/*
    * 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.filters;
  
  import java.net.URI;
  import org.springframework.cloud.gateway.filter.GatewayFilter;
  import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
  import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory.NameConfig;
  import org.springframework.http.server.reactive.ServerHttpRequest;
  import org.springframework.web.util.UriComponentsBuilder;
  
  public class QueryParamToRequestHeaderFilterFactory extends AbstractGatewayFilterFactory<NameConfig> {
  
      public QueryParamToRequestHeaderFilterFactory() {
          super(NameConfig.class);
      }
  
      @Override
      public GatewayFilter apply(final NameConfig config) {
          return (exchange, chain) -> {
              ServerHttpRequest originalRequest = exchange.getRequest();
  
              ServerHttpRequest mutatedRequest;
              if (originalRequest.getQueryParams().isEmpty()) {
                  mutatedRequest = originalRequest;
              } else {
                  URI newUri = UriComponentsBuilder.fromUri(originalRequest.getURI()).
                          replaceQueryParam(config.getName()).build().toUri();
  
                  mutatedRequest = exchange.getRequest().mutate().
                          uri(newUri).
                          headers(headers -> headers.addAll(
                          config.getName(), originalRequest.getQueryParams().get(config.getName()))).
                          build();
              }
  
              return chain.filter(exchange.mutate().request(mutatedRequest).build());
          };
      }
  }