package cz.cuni.amis.pogamut.base.utils.jmx.flag;
   
   import java.io.Serializable;
   
   import javax.management.InstanceAlreadyExistsException;
   import javax.management.ListenerNotFoundException;
   import javax.management.MBeanNotificationInfo;
   import javax.management.MBeanRegistrationException;
   import javax.management.MBeanServer;
  import javax.management.MalformedObjectNameException;
  import javax.management.NotCompliantMBeanException;
  import javax.management.Notification;
  import javax.management.NotificationBroadcasterSupport;
  import javax.management.NotificationEmitter;
  import javax.management.NotificationFilter;
  import javax.management.NotificationListener;
  import javax.management.ObjectName;
  
  import cz.cuni.amis.pogamut.base.utils.jmx.PogamutJMX;
  import cz.cuni.amis.utils.flag.Flag;
  import cz.cuni.amis.utils.flag.FlagListener;
  
  /**
   * Translates Flag events to JMX events. Adds a listener on the flag and resends 
   * the events to supplied broadcaster support.
   * @author Ik
   */
  public class JMXFlagDecorator<T extends Serializable> implements JMXFlagDecoratorMBean, NotificationEmitter {
  
      protected Flag<T> flag = null;
      protected ObjectName source;
      protected int eventCounter = 0;
      protected String flagName = null;
  
      protected FlagListener<T> listener = new FlagListener<T>() {
  
          @Override
          public void flagChanged(T changedValue) {
              Notification notification = new Notification(
                      flagName,
                      source,
                      eventCounter++,
                      changedValue.toString());
              notification.setUserData(flag.getFlag());
              nbs.sendNotification(notification);
          }
      };
  
      /**
       * 
       * @param flag Flag to be exposed through JMX.
       * @param source MBean or ObjectName of the object where the flag resides.
       * @param nbs NotificationBroadcasterSupport through which the events will be send.
       */
      public JMXFlagDecorator(Flag<T> flag, ObjectName source, MBeanServer mbs, String flagName) throws MalformedObjectNameException, InstanceAlreadyExistsException, MBeanRegistrationException, NotCompliantMBeanException {
          this.flag = flag;
          this.source = source;
          this.flagName = flagName;
          ObjectName name = PogamutJMX.getObjectName(source, flagName, PogamutJMX.FLAGS_SUBTYPE);
          mbs.registerMBean(this, name);
          flag.addListener(listener);
      }
  
      /**
       * Stops listening for the flag events.
       */
      public void stop() {
          flag.removeListener(listener);
      }
  
      /**
       * 
       * @return Notification info about this events possibly raised by this flag.
       */
      public MBeanNotificationInfo getMBeanNotificationInfo() {
          return new MBeanNotificationInfo(new String[]{flagName},
                  Notification.class.getName(), "The flag has changed it's value.");
      }
  
      @Override
      public Serializable getFlag() {
          return flag.getFlag();
      }
  
      
          /**
       * Support object for sending notifications.
       */
      protected NotificationBroadcasterSupport nbs = new NotificationBroadcasterSupport();
      @Override
      public void removeNotificationListener(NotificationListener listener, NotificationFilter filter, Object handback) throws ListenerNotFoundException {
          nbs.removeNotificationListener(listener, filter, handback);
      }
  
      @Override
      public void addNotificationListener(NotificationListener listener, NotificationFilter filter, Object handback) throws IllegalArgumentException {
          nbs.addNotificationListener(listener, filter, handback);
      }
  
     @Override
     public void removeNotificationListener(NotificationListener listener) throws ListenerNotFoundException {
         nbs.removeNotificationListener(listener);
     }
 
     @Override
     public MBeanNotificationInfo[] getNotificationInfo() {
         return new MBeanNotificationInfo[]{
                     getMBeanNotificationInfo()
                 };
     }
 }