/**
 * 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.usecases;

import javax.jms.Connection;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageConsumer;
import javax.jms.MessageListener;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;
import java.net.URI;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import org.apache.activemq.JmsMultipleBrokersTestSupport;
import org.apache.activemq.broker.region.AbstractRegion;
import org.apache.activemq.broker.region.RegionBroker;
import org.apache.activemq.network.NetworkConnector;
import org.apache.activemq.util.Wait;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * @author <a href="http://www.christianposta.com/blog">Christian Posta</a>
 */
public class ThreeBrokerTempDestDemandSubscriptionCleanupTest extends JmsMultipleBrokersTestSupport {

   private static final Logger LOG = LoggerFactory.getLogger(ThreeBrokerTempDestDemandSubscriptionCleanupTest.class);

   boolean enableTempDestinationBridging = true;

   private static final String BROKER_A = "BrokerA";
   private static final String BROKER_B = "BrokerB";
   private static final String BROKER_C = "BrokerC";

   private static final String ECHO_QUEUE_NAME = "echo";
   private static final int NUM_ITER = 100;
   private static final long CONSUME_TIMEOUT = 500;

   /**
    * So we network three brokers together, and send a message with request-reply semantics.
    * The message goes to an echo service listening on broker C. We send a message on a queue
    * to broker A which gets demand forwarded to broker C. the echo service will respond to the
    * temp destination listed in the JMSReplyTo header. that will get demand forwarded back to
    * broker A. When the consumer of the temp dest on broker A closes, that subscription should
    * be removed on broker A. advisories firing from broker A to broker B should remove that
    * subscription on broker B. advisories firing from broker B to broker C should remove that
    * subscription on broker C.
    *
    * @throws Exception
    */
   public void testSubscriptionsCleanedUpRace() throws Exception {

      final BrokerItem brokerA = brokers.get(BROKER_A);

      Runnable tester = new Runnable() {

         @Override
         public void run() {
            for (int i = 0; i < NUM_ITER; i++) {

               Connection conn = null;
               try {
                  conn = brokerA.createConnection();

                  conn.start();

                  final Session sess = conn.createSession(false, Session.AUTO_ACKNOWLEDGE);
                  Destination destination = sess.createQueue(ECHO_QUEUE_NAME);

                  MessageProducer producer = sess.createProducer(destination);

                  LOG.info("Starting iter: " + i);
                  Destination replyTo = sess.createTemporaryQueue();
                  MessageConsumer responseConsumer = sess.createConsumer(replyTo);

                  Message message = sess.createTextMessage("Iteration: " + i);
                  message.setJMSReplyTo(replyTo);

                  producer.send(message);

                  TextMessage response = (TextMessage) responseConsumer.receive(CONSUME_TIMEOUT);
                  assertNotNull("We should have gotten a response, but didn't for iter: " + i, response);
                  assertEquals("We got the wrong response from the echo service", "Iteration: " + i, response.getText());

                  // so we close the consumer so that an actual RemoveInfo command gets propagated through the
                  // network
                  responseConsumer.close();
                  conn.close();

               } catch (Exception e) {
                  e.printStackTrace();
                  fail();
               }

            }
         }
      };

      ExecutorService threadService = Executors.newFixedThreadPool(2);
      threadService.submit(tester);
      threadService.submit(tester);

      threadService.shutdown();
      assertTrue("executor done on time", threadService.awaitTermination(30L, TimeUnit.SECONDS));

      // for the real test... we should not have any subscriptions left on broker C for the temp dests
      BrokerItem brokerC = brokers.get(BROKER_C);
      RegionBroker regionBroker = (RegionBroker) brokerC.broker.getRegionBroker();
      final AbstractRegion region = (AbstractRegion) regionBroker.getTempQueueRegion();

      assertTrue("There were no lingering temp-queue destinations", Wait.waitFor(new Wait.Condition() {
         @Override
         public boolean isSatisified() throws Exception {
            LOG.info("Lingering temps: " + region.getSubscriptions().size());
            return 0 == region.getSubscriptions().size();
         }
      }));
   }

