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.errorhandler;
  
  import java.util.function.Predicate;
  
  import org.apache.camel.component.kafka.SeekPolicy;
  import org.apache.camel.component.kafka.consumer.support.ProcessingResult;
  import org.apache.camel.resume.ConsumerListener;
  import org.apache.kafka.clients.consumer.Consumer;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  public class KafkaConsumerListener implements ConsumerListener<Object, ProcessingResult> {
      private static final Logger LOG = LoggerFactory.getLogger(KafkaConsumerListener.class);
      private Consumer<?, ?> consumer;
      private SeekPolicy seekPolicy;
  
      private Predicate<?> afterConsumeEval;
      private boolean paused;
  
      public Consumer<?, ?> getConsumer() {
          return consumer;
      }
  
      public void setConsumer(Consumer<?, ?> consumer) {
          this.consumer = consumer;
      }
  
      public SeekPolicy getSeekPolicy() {
          return seekPolicy;
      }
  
      public void setSeekPolicy(SeekPolicy seekPolicy) {
          this.seekPolicy = seekPolicy;
      }
  
      @Override
      public void setResumableCheck(Predicate<?> afterConsumeEval) {
          this.afterConsumeEval = afterConsumeEval;
      }
  
      @Override
      public boolean afterConsume(@SuppressWarnings("unused") Object ignored) {
          if (paused) {
              if (afterConsumeEval.test(null)) {
                  LOG.warn("State changed, therefore resuming the consumer");
                  consumer.resume(consumer.assignment());
  
                  return true;
              }
  
              LOG.warn("The consumer is not yet resumable");
              return false;
          }
  
          // It's not paused, so we can continue processing
          return true;
      }
  
      @Override
      public boolean afterProcess(ProcessingResult result) {
          if (result.isFailed()) {
              LOG.warn("Pausing consumer due to error on the last processing");
              consumer.pause(consumer.assignment());
              paused = true;
  
              if (seekPolicy == SeekPolicy.BEGINNING) {
                  LOG.debug("Seeking from the beginning of topic");
                  consumer.seekToBeginning(consumer.assignment());
              } else if (seekPolicy == SeekPolicy.END) {
                  LOG.debug("Seeking from the end off the topic");
                  consumer.seekToEnd(consumer.assignment());
              }
  
              return false;
          }
  
          return true;
      }
  }
  