/*
    * 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.util.Set;
  import java.util.concurrent.ConcurrentHashMap;
  import org.apache.syncope.common.lib.to.SRARouteTO;
  import org.springframework.cloud.gateway.route.Route;
  import org.springframework.http.HttpMethod;
  import org.springframework.http.HttpRequest;
  import org.springframework.web.server.ServerWebExchange;
  import reactor.core.publisher.Mono;
  
  public class CsrfRouteMatcher extends AbstractRouteMatcher {
  
      private static final String CACHE_NAME = CsrfRouteMatcher.class.getName();
  
      private static final Set<HttpMethod> ALLOWED_METHODS = Set.of(
              HttpMethod.GET, HttpMethod.HEAD, HttpMethod.TRACE, HttpMethod.OPTIONS);
  
      static {
          CACHE.put(CACHE_NAME, new ConcurrentHashMap<>());
      }
  
      private final PublicRouteMatcher publicRouteMatcher;
  
      public CsrfRouteMatcher(final PublicRouteMatcher publicRouteMatcher) {
          this.publicRouteMatcher = publicRouteMatcher;
      }
  
      @Override
      protected String getCacheName() {
          return CACHE_NAME;
      }
  
      @Override
      protected boolean routeBehavior(final Route route) {
          return routeProvider.getRouteTOs().stream().
                  filter(r -> route.getId().equals(r.getKey())).findFirst().
                  map(SRARouteTO::isCsrf).orElse(true)
                  && !publicRouteMatcher.routeBehavior(route);
      }
  
      @Override
      public Mono<MatchResult> matches(final ServerWebExchange exchange) {
          return Mono.just(exchange.getRequest()).
                  map(HttpRequest::getMethod).
                  filter(ALLOWED_METHODS::contains).
                  flatMap(m -> MatchResult.notMatch()).
                  switchIfEmpty(super.matches(exchange));
      }
  }