/**
 * 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.util.Iterator;
import java.util.LinkedHashSet;
import java.util.concurrent.TimeUnit;

import org.apache.activemq.ActiveMQConnection;
import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.activemq.RedeliveryPolicy;
import org.apache.activemq.broker.BrokerService;
import org.apache.activemq.util.Wait;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;

public class NonBlockingConsumerRedeliveryTest {

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

   private final String destinationName = "Destination";
   private final int MSG_COUNT = 100;

   private BrokerService broker;
   private String connectionUri;

   private ActiveMQConnectionFactory connectionFactory;

   @Test
   public void testMessageDeleiveredWhenNonBlockingEnabled() throws Exception {

      final LinkedHashSet<Message> received = new LinkedHashSet<>();
      final LinkedHashSet<Message> beforeRollback = new LinkedHashSet<>();
      final LinkedHashSet<Message> afterRollback = new LinkedHashSet<>();

      Connection connection = connectionFactory.createConnection();
      Session session = connection.createSession(true, Session.AUTO_ACKNOWLEDGE);
      Destination destination = session.createQueue(destinationName);
      MessageConsumer consumer = session.createConsumer(destination);

      consumer.setMessageListener(new MessageListener() {
         @Override
         public void onMessage(Message message) {
            received.add(message);
         }
      });

      sendMessages();

      session.commit();
      connection.start();

      assertTrue("Pre-Rollback expects to receive: " + MSG_COUNT + " messages.", Wait.waitFor(new Wait.Condition() {
         @Override
         public boolean isSatisified() throws Exception {
            LOG.info("Consumer has received " + received.size() + " messages.");
            return received.size() == MSG_COUNT;
         }
      }));

      beforeRollback.addAll(received);
      received.clear();
      session.rollback();

      assertTrue("Post-Rollback expects to receive: " + MSG_COUNT + " messages.", Wait.waitFor(new Wait.Condition() {
         @Override
         public boolean isSatisified() throws Exception {
            LOG.info("Consumer has received " + received.size() + " messages since rollback.");
            return received.size() == MSG_COUNT;
         }
      }));

      afterRollback.addAll(received);
      received.clear();

      assertEquals(beforeRollback.size(), afterRollback.size());
      assertEquals(beforeRollback, afterRollback);
      session.commit();
   }

   @Test
   public void testMessageDeleiveredInCorrectOrder() throws Exception {

      final LinkedHashSet<Message> received = new LinkedHashSet<>();
      final LinkedHashSet<Message> beforeRollback = new LinkedHashSet<>();
      final LinkedHashSet<Message> afterRollback = new LinkedHashSet<>();

      Connection connection = connectionFactory.createConnection();
      Session session = connection.createSession(true, Session.AUTO_ACKNOWLEDGE);
      Destination destination = session.createQueue(destinationName);
      MessageConsumer consumer = session.createConsumer(destination);

      consumer.setMessageListener(new MessageListener() {
         @Override
         public void onMessage(Message message) {
            received.add(message);
         }
      });

      sendMessages();

      session.commit();
      connection.start();

      assertTrue("Pre-Rollback expects to receive: " + MSG_COUNT + " messages.", Wait.waitFor(new Wait.Condition() {
         @Override
         public boolean isSatisified() throws Exception {
            LOG.info("Consumer has received " + received.size() + " messages.");
            return received.size() == MSG_COUNT;
         }
      }));

      beforeRollback.addAll(received);
      received.clear();
      session.rollback();

      assertTrue("Post-Rollback expects to receive: " + MSG_COUNT + " messages.", Wait.waitFor(new Wait.Condition() {
         @Override
         public boolean isSatisified() throws Exception {
            LOG.info("Consumer has received " + received.size() + " messages since rollback.");
            return received.size() == MSG_COUNT;
         }
      }));

      afterRollback.addAll(received);
      received.clear();

      assertEquals(beforeRollback.size(), afterRollback.size());
      assertEquals(beforeRollback, afterRollback);

      Iterator<Message> after = afterRollback.iterator();
      Iterator<Message> before = beforeRollback.iterator();

      while (before.hasNext() && after.hasNext()) {
         TextMessage original = (TextMessage) before.next();
         TextMessage rolledBack = (TextMessage) after.next();

         int originalInt = Integer.parseInt(original.getText());
         int rolledbackInt = Integer.parseInt(rolledBack.getText());

         assertEquals(originalInt, rolledbackInt);
      }

      session.commit();
   }

   @Test
   public void testMessageDeleiveryDoesntStop() throws Exception {

      final LinkedHashSet<Message> received = new LinkedHashSet<>();
      final LinkedHashSet<Message> beforeRollback = new LinkedHashSet<>();
      final LinkedHashSet<Message> afterRollback = new LinkedHashSet<>();

