/**
 * 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;

import javax.jms.ConnectionFactory;
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 java.io.IOException;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;

import org.apache.activemq.broker.BrokerService;
import org.apache.activemq.broker.TransportConnector;
import org.apache.activemq.broker.region.policy.PolicyEntry;
import org.apache.activemq.broker.region.policy.PolicyMap;
import org.apache.activemq.broker.region.policy.VMPendingQueueMessageStoragePolicy;
import org.apache.activemq.broker.region.policy.VMPendingSubscriberMessageStoragePolicy;
import org.apache.activemq.command.ActiveMQQueue;
import org.apache.activemq.transport.tcp.TcpTransport;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class ProducerFlowControlTest extends JmsTestSupport {

   static final Logger LOG = LoggerFactory.getLogger(ProducerFlowControlTest.class);
   ActiveMQQueue queueA = new ActiveMQQueue("QUEUE.A");
   ActiveMQQueue queueB = new ActiveMQQueue("QUEUE.B");
   protected TransportConnector connector;
   protected ActiveMQConnection connection;
   // used to test sendFailIfNoSpace on SystemUsage
   protected final AtomicBoolean gotResourceException = new AtomicBoolean(false);

   public void test2ndPublisherWithProducerWindowSendConnectionThatIsBlocked() throws Exception {
      ActiveMQConnectionFactory factory = (ActiveMQConnectionFactory) createConnectionFactory();
      factory.setProducerWindowSize(1024 * 64);
      connection = (ActiveMQConnection) factory.createConnection();
      connections.add(connection);
      connection.start();

      Session session = connection.createSession(false, Session.CLIENT_ACKNOWLEDGE);
      MessageConsumer consumer = session.createConsumer(queueB);

      // Test sending to Queue A
      // 1 few sends should not block until the producer window is used up.
      fillQueue(queueA);

      // Test sending to Queue B it should not block since the connection
      // should not be blocked.
      CountDownLatch pubishDoneToQeueuB = asyncSendTo(queueB, "Message 1");
      assertTrue(pubishDoneToQeueuB.await(2, TimeUnit.SECONDS));

      TextMessage msg = (TextMessage) consumer.receive();
      assertEquals("Message 1", msg.getText());
      msg.acknowledge();

      pubishDoneToQeueuB = asyncSendTo(queueB, "Message 2");
      assertTrue(pubishDoneToQeueuB.await(2, TimeUnit.SECONDS));

      msg = (TextMessage) consumer.receive();
      assertEquals("Message 2", msg.getText());
      msg.acknowledge();
   }

   public void testPublisherRecoverAfterBlock() throws Exception {
      ActiveMQConnectionFactory factory = (ActiveMQConnectionFactory) createConnectionFactory();
      connection = (ActiveMQConnection) factory.createConnection();
      connections.add(connection);
      connection.start();

      final Session session = connection.createSession(false, Session.CLIENT_ACKNOWLEDGE);
      final MessageProducer producer = session.createProducer(queueA);

      final AtomicBoolean done = new AtomicBoolean(true);
      final AtomicBoolean keepGoing = new AtomicBoolean(true);

      Thread thread = new Thread("Filler") {
         int i;

         @Override
         public void run() {
            while (keepGoing.get()) {
               done.set(false);
               try {
                  producer.send(session.createTextMessage("Test message " + ++i));
                  LOG.info("sent: " + i);
               } catch (JMSException e) {
               }
            }
         }
      };
      thread.start();
      waitForBlockedOrResourceLimit(done);

