/**
 * <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 java.security.cert.X509Certificate;
import java.util.Properties;

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

import at.gv.egiz.pdfas.algorithmSuite.AlgorithmSuiteObject;
import at.gv.egiz.pdfas.algorithmSuite.AlgorithmSuiteUtil;
import at.gv.egiz.pdfas.api.xmldsig.XMLDsigData;
import at.gv.egiz.pdfas.exceptions.ErrorCode;
import at.gv.egiz.pdfas.framework.ConnectorParameters;
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.sig.SignatureData;
import at.knowcenter.wag.egov.egiz.sig.SignatureObject;
import at.knowcenter.wag.egov.egiz.sig.SignatureResponse;
import at.knowcenter.wag.egov.egiz.sig.connectors.Connector;
import at.knowcenter.wag.egov.egiz.sig.connectors.ConnectorEnvironment;
import at.knowcenter.wag.egov.egiz.sig.connectors.LocalConnector;
import at.knowcenter.wag.egov.egiz.sig.connectors.TemplateReplaces;
import at.knowcenter.wag.egov.egiz.sig.connectors.moa.EnvelopingBase64MOAConnector;
import at.knowcenter.wag.egov.egiz.sig.sigid.HotfixIdFormatter;
import at.knowcenter.wag.egov.egiz.sig.sigkz.SigKZIDHelper;
import at.knowcenter.wag.egov.egiz.tools.CodingHelper;

/**
 * @author wprinz
 * 
 */
public class EnvelopedBase64BKUConnector implements Connector, LocalConnector
{
 //23.11.2010 changed by exthex - added reconstructXMLDsig method and moved xmldsig creation to chooseAndCreateXMLDsig method

  /**
   * The log.
   */
  private static Log log = LogFactory.getLog(EnvelopedBase64BKUConnector.class);

  /**
   * The environemnt configuration of this connector containing templates and
   * other configurable elements.
   */
  protected Environment environment = null;

  /**
   * Constructor that builds the configuration environment for this connector
   * according to the given profile.
   * 
   * <p>
   * If confuguration parameters are not defined on that profile, the default
   * parameters defined in the configuration are used.
   * </p>
   * 
   * <p>
   * This is the new "hotfix" base64 connector.
   * </p>
   * 
   * @param profile
   *          The profile from which the Environment should be assembled.
   * @throws ConnectorException
   *           f.e.
   */
  public EnvelopedBase64BKUConnector(String profile) throws ConnectorException
  {
    this.environment = new Environment(profile);
  }

  /**
   * @see at.knowcenter.wag.egov.egiz.sig.connectors.Connector#doSign(at.knowcenter.wag.egov.egiz.sig.SignatureData)
   */
  public SignSignatureObject doSign(SignatureData data) throws ConnectorException
  {
    log.debug("doSign:"); //$NON-NLS-1$

    String sign_request_xml = prepareSignRequest(data);
//    DebugHelper.debugStringToFile(sign_request_xml, "BKU_EnvB64_sign_request.xml"); //$NON-NLS-1$

    String url = this.environment.getSignURL();
    Properties response_properties = sendRequest(url, sign_request_xml);

//    DebugHelper.debugStringToFile(response_properties.getProperty(BKUPostConnection.RESPONSE_STRING_KEY), "BKU_EnvB64_sign_response.xml"); //$NON-NLS-1$
    SignSignatureObject sso = analyzeSignResponse(response_properties);

    sso.response_properties = response_properties;

    log.debug("doSign finished."); //$NON-NLS-1$
    return sso;
  }

  /**
   * @see at.knowcenter.wag.egov.egiz.sig.connectors.Connector#doVerify(at.knowcenter.wag.egov.egiz.sig.SignatureData,
   *      at.knowcenter.wag.egov.egiz.sig.connectors.bku.SignSignatureObject)
   */
  public SignatureResponse doVerify(SignatureData data, SignSignatureObject so, XMLDsigData dsig) throws ConnectorException
  {
    log.debug("doVerify:"); //$NON-NLS-1$

    String verify_request_xml = prepareVerifyRequest(data, so, dsig);
//    DebugHelper.debugStringToFile(verify_request_xml, "BKU_EnvB64_verify_request.xml"); //$NON-NLS-1$

    String url = this.environment.getVerifyURL();
    Properties response_properties = sendRequest(url, verify_request_xml);

