/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2006, Red Hat Middleware LLC, and individual contributors
 * as indicated by the @author tags. See the copyright.txt file in the
 * distribution for a full listing of individual contributors.
 *
 * This is free software; you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This software is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */
package javax.management.relation;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.io.ObjectStreamField;
import java.io.StreamCorruptedException;
import java.util.HashSet;
import java.util.List;
import java.util.Vector;

import javax.management.MBeanServerNotification;
import javax.management.Notification;
import javax.management.NotificationFilterSupport;
import javax.management.ObjectName;

import org.jboss.mx.util.Serialization;

/**
 * A helper class, used to filter notifications of registration,
 * unregistration of selected object names.
 * 
 * @author  <a href="mailto:Adrian.Brock@HappeningTimes.com">Adrian Brock</a>.
 * @version $Revision: 57200 $
 *
 * <p><b>Revisions:</b>
 * <p><b>20020711 Adrian Brock:</b>
 * <ul>
 * <li> Serialization </li>
 * </ul>
 */
public class MBeanServerNotificationFilter
   extends NotificationFilterSupport
{
   // Constants ---------------------------------------------------

   // Attributes --------------------------------------------------

   /**
    * Enabled Object Names.
    */
   private HashSet enabled = new HashSet();

   /**
    * Disable Object Names.
    */
   private HashSet disabled = null;

   // Static ------------------------------------------------------

   private static final long serialVersionUID;
   private static final ObjectStreamField[] serialPersistentFields;

   static
   {
      switch (Serialization.version)
      {
         case Serialization.V1R0:
            serialVersionUID = 6001782699077323605L;
            serialPersistentFields = new ObjectStreamField[]
            {
               new ObjectStreamField("myDeselectObjNameList", Vector.class),
               new ObjectStreamField("mySelectObjNameList", Vector.class),
            };
            break;
         default:
            serialVersionUID = 2605900539589789736L;
            serialPersistentFields = new ObjectStreamField[]
            {
               new ObjectStreamField("deselectedNames", List.class),
               new ObjectStreamField("selectedNames", List.class)
            };
      }
   }

   // Constructors ------------------------------------------------

   /**
    * Create a filter selecting nothing by default<p>
    *
    * WARNING!! WARNING!! The spec says the MBeanServerNotificationFilter
    * accepts everything by default. The RI does exactly the opposite.
    * I follow the RI.
    */
   public MBeanServerNotificationFilter()
   {
   }

   // Public ------------------------------------------------------

   /**
    * Disable all object names. Rejects all notifications.
    */
   public synchronized void disableAllObjectNames()
   {
      enabled = new HashSet();
      disabled = null;
   }

   /**
    * Disable an object name.
    *
    * @param objectName the object name to disable.
    * @exception IllegalArgumentException for a null object name
    */
   public synchronized void disableObjectName(ObjectName objectName)
      throws IllegalArgumentException
   {
      if (objectName == null)
         throw new IllegalArgumentException("null object name");
      if (enabled != null)
         enabled.remove(objectName);
      if (disabled != null && disabled.contains(objectName) == false)
         disabled.add(objectName);
   }

   /**
    * Enable all object names. Accepts all notifications.
    */
   public synchronized void enableAllObjectNames()
   {
      enabled = null;
      disabled = new HashSet();
   }

   /**
    * Enable an object name.
    *
    * @param objectName the object name to enable.
    * @exception IllegalArgumentException for a null object name
    */
   public synchronized void enableObjectName(ObjectName objectName)
      throws IllegalArgumentException
   {
      if (objectName == null)
         throw new IllegalArgumentException("null object name");
      if (disabled != null)
         disabled.remove(objectName);
      if (enabled != null && enabled.contains(objectName) == false)
         enabled.add(objectName);
   }

   /**
    * Get all the disabled object names.<p>
    *
    * Returns a vector of disabled object names.<br>
    * Null for all object names disabled.
    * An empty vector means all object names enabled.
    *
    * @return the vector of disabled object names.
    */
   public synchronized Vector getDisabledObjectNames()
   {
      if (disabled == null)
         return null;
      return new Vector(disabled);
   }

   /**
    * Get all the enabled object names.<p>
    *
    * Returns a vector of enabled object names.<br>
    * Null for all object names enabled.
    * An empty vector means all object names disabled.
    *
    * @return the vector of enabled object names.
    */
   public synchronized Vector getEnabledObjectNames()
   {
      if (enabled == null)
         return null;
      return new Vector(enabled);
   }

   /**
    * @return human readable string.
    */
   public String toString()
   {
      StringBuffer buffer = new StringBuffer(100);
      buffer.append(getClass().getName()).append(":");
      buffer.append(" enabledTypes=").append(getEnabledTypes());
      buffer.append(" enabledObjectNames=").append(getEnabledObjectNames());
      buffer.append(" disabledObjectNames=").append(getDisabledObjectNames());
      return buffer.toString();
   }

   // NotificationFilterSupport overrides -------------------------

   /**
    * Test to see whether this notification is enabled
    *
    * @param notification the notification to filter
    * @return true when the notification should be sent, false otherwise
    * @exception IllegalArgumentException for null notification.
    */
   public synchronized boolean isNotificationEnabled(Notification notification)
      throws IllegalArgumentException
   {
      if (notification == null)
         throw new IllegalArgumentException("null notification");

      // Check the notification type
      if (super.isNotificationEnabled(notification) == false)
         return false;

      // Get the object name
      MBeanServerNotification mbsNotification = (MBeanServerNotification) notification;
      ObjectName objectName = mbsNotification.getMBeanName();

      // Is it enabled?
      if (enabled != null)
         return enabled.contains(objectName);

      // Is it not disabled?
      if (disabled.contains(objectName) == false)
         return true;

      // Disabled
      return false;
   }

   // Private -----------------------------------------------------

   private void readObject(ObjectInputStream ois)
      throws IOException, ClassNotFoundException
   {
      ObjectInputStream.GetField getField = ois.readFields();
      List deselectedNames;
      List selectedNames;
      switch (Serialization.version)
      {
         case Serialization.V1R0:
            deselectedNames = (List) getField.get("myDeselectObjNameList", null);
            selectedNames = (List) getField.get("mySelectObjNameList", null);
            break;
         default:
            deselectedNames = (List) getField.get("deselectedNames", null);
            selectedNames = (List) getField.get("selectedNames", null);
      }
      if (deselectedNames == null && selectedNames == null)
         throw new StreamCorruptedException("Nothing enabled or disabled?");
      if (deselectedNames == null)
         disabled = null;
      else
         disabled = new HashSet(deselectedNames);
      if (selectedNames == null)
         enabled = null;
      else
         enabled = new HashSet(selectedNames);
   }

   private void writeObject(ObjectOutputStream oos)
      throws IOException
   {
      ObjectOutputStream.PutField putField = oos.putFields();
      switch (Serialization.version)
      {
         case Serialization.V1R0:
            putField.put("myDeselectObjNameList", getDisabledObjectNames());
            putField.put("mySelectObjNameList", getEnabledObjectNames());
            break;
         default:
            putField.put("deselectedNames", getDisabledObjectNames());
            putField.put("selectedNames", getEnabledObjectNames());
      }
      oos.writeFields();
   }
}