/*
    * 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.river.reggie.proxy;
  
  import java.io.IOException;
  import java.io.InvalidObjectException;
  import java.io.ObjectInput;
  import java.io.ObjectInputStream;
  import java.io.ObjectOutputStream;
  import java.lang.reflect.Proxy;
  import java.rmi.MarshalledObject;
  import java.rmi.RemoteException;
  import java.util.logging.Level;
  import java.util.logging.Logger;
  import net.jini.core.lookup.ServiceEvent;
  import net.jini.core.lookup.ServiceID;
  import net.jini.core.lookup.ServiceItem;
  import net.jini.export.ProxyAccessor;
  import net.jini.lookup.ServiceProxyAccessor;
  import net.jini.io.MarshalledInstance;
  import org.apache.river.api.io.AtomicSerial;
  import org.apache.river.api.io.AtomicSerial.GetArg;
  import org.apache.river.api.io.AtomicSerial.ReadInput;
  import org.apache.river.api.io.AtomicSerial.ReadObject;
  
  /**
   * Concrete implementation class for abstract ServiceEvent.
   *
   * @author Sun Microsystems, Inc.
   *
   */
  @AtomicSerial
  public class RegistrarEvent extends ServiceEvent implements ProxyAccessor {
  
      private static final long serialVersionUID = 2L;
  
      /**
       * The new state of the serviceItem, or null if the serviceItem has been
       * deleted from the lookup service.  This is either a ServiceItem,
       * an Item (to be converted to a ServiceItem when getServiceItem is called),
       * or a bootstrapProxy;
       *
       * @serial
       */
      private volatile Object serviceItem;
      /**
       * The service ID of the serviceItem that triggered the event.  This field is used
       * instead of the inherited serviceID field (which is set to null) and is
       * written directly as a 128-bit value in order to avoid potential codebase
       * annotation loss (see bug 4745728).
       */
      private transient ServiceID servID;
      
      private transient Proxy bootstrap;
      
      @ReadInput
      private static ReadObject getRO(){
  	return new RO();
      }
      
      private static GetArg check(GetArg arg) throws IOException {
  	Object serviceItem = arg.get("serviceItem", null);
  	if (serviceItem == null ||
  	    serviceItem instanceof ServiceItem ||
  	    serviceItem instanceof Item )
  	{
  	    RO r = (RO) arg.getReader();
  	    if (r.servID instanceof ServiceID) return arg;
  	}
  	throw new InvalidObjectException("Invariants weren't satisfied");
      }
      
      public RegistrarEvent(GetArg arg) throws IOException {
  	super(check(arg));
  	serviceItem = arg.get("serviceItem", null);
  	servID = ((RO) arg.getReader()).servID;
      }
  
      /**
       * Simple constructor.
       *
       * @param source the ServiceRegistrar that generated the event
       * @param eventID the registration eventID
       * @param seqNo the sequence number of this event
      * @param handback the client handback
      * @param serviceID the serviceID of the serviceItem that triggered the event
      * @param transition the transition that triggered the event
      * @param item the new state of the serviceItem, or null if deleted
      */
     @Deprecated
     public RegistrarEvent(Object source,
 			  long eventID,
 			  long seqNo,
 			  MarshalledObject handback,
 			  ServiceID serviceID,
 			  int transition,
 			  Object item)
     {
 	super(source, eventID, seqNo, handback, null, transition);
 	this.serviceItem = item;
 	servID = serviceID;
     }
     
     /**
      * Simple constructor.
      *
      * @param source the ServiceRegistrar that generated the event
      * @param eventID the registration eventID
      * @param seqNo the sequence number of this event
      * @param miHandback the client handback
      * @param serviceID the serviceID of the serviceItem that triggered the event
      * @param transition the transition that triggered the event
      * @param item the new state of the serviceItem, or null if deleted
      */
     public RegistrarEvent(Object source,
 			  long eventID,
 			  long seqNo,
 			  MarshalledInstance miHandback,
 			  ServiceID serviceID,
 			  int transition,
 			  Object item)
     {
 	super(source, eventID, seqNo, miHandback, null, transition);
 	this.serviceItem = item;
 	servID = serviceID;
     }
 
     /**
      * Returns the new state of the serviceItem, or null if the serviceItem was deleted
      * from the lookup service.
      */
     @Override
     public ServiceItem getServiceItem() {
 	if (serviceItem instanceof ServiceItem){
 	    return ((ServiceItem) serviceItem).clone();
 	} else if (serviceItem instanceof Item) {
 	    bootstrap = ((Item)serviceItem).getProxy();
 	    serviceItem = ((Item)serviceItem).get();
 	    return ((ServiceItem) serviceItem).clone();
 	} 
 	return null;
     }
     
     @Override
     public Object getBootstrapProxy(){
 	if (bootstrap != null) return bootstrap;
 	if (serviceItem instanceof Item){
 	    bootstrap = ((Item)serviceItem).getProxy();
 	    return bootstrap;
 	} 
 	return null;
     }
 
     // javadoc inherited from ServiceEvent
     public ServiceID getServiceID() {
 	return servID;
     }
 
     /**
      * Writes the default serializable field value for this instance, followed
      * by the serviceItem's service ID encoded as specified by the
      * ServiceID.writeBytes method.
      */
     private void writeObject(ObjectOutputStream out) throws IOException {
 	out.defaultWriteObject();
 	servID.writeBytes(out);
     }
 
     /**
      * Reads the default serializable field value for this instance, followed
      * by the serviceItem's service ID encoded as specified by the
      * ServiceID.writeBytes method. 
      */
     private void readObject(ObjectInputStream in)
 	throws IOException, ClassNotFoundException
     {
 	in.defaultReadObject();
 	servID = new ServiceID(in);
     }
 
     public Object getProxy() {
 	Object source = getSource();
 	if (source instanceof ProxyAccessor) return ((ProxyAccessor)source).getProxy();
 	throw new IllegalStateException("source wasn't a service registrar proxy");
     }
     
     private static class RO implements ReadObject {
 
 	ServiceID servID;
 	@Override
 	public void read(ObjectInput in) throws IOException, ClassNotFoundException {
 	    servID = new ServiceID(in);
 }
 	
     }
 }