/*
 * JBoss, the OpenSource J2EE webOS
 *
 * Distributable under LGPL license.
 * See terms of license at gnu.org.
 */
package org.jboss.monitor;

import org.jboss.util.NestedRuntimeException;
import org.jboss.logging.Logger;
import org.jboss.system.ServiceMBeanSupport;

import java.util.List;

import javax.management.ObjectName;
import javax.management.MBeanServer;
import javax.management.MBeanRegistration;
import java.util.ArrayList;
import java.util.Date;
import java.util.LinkedList;

/**
 * Comment
 *
 * @author <a href="mailto:bill@jboss.org">Bill Burke</a>
 * @version $Revision: 1.2 $
 *
 **/
public class SnapshotRecordingMonitor implements Runnable, SnapshotRecordingMonitorMBean, MBeanRegistration
{
   protected Logger log;
   protected String monitorName;
   protected ObjectName observedObject;
   protected String attribute;
   protected boolean recording;
   protected long period;
   protected ArrayList history;
   protected long startTime;
   protected long endTime;
   protected MBeanServer mbeanServer;

   public SnapshotRecordingMonitor()
   {
      log = Logger.getLogger(monitorName);
      history = new ArrayList(100);
   }

   protected void startMonitorThread()
   {
      Thread t = new Thread(this, "JBoss JMX Attribute Snapshot " + monitorName);
      t.start();
   }

   public String getMonitorName()
   {
      return monitorName;
   }

   public void setMonitorName(String name)
   {
      monitorName = name;
   }

   public ObjectName getObservedObject()
   {
      return observedObject;
   }

   public void setObservedObject(ObjectName oname)
   {
      this.observedObject = oname;
   }

   public String getObservedAttribute()
   {
      return attribute;
   }

   public void setObservedAttribute(String attr)
   {
      attribute = attr;
   }

   public boolean isRecording() { return recording; }
   public void setRecording(boolean start)
   {
      if (start == recording) return;
      recording = start;

      if (start)
      {
         startMonitorThread();
      }
   }

   public long getPeriod()
   {
      return period;
   }

   public void setPeriod(long period)
   {
      this.period = period;
   }

   public ArrayList getData()
   {
      return history;
   }

   public void clearData()
   {
      history.clear();
   }

   public void startSnapshot()
   {
      history.clear();
      setRecording(true);
   }

   public void endSnapshot()
   {
      recording = false;
   }

   public long getStartTime()
   {
      return startTime;
   }

   public long getEndTime()
   {
      return endTime;
   }

   public void run()
   {
      startTime = System.currentTimeMillis();
      while (recording)
      {
         try
         {
            Object value = mbeanServer.getAttribute(observedObject, attribute);
            history.add(value);
            endTime = System.currentTimeMillis();
         }
         catch (Exception ex)
         {
            log.error(monitorName + " had error while monitoring", ex);
         }
         if (recording)
         {
            try
            {
               Thread.sleep(period);
            }
            catch (InterruptedException ignored)
            {
            }
         }
      }
   }

   // MBeanRegistrationImplementation overrides ---------------------

   public ObjectName preRegister(MBeanServer server, ObjectName objectName)
     throws Exception
   {
      mbeanServer = server;
      return objectName;
   }

   public void postRegister(Boolean registrationDone)
   {
   }

   public void preDeregister()
     throws Exception
   {
   }

   public void postDeregister()
   {
   }


}