/**
 * 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.core.tasks;

import java.io.File;
import java.io.FileInputStream;
import java.io.FilenameFilter;
import java.io.IOException;
import java.security.cert.X509Certificate;

import org.glite.security.voms.admin.configuration.VOMSConfiguration;
import org.glite.security.voms.admin.configuration.VOMSConfigurationConstants;
import org.glite.security.voms.admin.error.VOMSException;
import org.glite.security.voms.admin.persistence.dao.VOMSCADAO;
import org.glite.security.voms.admin.util.DNUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import eu.emi.security.authn.x509.impl.CertificateUtils;
import eu.emi.security.authn.x509.impl.CertificateUtils.Encoding;

/**
 * @author <a href="mailto:andrea.ceccanti@cnaf.infn.it">Andrea Ceccanti</a>
 */
public final class UpdateCATask implements Runnable {

  static final Logger log = LoggerFactory.getLogger(UpdateCATask.class);

  private void directorySanityChecks(File directory) {

    if (!directory.exists())
      throw new VOMSException("Local trust directory does not exists:"
        + directory.getAbsolutePath());

    if (!directory.isDirectory())
      throw new VOMSException("Local trust directory is not a directory:"
        + directory.getAbsolutePath());

    if (!directory.canRead())
      throw new VOMSException("Local trust directory is not readable:"
        + directory.getAbsolutePath());

    if (!directory.canExecute())
      throw new VOMSException("Local trust directory is not traversable:"
        + directory.getAbsolutePath());
  }

  public void run() {

    String trustAnchorsDir = VOMSConfiguration.instance().getString(
      VOMSConfigurationConstants.TRUST_ANCHORS_DIR,
      "/etc/grid-security/certificates");

    log.debug("Updating CAs from: " + trustAnchorsDir);

    VOMSCADAO dao = VOMSCADAO.instance();

    File dir = new File(trustAnchorsDir);
    directorySanityChecks(dir);

    File[] certFiles = dir.listFiles(new FilenameFilter() {

      public boolean accept(File dir, String name) {

        return name.matches(".*\\.\\d");
      }
    });

    for (File caFile : certFiles) {
      log.debug("Parsing CA certificate from {}.", caFile);

      X509Certificate caCert;

      try {
        caCert = CertificateUtils.loadCertificate(new FileInputStream(caFile),
          Encoding.PEM);

      } catch (IOException e) {
        log.error(e.getMessage(), e);
        continue;
      }

      String caDN = DNUtil.getOpenSSLSubject(caCert.getSubjectX500Principal());

      log.debug("Checking CA: " + caDN);

      dao.createIfMissing(caDN, null);

    }
  }
}