/**
 * <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: Signator.java,v 1.1 2006/08/25 17:07:21 wprinz Exp $
 */
package at.knowcenter.wag.egov.egiz.framework;

import at.gv.egiz.pdfas.framework.input.PdfDataSource;
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.pdf.IncrementalUpdateInformation;
import at.knowcenter.wag.egov.egiz.pdf.TablePos;

/**
 * The basic interface for signator algorithms.
 * 
 * @author wprinz
 */
public interface Signator
{
  /**
   * Returns the PdfASID of this Connector.
   * 
   * <p>
   * This should always return the MY_ID static field of the connector. Dont't
   * forget to override this.
   * </p>
   * <p>
   * Within connector code always use this method so that code reuse through
   * derivation can take place correctly.
   * </p>
   * 
   * @return Returns the PdfASID of this Connector.
   */
  public PdfASID getMyId();

  /**
   * This is called before the data is sent to the connector.
   * 
   * @param pdf
   *          The PDF document to be signed.
   * @param signature_type
   *          The type/profile of the signature to apply.
   * @param pos
   *          The table position. If null, the position is read from the
   *          profile, if this is null too, the position is computed.
   * @param has_SIG_ID
   *          Tells the algorithm, id a SIG_ID field will be required after
   *          signing. Algorithms with fixed formatted signature blocks need to
   *          know this.
   * @return Returns the IncrementalUpdateInformation.
   * @throws PresentableException
   *           Forwarded exception.
   */
  public IncrementalUpdateInformation prepareSign(PdfDataSource pdfDataSource,
      String signature_type, TablePos pos, boolean has_SIG_ID) throws PresentableException;

  /**
   * This is called after the data has been signed by the connector.
   * 
   * <p>
   * Replaces all the left out placeholders with their values retrieved from the
   * signation process.
   * </p>
   * 
   * @param iui
   *          The IncrementalUpdateInformation.
   * @throws PDFDocumentException
   *           Forwarded exception.
   */
  public SignResult finishSign(IncrementalUpdateInformation iui) throws PresentableException;
}