//    DebugHelper.debugStringToFile(response_properties.getProperty(BKUPostConnection.RESPONSE_STRING_KEY), "BKU_EnvB64_verify_response.xml"); //$NON-NLS-1$
    SignatureResponse signature_response = analyzeVerifyResponse(response_properties);

    log.debug("doVerify finished."); //$NON-NLS-1$
    return signature_response;
  }

//  /**
//   * This emthod extracts id-values from a text. The id is given by the name.
//   * 
//   * @param text
//   *          the id-value that should extract from
//   * @param name
//   *          the id-key
//   * @return the value of the given key in the text
//   */
//  private String extractId(String text, String name)
//  {
//    String id = null;
//    int start_idx = text.indexOf(name) + name.length();
//    int end_idx = text.indexOf("\"", start_idx);
//
//    // TODO hotfix!
//    final int quot_end_idx = end_idx;
//    final int squot_end_idx = text.indexOf("'", start_idx);
//    end_idx = Math.min(quot_end_idx, squot_end_idx);
//    // TODO hotfix end!
//
//    id = text.substring(start_idx, end_idx);
//    if (log.isDebugEnabled())
//    {
//      log.debug("extract id:" + name + id);
//    }
//    return id;
//  }

  /**
   * Prepares the XML content the holds the actual signature data.
   * 
   * <p>
   * This strongly rebuilds the XML content as retuned from a sign request.
   * </p>
   * 
   * @param data
   *          The data.
   * @param so
   *          The signature object containing the signature information.
   * @return Returns the XML content.
   * @throws ConnectorException
   *           f.e.
   */
  public String prepareXMLContent(SignatureData data, SignSignatureObject so) throws ConnectorException
  {
    log.debug("prepareXMLContent:"); //$NON-NLS-1$
    try
    {
       String ids_string = so.getSigID();
       String[] ids = SignatureObject.parseSigIds(ids_string);
       
       X509Certificate cert = so.getX509Certificate();
       
       // dferbas
       AlgorithmSuiteObject algSuite = new AlgorithmSuiteObject();
       String verify_xml = AlgorithmSuiteUtil.evaluateReplaceAlgs(algSuite, this.environment, so);
       
      // data digest replace
      byte[] data_value = BKUHelper.prepareEnvelopingData(data);
      {
        byte[] data_value_hash = CodingHelper.buildDigest(data_value, algSuite.getDataDigestMethod());
        String object_data_hash = CodingHelper.encodeBase64(data_value_hash);

        verify_xml = verify_xml.replaceFirst(TemplateReplaces.DIGEST_VALUE_SIGNED_DATA_REPLACE, object_data_hash);
      }

      // SIG id replaces
      verify_xml = verify_xml.replaceAll(TemplateReplaces.SIG_DATA_REF_REPLACE, ids[1]);
      verify_xml = verify_xml.replaceAll(TemplateReplaces.ETSI_DATA_REF_REPLACE, ids[3]);
      verify_xml = verify_xml.replaceAll(TemplateReplaces.SIG_DATA_OBJ_URI_REPLACE, ids[2]);

      verify_xml = verify_xml.replaceFirst(TemplateReplaces.SIGNATURE_VALUE_REPLACE, so.getSignatureValue());

      // X.509 Certificate replace
      byte[] der = cert.getEncoded();
      byte[] cert_hash = CodingHelper.buildDigest(der, algSuite.getCertDigestMethod());
      String certDigest = CodingHelper.encodeBase64(cert_hash);
      String x509_cert_string = CodingHelper.encodeBase64(der);
      verify_xml = verify_xml.replaceFirst(TemplateReplaces.X509_CERTIFICATE_REPLACE, x509_cert_string);

      // Base64 content replace
      String base64 = CodingHelper.encodeBase64(data_value);
      verify_xml = verify_xml.replaceFirst(TemplateReplaces.BASE64_CONTENT_REPLACE, base64);

      // Qualified Properties replaces
      verify_xml = verify_xml.replaceAll(TemplateReplaces.ETSI_DATA_OBJ_URI_REPLACE, ids[4]);
      verify_xml = verify_xml.replaceAll(TemplateReplaces.SIG_ID_REPLACE, ids[0]);
      verify_xml = verify_xml.replaceFirst(TemplateReplaces.SIGNING_TIME_REPLACE, so.getDate());
      verify_xml = verify_xml.replaceFirst(TemplateReplaces.DIGEST_VALUE_CERTIFICATE_REPLACE, certDigest);
      verify_xml = verify_xml.replaceFirst(TemplateReplaces.X509_ISSUER_NAME_REPLACE, so.getIssuer());
      verify_xml = verify_xml.replaceFirst(TemplateReplaces.X509_SERIAL_NUMBER_REPLACE, so.getSerialNumber());
      // SigDataRefReplace already done above