      Connection connection = connectionFactory.createConnection();
      Session session = connection.createSession(true, Session.AUTO_ACKNOWLEDGE);
      Destination destination = session.createQueue(destinationName);
      MessageConsumer consumer = session.createConsumer(destination);

      consumer.setMessageListener(new MessageListener() {
         @Override
         public void onMessage(Message message) {
            received.add(message);
         }
      });

      sendMessages();
      connection.start();

      assertTrue("Pre-Rollback expects to receive: " + MSG_COUNT + " messages.", Wait.waitFor(new Wait.Condition() {
         @Override
         public boolean isSatisified() throws Exception {
            LOG.info("Consumer has received " + received.size() + " messages.");
            return received.size() == MSG_COUNT;
         }
      }));

      beforeRollback.addAll(received);
      received.clear();
      session.rollback();

      sendMessages();

      assertTrue("Post-Rollback expects to receive: " + MSG_COUNT + " messages.", Wait.waitFor(new Wait.Condition() {
         @Override
         public boolean isSatisified() throws Exception {
            LOG.info("Consumer has received " + received.size() + " messages since rollback.");
            return received.size() == MSG_COUNT * 2;
         }
      }));

      afterRollback.addAll(received);
      received.clear();

      assertEquals(beforeRollback.size() * 2, afterRollback.size());

      session.commit();
   }

   @Test
   public void testNonBlockingMessageDeleiveryIsDelayed() throws Exception {
      final LinkedHashSet<Message> received = new LinkedHashSet<>();

      ActiveMQConnection connection = (ActiveMQConnection) connectionFactory.createConnection();
      connection.getRedeliveryPolicy().setInitialRedeliveryDelay(TimeUnit.SECONDS.toMillis(6));
      Session session = connection.createSession(true, Session.AUTO_ACKNOWLEDGE);
      Destination destination = session.createQueue(destinationName);
      MessageConsumer consumer = session.createConsumer(destination);

      consumer.setMessageListener(new MessageListener() {
         @Override
         public void onMessage(Message message) {
            received.add(message);
         }
      });

      sendMessages();
      connection.start();

      assertTrue("Pre-Rollback expects to receive: " + MSG_COUNT + " messages.", Wait.waitFor(new Wait.Condition() {
         @Override
         public boolean isSatisified() throws Exception {
            LOG.info("Consumer has received " + received.size() + " messages.");
            return received.size() == MSG_COUNT;
         }
      }));

      received.clear();
      session.rollback();

      assertFalse("Delayed redelivery test not expecting any messages yet.", Wait.waitFor(new Wait.Condition() {
         @Override
         public boolean isSatisified() throws Exception {
            return received.size() > 0;
         }
      }, TimeUnit.SECONDS.toMillis(4)));

      session.commit();
      session.close();
   }

   @Test
   public void testNonBlockingMessageDeleiveryWithRollbacks() throws Exception {
      final LinkedHashSet<Message> received = new LinkedHashSet<>();

      ActiveMQConnection connection = (ActiveMQConnection) connectionFactory.createConnection();
      final Session session = connection.createSession(true, Session.AUTO_ACKNOWLEDGE);
      final Destination destination = session.createQueue(destinationName);
      final MessageConsumer consumer = session.createConsumer(destination);

      consumer.setMessageListener(new MessageListener() {
         @Override
         public void onMessage(Message message) {
            received.add(message);
         }
      });

      sendMessages();
      connection.start();

      assertTrue("Pre-Rollback expects to receive: " + MSG_COUNT + " messages.", Wait.waitFor(new Wait.Condition() {
         @Override
         public boolean isSatisified() throws Exception {
            LOG.info("Consumer has received " + received.size() + " messages.");
            return received.size() == MSG_COUNT;
         }
      }));

      received.clear();

      consumer.setMessageListener(new MessageListener() {

         int count = 0;

