/*
    * 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.sra.security.cas;
  
  import java.net.URI;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.syncope.sra.SessionConfig;
  import org.apache.syncope.sra.security.web.server.DoNothingIfCommittedServerRedirectStrategy;
  import org.springframework.cache.CacheManager;
  import org.springframework.security.core.Authentication;
  import org.springframework.security.web.server.ServerRedirectStrategy;
  import org.springframework.security.web.server.WebFilterExchange;
  import org.springframework.security.web.server.authentication.logout.ServerLogoutHandler;
  import reactor.core.publisher.Mono;
  
  public class CASServerLogoutHandler implements ServerLogoutHandler {
  
      private final ServerRedirectStrategy redirectStrategy = new DoNothingIfCommittedServerRedirectStrategy();
  
      private final CacheManager cacheManager;
  
      /**
       * The URL to the CAS Server logout.
       */
      private final String casServerLogoutUrl;
  
      public CASServerLogoutHandler(final CacheManager cacheManager, final String casServerUrlPrefix) {
          this.cacheManager = cacheManager;
          this.casServerLogoutUrl = StringUtils.appendIfMissing(casServerUrlPrefix, "/") + "logout";
      }
  
      @Override
      public Mono<Void> logout(final WebFilterExchange exchange, final Authentication authentication) {
          return exchange.getExchange().getSession().
                  flatMap(session -> {
                      cacheManager.getCache(SessionConfig.DEFAULT_CACHE).evictIfPresent(session.getId());
  
                      return session.invalidate().then(
                              redirectStrategy.sendRedirect(exchange.getExchange(), URI.create(this.casServerLogoutUrl)));
                  }).onErrorResume(Mono::error);
      }
  }