      // Signed Properties hash
      {
        String sig_prop_hash = computeSignedPropertiesReplace(verify_xml, algSuite);

        verify_xml = verify_xml.replaceFirst(TemplateReplaces.DIGEST_VALUE_SIGNED_PROPERTIES_REPLACE, sig_prop_hash);
      }

      log.debug("prepareXMLContent finished."); //$NON-NLS-1$
      return verify_xml;
    }
    catch (Exception e)
    {
      log.debug(e);
      throw new ConnectorException(310, e);
    }
  }

  protected String computeSignedPropertiesReplace(String verify_xml, AlgorithmSuiteObject algSuite)
  {
    try
    {
      final String ETSI_SIGNED_PROPERTIES_START_TAG = "<etsi:SignedProperties"; //$NON-NLS-1$
      final String ETSI_SIGNED_PROPERTIES_END_TAG = "</etsi:SignedProperties>"; //$NON-NLS-1$

      final int hash_start = verify_xml.indexOf(ETSI_SIGNED_PROPERTIES_START_TAG);
      assert hash_start >= 0;
      final int hash_end = verify_xml.indexOf(ETSI_SIGNED_PROPERTIES_END_TAG, hash_start) + ETSI_SIGNED_PROPERTIES_END_TAG.length();
      assert hash_end - ETSI_SIGNED_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:SignedProperties 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);
    }
  }

  /**
   * Prepares the sign request xml to be sent using the sign request template.
   * 
   * @param data
   *          The SignatureData.
   * @return Returns the sign request xml to be sent.
   * @throws ConnectorException
   *           f.e.
   */
  public String prepareSignRequest(SignatureData data) throws ConnectorException
  {
    log.debug("prepareSignRequest:"); //$NON-NLS-1$

    String sign_request_template = this.environment.getSignRequestTemplate();

    String sign_keybox_identifier = this.environment.getSignKeyboxIdentifier();
    String base64 = BKUHelper.prepareBase64Content(data);

    String sign_request_xml = sign_request_template.replaceFirst(TemplateReplaces.KEYBOX_IDENTIFIER_REPLACE, sign_keybox_identifier);
    sign_request_xml = sign_request_xml.replaceFirst(TemplateReplaces.BASE64_CONTENT_REPLACE, base64);

    log.debug("prepareSignRequest finished."); //$NON-NLS-1$
    return sign_request_xml;
  }

  /**
   * Prepares the verify request xml to be sent using the verify request
   * template.
   * 
   * @param data
   *          The SignatureData.
   * @param so
   *          The signature information object.
   * @return Returns the verify request xml to be sent.
   * @throws ConnectorException
   *           f.e.
   */
  public String prepareVerifyRequest(SignatureData data, SignSignatureObject so, XMLDsigData dsigData) throws ConnectorException
  {
    String verify_request_template = this.environment.getVerifyRequestTemplate();

    String xml_content = null;
    if (dsigData != null && dsigData.getXmlDsig() != null)
    {
       xml_content = dsigData.getXmlDsig();
    }
    else
    {
       xml_content = chooseAndCreateXMLDsig(data, so);
    }

    String verify_request_xml = verify_request_template.replaceFirst(TemplateReplaces.XML_CONTENT_REPLACE, xml_content);

//    log.debug("\r\n\r\n" + verify_request_xml + "\r\n\r\n");

    return verify_request_xml;
  }

  private String chooseAndCreateXMLDsig(SignatureData data, SignSignatureObject so) throws ConnectorException {
     if (SigKZIDHelper.isMOASigned(so))
     {
       log.debug("The signature is MOA signed -> getting XML content from Base64MOA connector.");
       ConnectorParameters cp = new ConnectorParameters();
       cp.setProfileId(this.environment.getProfile());
       EnvelopingBase64MOAConnector moa_conn = new EnvelopingBase64MOAConnector(cp);
       return moa_conn.prepareXMLContent(data, so);
     }
     else
     {
       return prepareXMLContent(data, so);
     }
  }

