/**
 * 
 */
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.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)
  {
    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);
      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(300, e);
      }

      String verify_filename = getConnectorValueFromProfile(settings, profile, VERIFY_TEMPLATE_KEY);
      this.verify_template = FileHelper.readFromFile(SettingsReader.relocateFile(verify_filename));
      if (this.verify_template == null)
      {
        // TODO make this a settings exception
        throw new ConnectorException(300, "Can not read the verify template"); //$NON-NLS-1$
      }

    }
  }

}