      // after receiveing messges, producer should continue sending messages
      // (done == false)
      MessageConsumer consumer = session.createConsumer(queueA);
      TextMessage msg;
      for (int idx = 0; idx < 5; ++idx) {
         msg = (TextMessage) consumer.receive(1000);
         LOG.info("received: " + idx + ", msg: " + msg.getJMSMessageID());
         msg.acknowledge();
      }
      Thread.sleep(1000);
      keepGoing.set(false);

      assertFalse("producer has resumed", done.get());
   }

   public void testAsyncPublisherRecoverAfterBlock() throws Exception {
      ActiveMQConnectionFactory factory = (ActiveMQConnectionFactory) createConnectionFactory();
      factory.setProducerWindowSize(1024 * 5);
      factory.setUseAsyncSend(true);
      connection = (ActiveMQConnection) factory.createConnection();
      connections.add(connection);
      connection.start();

      final Session session = connection.createSession(false, Session.CLIENT_ACKNOWLEDGE);
      final MessageProducer producer = session.createProducer(queueA);

      final AtomicBoolean done = new AtomicBoolean(true);
      final AtomicBoolean keepGoing = new AtomicBoolean(true);

      Thread thread = new Thread("Filler") {
         int i;

         @Override
         public void run() {
            while (keepGoing.get()) {
               done.set(false);
               try {
                  producer.send(session.createTextMessage("Test message " + ++i));
                  LOG.info("sent: " + i);
               } catch (JMSException e) {
               }
            }
         }
      };
      thread.start();
      waitForBlockedOrResourceLimit(done);

      // after receiveing messges, producer should continue sending messages
      // (done == false)
      MessageConsumer consumer = session.createConsumer(queueA);
      TextMessage msg;
      for (int idx = 0; idx < 5; ++idx) {
         msg = (TextMessage) consumer.receive(1000);
         assertNotNull("Got a message", msg);
         LOG.info("received: " + idx + ", msg: " + msg.getJMSMessageID());
         msg.acknowledge();
      }
      Thread.sleep(1000);
      keepGoing.set(false);

      assertFalse("producer has resumed", done.get());
   }

   public void test2ndPublisherWithSyncSendConnectionThatIsBlocked() throws Exception {
      ActiveMQConnectionFactory factory = (ActiveMQConnectionFactory) createConnectionFactory();
      factory.setAlwaysSyncSend(true);
      connection = (ActiveMQConnection) factory.createConnection();
      connections.add(connection);
      connection.start();

      Session session = connection.createSession(false, Session.CLIENT_ACKNOWLEDGE);
      MessageConsumer consumer = session.createConsumer(queueB);

      // Test sending to Queue A
      // 1st send should not block. But the rest will.
      fillQueue(queueA);

      // Test sending to Queue B it should not block.
      CountDownLatch pubishDoneToQeueuB = asyncSendTo(queueB, "Message 1");
      assertTrue(pubishDoneToQeueuB.await(2, TimeUnit.SECONDS));

      TextMessage msg = (TextMessage) consumer.receive();
      assertEquals("Message 1", msg.getText());
      msg.acknowledge();

      pubishDoneToQeueuB = asyncSendTo(queueB, "Message 2");
      assertTrue(pubishDoneToQeueuB.await(2, TimeUnit.SECONDS));

      msg = (TextMessage) consumer.receive();
      assertEquals("Message 2", msg.getText());
      msg.acknowledge();
   }

   public void testSimpleSendReceive() throws Exception {
      ActiveMQConnectionFactory factory = (ActiveMQConnectionFactory) createConnectionFactory();
      factory.setAlwaysSyncSend(true);
      connection = (ActiveMQConnection) factory.createConnection();
      connections.add(connection);
      connection.start();

      Session session = connection.createSession(false, Session.CLIENT_ACKNOWLEDGE);
      MessageConsumer consumer = session.createConsumer(queueA);

      // Test sending to Queue B it should not block.
      CountDownLatch pubishDoneToQeueuA = asyncSendTo(queueA, "Message 1");
      assertTrue(pubishDoneToQeueuA.await(2, TimeUnit.SECONDS));

      TextMessage msg = (TextMessage) consumer.receive();
      assertEquals("Message 1", msg.getText());
      msg.acknowledge();

      pubishDoneToQeueuA = asyncSendTo(queueA, "Message 2");
      assertTrue(pubishDoneToQeueuA.await(2, TimeUnit.SECONDS));

      msg = (TextMessage) consumer.receive();
      assertEquals("Message 2", msg.getText());
      msg.acknowledge();
   }

   public void test2ndPublisherWithStandardConnectionThatIsBlocked() throws Exception {
      ConnectionFactory factory = createConnectionFactory();
      connection = (ActiveMQConnection) factory.createConnection();
      connections.add(connection);
      connection.start();