   /**
    * This test is slightly different from the above. We don't explicitly close the consumer down
    * (which we did in the previous test to force the RemoveInfo to be sent). Here we just close
    * the connection which should still clean up the subscriptions and temp destinations on the
    * networked brokers.
    *
    * @throws Exception
    */
   public void testSubscriptionsCleanedUpAfterConnectionClose() throws Exception {

      final BrokerItem brokerA = brokers.get(BROKER_A);

      for (int i = 0; i < NUM_ITER; i++) {

         Connection conn = null;
         try {
            conn = brokerA.createConnection();

            conn.start();

            final Session sess = conn.createSession(false, Session.AUTO_ACKNOWLEDGE);
            Destination destination = sess.createQueue(ECHO_QUEUE_NAME);

            MessageProducer producer = sess.createProducer(destination);

            LOG.info("Starting iter: " + i);
            Destination replyTo = sess.createTemporaryQueue();
            MessageConsumer responseConsumer = sess.createConsumer(replyTo);

            Message message = sess.createTextMessage("Iteration: " + i);
            message.setJMSReplyTo(replyTo);

            producer.send(message);

            TextMessage response = (TextMessage) responseConsumer.receive(CONSUME_TIMEOUT);
            assertNotNull("We should have gotten a response, but didn't for iter: " + i, response);
            assertEquals("We got the wrong response from the echo service", "Iteration: " + i, response.getText());

            // so closing the connection without closing the consumer first will leak subscriptions
            // in a nob?
            //              responseConsumer.close();
            conn.close();

         } catch (Exception e) {
            e.printStackTrace();
            fail();
         }

      }

      // for the real test... we should not have any subscriptions left on broker C for the temp dests
      BrokerItem brokerC = brokers.get(BROKER_C);
      RegionBroker regionBroker = (RegionBroker) brokerC.broker.getRegionBroker();
      final AbstractRegion region = (AbstractRegion) regionBroker.getTempQueueRegion();

      assertTrue("There were no lingering temp-queue destinations", Wait.waitFor(new Wait.Condition() {
         @Override
         public boolean isSatisified() throws Exception {
            LOG.info("Lingering temps: " + region.getSubscriptions().size());
            return 0 == region.getSubscriptions().size();
         }
      }));

   }

   private void installEchoClientOnBrokerC() throws Exception {
      BrokerItem brokerC = brokers.get(BROKER_C);
      Connection conn = brokerC.createConnection();
      conn.start();

      final Session sess = conn.createSession(false, Session.AUTO_ACKNOWLEDGE);
      Destination destination = sess.createQueue(ECHO_QUEUE_NAME);
      MessageConsumer consumer = sess.createConsumer(destination);

      consumer.setMessageListener(new MessageListener() {
         @Override
         public void onMessage(Message message) {

            TextMessage textMessage = (TextMessage) message;

            try {
               Destination replyTo = message.getJMSReplyTo();

               MessageProducer producer = sess.createProducer(replyTo);
               Message response = sess.createTextMessage(textMessage.getText());

               LOG.info("Replying to this request: " + textMessage.getText());
               producer.send(response);
               producer.close();

            } catch (JMSException e) {
               e.printStackTrace();
               fail("Could not respond to an echo request");
            }
         }
      });
   }

   @Override
   protected void setUp() throws Exception {
      super.setUp();
      createBroker(new URI("broker:(tcp://localhost:61616)/" + BROKER_A + "?persistent=false&useJmx=false"));
      createBroker(new URI("broker:(tcp://localhost:61617)/" + BROKER_B + "?persistent=false&useJmx=false"));
      createBroker(new URI("broker:(tcp://localhost:61618)/" + BROKER_C + "?persistent=false&useJmx=false"));

      bridgeBrokers("BrokerA", "BrokerB", false, 3);
      bridgeBrokers("BrokerB", "BrokerC", false, 3);

      startAllBrokers();

      // set up a listener on broker C that will demand forward subscriptions over the network
      installEchoClientOnBrokerC();
   }

   protected NetworkConnector bridgeBrokers(String localBrokerName,
                                            String remoteBrokerName,
                                            boolean dynamicOnly,
                                            int networkTTL) throws Exception {
      NetworkConnector connector = super.bridgeBrokers(localBrokerName, remoteBrokerName, dynamicOnly, networkTTL, true);
      connector.setBridgeTempDestinations(enableTempDestinationBridging);
      connector.setDuplex(true);
      return connector;
   }
}
