/**
 * Copyright (c) Istituto Nazionale di Fisica Nucleare (INFN). 2006-2016
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.glite.security.voms.admin.util;

import java.security.cert.CertificateParsingException;
import java.security.cert.X509Certificate;
import java.util.Collection;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.security.auth.x500.X500Principal;

import org.glite.security.voms.admin.error.VOMSException;

import eu.emi.security.authn.x509.impl.OpensslNameUtils;
import eu.emi.security.authn.x509.impl.X500NameUtils;

/**
 * Utility class to convert principal names to convenient format.
 * 
 * @see DNUtil
 * 
 */
public class DNUtil {

  /**
   * Converts BouncyCastle's X500 principal to something, which is used in the
   * Globus libraries by default (whatever it is).
   * 
   * @param principal
   *          the subject's or the issuer's X500 principal
   * @return the proper string represetnation
   */
  public static String getOpenSSLSubject(X500Principal principal) {

    return OpensslNameUtils.convertFromRfc2253(
      X500NameUtils.getReadableForm(principal), false);
  }

  public static String normalizeEmailAddressInDN(String dn) {

    return dn.replaceAll(
      "/(E|e|((E|e|)(mail|mailAddress|mailaddress|MAIL|MAILADDRESS)))=",
      "/Email=");
  }

  public static String normalizeUIDInDN(String dn) {

    return dn.replaceAll("/(UserId|USERID|userId|userid|uid|Uid)=", "/UID=");
  }

  public static String normalizeDN(String dn) {

    return normalizeUIDInDN(normalizeEmailAddressInDN(dn));
  }

  public static String getEmailAddressFromDN(String dn) {

    Pattern emailPattern = Pattern.compile("Email=([^/]*)");
    Matcher m = emailPattern.matcher(dn);

    if (m.find()) {

      return m.group(1);
    }

    return null;
  }

  public static String getEmailAddressFromExtensions(X509Certificate cert) {

    try {

      Collection<List<?>> altNames = cert.getSubjectAlternativeNames();

      if (altNames == null)
        return null;

      // Iterate over alternative names
      for (List<?> entry : altNames) {

        // First item in the list is an integer specify the altName
        // 'kind'
        int entryType = (Integer) entry.get(0);

        // 1 is the code for rfc822 name, we consider only the first
        // address
        // in the list.

        if (entryType == 1)
          return (String) entry.get(1);
        else
          continue;

      }

    } catch (CertificateParsingException e) {
      throw new VOMSException("Error accessing subject alternative names: "
        + e.getMessage(), e);
    }

    return null;
  }

  public static boolean isRFC2253Conformant(String subjectNameIDValue) {

    // TODO: Migrate this method from old VOMS SAML codebase
    return true;
  }

  public static String getBCasX500(String principalString) {

    return getOpenSSLSubject(new X500Principal(principalString));

  }
}

// Please do not change this line.
// arch-tag: b7901446-4a9f-4e35-b334-55e4ef43d304