/**
   * Sends the request to the given URL.
   * 
   * @param url
   *          The URL.
   * @param request_string
   *          The request string.
   * @return Returns the response string.
   * @throws ConnectorException
   *           F.e.
   */
  protected Properties sendRequest(String url, String request_string) throws ConnectorException
  {
    try
    {
      Properties response_properties = at.knowcenter.wag.egov.egiz.sig.connectors.BKUPostConnection.doPostRequest(url, request_string);
      return response_properties;
    }
    catch (Exception e)
    {
      throw new ConnectorException(320, e);
    }
  }

  /**
   * Analyzes the sign response xml and extracts the signature data.
   * 
   * @param response_properties
   *          The response properties containing the response String and
   *          transport related information.
   * @return Returns the extracted data encapsulated in a SignatureObject.
   * @throws ConnectorException
   *           f.e.
   */
  public SignSignatureObject analyzeSignResponse(Properties response_properties) throws ConnectorException
  {
    log.debug("analyzeSignResponse:"); //$NON-NLS-1$

    String response_string = response_properties.getProperty(BKUPostConnection.RESPONSE_STRING_KEY);

    BKUHelper.checkResponseForError(response_string);

    String bkuIdentifier = BKUHelper.getBKUIdentifier(response_properties);
    log.debug("BKU identifier: \"" + bkuIdentifier + "\"");
    
    SignSignatureObject so = BKUHelper.parseCreateXMLResponse(response_string, new HotfixIdFormatter(), this.environment);

    log.debug("analyzeSignResponse finished."); //$NON-NLS-1$
    return so;
  }

  /**
   * Analyzes the verify response string.
   * 
   * @param response_properties
   *          The response properties containing the response XML.
   * @return Returns the SignatureResponse containing the verification result.
   * @throws ConnectorException
   *           f.e.
   */
  public SignatureResponse analyzeVerifyResponse(Properties response_properties) throws ConnectorException
  {
    log.debug("analyzeVerifyResponse:"); //$NON-NLS-1$

    String response_string = response_properties.getProperty(BKUPostConnection.RESPONSE_STRING_KEY);

    BKUHelper.checkResponseForError(response_string);

    SignatureResponse signature_response = BKUHelper.parseVerifyXMLResponse(response_string);

    log.debug("analyzeVerifyResponse finished."); //$NON-NLS-1$
    return signature_response;
  }

  /**
   * Holds environment configuration information like templates.
   * 
   * @author wprinz
   */
  public static class Environment extends ConnectorEnvironment
  {
    /**
     * The configuration key of the sign keybox identifier.
     */
    protected static final String SIGN_KEYBOX_IDENTIFIER_KEY = "bku.sign.KeyboxIdentifier"; //$NON-NLS-1$

    /**
     * The configuration key of the sign request template.
     */
    protected static final String SIGN_REQUEST_TEMPLATE_KEY = "bku.sign.request.base64"; //$NON-NLS-1$

    /**
     * The configuration key of the sign URL.
     */
    protected static final String SIGN_URL_KEY = "bku.sign.url"; //$NON-NLS-1$

    /**
     * The configuration key of the verify request template.
     */
    protected static final String VERIFY_REQUEST_TEMPLATE_KEY = "bku.verify.request.base64"; //$NON-NLS-1$

    /**
     * The configuration key of the verify template.
     */
    protected static final String VERIFY_TEMPLATE_KEY = "bku.verify.template.base64"; //$NON-NLS-1$

    /**
     * The configuration key of the verify URL.
     */
    protected static final String VERIFY_URL_KEY = "bku.verify.url"; //$NON-NLS-1$

    /**
     * The configuration key for the ECDSA cert alg property.
     */
    protected static final String ECDSA_CERT_ALG_KEY = "cert.alg.ecdsa"; //$NON-NLS-1$

    /**
     * The configuration key for the RSA cert alg property.
     */
    protected static final String RSA_CERT_ALG_KEY = "cert.alg.rsa"; //$NON-NLS-1$

    protected String profile = null;

    protected String sign_keybox_identifier = null;

    protected String sign_request_template = null;

    protected String sign_url = null;

    protected String verify_request_template = null;

    protected String verify_template = null;

    protected String verify_url = null;

    protected String cert_alg_ecdsa = null;

    protected String cert_alg_rsa = null;

    /**
     * Initializes the environment with a given profile.
     * 
     * @param profile
     *          The configuration profile.
     * @throws ConnectorException
     *           f.e.
     */
    public Environment(String profile) throws ConnectorException
    {
      this.profile = profile;

