content: /*
   *  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.causeway.viewer.restfulobjects.rendering.service.acceptheader;
  
  import java.io.IOException;
  import java.util.List;
  import java.util.stream.Collectors;
  
  import jakarta.inject.Named;
  import jakarta.ws.rs.container.ContainerRequestContext;
  import jakarta.ws.rs.container.ContainerRequestFilter;
  import jakarta.ws.rs.container.ContainerResponseContext;
  import jakarta.ws.rs.container.ContainerResponseFilter;
  import jakarta.ws.rs.core.MediaType;
  import jakarta.ws.rs.ext.Provider;
  
  import org.springframework.beans.factory.annotation.Qualifier;
  import org.springframework.stereotype.Component;
  import org.springframework.stereotype.Service;
  
  import org.apache.causeway.applib.annotation.InteractionScope;
  import org.apache.causeway.applib.annotation.PriorityPrecedence;
  import org.apache.causeway.applib.services.acceptheader.AcceptHeaderService;
  import org.apache.causeway.commons.internal.base._NullSafe;
  import org.apache.causeway.viewer.restfulobjects.applib.CausewayModuleViewerRestfulObjectsApplib;
  
  import static org.apache.causeway.commons.internal.base._NullSafe.stream;
  
  /**
   * @since 1.x {@index}
   */
  @Service
  @Named(AcceptHeaderServiceForRest.LOGICAL_TYPE_NAME)
  @jakarta.annotation.Priority(PriorityPrecedence.MIDPOINT)
  @Qualifier("ForRest")
  @InteractionScope
  public class AcceptHeaderServiceForRest implements AcceptHeaderService {
  
      public static final String LOGICAL_TYPE_NAME =
              CausewayModuleViewerRestfulObjectsApplib.NAMESPACE + ".AcceptHeaderServiceForRest";
  
      private static ThreadLocal<List<MediaType>> mediaTypesByThread = new ThreadLocal<>();
  
      /**
       * Not API - called by RO viewer filter.
       */
      private static void setMediaTypes(List<MediaType> mediaTypes) {
          mediaTypesByThread.set(mediaTypes);
      }
      /**
       * Not API - called by RO viewer filter.
       */
      private static void removeMediaTypes() {
          mediaTypesByThread.remove();
      }
  
      @Override
      public List<MediaType> getAcceptableMediaTypes() {
          return mediaTypesByThread.get();
      }
  
      @Component
      @Provider
      public static class RequestFilter implements ContainerRequestFilter  {
          @Override
          public void filter(final ContainerRequestContext requestContext) throws IOException {
              final List<MediaType> acceptableMediaTypes = requestContext.getAcceptableMediaTypes();
  
              final List<MediaType> mediaTypes = stream(acceptableMediaTypes)
                      .filter(_NullSafe::isPresent)
                      .collect(Collectors.toList());
  
              setMediaTypes(mediaTypes);
          }
      }
  
      @Component
      @Provider
      public static class ResponseFilter implements ContainerResponseFilter {
          @Override
          public void filter(
                  final ContainerRequestContext requestContext,
                  final ContainerResponseContext responseContext) throws IOException {
  
              removeMediaTypes();
          }
      }
  
  }
  