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.activemq.transport.mqtt.strategy;
  
  import java.io.IOException;
  import java.util.List;
  
  import org.apache.activemq.ActiveMQPrefetchPolicy;
  import org.apache.activemq.command.ActiveMQDestination;
  import org.apache.activemq.command.ActiveMQTopic;
  import org.apache.activemq.command.ConsumerInfo;
  import org.apache.activemq.command.RemoveSubscriptionInfo;
  import org.apache.activemq.command.Response;
  import org.apache.activemq.command.SubscriptionInfo;
  import org.apache.activemq.transport.mqtt.MQTTProtocolConverter;
  import org.apache.activemq.transport.mqtt.MQTTProtocolException;
  import org.apache.activemq.transport.mqtt.MQTTProtocolSupport;
  import org.apache.activemq.transport.mqtt.MQTTSubscription;
  import org.apache.activemq.transport.mqtt.ResponseHandler;
  import org.fusesource.mqtt.client.QoS;
  import org.fusesource.mqtt.codec.CONNECT;
  
  /**
   * Default implementation that uses unmapped topic subscriptions.
   */
  public class MQTTDefaultSubscriptionStrategy extends AbstractMQTTSubscriptionStrategy {
  
      @Override
      public void onConnect(CONNECT connect) throws MQTTProtocolException {
          List<SubscriptionInfo> subs = lookupSubscription(protocol.getClientId());
  
          if (connect.cleanSession()) {
              deleteDurableSubs(subs);
          } else {
              restoreDurableSubs(subs);
          }
      }
  
      @Override
      public byte onSubscribe(String topicName, QoS requestedQoS) throws MQTTProtocolException {
          ActiveMQDestination destination = new ActiveMQTopic(MQTTProtocolSupport.convertMQTTToActiveMQ(topicName));
  
          ConsumerInfo consumerInfo = new ConsumerInfo(getNextConsumerId());
          consumerInfo.setDestination(destination);
          consumerInfo.setPrefetchSize(ActiveMQPrefetchPolicy.DEFAULT_TOPIC_PREFETCH);
          consumerInfo.setRetroactive(true);
          consumerInfo.setDispatchAsync(true);
          // create durable subscriptions only when clean session is false
          if (!protocol.isCleanSession() && protocol.getClientId() != null && requestedQoS.ordinal() >= QoS.AT_LEAST_ONCE.ordinal()) {
              consumerInfo.setSubscriptionName(requestedQoS + ":" + topicName);
              consumerInfo.setPrefetchSize(ActiveMQPrefetchPolicy.DEFAULT_DURABLE_TOPIC_PREFETCH);
          }
  
          if (protocol.getActiveMQSubscriptionPrefetch() > 0) {
              consumerInfo.setPrefetchSize(protocol.getActiveMQSubscriptionPrefetch());
          }
  
          return doSubscribe(consumerInfo, topicName, requestedQoS);
      }
  
      @Override
      public void onReSubscribe(MQTTSubscription mqttSubscription) throws MQTTProtocolException {
  
          ActiveMQDestination destination = mqttSubscription.getDestination();
  
          // check whether the Topic has been recovered in restoreDurableSubs
          // mark subscription available for recovery for duplicate subscription
          if (restoredDurableSubs.remove(destination.getPhysicalName())) {
              return;
          }
  
          super.onReSubscribe(mqttSubscription);
      }
  
      @Override
      public void onUnSubscribe(String topicName) throws MQTTProtocolException {
          MQTTSubscription subscription = mqttSubscriptionByTopic.remove(topicName);
          if (subscription != null) {
              doUnSubscribe(subscription);
  
              // check if the durable sub also needs to be removed
              if (subscription.getConsumerInfo().getSubscriptionName() != null) {
                  // also remove it from restored durable subscriptions set
                  restoredDurableSubs.remove(MQTTProtocolSupport.convertMQTTToActiveMQ(subscription.getTopicName()));
  
                  RemoveSubscriptionInfo rsi = new RemoveSubscriptionInfo();
                  rsi.setConnectionId(protocol.getConnectionId());
                  rsi.setSubscriptionName(subscription.getConsumerInfo().getSubscriptionName());
                  rsi.setClientId(protocol.getClientId());
                  protocol.sendToActiveMQ(rsi, new ResponseHandler() {
                      @Override
                      public void onResponse(MQTTProtocolConverter converter, Response response) throws IOException {
                          // ignore failures..
                      }
                  });
              }
          }
      }
  }
  