.wag.egov.egiz.pdf.TablePos;
import at.knowcenter.wag.egov.egiz.sig.SignatureData;
import at.knowcenter.wag.egov.egiz.sig.SignatureDataImpl;
import at.knowcenter.wag.egov.egiz.sig.SignatureFieldDefinition;
import at.knowcenter.wag.egov.egiz.sig.SignatureObject;
import at.knowcenter.wag.egov.egiz.sig.SignatureTypes;
import at.knowcenter.wag.exactparser.ByteArrayUtils;

import com.lowagie.text.pdf.PdfPTable;

/**
 * Signs the document binary.
 * 
 * <p>
 * In prepareSign, an Incremental Update is created that contains the Signature
 * block and the egiz dictionary. For formatting the layout, variable values are
 * filled with placeholders. After the layout has been fixed, all variable
 * fields (all holes in the byte ranges) are replaced with 0. This document is
 * then base64 encoded and signed.
 * </p>
 * <p>
 * In finishSign, the variable fields (values, /Cert) are replaced with the
 * values according to the encoding.
 * </p>
 * 
 * @deprecated moved to new-framework
 * 
 * @author wprinz
 */
public class BinarySignator_1_0_0 implements Signator
{
  /**
   * The Pdf-AS ID of this Signator.
   */
  public static final PdfASID MY_ID = new PdfASID(SignatorFactory.VENDOR, SignatorFactory.TYPE_BINARY, SignatorFactory.VERSION_1_0_0);

  /**
   * @see at.knowcenter.wag.egov.egiz.framework.Signator#getMyId()
   */
  public PdfASID getMyId()
  {
    return MY_ID;
  }

  /**
   * Default constructor.
   */
  public BinarySignator_1_0_0()
  {
    // Default constructor.
  }

  /**
   * @see at.knowcenter.wag.egov.egiz.framework.Signator#prepareSign(byte[],
   *      String, TablePos, boolean)
   */
  public IncrementalUpdateInformation prepareSign(PdfDataSource pdf, String signature_type, TablePos pos, boolean has_SIG_ID) throws PresentableException
  {
    try
    {
      SignatureObject signature_object = PdfAS.createSignatureObjectFromType(signature_type);
      signature_object.fillValues((char) BinarySignature.LAYOUT_PLACEHOLDER, has_SIG_ID, false);

      signature_object.setKZ(getMyId());

      PdfPTable pdf_table = PdfAS.createPdfPTableFromSignatureObject(signature_object);

      PositioningInstruction pi = PdfAS.determineTablePositioning(pos, signature_type, pdf, pdf_table);

      List all_field_definitions = signature_object.getSignatureTypeDefinition().getFieldDefinitions();
      List variable_field_definitions = new ArrayList();
      for (int i = 0; i < all_field_definitions.size(); i++)
      {
        SignatureFieldDefinition sfd = (SignatureFieldDefinition) all_field_definitions.get(i);
        if (sfd.placeholder_length > 0)
        {
          if (sfd.field_name.equals(SignatureTypes.SIG_ID) && has_SIG_ID == false)
          {
            continue;
          }
          variable_field_definitions.add(sfd);
        }
      }
      
      //check if signature block is invisible, and if so and if also signature block is positioned
      //on a new page, prevent pdf-as to do that, because why should make a new page just for an invisible block
      //added by rpiazzi
      if (signature_object.getSignatureTypeDefinition().getInvisibleFieldDefinitions().size()==SignatureTypes.REQUIRED_SIG_KEYS.length) {
    	  if (pi.isMakeNewPage()) {
    		  int pageNumber = pi.getPage();
    		  pi = new PositioningInstruction(false, pageNumber-1, 0, 0);
    	  }
      }
      //end added
      
      IncrementalUpdateInformation iui = IncrementalUpdateHelper.writeIncrementalUpdate(pdf, pdf_table, signature_type, pi, variable_field_definitions, all_field_definitions, null, null, null);

      String temp_string = iui.temp_ir_number + " " + iui.temp_ir_generation + " obj"; //$NON-NLS-1$//$NON-NLS-2$
      byte[] temp_bytes = temp_string.getBytes("US-ASCII"); //$NON-NLS-1$
      int temp_start = ByteArrayUtils.lastIndexOf(iui.signed_pdf, temp_bytes);
      byte[] stream_bytes = new byte[] { '>', '>', 's', 't', 'r', 'e', 'a', 'm', 0x0A };
      int stream_start = ByteArrayUtils.indexOf(iui.signed_pdf, temp_start, stream_bytes);
      iui.content_stream_start = stream_start + stream_bytes.length;

