/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you 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.apache.syncope.wa.starter.pac4j.saml;
  
  import java.io.ByteArrayInputStream;
  import java.io.ByteArrayOutputStream;
  import java.io.InputStream;
  import java.security.KeyStore;
  import java.security.PrivateKey;
  import java.security.cert.X509Certificate;
  import java.util.Base64;
  import org.apache.syncope.common.lib.to.SAML2SPEntityTO;
  import org.apache.syncope.common.rest.api.service.SAML2SPEntityService;
  import org.apache.syncope.wa.bootstrap.WARestClient;
  import org.pac4j.saml.client.SAML2Client;
  import org.pac4j.saml.metadata.keystore.BaseSAML2KeystoreGenerator;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  public class WASAML2ClientKeystoreGenerator extends BaseSAML2KeystoreGenerator {
  
      protected static final Logger LOG = LoggerFactory.getLogger(WASAML2ClientKeystoreGenerator.class);
  
      protected final WARestClient waRestClient;
  
      protected final SAML2Client saml2Client;
  
      public WASAML2ClientKeystoreGenerator(final WARestClient waRestClient, final SAML2Client saml2Client) {
          super(saml2Client.getConfiguration());
          this.waRestClient = waRestClient;
          this.saml2Client = saml2Client;
      }
  
      @Override
      public boolean shouldGenerate() {
          return true;
      }
  
      @Override
      protected void store(final KeyStore ks, final X509Certificate certificate, final PrivateKey privateKey)
              throws Exception {
  
          try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {
              char[] password = saml2Configuration.getKeystorePassword().toCharArray();
              ks.store(out, password);
              out.flush();
              String encodedKeystore = Base64.getEncoder().encodeToString(out.toByteArray());
              LOG.debug("Encoded keystore {}", encodedKeystore);
  
              SAML2SPEntityTO entityTO;
              try {
                  entityTO = waRestClient.getService(SAML2SPEntityService.class).get(saml2Client.getName());
                  entityTO.setKeystore(encodedKeystore);
              } catch (Exception e) {
                  LOG.debug("SP Entity {} not found, creating new", saml2Client.getName(), e);
  
                  entityTO = new SAML2SPEntityTO.Builder().
                          key(saml2Client.getName()).
                          keystore(encodedKeystore).
                          build();
              }
  
              LOG.debug("Storing SP Entity {}", entityTO);
              waRestClient.getService(SAML2SPEntityService.class).set(entityTO);
          }
      }
  
      @Override
      public InputStream retrieve() throws Exception {
          try {
              SAML2SPEntityTO spEntity = waRestClient.getService(SAML2SPEntityService.class).get(saml2Client.getName());
  
              LOG.debug("Retrieved keystore {}", spEntity.getKeystore());
              return new ByteArrayInputStream(Base64.getDecoder().decode(spEntity.getKeystore()));
          } catch (Exception e) {
              String message = "Unable to fetch SAML2 SP keystore for " + saml2Client.getName();
              LOG.error(message, e);
              throw new Exception(message);
          }
      }
  }