/*
 * JBoss, Home of Professional Open Source
 * Copyright 2011 Red Hat Inc. and/or its affiliates and other contributors
 * as indicated by the @authors tag. All rights reserved.
 * See the copyright.txt in the distribution for a
 * full listing of individual contributors.
 *
 * Licensed 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.jboss.arquillian.container.spi.client.protocol.metadata;

import java.io.IOException;
import java.lang.ref.Reference;
import java.lang.ref.WeakReference;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
import java.util.logging.Logger;

import javax.management.MBeanServerConnection;
import javax.management.remote.JMXConnector;
import javax.management.remote.JMXConnectorFactory;
import javax.management.remote.JMXServiceURL;

/**
 * JMXContext
 *
 * @author <a href="mailto:aslak@redhat.com">Aslak Knutsen</a>
 * @version $Revision: $
 */
public class JMXContext extends NamedContext
{
   private static final Logger log = Logger.getLogger(JMXContext.class.getName());

   private static Set<Reference<MBeanServerConnection>> jmxConnectorRefs =
         Collections.synchronizedSet(new HashSet<Reference<MBeanServerConnection>>());

   /*
    * The Host and Port of a Remote MBean Server
    */
   private String host;
   private int port;
   
   /*
    * A existing MBeanServerConnection provided by the Container
    */
   private MBeanServerConnection connection;
   
   public JMXContext(String host, int port)
   {
      this("no-named", host, port);
   }
   
   public JMXContext(String name, String host, int port)
   {
      super(name);
      this.host = host;
      this.port = port;
   }
   
   public JMXContext(MBeanServerConnection connection)
   {
      this("no-named", connection);
   }
   
   public JMXContext(String name, MBeanServerConnection connection)
   {
      super(name);
      this.connection = connection;
   }

   /**
    * @return the openConnection
    */
   public MBeanServerConnection getConnection()
   {
      if(connection == null)
      {
         try
         {
            JMXConnector connector = JMXConnectorFactory.connect(getRemoteJMXURL(), null);
            connection = connector.getMBeanServerConnection();
            WeakReference<MBeanServerConnection> ref = new JMXConnectorReference(connection, connector);
            jmxConnectorRefs.add(ref);
         } catch (IOException e) {
            throw new RuntimeException("Could not create remote JMX connection: " + this, e);
         }
      }
      return connection;
   }
   
   private JMXServiceURL getRemoteJMXURL() 
   {
      try
      {
         return new JMXServiceURL("service:jmx:rmi:///jndi/rmi://" + host + ":" + port + "/jmxrmi");
      } 
      catch (Exception e) 
      {
         throw new RuntimeException("Could not create JMXServiceURL:" + this, e);
      }
   }

   @Override
   public String toString()
   {
      return "JMXContext [host=" + host + ", port=" + port + ", connection=" + connection + "]";
   }

   private static class JMXConnectorReference extends WeakReference<MBeanServerConnection>
   {
      private JMXConnector connector;

      public JMXConnectorReference(final MBeanServerConnection connection, JMXConnector connector)
      {
         super(connection);
         this.connector = connector;
      }

      @Override
      public boolean enqueue()
      {
         try
         {
            connector.close();
         } catch (Exception ignored) {
            log.warning("Could not close JMXConnector: " + connector);
         } finally {
            connector = null;
            jmxConnectorRefs.remove(this);
         }
         return super.enqueue();
      }
   }
}
