/*
    * Copyright 2022 the original author or authors.
    *
    * Licensed 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.bremersee.apiclient.webflux.contract.spring;
  
  import java.util.function.Function;
  import org.bremersee.apiclient.webflux.Invocation;
  import org.springframework.util.LinkedMultiValueMap;
  import org.springframework.util.MultiValueMap;
  import org.springframework.web.bind.annotation.RequestHeader;
  
  /**
   * The request headers resolver.
   *
   * @author Christian Bremer
   */
  public class RequestHeadersResolver implements
      Function<Invocation, MultiValueMap<String, String>> {
  
    @Override
    public MultiValueMap<String, String> apply(Invocation invocation) {
      return invocation.toMethodParameterStream()
          .map(invocationParameter -> invocationParameter.toMultiValueMap(
              RequestHeader.class,
              RequestHeader::value,
              String::valueOf))
          .collect(
              LinkedMultiValueMap::new,
              LinkedMultiValueMap::addAll,
              LinkedMultiValueMap::addAll);
    }
  
  }