/**
 * 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.BytesMessage;
import javax.jms.Connection;
import javax.jms.DeliveryMode;
import javax.jms.Destination;
import javax.jms.JMSException;
import javax.jms.MessageProducer;
import javax.jms.ResourceAllocationException;
import javax.jms.Session;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.activemq.broker.BrokerService;
import org.apache.activemq.broker.region.policy.FilePendingQueueMessageStoragePolicy;
import org.apache.activemq.broker.region.policy.PolicyEntry;
import org.apache.activemq.broker.region.policy.PolicyMap;
import org.apache.activemq.util.Wait;
import org.junit.Before;
import org.junit.Test;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import static org.junit.Assert.assertTrue;

public class UnlimitedEnqueueTest {

   private static final Logger LOG = LoggerFactory.getLogger(UnlimitedEnqueueTest.class);
   BrokerService brokerService = null;
   final long numMessages = 5000;
   final long numThreads = 10;
   final int payLoadSize = 100 * 1024;

   @Test
   public void testEnqueueIsOnlyLimitedByDisk() throws Exception {
      ExecutorService executor = Executors.newCachedThreadPool();
      for (int i = 0; i < numThreads; i++) {
         executor.execute(new Producer(numMessages / numThreads));
      }

      assertTrue("Temp Store is filling ", Wait.waitFor(new Wait.Condition() {
         @Override
         public boolean isSatisified() throws Exception {
            LOG.info("Temp Usage,  " + brokerService.getSystemUsage().getTempUsage() + ", full=" + brokerService.getSystemUsage().getTempUsage().isFull() + ", % usage: " + brokerService.getSystemUsage().getTempUsage().getPercentUsage());
            return brokerService.getSystemUsage().getTempUsage().getPercentUsage() > 1;
         }
      }, TimeUnit.MINUTES.toMillis(4)));
      executor.shutdownNow();
   }

   @Before
   public void createBrokerService() throws Exception {
      brokerService = new BrokerService();
      brokerService.setDeleteAllMessagesOnStartup(true);
      brokerService.setAdvisorySupport(false);

      // optional, reduce the usage limit so that spooling will occur faster
      brokerService.getSystemUsage().getMemoryUsage().setLimit(10 * 1024 * 1024);
      brokerService.getSystemUsage().getTempUsage().setLimit((numMessages * payLoadSize) + (1000 * payLoadSize));

      PolicyMap policyMap = new PolicyMap();
      List<PolicyEntry> entries = new ArrayList<>();
      PolicyEntry policy = new PolicyEntry();

      // NB: ensure queue cursor limit is below the default 70% usage that the destination will use
      // if they are the same, the queue memory limit and flow control will kick in first
      policy.setCursorMemoryHighWaterMark(20);

      // on by default
      //policy.setProducerFlowControl(true);
      policy.setQueue(">");

      // policy that will spool references to disk
      policy.setPendingQueuePolicy(new FilePendingQueueMessageStoragePolicy());
      entries.add(policy);
      policyMap.setPolicyEntries(entries);
      brokerService.setDestinationPolicy(policyMap);

      brokerService.start();
   }

   public class Producer implements Runnable {

      private final long numberOfMessages;

      public Producer(final long n) {
         this.numberOfMessages = n;
      }

      @Override
      public void run() {
         ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory(brokerService.getVmConnectorURI());
         try {
            Connection conn = factory.createConnection();
            conn.start();
            byte[] bytes = new byte[payLoadSize];
            for (int i = 0; i < numberOfMessages; i++) {
               Session session = conn.createSession(false, Session.AUTO_ACKNOWLEDGE);
               Destination destination = session.createQueue("test-queue");
               MessageProducer producer = session.createProducer(destination);
               producer.setDeliveryMode(DeliveryMode.PERSISTENT);
               BytesMessage message = session.createBytesMessage();
               message.writeBytes(bytes);
               try {
                  producer.send(message);
               } catch (ResourceAllocationException e) {
                  e.printStackTrace();
               }
               session.close();
            }
         } catch (JMSException e) {
            // expect interrupted exception on shutdownNow
         }
      }
   }
}
