/**
 * 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.assertEquals;

import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;

import javax.jms.ConnectionConsumer;
import javax.jms.JMSException;
import javax.jms.Message;
import javax.jms.MessageListener;
import javax.jms.ServerSession;
import javax.jms.ServerSessionPool;
import javax.jms.Session;
import javax.jms.TopicConnection;
import javax.jms.TopicPublisher;
import javax.jms.TopicSession;
import javax.jms.TopicSubscriber;

import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.activemq.broker.BrokerService;
import org.apache.activemq.command.ActiveMQTopic;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

public class AMQ3961Test {

   private static BrokerService brokerService;
   private static String BROKER_ADDRESS = "tcp://localhost:0";

   private ActiveMQConnectionFactory connectionFactory;
   private String connectionUri;

   @Before
   public void setUp() throws Exception {
      brokerService = new BrokerService();
      brokerService.setPersistent(false);
      brokerService.setUseJmx(true);
      brokerService.setDeleteAllMessagesOnStartup(true);
      connectionUri = brokerService.addConnector(BROKER_ADDRESS).getPublishableConnectString();
      brokerService.start();
      brokerService.waitUntilStarted();

      connectionFactory = new ActiveMQConnectionFactory(connectionUri);
   }

   @After
   public void tearDown() throws Exception {
      brokerService.stop();
      brokerService.waitUntilStopped();
   }

   public class TestServerSessionPool implements ServerSessionPool {

      private final TopicConnection connection;

      public TestServerSessionPool(final TopicConnection connection) {
         this.connection = connection;
      }

      @Override
      public ServerSession getServerSession() throws JMSException {
         final TopicSession topicSession = connection.createTopicSession(true, Session.AUTO_ACKNOWLEDGE);
         return new TestServerSession(topicSession);
      }
   }

   public class TestServerSession implements ServerSession, MessageListener {

      private final TopicSession session;

      public TestServerSession(final TopicSession session) throws JMSException {
         this.session = session;
         session.setMessageListener(this);
      }

      @Override
      public Session getSession() throws JMSException {
         return session;
      }

      @Override
      public void start() throws JMSException {
         session.run();
      }

      @Override
      public void onMessage(final Message message) {
         synchronized (processedSessions) {
            processedSessions.add(this);
         }
      }
   }

   public static final int MESSAGE_COUNT = 16;
   private final List<TestServerSession> processedSessions = new LinkedList<TestServerSession>();
   private final List<TestServerSession> committedSessions = new LinkedList<TestServerSession>();

   @Test
   public void testPrefetchInDurableSubscription() throws Exception {
      final ActiveMQTopic topic = new ActiveMQTopic("TestTopic");

      final TopicConnection initialSubConnection = connectionFactory.createTopicConnection();
      initialSubConnection.setClientID("TestClient");
      initialSubConnection.start();
      final TopicSession initialSubSession = initialSubConnection.createTopicSession(false, Session.CLIENT_ACKNOWLEDGE);
      final TopicSubscriber initialSubscriber = initialSubSession.createDurableSubscriber(topic, "TestSubscriber");

      initialSubscriber.close();
      initialSubSession.close();
      initialSubConnection.close();

      final TopicConnection publisherConnection = connectionFactory.createTopicConnection();
      publisherConnection.start();
      final TopicSession publisherSession = publisherConnection.createTopicSession(false, Session.AUTO_ACKNOWLEDGE);
      final TopicPublisher publisher = publisherSession.createPublisher(topic);
      for (int i = 1; i <= MESSAGE_COUNT; i++) {
         final Message msg = publisherSession.createTextMessage("Message #" + i);
         publisher.publish(msg);
      }
      publisher.close();
      publisherSession.close();
      publisherConnection.close();

      final TopicConnection connection = connectionFactory.createTopicConnection();
      connection.setClientID("TestClient");
      connection.start();
      final TestServerSessionPool pool = new TestServerSessionPool(connection);
      final ConnectionConsumer connectionConsumer = connection.createDurableConnectionConsumer(topic, "TestSubscriber", null, pool, 1);
      while (true) {
         int lastMsgCount = 0;
         int msgCount = 0;
         do {
            lastMsgCount = msgCount;
            Thread.sleep(200L);
            synchronized (processedSessions) {
               msgCount = processedSessions.size();
            }
         } while (lastMsgCount < msgCount);

         if (lastMsgCount == 0) {
            break;
         }

         final LinkedList<TestServerSession> collected;
         synchronized (processedSessions) {
            collected = new LinkedList<TestServerSession>(processedSessions);
            processedSessions.clear();
         }

         final Iterator<TestServerSession> sessions = collected.iterator();
         while (sessions.hasNext()) {
            final TestServerSession session = sessions.next();
            committedSessions.add(session);
            session.getSession().commit();
            session.getSession().close();
         }
      }

      connectionConsumer.close();
      final TopicSession finalSession = connection.createTopicSession(false, Session.AUTO_ACKNOWLEDGE);
      finalSession.unsubscribe("TestSubscriber");
      finalSession.close();
      connection.close();
      assertEquals(MESSAGE_COUNT, committedSessions.size());
   }
}
