/**
 * 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 junit.framework.TestCase;

import org.apache.activemq.ActiveMQConnectionFactory;
import org.apache.activemq.broker.BrokerService;
import org.apache.activemq.store.kahadb.KahaDBStore;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.jms.Connection;
import java.io.File;
import java.text.DateFormat;
import java.util.Date;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicLong;

public class VerifySteadyEnqueueRate extends TestCase {

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

   private static int max_messages = 1000000;
   private final String destinationName = getName() + "_Queue";
   private BrokerService broker;
   final boolean useTopic = false;

   protected static final String payload = new String(new byte[24]);

   @Override
   public void setUp() throws Exception {
      startBroker();
   }

   @Override
   public void tearDown() throws Exception {
      broker.stop();
   }

   @SuppressWarnings("unused")
   public void testEnqueueRateCanMeetSLA() throws Exception {
      if (true) {
         return;
      }
      doTestEnqueue(false);
   }

   private void doTestEnqueue(final boolean transacted) throws Exception {
      final long min = 100;
      final AtomicLong total = new AtomicLong(0);
      final AtomicLong slaViolations = new AtomicLong(0);
      final AtomicLong max = new AtomicLong(0);
      final int numThreads = 6;

      Runnable runner = new Runnable() {

         @Override
         public void run() {
            try {
               MessageSender producer = new MessageSender(destinationName, createConnection(), transacted, useTopic);

               for (int i = 0; i < max_messages; i++) {
                  long startT = System.currentTimeMillis();
                  producer.send(payload);
                  long endT = System.currentTimeMillis();
                  long duration = endT - startT;

                  total.incrementAndGet();

                  if (duration > max.get()) {
                     max.set(duration);
                  }

                  if (duration > min) {
                     slaViolations.incrementAndGet();
                     System.err.println("SLA violation @ " + Thread.currentThread().getName() + " " + DateFormat.getTimeInstance().format(new Date(startT)) + " at message " + i + " send time=" + duration + " - Total SLA violations: " + slaViolations.get() + "/" + total.get() + " (" + String.format("%.6f", 100.0 * slaViolations.get() / total.get()) + "%)");
                  }
               }

            }
            catch (Exception e) {
               // TODO Auto-generated catch block
               e.printStackTrace();
            }
            System.out.println("Max Violation = " + max + " - Total SLA violations: " + slaViolations.get() + "/" + total.get() + " (" + String.format("%.6f", 100.0 * slaViolations.get() / total.get()) + "%)");
         }
      };
      ExecutorService executor = Executors.newCachedThreadPool();

      for (int i = 0; i < numThreads; i++) {
         executor.execute(runner);
      }

      executor.shutdown();
      while (!executor.isTerminated()) {
         executor.awaitTermination(10, TimeUnit.SECONDS);
      }
   }

   private Connection createConnection() throws Exception {
      ActiveMQConnectionFactory factory = new ActiveMQConnectionFactory(broker.getTransportConnectors().get(0).getConnectUri());
      return factory.createConnection();
   }

   private void startBroker() throws Exception {
      broker = new BrokerService();
      //broker.setDeleteAllMessagesOnStartup(true);
      broker.setPersistent(true);
      broker.setUseJmx(true);

      KahaDBStore kaha = new KahaDBStore();
      kaha.setDirectory(new File("target/activemq-data/kahadb"));
      // The setEnableJournalDiskSyncs(false) setting is a little dangerous right now, as I have not verified
      // what happens if the index is updated but a journal update is lost.
      // Index is going to be in consistent, but can it be repaired?
      kaha.setEnableJournalDiskSyncs(false);
      // Using a bigger journal file size makes he take fewer spikes as it is not switching files as often.
      kaha.setJournalMaxFileLength(1024 * 1024 * 100);

      // small batch means more frequent and smaller writes
      kaha.setIndexWriteBatchSize(100);
      // do the index write in a separate thread
      kaha.setEnableIndexWriteAsync(true);

      broker.setPersistenceAdapter(kaha);

      broker.addConnector("tcp://localhost:0").setName("Default");
      broker.start();
      LOG.info("Starting broker..");
   }
}
