/*

  * Copyright 2006-2011 The Kuali Foundation

  *

  * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php

  *

  * 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.kuali.rice.ksb.messaging.serviceproxies;

 import java.io.Serializable;

 import java.lang.reflect.Method;

 import java.lang.reflect.Proxy;

 import java.util.List;

 import org.apache.log4j.Logger;

 import org.kuali.rice.core.api.exception.RiceRuntimeException;

 import org.kuali.rice.core.impl.resourceloader.ContextClassLoaderProxy;

 import org.kuali.rice.core.util.ClassLoaderUtils;

 import org.kuali.rice.core.util.reflect.BaseInvocationHandler;

 import org.kuali.rice.core.util.reflect.TargetedInvocationHandler;

 import org.kuali.rice.ksb.api.bus.Endpoint;

 import org.kuali.rice.ksb.api.bus.ServiceConfiguration;

 import org.kuali.rice.ksb.api.messaging.AsynchronousCallback;

 import org.kuali.rice.ksb.api.messaging.AsynchronousCall;

 import org.kuali.rice.ksb.messaging.PersistedMessageBO;

 import org.kuali.rice.ksb.service.KSBServiceLocator;

 import org.kuali.rice.ksb.util.KSBConstants;

 /**

  * Standard default proxy used to call services asynchronously. Persists the method call to the db so call is never lost and

  * only sent when transaction is committed.

  * 

  * @author Kuali Rice Team (rice.collab@kuali.org)

  * 

  */

 public class AsynchronousServiceCallProxy extends BaseInvocationHandler implements TargetedInvocationHandler {

     private static final Logger LOG = Logger.getLogger(AsynchronousServiceCallProxy.class);

     private AsynchronousCallback callback;

     private List<Endpoint> endpoints;

     private Serializable context;

     private String value1;

     private String value2;

     protected AsynchronousServiceCallProxy(List<Endpoint> endpoints, AsynchronousCallback callback,

             Serializable context, String value1, String value2) {

         this.endpoints = endpoints;

         this.callback = callback;

         this.context = context;

         this.value1 = value1;

         this.value2 = value2;

     }

     public static Object createInstance(List<Endpoint> endpoints, AsynchronousCallback callback,

             Serializable context, String value1, String value2) {

         if (endpoints == null || endpoints.isEmpty()) {

             throw new RuntimeException("Cannot create service proxy, no service(s) passed in.");

         }

         try {

             return Proxy.newProxyInstance(ClassLoaderUtils.getDefaultClassLoader(), ContextClassLoaderProxy

                     .getInterfacesToProxy(endpoints.get(0).getService()), new AsynchronousServiceCallProxy(

                     endpoints, callback, context, value1, value2));

         } catch (Exception e) {

             throw new RiceRuntimeException(e);

         }

     }

     @Override

     protected Object invokeInternal(Object proxy, Method method, Object[] arguments) throws Throwable {

         if (LOG.isDebugEnabled()) {

             LOG.debug("creating messages for method invocation: " + method.getName());

         }

         // there are multiple service calls to make in the case of topics.

         AsynchronousCall methodCall = null;

         PersistedMessageBO message = null;

         synchronized (this) {

             // consider moving all this topic invocation stuff to the service

             // invoker for speed reasons

             for (Endpoint endpoint : this.endpoints) {

                 ServiceConfiguration serviceConfiguration = endpoint.getServiceConfiguration();

                 methodCall = new AsynchronousCall(method.getParameterTypes(), arguments, serviceConfiguration, method.getName(),

                         this.callback, this.context);

                 message = KSBServiceLocator.getMessageQueueService().getMessage(serviceConfiguration, methodCall);

                 message.setValue1(this.value1);

                 message.setValue2(this.value2);

                 saveMessage(message);

                 executeMessage(message);

                 // only do one iteration if this is a queue. The load balancing

                 // will be handled when the service is

                 // fetched by the MessageServiceInvoker through the GRL (and

                 // then through the RemoteResourceServiceLocatorImpl)

                 if (serviceConfiguration.isQueue()) {

                     break;

                 }

             }

         }

         if (LOG.isDebugEnabled()) {

             LOG.debug("finished creating messages for method invocation: " + method.getName());

         }

         return null;

     }

     protected void saveMessage(PersistedMessageBO message) {

         message.setQueueStatus(KSBConstants.ROUTE_QUEUE_ROUTING);

         KSBServiceLocator.getMessageQueueService().save(message);

     }

     protected void executeMessage(PersistedMessageBO message) throws Exception {

         MessageSender.sendMessage(message);

     }

     /**

          * Returns the List<RemotedServiceHolder> of asynchronous services which will be invoked by calls to this proxy.

          * This is a List because, in the case of Topics, there can be more than one service invoked.

          */

     public Object getTarget() {

             return this.endpoints;

     }

     public AsynchronousCallback getCallback() {

         return this.callback;

     }

     public void setCallback(AsynchronousCallback callback) {

         this.callback = callback;

     }

 }