/**
    * Copyright 2005-2011 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.serviceexporters;
  
  import java.util.List;
  
  import org.apache.cxf.Bus;
  import org.apache.cxf.endpoint.Server;
  import org.apache.cxf.endpoint.ServerRegistry;
  import org.apache.log4j.Logger;
  import org.kuali.rice.ksb.api.bus.ServiceDefinition;
  import org.kuali.rice.ksb.messaging.bam.BAMServerProxy;
  import org.kuali.rice.ksb.messaging.servlet.CXFServletControllerAdapter;
  
  /**
   * Abstract ServiceExporter for web services 
   * 
   * @author Kuali Rice Team (rice.collab@kuali.org)
   *
   */
  public abstract class AbstractWebServiceExporter implements ServiceExporter {
  
      static final Logger LOG = Logger.getLogger(AbstractWebServiceExporter.class);
      
      private final ServiceDefinition serviceDefinition;
      private final Bus cxfBus;
      private final ServerRegistry cxfServerRegistry;
  
      protected abstract void publishService(ServiceDefinition serviceDefinition, Object serviceImpl, String address) throws Exception;
  
      public AbstractWebServiceExporter(ServiceDefinition serviceDefinition, Bus cxfBus, ServerRegistry cxfServerRegistry) {
          this.serviceDefinition = serviceDefinition;
          this.cxfBus = cxfBus;
          this.cxfServerRegistry = cxfServerRegistry;
      }
      
      @Override
      public Object exportService(ServiceDefinition serviceDefinition) {
      	try {			
      		String serviceAddress = getServiceAddress(serviceDefinition);
      		
      		//Publish the CXF service if it hasn't already been published
      		if (!(isServicePublished(serviceAddress))){
      			publishService(serviceDefinition, serviceDefinition.getService(), serviceAddress);
      		}
      		
      		//Create a CXF mvc controller for this service
      		CXFServletControllerAdapter cxfController = new CXFServletControllerAdapter();
      		
      		return BAMServerProxy.wrap(cxfController, serviceDefinition);
      	} catch (Exception e) {
      		throw new RuntimeException(e);
      	}
      	
      }
  
      /**
       * @return the address where the service is (or will be) published
       */
      protected String getServiceAddress(ServiceDefinition serviceDefinition) {
          //Determine endpoint address to publish service on
          String serviceAddress = serviceDefinition.getServicePath();
          if (("/").equals(serviceAddress)){
          	serviceAddress = serviceAddress + serviceDefinition.getServiceName().getLocalPart();
          } else {
          	serviceAddress = serviceAddress + "/" + serviceDefinition.getServiceName().getLocalPart();
          }
          return serviceAddress;
      }
  
      /** 
       * This determines if the service has already been published on the CXF bus.
       * 
       * @return true if cxf server exists for this service.
       */
      protected boolean isServicePublished(String serviceAddress) {
      	
      	ServerRegistry serverRegistry = getCXFServerRegistry();
      	List<Server> servers = serverRegistry.getServers();
      	
      	for (Server server:servers){		
      		String endpointAddress = server.getEndpoint().getEndpointInfo().getAddress();
      
      		if (endpointAddress.equals(serviceAddress)){
      			LOG.info("Service already published on CXF, not republishing: " + serviceAddress);
      			return true;
     		}		
     	}
     	
     	return false;
     }
 
     protected ServiceDefinition getServiceDefinition() {
     	return this.serviceDefinition;
     }
 
     protected Bus getCXFBus() {
     	return this.cxfBus;
     }
 
     protected ServerRegistry getCXFServerRegistry() {
     	return this.cxfServerRegistry;
     }
 
 }