      // update the stream indices
      Iterator it = iui.replaces.iterator();
      while (it.hasNext())
      {
        ReplaceInfo ri = (ReplaceInfo) it.next();

        Iterator sit = ri.replaces.iterator();
        while (sit.hasNext())
        {
          StringInfo si = (StringInfo) sit.next();
          si.string_start += iui.content_stream_start;
        }
      }
      // update KZ list indices:
      it = iui.kz_list.iterator();
      while (it.hasNext())
      {
        StringInfo si = (StringInfo) it.next();
        si.string_start += iui.content_stream_start;
      }

      BinarySignature.markByteRanges(iui);

      // byte [] old_signed_pdf = iui.signed_pdf;
      iui.signed_pdf = BinarySignature.prepareDataToSign(iui.signed_pdf, iui.byte_ranges);

      reduceToIUBlock(iui);

      iui.signature_data = formSignatureData(iui);

      return iui;

    }
    catch (UnsupportedEncodingException e)
    {
      e.printStackTrace();
      throw new PDFDocumentException(201, e);
    }
  }

  /**
   * @see at.knowcenter.wag.egov.egiz.framework.Signator#finishSign(at.knowcenter.wag.egov.egiz.pdf.IncrementalUpdateInformation)
   */
  public SignResult finishSign(IncrementalUpdateInformation iui) throws PresentableException
  {
    restoreSignedPdf(iui);
    
    // PdfAS.prefixID(iui.signed_signature_object, PdfAS.BINARY_ID);
    fillReplacesWithValues(iui);
    
    BinarySignature.replaceCertificate(iui);
    BinarySignature.replacePlaceholders(iui);

    SignResult sign_result = new SignResult(PdfAS.PDF_MIME_TYPE, iui.signed_pdf);
    return sign_result;
  }

  /**
   * Reads the signature values from the signed signature object and fills the
   * corresponding value in the Replaces array.
   * 
   * @param iui
   *          The IncrementalUpdateInformation.
   */
  protected void fillReplacesWithValues(IncrementalUpdateInformation iui)
  {
    Iterator it = iui.replaces.iterator();
    while (it.hasNext())
    {
      ReplaceInfo ri = (ReplaceInfo) it.next();
      
      ri.value = iui.signed_signature_object.retrieveStringValue(ri.sfd.field_name);
    }
  }

  protected void reduceToIUBlock(IncrementalUpdateInformation iui)
  {
    byte[] iu_block = new byte[iui.signed_pdf.length - iui.original_document.getLength()];
    System.arraycopy(iui.signed_pdf, iui.original_document.getLength(), iu_block, 0, iu_block.length);

    iui.signed_pdf = null;
    iui.sign_iui_block = iu_block;
  }

  protected void restoreSignedPdf(IncrementalUpdateInformation iui)
  {
    iui.signed_pdf = new byte[iui.original_document.getLength() + iui.sign_iui_block.length];

    try
    {
      InputStream is = iui.original_document.createInputStream();
      is.read(iui.signed_pdf, 0, iui.original_document.getLength());
      is.close();
    }
    catch (IOException e)
    {
      throw new RuntimeException(e);
    }

    System.arraycopy(iui.sign_iui_block, 0, iui.signed_pdf, iui.original_document.getLength(), iui.sign_iui_block.length);
  }

  /**
   * Forms the SignatureData to be used for signing.
   * 
   * @param iui
   *          The IncrementalUpdateInformation.
   * @return Returns the SignatureData to be used for signing.
   */
  protected SignatureData formSignatureData(IncrementalUpdateInformation iui)
  {
    // String document_text =
    // BinarySignature.retrieveSignableTextFromData(iui.signed_pdf,
    // iui.signed_pdf.length); // signed_pdf.length);
    //
    // byte[] data;
    // try
    // {
    // data = document_text.getBytes("UTF-8"); //$NON-NLS-1$
    // }
    // catch (UnsupportedEncodingException e)
    // {
    // throw new RuntimeException("Very strange: UTF-8 character encoding not
    // supported.", e); //$NON-NLS-1$
    // }
    DataSource ds = new CompoundPdfDataSourceImpl(iui.original_document, iui.sign_iui_block);
    SignatureData signature_data = new SignatureDataImpl(ds, PdfAS.PDF_MIME_TYPE);

    return signature_data;
  }
}