         @Override
         public void onMessage(Message message) {

            if (++count > 10) {
               try {
                  session.rollback();
                  LOG.info("Rolling back session.");
                  count = 0;
               } catch (JMSException e) {
                  LOG.warn("Caught an unexpected exception: " + e.getMessage());
               }
            } else {
               received.add(message);
               try {
                  session.commit();
               } catch (JMSException e) {
                  LOG.warn("Caught an unexpected exception: " + e.getMessage());
               }
            }
         }
      });

      session.rollback();

      assertTrue("Post-Rollback expects to receive: " + MSG_COUNT + " messages.", Wait.waitFor(new Wait.Condition() {
         @Override
         public boolean isSatisified() throws Exception {
            LOG.info("Consumer has received " + received.size() + " messages since rollback.");
            return received.size() == MSG_COUNT;
         }
      }));

      assertEquals(MSG_COUNT, received.size());
      session.commit();
   }

   @Test
   public void testNonBlockingMessageDeleiveryWithAllRolledBack() throws Exception {
      final LinkedHashSet<Message> received = new LinkedHashSet<>();
      final LinkedHashSet<Message> dlqed = new LinkedHashSet<>();

      ActiveMQConnection connection = (ActiveMQConnection) connectionFactory.createConnection();
      connection.getRedeliveryPolicy().setMaximumRedeliveries(5);
      final Session session = connection.createSession(true, Session.AUTO_ACKNOWLEDGE);
      final Destination destination = session.createQueue(destinationName);
      final Destination dlq = session.createQueue("ActiveMQ.DLQ");
      final MessageConsumer consumer = session.createConsumer(destination);
      final MessageConsumer dlqConsumer = session.createConsumer(dlq);

      dlqConsumer.setMessageListener(new MessageListener() {
         @Override
         public void onMessage(Message message) {
            dlqed.add(message);
         }
      });

      consumer.setMessageListener(new MessageListener() {
         @Override
         public void onMessage(Message message) {
            received.add(message);
         }
      });

      sendMessages();
      connection.start();

      assertTrue("Pre-Rollback expects to receive: " + MSG_COUNT + " messages.", Wait.waitFor(new Wait.Condition() {
         @Override
         public boolean isSatisified() throws Exception {
            LOG.info("Consumer has received " + received.size() + " messages.");
            return received.size() == MSG_COUNT;
         }
      }));

      session.rollback();

      consumer.setMessageListener(new MessageListener() {
         @Override
         public void onMessage(Message message) {
            try {
               session.rollback();
            } catch (JMSException e) {
               LOG.warn("Caught an unexpected exception: " + e.getMessage());
            }
         }
      });

      assertTrue("Post-Rollback expects to DLQ: " + MSG_COUNT + " messages.", Wait.waitFor(new Wait.Condition() {
         @Override
         public boolean isSatisified() throws Exception {
            LOG.info("Consumer has received " + dlqed.size() + " messages in DLQ.");
            return dlqed.size() == MSG_COUNT;
         }
      }));

      session.commit();
   }

   private void sendMessages() throws Exception {
      Connection connection = connectionFactory.createConnection();
      Session session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
      Destination destination = session.createQueue(destinationName);
      MessageProducer producer = session.createProducer(destination);
      for (int i = 0; i < MSG_COUNT; ++i) {
         producer.send(session.createTextMessage("" + i));
      }
   }

   @Before
   public void startBroker() throws Exception {
      broker = new BrokerService();
      broker.setDeleteAllMessagesOnStartup(true);
      broker.setPersistent(false);
      broker.setUseJmx(false);
      broker.addConnector("tcp://0.0.0.0:0");
      broker.start();
      broker.waitUntilStarted();

      connectionUri = broker.getTransportConnectors().get(0).getPublishableConnectString();
      connectionFactory = new ActiveMQConnectionFactory(connectionUri);
      connectionFactory.setNonBlockingRedelivery(true);

      RedeliveryPolicy policy = connectionFactory.getRedeliveryPolicy();
      policy.setInitialRedeliveryDelay(TimeUnit.SECONDS.toMillis(2));
      policy.setBackOffMultiplier(-1);
      policy.setRedeliveryDelay(TimeUnit.SECONDS.toMillis(2));
      policy.setMaximumRedeliveryDelay(-1);
      policy.setUseExponentialBackOff(false);
      policy.setMaximumRedeliveries(-1);
   }

   @After
   public void stopBroker() throws Exception {
      broker.stop();
      broker.waitUntilStopped();
   }

}
