/*
 * 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());
        };
    }
}