      SettingsReader settings = null;
      try
      {
        settings = SettingsReader.getInstance();
      }
      catch (SettingsException e)
      {
        throw new ConnectorException(300, e);
      }

      this.sign_keybox_identifier = getConnectorValueFromProfile(settings, profile, SIGN_KEYBOX_IDENTIFIER_KEY);

      String sign_request_filename = getConnectorValueFromProfile(settings, profile, SIGN_REQUEST_TEMPLATE_KEY);
      //this.sign_request_template = FileHelper.readFromFile(SettingsReader.relocateFile(sign_request_filename));
      this.sign_request_template = settings.readInternalResourceAsString(sign_request_filename);
      if (this.sign_request_template == null)
      {
        throw new ConnectorException(300, "Can not read the create xml request template"); //$NON-NLS-1$
      }

      this.sign_url = getConnectorValueFromProfile(settings, profile, SIGN_URL_KEY);

      String verify_request_filename = getConnectorValueFromProfile(settings, profile, VERIFY_REQUEST_TEMPLATE_KEY);
      //this.verify_request_template = FileHelper.readFromFile(SettingsReader.relocateFile(verify_request_filename));
      this.verify_request_template = settings.readInternalResourceAsString(verify_request_filename);
      log.debug("Verify request template filename = " + verify_request_filename);
      
      if (this.verify_request_template == null)
      {
        throw new ConnectorException(ErrorCode.SETTING_NOT_FOUND, "Can not read the verify xml request template"); //$NON-NLS-1$
      }

      log.debug("Verify request template = " + this.verify_request_template);

      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"); //$NON-NLS-1$
      }

      this.verify_url = getConnectorValueFromProfile(settings, profile, VERIFY_URL_KEY);

      this.cert_alg_ecdsa = settings.getValueFromKey(ECDSA_CERT_ALG_KEY);

      this.cert_alg_rsa = settings.getValueFromKey(RSA_CERT_ALG_KEY);

    }

    public String getProfile()
    {
      return this.profile;
    }

    /**
     * Returns the sign keybox identifier.
     * 
     * @return Returns the sign keybox identifier.
     */
    public String getSignKeyboxIdentifier()
    {
      return this.sign_keybox_identifier;
    }

    /**
     * Returns the sign request template.
     * 
     * @return Returns the sign request template.
     */
    public String getSignRequestTemplate()
    {
      return this.sign_request_template;
    }

    /**
     * Returns the sign URL.
     * 
     * @return Returns the sign URL.
     */
    public String getSignURL()
    {
      return this.sign_url;
    }

    /**
     * Returns the verify request template.
     * 
     * @return Returns the verify request template.
     */
    public String getVerifyRequestTemplate()
    {
      return this.verify_request_template;
    }

    /**
     * Returns the verify template.
     * 
     * @return Returns the verify template.
     */
    public String getVerifyTemplate()
    {
      return this.verify_template;
    }

    /**
     * Returns the verify URL.
     * 
     * @return Returns the verify URL.
     */
    public String getVerifyURL()
    {
      return this.verify_url;
    }

    /**
     * Returns the ecdsa cert alg property.
     * 
     * @return Returns the ecdsa cert alg property.
     */
    public String getCertAlgEcdsa()
    {
      return this.cert_alg_ecdsa;
    }

    /**
     * Returns the rsa cert alg property.
     * 
     * @return Returns the rsa cert alg property.
     */
    public String getCertAlgRsa()
    {
      return this.cert_alg_rsa;
    }

    /**
     * Reads the configuration entry given by the key, first from the given
     * profile, if not found from the defaults.
     * 
     * @param settings
     *          The settings.
     * @param profile
     *          The profile.
     * @param key
     *          The configuration key.
     * @return Returns the configuration entry.
     */
    public static String getConnectorValueFromProfile(SettingsReader settings,
        String profile, String key)
    {
      String value = settings.getValueFromKey("sig_obj." + profile + "." + key); //$NON-NLS-1$//$NON-NLS-2$
      if (value == null)
      {
        value = settings.getValueFromKey(key);
      }
      return value;
    }
  }


  public XMLDsigData reconstructXMLDsig(SignatureData data, SignSignatureObject so)
      throws ConnectorException {
     String xmldsig = chooseAndCreateXMLDsig(data, so);
     return new XMLDsigData(xmldsig, false);
  }
}