/**
 * 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.bugs;

import static org.junit.Assert.assertTrue;

import java.io.File;
import java.util.Random;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import javax.jms.DeliveryMode;
import javax.jms.JMSException;
import javax.jms.MessageConsumer;
import javax.jms.MessageProducer;
import javax.jms.Session;
import javax.jms.TextMessage;

import org.apache.activemq.ActiveMQConnection;
import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.activemq.broker.Broker;
import org.apache.activemq.broker.BrokerService;
import org.apache.activemq.broker.region.policy.PolicyEntry;
import org.apache.activemq.broker.region.policy.PolicyMap;
import org.apache.activemq.broker.region.policy.SharedDeadLetterStrategy;
import org.apache.activemq.command.ActiveMQQueue;
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;

public class MemoryUsageCleanupTest {

   private static final Logger LOG = LoggerFactory.getLogger(MemoryUsageCleanupTest.class);
   private static final String QUEUE_NAME = MemoryUsageCleanupTest.class.getName() + "Queue";

   private final String str = new String("QAa0bcLdUK2eHfJgTP8XhiFj61DOklNm9nBoI5pGqYVrs3CtSuMZvwWx4yE7zR");

   private BrokerService broker;
   private String connectionUri;
   private ExecutorService pool;
   private String queueName;
   private Random r = new Random();

   @Before
   public void setUp() throws Exception {

      broker = new BrokerService();
      broker.setDataDirectory("target" + File.separator + "activemq-data");
      broker.setPersistent(true);
      broker.setUseJmx(true);
      broker.setDedicatedTaskRunner(false);
      broker.setAdvisorySupport(false);
      broker.setDeleteAllMessagesOnStartup(true);

      SharedDeadLetterStrategy strategy = new SharedDeadLetterStrategy();
      strategy.setProcessExpired(false);
      strategy.setProcessNonPersistent(false);

      PolicyEntry defaultPolicy = new PolicyEntry();
      defaultPolicy.setQueue(">");
      defaultPolicy.setOptimizedDispatch(true);
      defaultPolicy.setDeadLetterStrategy(strategy);
      defaultPolicy.setMemoryLimit(300000000);

      PolicyMap policyMap = new PolicyMap();
      policyMap.setDefaultEntry(defaultPolicy);

      broker.setDestinationPolicy(policyMap);

      broker.getSystemUsage().getMemoryUsage().setLimit(300000000L);

      broker.addConnector("tcp://localhost:0").setName("Default");
      broker.start();
      broker.waitUntilStarted();

      connectionUri = broker.getTransportConnectors().get(0).getPublishableConnectString();
      pool = Executors.newFixedThreadPool(10);
   }

   @After
   public void tearDown() throws Exception {
      if (broker != null) {
         broker.stop();
         broker.waitUntilStopped();
      }

      if (pool != null) {
         pool.shutdown();
      }
   }

   @Test
   public void testIt() throws Exception {

      final int startPercentage = broker.getAdminView().getMemoryPercentUsage();
      LOG.info("MemoryUsage at test start = " + startPercentage);

      for (int i = 0; i < 2; i++) {
         LOG.info("Started the test iteration: " + i + " using queueName = " + queueName);
         queueName = QUEUE_NAME + i;
         final CountDownLatch latch = new CountDownLatch(11);

         pool.execute(new Runnable() {
            @Override
            public void run() {
               receiveAndDiscard100messages(latch);
            }
         });

         for (int j = 0; j < 10; j++) {
            pool.execute(new Runnable() {
               @Override
               public void run() {
                  send10000messages(latch);
               }
            });
         }

         LOG.info("Waiting on the send / receive latch");
         latch.await(5, TimeUnit.MINUTES);
         LOG.info("Resumed");

         destroyQueue();
         TimeUnit.SECONDS.sleep(2);
      }

      LOG.info("MemoryUsage before awaiting temp store cleanup = " + broker.getAdminView().getMemoryPercentUsage());

      assertTrue("MemoryUsage should return to: " + startPercentage +
                    "% but was " + broker.getAdminView().getMemoryPercentUsage() + "%", Wait.waitFor(new Wait.Condition() {

         @Override
         public boolean isSatisified() throws Exception {
            return broker.getAdminView().getMemoryPercentUsage() <= startPercentage + 1;
         }
      }));

      int endPercentage = broker.getAdminView().getMemoryPercentUsage();
      LOG.info("MemoryUsage at test end = " + endPercentage);
   }

   public void destroyQueue() {
      try {
         Broker broker = this.broker.getBroker();
         if (!broker.isStopped()) {
            LOG.info("Removing: " + queueName);
            broker.removeDestination(this.broker.getAdminConnectionContext(), new ActiveMQQueue(queueName), 10);
         }
      }
      catch (Exception e) {
         LOG.warn("Got an error while removing the test queue", e);
      }
   }

   private void send10000messages(CountDownLatch latch) {
      ActiveMQConnection activeMQConnection = null;
      try {
         activeMQConnection = createConnection(null);
         Session session = activeMQConnection.createSession(false, Session.AUTO_ACKNOWLEDGE);
         MessageProducer producer = session.createProducer(session.createQueue(queueName));
         producer.setDeliveryMode(DeliveryMode.NON_PERSISTENT);
         activeMQConnection.start();
         for (int i = 0; i < 10000; i++) {
            TextMessage textMessage = session.createTextMessage();
            textMessage.setText(generateBody(1000));
            textMessage.setJMSDeliveryMode(DeliveryMode.NON_PERSISTENT);
            producer.send(textMessage);
            try {
               Thread.sleep(10);
            }
            catch (InterruptedException e) {
            }
         }
         producer.close();
      }
      catch (JMSException e) {
         LOG.warn("Got an error while sending the messages", e);
      }
      finally {
         if (activeMQConnection != null) {
            try {
               activeMQConnection.close();
            }
            catch (JMSException e) {
            }
         }
      }
      latch.countDown();
   }

   private void receiveAndDiscard100messages(CountDownLatch latch) {
      ActiveMQConnection activeMQConnection = null;
      try {
         activeMQConnection = createConnection(null);
         Session session = activeMQConnection.createSession(false, Session.AUTO_ACKNOWLEDGE);
         MessageConsumer messageConsumer = session.createConsumer(session.createQueue(queueName));
         activeMQConnection.start();
         for (int i = 0; i < 100; i++) {
            messageConsumer.receive();
         }
         messageConsumer.close();
         LOG.info("Created and disconnected");
      }
      catch (JMSException e) {
         LOG.warn("Got an error while receiving the messages", e);
      }
      finally {
         if (activeMQConnection != null) {
            try {
               activeMQConnection.close();
            }
            catch (JMSException e) {
            }
         }
      }
      latch.countDown();
   }

   private ActiveMQConnection createConnection(String id) throws JMSException {
      ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory(connectionUri);
      if (id != null) {
         factory.setClientID(id);
      }

      ActiveMQConnection connection = (ActiveMQConnection) factory.createConnection();
      return connection;
   }

   private String generateBody(int length) {

      StringBuilder sb = new StringBuilder();
      int te = 0;
      for (int i = 1; i <= length; i++) {
         te = r.nextInt(62);
         sb.append(str.charAt(te));
      }
      return sb.toString();
   }
}
