/**
 * <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.
 */
package at.gv.egiz.pdfas.framework.input;

import java.util.List;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import at.gv.egiz.pdfas.exceptions.ErrorCode;
import at.gv.egiz.pdfas.exceptions.framework.VerificationFilterException;
import at.gv.egiz.pdfas.framework.DataSourceHolder;
import at.gv.egiz.pdfas.framework.vfilter.VerificationFilter;
import at.gv.egiz.pdfas.framework.vfilter.VerificationFilterParameters;
import at.gv.egiz.pdfas.impl.input.IncrementalUpdateParser;
import at.gv.egiz.pdfas.impl.vfilter.VerificationFilterImpl;
import at.knowcenter.wag.egov.egiz.exceptions.PDFDocumentException;
import at.knowcenter.wag.egov.egiz.exceptions.PresentableException;

/**
 * Extracts all signatures from a given input DataSource.
 * 
 * @author wprinz
 */
public class ExtractionStage
{
  /**
   * The log.
   */
  private static final Log log = LogFactory.getLog(ExtractionStage.class);

  public List extractSignatureHolders(final DataSourceHolder dataSource, VerificationFilterParameters parameters) throws PresentableException
  {
    if (dataSource.getDataSource() instanceof PdfDataSource)
    {
      PdfDataSource pdfDataSource = (PdfDataSource) dataSource.getDataSource();

      PdfDataSourceHolder pdsh = new PdfDataSourceHolder(pdfDataSource);
      List blocks = parsePdfIntoBlocks(pdsh);
      dataSource.setDataSource(pdsh.getDataSource());
      parameters.setBeenCorrected(pdsh.hasChanged());

      VerificationFilter vf = new VerificationFilterImpl();
      List signatures = vf.extractSignatureHolders(pdsh.getDataSource(), blocks, parameters);

      return signatures;
    }

    if (dataSource.getDataSource() instanceof TextDataSource)
    {
      TextDataSource textDataSource = (TextDataSource) dataSource.getDataSource();

      VerificationFilter vf = new VerificationFilterImpl();
      List signatures = vf.extractSignaturHolders(textDataSource, parameters);

      return signatures;
    }

    String msg = "The input DataSource is neither pdf nor text. class.name = " + dataSource.getClass().getName();
    log.error(msg);
    throw new VerificationFilterException(ErrorCode.DOCUMENT_CANNOT_BE_READ, msg);
  }

  protected List parsePdfIntoBlocks(PdfDataSourceHolder pdfDataSource) throws PDFDocumentException
  {
    List blocks = IncrementalUpdateParser.parsePdfIntoIUBlocks(pdfDataSource);
    return blocks;
  }
}