/**
    * Copyright 2005-2016 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 org.apache.commons.collections.CollectionUtils;
  import org.apache.log4j.Logger;
  import org.kuali.rice.core.api.exception.RiceRuntimeException;
  import org.kuali.rice.core.api.util.ClassLoaderUtils;
  import org.kuali.rice.core.api.util.ContextClassLoaderProxy;
  import org.kuali.rice.core.api.util.reflect.BaseInvocationHandler;
  import org.kuali.rice.core.api.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.AsynchronousCall;
  import org.kuali.rice.ksb.api.messaging.AsynchronousCallback;
  import org.kuali.rice.ksb.messaging.PersistedMessageBO;
  import org.kuali.rice.ksb.service.KSBServiceLocator;
  import org.kuali.rice.ksb.util.KSBConstants;
  
  import java.io.Serializable;
  import java.lang.reflect.Method;
  import java.lang.reflect.Proxy;
  import java.util.List;
  
  /**
   * 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 = PersistedMessageBO.buildMessage(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;
     }
 
     @Override
     protected String proxyToString(Object proxy) {
         StringBuilder builder = new StringBuilder();
         builder.append("Service call proxy (" + getClass().getName() + ") - for endpoints with service name: ");
         if (CollectionUtils.isNotEmpty(this.endpoints)) {
             builder.append(this.endpoints.get(0).getServiceConfiguration().getServiceName().toString());
         } else {
             builder.append("<< no endpoints on this proxy!!! >>");
         }
         return builder.toString();
     }
 
     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;
     }
 
 }