/**
 * <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: TextualVerificator_1_0_0.java,v 1.4 2006/10/31 08:08:00 wprinz Exp $
 */
package at.knowcenter.wag.egov.egiz.framework.verificators;

import java.util.ArrayList;
import java.util.List;

import org.apache.log4j.Logger;

import at.knowcenter.wag.egov.egiz.PdfAS;
import at.knowcenter.wag.egov.egiz.PdfASID;
import at.knowcenter.wag.egov.egiz.cfg.ConfigLogger;
import at.knowcenter.wag.egov.egiz.exceptions.PresentableException;
import at.knowcenter.wag.egov.egiz.framework.SignatorFactory;
import at.knowcenter.wag.egov.egiz.framework.Verificator;
import at.knowcenter.wag.egov.egiz.pdf.AbsoluteTextSignature;
import at.knowcenter.wag.egov.egiz.pdf.SignatureHolder;
import at.knowcenter.wag.exactparser.parsing.results.FooterParseResult;


/**
 * The textual verificator.
 * 
 * <p>
 * All holders of the document so far including the block itself are extracted.
 * If at least one has been found it is checked that this one doesn't belong to
 * a previous block.
 * </p>
 * <p>
 * Note that the KZ is not explicitely checked here, so this algorithm will find
 * all blocks.
 * </p>
 * <p>
 * Note that it will not find old style blocks as they don't have the SIG_KZ.
 * </p>
 * 
 * @author wprinz
 */
public class TextualVerificator_1_0_0 implements Verificator
{
  /**
   * The Pdf-AS ID of this Verificator.
   */
  public static final PdfASID MY_ID = new PdfASID(SignatorFactory.VENDOR, SignatorFactory.TYPE_TEXTUAL, SignatorFactory.VERSION_1_0_0);

  /**
   * The logger definition.
   */
  private static final Logger logger_ = ConfigLogger.getLogger(TextualVerificator_1_0_0.class);

  /**
   * Default constructor.
   */
  public TextualVerificator_1_0_0()
  {
    // Default constructor.
  }

  /**
   * @see at.knowcenter.wag.egov.egiz.framework.Verificator#parseBlock(byte[],
   *      at.knowcenter.wag.exactparser.parsing.results.FooterParseResult, int)
   */
  public List parseBlock(byte[] pdf, FooterParseResult block,
      int start_of_whole_block) throws PresentableException
  {
    String block_text = PdfAS.extractNormalizedTextTextual(pdf, block.next_index);

    logger_.debug("Scanning block:");
    //List signature_holders = PdfAS.extractSignatureHoldersTextual(block_text, false);
    List signature_holders = AbsoluteTextSignature.extractSignatureHoldersFromText(block_text);
    logger_.debug(": end of Scanning block");

    // logger_.debug("signature_holders = " + signature_holders.size());

    if (signature_holders.isEmpty())
    {
      return signature_holders;
    }

    List text_holder_candidates = null;
    if (start_of_whole_block > 0)
    {
      text_holder_candidates = new ArrayList();
      
      String prev_text = PdfAS.extractNormalizedTextTextual(pdf, start_of_whole_block);

      logger_.debug("Scanning prev block:");
      //List prev_signature_holders = PdfAS.extractSignatureHoldersTextual(prev_text, false);
      List prev_signature_holders = AbsoluteTextSignature.extractSignatureHoldersFromText(prev_text);
      logger_.debug(": end of Scanning prev block");

      // logger_.debug("prev_signature_holders = " +
      // prev_signature_holders.size());

      for (int i = prev_signature_holders.size(); i < signature_holders.size(); i++)
      {
        SignatureHolder holder = (SignatureHolder) signature_holders.get(i);
        text_holder_candidates.add(holder);
      }
    }
    else
    {
      logger_.debug("there is no prev - so all found signatures are possible candidates.");
      text_holder_candidates = signature_holders;
    }

    List text_holders = new ArrayList();
    for (int i = 0; i < text_holder_candidates.size(); i++)
    {
      SignatureHolder holder = (SignatureHolder) text_holder_candidates.get(i);
      if (!holder.getSignatureObject().isTextual())
      {
        logger_.debug("Skipping found signature block because it's not textual.");
        continue;
      }
      text_holders.add(holder);
    }

    return text_holders;
  }
}