      // Test sending to Queue A
      // 1st send should not block.
      fillQueue(queueA);

      // Test sending to Queue B it should block.
      // Since even though the it's queue limits have not been reached, the
      // connection
      // is blocked.
      CountDownLatch pubishDoneToQeueuB = asyncSendTo(queueB, "Message 1");
      assertFalse(pubishDoneToQeueuB.await(2, TimeUnit.SECONDS));
   }

   private void fillQueue(final ActiveMQQueue queue) throws JMSException, InterruptedException {
      final AtomicBoolean done = new AtomicBoolean(true);
      final AtomicBoolean keepGoing = new AtomicBoolean(true);

      // Starts an async thread that every time it publishes it sets the done
      // flag to false.
      // Once the send starts to block it will not reset the done flag
      // anymore.
      new Thread("Fill thread.") {
         @Override
         public void run() {
            Session session = null;
            try {
               session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
               MessageProducer producer = session.createProducer(queue);
               producer.setDeliveryMode(DeliveryMode.NON_PERSISTENT);
               while (keepGoing.get()) {
                  done.set(false);
                  producer.send(session.createTextMessage("Hello World"));
               }
            } catch (JMSException e) {
            } finally {
               safeClose(session);
            }
         }
      }.start();

      waitForBlockedOrResourceLimit(done);
      keepGoing.set(false);
   }

   protected void waitForBlockedOrResourceLimit(final AtomicBoolean done) throws InterruptedException {
      while (true) {
         Thread.sleep(1000);
         // the producer is blocked once the done flag stays true or there is a resource exception
         if (done.get() || gotResourceException.get()) {
            break;
         }
         done.set(true);
      }
   }

   private CountDownLatch asyncSendTo(final ActiveMQQueue queue, final String message) throws JMSException {
      final CountDownLatch done = new CountDownLatch(1);
      new Thread("Send thread.") {
         @Override
         public void run() {
            Session session = null;
            try {
               session = connection.createSession(false, Session.AUTO_ACKNOWLEDGE);
               MessageProducer producer = session.createProducer(queue);
               producer.setDeliveryMode(DeliveryMode.NON_PERSISTENT);
               producer.send(session.createTextMessage(message));
               done.countDown();
            } catch (JMSException e) {
            } finally {
               safeClose(session);
            }
         }
      }.start();
      return done;
   }

   @Override
   protected BrokerService createBroker() throws Exception {
      BrokerService service = new BrokerService();
      service.setPersistent(false);
      service.setUseJmx(false);

      // Setup a destination policy where it takes only 1 message at a time.
      PolicyMap policyMap = new PolicyMap();
      PolicyEntry policy = new PolicyEntry();
      policy.setMemoryLimit(1);
      policy.setPendingSubscriberPolicy(new VMPendingSubscriberMessageStoragePolicy());
      policy.setPendingQueuePolicy(new VMPendingQueueMessageStoragePolicy());
      policy.setProducerFlowControl(true);
      policyMap.setDefaultEntry(policy);
      service.setDestinationPolicy(policyMap);

      connector = service.addConnector("tcp://localhost:0");
      return service;
   }

   @Override
   public void setUp() throws Exception {
      setAutoFail(true);
      super.setUp();
   }

   @Override
   protected void tearDown() throws Exception {
      if (connection != null) {
         TcpTransport t = connection.getTransport().narrow(TcpTransport.class);
         t.getTransportListener().onException(new IOException("Disposed."));
         connection.getTransport().stop();
      }
      super.tearDown();
   }

   @Override
   protected ConnectionFactory createConnectionFactory() throws Exception {
      return new ActiveMQConnectionFactory(connector.getConnectUri());
   }
}
