/*

  * Copyright 2011 The Kuali Foundation

  *

  * Licensed under the Educational Community License, Version 1.0 (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/ecl1.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.impl.registry;

 import java.util.List;

 import javax.xml.namespace.QName;

 import org.apache.commons.lang.StringUtils;

 import org.apache.cxf.Bus;

 import org.apache.cxf.frontend.ClientProxyFactoryBean;

 import org.apache.cxf.jaxws.JaxWsProxyFactoryBean;

 import org.kuali.rice.core.api.config.property.ConfigContext;

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

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

 import org.kuali.rice.ksb.api.registry.RemoveAndPublishResult;

 import org.kuali.rice.ksb.api.registry.ServiceDescriptor;

 import org.kuali.rice.ksb.api.registry.ServiceEndpoint;

 import org.kuali.rice.ksb.api.registry.ServiceEndpointStatus;

 import org.kuali.rice.ksb.api.registry.ServiceInfo;

 import org.kuali.rice.ksb.api.registry.ServiceRegistry;

 import org.kuali.rice.ksb.security.soap.CXFWSS4JInInterceptor;

 import org.kuali.rice.ksb.security.soap.CXFWSS4JOutInterceptor;

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

 /**

  * TODO... 

  * 

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

  *

  */

 public class LazyRemoteServiceRegistryConnector implements ServiceRegistry {

         private final Object initLock = new Object();

         private volatile ServiceRegistry delegate;

         // injected

         private Bus cxfBus;

         public void setCxfBus(Bus cxfBus) {

                 this.cxfBus = cxfBus;

         }

         @Override

         public List<ServiceInfo> getOnlineServicesByName(QName serviceName)

                         throws RiceIllegalArgumentException {

                 return getDelegate().getOnlineServicesByName(serviceName);

         }

         @Override

         public List<ServiceInfo> getAllOnlineServices() {

                 return getDelegate().getAllOnlineServices();

         }

         @Override

         public List<ServiceInfo> getAllServices() {

                 return getDelegate().getAllServices();

         }

         @Override

         public List<ServiceInfo> getAllServicesForInstance(String instanceId) {

                 return getDelegate().getAllServicesForInstance(instanceId);

         }

         @Override

         public ServiceDescriptor getServiceDescriptor(String serviceDescriptorId)

                         throws RiceIllegalArgumentException {

                 return getDelegate().getServiceDescriptor(serviceDescriptorId);

         }

         @Override

         public List<ServiceDescriptor> getServiceDescriptors(

                         List<String> serviceDescriptorIds)

                         throws RiceIllegalArgumentException {

                 return getDelegate().getServiceDescriptors(serviceDescriptorIds);

         }

         @Override

         public ServiceEndpoint publishService(ServiceEndpoint serviceEndpoint)

                         throws RiceIllegalArgumentException {

                 return getDelegate().publishService(serviceEndpoint);

         }

         @Override

         public List<ServiceEndpoint> publishServices(List<ServiceEndpoint> serviceEndpoints)

                         throws RiceIllegalArgumentException {

                 return getDelegate().publishServices(serviceEndpoints);

         }

         @Override

         public ServiceEndpoint removeServiceEndpoint(String serviceId)

                         throws RiceIllegalArgumentException {

                 return getDelegate().removeServiceEndpoint(serviceId);

         }

         @Override

         public List<ServiceEndpoint> removeServiceEndpoints(List<String> serviceIds)

                         throws RiceIllegalArgumentException {

                 return getDelegate().removeServiceEndpoints(serviceIds);

         }

         @Override

         public RemoveAndPublishResult removeAndPublish(List<String> removeServiceIds,

                         List<ServiceEndpoint> publishServiceEndpoints) {

                 return getDelegate().removeAndPublish(removeServiceIds, publishServiceEndpoints);

         }

         @Override

         public boolean updateStatus(String serviceId, ServiceEndpointStatus status) throws RiceIllegalArgumentException {

                 return getDelegate().updateStatus(serviceId, status);

         }

         @Override

         public List<String> updateStatuses(List<String> serviceIds, ServiceEndpointStatus status) throws RiceIllegalArgumentException {

                 return getDelegate().updateStatuses(serviceIds, status);

         }

         @Override

         public void takeInstanceOffline(String instanceId)

                         throws RiceIllegalArgumentException {

                 getDelegate().takeInstanceOffline(instanceId);

         }

         private ServiceRegistry getDelegate() {

                 // double-checked locking idiom - see Effective Java, Item 71

                 ServiceRegistry internalDelegate = this.delegate;

                 if (internalDelegate == null) {

                         synchronized (initLock) {

                                 internalDelegate = this.delegate;

                                 if (internalDelegate == null) {

                                         this.delegate = internalDelegate = initializeRemoteServiceRegistry();

                                 }

                         }

                 }

                 return internalDelegate;

         }

         protected ServiceRegistry initializeRemoteServiceRegistry() {

                 String registryBootstrapUrl = ConfigContext.getCurrentContextConfig().getProperty(KSBConstants.Config.REGISTRY_SERVICE_URL);

                 if (StringUtils.isBlank(registryBootstrapUrl)) {

                         throw new RiceRuntimeException("Failed to load registry bootstrap service from url: " + registryBootstrapUrl);

                 }

                 ClientProxyFactoryBean clientFactory = new JaxWsProxyFactoryBean();

                 clientFactory.setServiceClass(ServiceRegistry.class);

                 clientFactory.setBus(cxfBus);

                 clientFactory.setAddress(registryBootstrapUrl);

                 // Set security interceptors

                 clientFactory.getOutInterceptors().add(new CXFWSS4JOutInterceptor(true));

                 clientFactory.getInInterceptors().add(new CXFWSS4JInInterceptor(true));

                 Object service = clientFactory.create();

                 if (!(service instanceof ServiceRegistry)) {

                         throw new RiceRuntimeException("Endpoint to service registry at URL '" + registryBootstrapUrl + "' was not an instance of ServiceRegistry, instead was: " + service);

                 }

                 return (ServiceRegistry)service;

         }

 }