/**
 * <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: 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.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import com.lowagie.text.pdf.PdfPTable;

import at.knowcenter.wag.egov.egiz.PdfAS;
import at.knowcenter.wag.egov.egiz.PdfASID;
import at.knowcenter.wag.egov.egiz.cfg.SettingsReader;
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.ReplaceInfo;
import at.knowcenter.wag.egov.egiz.pdf.StringInfo;
import at.knowcenter.wag.egov.egiz.pdf.TablePos;
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;

/**
 * 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>
 * 
 * @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);

  /**
   * 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(byte[] 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);

      signature_object.setKZ(MY_ID);

      PdfPTable pdf_table = PdfAS.createPdfPTableFromSignatureObject(signature_object);

      if (pos == null)
      {
        String pos_string = SettingsReader.getInstance().getSetting(SignatureTypes.SIG_OBJ + signature_type + ".pos", null);
        if (pos_string != null)
        {
          pos = PdfAS.parsePositionFromPosString(pos_string);
          pdf_table.setTotalWidth(pos.width);
          pdf_table.setLockedWidth(true);
        }
        else
        {
          pos = PdfAS.adjustTableAndCalculatePosition(pdf, pdf_table);
        }
      }
      else
      {
        pdf_table.setTotalWidth(pos.width);
        pdf_table.setLockedWidth(true);
      }

      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);
        }
      }
      IncrementalUpdateInformation iui = BinarySignature.writeIncrementalUpdate(pdf, pdf_table, pos, variable_field_definitions, all_field_definitions);

      String temp_string = iui.temp_ir_number + " " + iui.temp_ir_generation + " obj";
      byte[] temp_bytes = temp_string.getBytes("US-ASCII");
      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);

      iui.document_text = BinarySignature.retrieveSignableTextFromData(iui.signed_pdf, iui.signed_pdf.length); // signed_pdf.length);

      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
  {
    // PdfAS.prefixID(iui.signed_signature_object, PdfAS.BINARY_ID);
    Iterator it = iui.replaces.iterator();
    while (it.hasNext())
    {
      ReplaceInfo ri = (ReplaceInfo) it.next();

      ri.value = iui.signed_signature_object.getSigValue(ri.sfd.field_name);
    }
    BinarySignature.replaceCertificate(iui);
    BinarySignature.replacePlaceholders(iui);

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

}