/*******************************************************************************
 * Copyright 2014 Federal Chancellery Austria
 * MOA-ID has been developed in a cooperation between BRZ, the Federal
 * Chancellery Austria - ICT staff unit, 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.
 ******************************************************************************/
/*
 * Copyright 2003 Federal Chancellery Austria
 * MOA-ID has been developed in a cooperation between BRZ, the Federal
 * Chancellery Austria - ICT staff unit, 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.egovernment.moa.id.auth.builder;

import java.security.MessageDigest;

import at.gv.egovernment.moa.id.auth.exception.BuildException;
import at.gv.egovernment.moa.util.Base64Utils;
import at.gv.egovernment.moa.util.Constants;

/**
 * Builder for the bPK, as defined in
 * <code>&quot;Ableitung f&uml;r die bereichsspezifische Personenkennzeichnung&quot;</code>
 * version <code>1.0.1</code> from <code>&quot;reference.e-government.gv.at&quot;</code>.
 *  
 * @author Paul Schamberger
 * @version $Id$
 */
public class BPKBuilder {

  /**
   * Builds the bPK from the given parameters. 
   * @param identificationValue Base64 encoded "Stammzahl" 
   * @param target "Bereich lt. Verordnung des BKA"
   * @return bPK in a BASE64 encoding
   * @throws BuildException if an error occurs on building the bPK
   */
  public String buildBPK(String identificationValue, String target) 
    throws BuildException {
    
    if ((identificationValue == null || 
         identificationValue.length() == 0 ||
    		 target == null || 
         target.length() == 0)) 
    {
      throw new BuildException("builder.00", 
      		                     new Object[] {"BPK", "Unvollständige Parameterangaben: identificationValue=" + 
                                             identificationValue + ",target=" + target});
    }
    String basisbegriff;
	if (target.startsWith(Constants.URN_PREFIX_CDID + "+"))
		basisbegriff = identificationValue + "+" + target;
	else
		basisbegriff = identificationValue + "+" + Constants.URN_PREFIX_CDID + "+" + target;
	
    try {
      MessageDigest md = MessageDigest.getInstance("SHA-1");
      byte[] hash = md.digest(basisbegriff.getBytes("ISO-8859-1"));
      String hashBase64 = Base64Utils.encode(hash);
      return hashBase64;
    } catch (Exception ex) {
      throw new BuildException("builder.00", new Object[] {"bPK", ex.toString()}, ex);
    }
  }

  /**
   * Builds the wbPK from the given parameters. 
   * @param identificationValue Base64 encoded "Stammzahl" 
   * @param registerAndOrdNr type of register + "+" + number in register.
   * @return wbPK in a BASE64 encoding
   * @throws BuildException if an error occurs on building the wbPK
   */
  public String buildWBPK(String identificationValue, String registerAndOrdNr) 
    throws BuildException {
    
    if ((identificationValue == null || 
         identificationValue.length() == 0 ||
         registerAndOrdNr == null || 
         registerAndOrdNr.length() == 0)) 
    {
      throw new BuildException("builder.00", 
          new Object[] {"wbPK", "Unvollständige Parameterangaben: identificationValue=" + 
                        identificationValue + ",Register+Registernummer=" + registerAndOrdNr});
    }
     
    String basisbegriff;
    if (registerAndOrdNr.startsWith(Constants.URN_PREFIX_WBPK + "+" ))
    	basisbegriff = identificationValue + "+" + registerAndOrdNr;
    else
    	basisbegriff = identificationValue + "+" + Constants.URN_PREFIX_WBPK + "+" + registerAndOrdNr;
    
    try {
      MessageDigest md = MessageDigest.getInstance("SHA-1");
      byte[] hash = md.digest(basisbegriff.getBytes("ISO-8859-1"));
      String hashBase64 = Base64Utils.encode(hash);
      return hashBase64;
    } catch (Exception ex) {
      throw new BuildException("builder.00", new Object[] {"wbPK", ex.toString()}, ex);
    }
  }

}