content: /*
   * Copyright 2017-2025 Hyland Software, Inc. and its affiliates.
   *
   * 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.activiti.cloud.services.messages.core.router;
  
  import static org.activiti.cloud.services.messages.core.integration.MessageEventHeaders.MESSAGE_EVENT_OUTPUT_DESTINATION;
  
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.Optional;
  import org.springframework.integration.mapping.MessageMappingException;
  import org.springframework.integration.router.AbstractMessageRouter;
  import org.springframework.messaging.Message;
  import org.springframework.messaging.MessageChannel;
  import org.springframework.messaging.core.DestinationResolver;
  
  public class CommandConsumerMessageRouter extends AbstractMessageRouter {
  
      private final DestinationResolver<MessageChannel> destinationResolver;
  
      public CommandConsumerMessageRouter(DestinationResolver<MessageChannel> destinationResolver) {
          this.destinationResolver = destinationResolver;
      }
  
      @Override
      protected Collection<MessageChannel> determineTargetChannels(Message<?> message) {
          Optional<String> destination = getHeader(message, MESSAGE_EVENT_OUTPUT_DESTINATION);
  
          MessageChannel messageChannel = destination
              .map(destinationResolver::resolveDestination)
              .orElseThrow(() -> new MessageMappingException(message, "Unable to determine target channel for message"));
          return Arrays.asList(messageChannel);
      }
  
      private Optional<String> getHeader(Message<?> message, String key) {
          return Optional.ofNullable(message.getHeaders().get(key, String.class));
      }
  }
  