/**
 * <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.knowcenter.wag.egov.egiz.sig.connectors.bku;

import java.io.UnsupportedEncodingException;

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


import at.gv.egiz.pdfas.algorithmSuite.AlgorithmSuiteObject;
import at.gv.egiz.pdfas.exceptions.ErrorCode;
import at.knowcenter.wag.egov.egiz.cfg.SettingsReader;
import at.knowcenter.wag.egov.egiz.exceptions.ConnectorException;
import at.knowcenter.wag.egov.egiz.exceptions.SettingsException;
import at.knowcenter.wag.egov.egiz.tools.CodingHelper;
import at.knowcenter.wag.egov.egiz.tools.FileHelper;

/**
 * 
 * <p>
 * This is the old base64 connector. The difference is in the way the sign
 * response is parsed and the verify content_xml.
 * </p>
 * 
 * @author wprinz
 * 
 */
public class OldEnvelopingBase64BKUConnector extends EnvelopedBase64BKUConnector
{
  /**
   * The log.
   */
  private static Log log = LogFactory.getLog(OldEnvelopingBase64BKUConnector.class);

  // TODO implement signing - with old pre 2.7.2 BKUs... not really necessary
  // though because this connector is only used for verification

  public OldEnvelopingBase64BKUConnector(String profile) throws ConnectorException
  {
    super(profile);

    this.environment = new OverriddenEnvironment(profile);
  }
  
  

  /**
   * @see at.knowcenter.wag.egov.egiz.sig.connectors.bku.EnvelopedBase64BKUConnector#computeSignedPropertiesReplace(java.lang.String)
   */
  protected String computeSignedPropertiesReplace(String verify_xml, AlgorithmSuiteObject algSuite)
  {
    try
    {
      final String ETSI_QUALIFYING_PROPERTIES_START_TAG = "<etsi:QualifyingProperties"; //$NON-NLS-1$
      final String ETSI_QUALIFYING_PROPERTIES_END_TAG = "</etsi:QualifyingProperties>"; //$NON-NLS-1$

      final int hash_start = verify_xml.indexOf(ETSI_QUALIFYING_PROPERTIES_START_TAG);
      assert hash_start >= 0;
      final int hash_end = verify_xml.indexOf(ETSI_QUALIFYING_PROPERTIES_END_TAG, hash_start) + ETSI_QUALIFYING_PROPERTIES_END_TAG.length();
      assert hash_end - ETSI_QUALIFYING_PROPERTIES_END_TAG.length() >= 0;
      assert hash_end > hash_start;

      final String string_to_be_hashed = verify_xml.substring(hash_start, hash_end);
      log.debug("etsi:QualifyingProperties string to be hashed: " + string_to_be_hashed); //$NON-NLS-1$

      final byte[] bytes_to_be_hashed = string_to_be_hashed.getBytes("UTF-8"); //$NON-NLS-1$
      byte[] sig_prop_code = CodingHelper.buildDigest(bytes_to_be_hashed, algSuite.getPropertiesDigestMethod());
      String sig_prop_hash = CodingHelper.encodeBase64(sig_prop_code);

      return sig_prop_hash;
    }
    catch (UnsupportedEncodingException e)
    {
      throw new RuntimeException("Very Strange: UTF-8 character encoding not supported.", e);
    }
  }



  public static class OverriddenEnvironment extends EnvelopedBase64BKUConnector.Environment
  {

    /**
     * The configuration key of the verify template.
     */
    protected static final String VERIFY_TEMPLATE_KEY = "bku.verify.template.base64old"; //$NON-NLS-1$

    public OverriddenEnvironment(String profile) throws ConnectorException
    {
      super(profile);

      SettingsReader settings = null;
      try
      {
        settings = SettingsReader.getInstance();
      }
      catch (SettingsException e)
      {
        throw new ConnectorException(ErrorCode.SETTING_NOT_FOUND, e);
      }

      String verify_filename = getConnectorValueFromProfile(settings, profile, VERIFY_TEMPLATE_KEY);
      //this.verify_template = FileHelper.readFromFile(SettingsReader.relocateFile(verify_filename));
      this.verify_template = settings.readInternalResourceAsString(verify_filename);
      if (this.verify_template == null)
      {
        throw new ConnectorException(ErrorCode.SETTING_NOT_FOUND, "Can not read the verify template"); //$NON-NLS-1$
      }

    }
  }

}