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.camel.component.kafka.consumer.support.subcription;
  
  import org.apache.camel.component.kafka.consumer.support.TopicHelper;
  import org.apache.kafka.clients.consumer.Consumer;
  import org.apache.kafka.clients.consumer.ConsumerRebalanceListener;
  import org.apache.kafka.common.errors.UnknownTopicOrPartitionException;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  public class DefaultSubscribeAdapter implements SubscribeAdapter {
  
      private static final Logger LOG = LoggerFactory.getLogger(DefaultSubscribeAdapter.class);
  
      private final String topic;
      private final boolean topicMustExists;
  
      public DefaultSubscribeAdapter() {
          this(null, false);
      }
  
      public DefaultSubscribeAdapter(String topic, boolean topicMustExists) {
          this.topic = topic;
          this.topicMustExists = topicMustExists;
      }
  
      @Override
      public void subscribe(Consumer<?, ?> consumer, ConsumerRebalanceListener reBalanceListener, TopicInfo topicInfo) {
          if (LOG.isInfoEnabled()) {
              LOG.info("Subscribing to {}", TopicHelper.getPrintableTopic(topicInfo));
          }
  
          if (topicInfo.isPattern()) {
              consumer.subscribe(topicInfo.getPattern(), reBalanceListener);
          } else {
              consumer.subscribe(topicInfo.getTopics(), reBalanceListener);
          }
  
          if (topicMustExists) {
              boolean found = false;
              var it = consumer.listTopics().keySet().iterator();
              while (!found && it.hasNext()) {
                  String id = it.next();
                  if (topicInfo.isPattern()) {
                      found = topicInfo.getPattern().matcher(id).matches();
                  } else {
                      found = topicInfo.getTopics().contains(id);
                  }
              }
              if (!found) {
                  throw new UnknownTopicOrPartitionException("Topic " + topic + " does not exists");
              }
          }
      }
  }
  