/*
    * 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;
  
  import java.net.URI;
  import java.util.Map;
  import java.util.Optional;
  import java.util.concurrent.ConcurrentHashMap;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.syncope.common.lib.to.SRARouteTO;
  import org.apache.syncope.sra.RouteProvider;
  import org.apache.syncope.sra.SRAProperties;
  import org.apache.syncope.sra.security.web.server.DoNothingIfCommittedServerRedirectStrategy;
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.cloud.gateway.event.RefreshRoutesEvent;
  import org.springframework.cloud.gateway.support.ServerWebExchangeUtils;
  import org.springframework.context.ApplicationListener;
  import org.springframework.security.web.server.ServerRedirectStrategy;
  import org.springframework.security.web.server.WebFilterExchange;
  import org.springframework.security.web.server.authentication.logout.ServerLogoutSuccessHandler;
  
  public abstract class AbstractServerLogoutSuccessHandler
          implements ServerLogoutSuccessHandler, ApplicationListener<RefreshRoutesEvent> {
  
      private static final Map<String, Optional<URI>> CACHE = new ConcurrentHashMap<>();
  
      protected final ServerRedirectStrategy redirectStrategy = new DoNothingIfCommittedServerRedirectStrategy();
  
      @Autowired
      private RouteProvider routeProvider;
  
      @Autowired
      private SRAProperties props;
  
      @Override
      public void onApplicationEvent(final RefreshRoutesEvent event) {
          CACHE.clear();
      }
  
      protected URI getPostLogout(final WebFilterExchange exchange) {
          URI postLogout = props.getGlobal().getPostLogout();
          String routeId = exchange.getExchange().getAttribute(ServerWebExchangeUtils.GATEWAY_PREDICATE_ROUTE_ATTR);
          if (StringUtils.isNotBlank(routeId)) {
              Optional<URI> routePostLogout = Optional.ofNullable(CACHE.get(routeId)).orElseGet(() -> {
                  Optional<SRARouteTO> route = routeProvider.getRouteTOs().stream().
                          filter(r -> routeId.equals(r.getKey())).findFirst();
                  URI uri = route.map(SRARouteTO::getPostLogout).orElse(null);
  
                  CACHE.put(routeId, Optional.ofNullable(uri));
                  return CACHE.get(routeId);
              });
              if (routePostLogout.isPresent()) {
                  postLogout = routePostLogout.get();
              }
          }
          return postLogout;
      }
  }