/**
    * 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.net.URI;
  import java.net.URL;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.ConcurrentMap;
  
  import javax.xml.namespace.QName;
  
  import org.apache.commons.lang.StringUtils;
  import org.apache.cxf.Bus;
  import org.apache.cxf.endpoint.ServerRegistry;
  import org.kuali.rice.core.api.config.property.Config;
  import org.kuali.rice.core.api.config.property.ConfigContext;
  import org.kuali.rice.ksb.api.bus.ServiceDefinition;
  
  public class ServiceExportManagerImpl implements ServiceExportManager {
  
  	private final ConcurrentMap<QName, ExportedServiceHolder> exportedServices;
  	private final ServiceNameFinder serviceNameFinder;
  	
  	private Bus cxfBus;
  	private ServerRegistry cxfServerRegistry;
  	
  	public ServiceExportManagerImpl() {
  		this.exportedServices = new ConcurrentHashMap<QName, ExportedServiceHolder>();
  		this.serviceNameFinder = new ServiceNameFinder();
  	}
  	
  	@Override
  	public QName getServiceName(String endpointUrl) {
  		return getServiceNameFinder().lookup(endpointUrl);
  	}
  	
  	protected ServiceNameFinder getServiceNameFinder() {
  		return serviceNameFinder;
  	}
  	
  	@Override
  	public Object getService(QName serviceName) {
  		ExportedServiceHolder holder = exportedServices.get(serviceName);
  		if (holder == null) {
  			return null;
  		}
  		return holder.getExportedService();
  	}
  	
  	@Override
  	public void exportService(ServiceDefinition serviceDefinition) {
  		if (serviceDefinition == null) {
  			throw new IllegalArgumentException("serviceDefinition was null");
  		}
  		ServiceExporter serviceExporter = ServiceExporterFactory.getServiceExporter(serviceDefinition, cxfBus, cxfServerRegistry);
  		Object exportedService = serviceExporter.exportService(serviceDefinition);
  		exportedServices.put(serviceDefinition.getServiceName(), new ExportedServiceHolder(exportedService, serviceDefinition));
  		getServiceNameFinder().register(serviceDefinition);
  	}
  
  	@Override
  	public void removeService(QName serviceName) {
  		ExportedServiceHolder exportedServiceHolder = exportedServices.remove(serviceName);
  		getServiceNameFinder().remove(exportedServiceHolder.getServiceDefinition().getEndpointUrl());
  	}
  		
  	protected ConcurrentMap<QName, ExportedServiceHolder> getExportedServices() {
  		return exportedServices;
  	}
  	
  	public void setCxfBus(Bus cxfBus) {
  		this.cxfBus = cxfBus;
  	}
  	
  	public void setCxfServerRegistry(ServerRegistry cxfServerRegistry) {
  		this.cxfServerRegistry = cxfServerRegistry;
  	}
  	
  	protected static class ExportedServiceHolder {
  		
  		private final Object exportedService;
  		private final ServiceDefinition serviceDefinition;
  		
  		ExportedServiceHolder(Object exportedService, ServiceDefinition serviceDefinition) {
  			this.exportedService = exportedService;
  			this.serviceDefinition = serviceDefinition;
 		}
 		
 		public Object getExportedService() {
 			return exportedService;
 		}
 		
 		public ServiceDefinition getServiceDefinition() {
 			return serviceDefinition;
 		}
 		
 	}
 	
 	/**
 	 * Looks up service QNameS based on URL StringS.  API is Map-like, but non-service specific portions of the
 	 * URL are trimmed prior to accessing its internal Map.
 	 * 
 	 * @author Kuali Rice Team (rice.collab@kuali.org)
 	 *
 	 */
 	protected static class ServiceNameFinder {
 	    
 		/**
 		 * A service path to service QName map
 		 */
 		private ConcurrentMap<String, QName> servicePathToQName = new ConcurrentHashMap<String, QName>();
 		
 
 		/**
 		 * This method trims the endpoint url base ({@link Config#getEndPointUrl()}) base off of the full service URL, e.g.
 		 * "http://kuali.edu/kr-dev/remoting/SomeService" -> "SomeService".  It makes an effort to do so even if the host
 		 * and ip don't match what is in {@link Config#getEndPointUrl()} by stripping host/port info.
 		 * 
 		 * If the service URL contains the configured subpath for RESTful service, additional trimming is done to
 		 * isolate the service name from the rest of the url.
 		 * 
 		 * @param url
 		 * @return the service specific suffix.  If fullServiceUrl doesn't contain the endpoint url base,
 		 * fullServiceUrl is returned unmodified.  
 		 */
 		private String trimServiceUrlBase(String url) {
 			String trimmedUrl = StringUtils.removeStart(url, ConfigContext.getCurrentContextConfig().getEndPointUrl());
 			
 			if (trimmedUrl.length() == url.length()) { // it didn't contain the endpoint url base.
 				// Perhaps the incoming url has a different host (or the ip) or a different port.
 				// Trim off the host & port, then trim off the common base.
 				URI serviceUri = URI.create(url);
 				URI endpointUrlBase = URI.create(ConfigContext.getCurrentContextConfig().getEndPointUrl());
 				
 				String reqPath = serviceUri.getPath();
 				String basePath = endpointUrlBase.getPath();
 				
 				trimmedUrl = StringUtils.removeStart(reqPath, basePath);
 			}
 			
 			return trimmedUrl;
 		}
 		
 		/**
 		 * adds a mapping from the service specific portion of the service URL to the service name.
 		 * 
 		 * @param serviceUrl
 		 * @param serviceName
 		 */
 		public void register(ServiceDefinition serviceDefinition) {
 			String serviceUrlBase = trimServiceUrlBase(serviceDefinition.getEndpointUrl().toExternalForm());
 			if (serviceUrlBase.endsWith("/")) {
 				serviceUrlBase = StringUtils.chop(serviceUrlBase);
 			}
 			servicePathToQName.put(serviceUrlBase, serviceDefinition.getServiceName());
 		}
 		
 		/**
 		 * removes the mapping (if one exists) for the service specific portion of this url.
 		 * 
 		 * @param serviceUrl
 		 */
 		public void remove(URL endpointUrl) {
 			servicePathToQName.remove(trimServiceUrlBase(endpointUrl.toExternalForm()));
 		}
 		
 		/**
 		 * gets the QName for the service
 		 * 
 		 * @param serviceUrl
 		 * @return
 		 */
 		public QName lookup(String serviceUrl) {
 			String serviceUrlBase = trimServiceUrlBase(serviceUrl);
 
 			// First, make sure we don't have any query params
 			if (serviceUrlBase.length() > 0 && serviceUrlBase.lastIndexOf('?') != -1) {
 				serviceUrlBase = serviceUrlBase.substring(0, serviceUrlBase.lastIndexOf('?'));
 			}
 
 			QName qname = null;
 			// Now, iterate backwards through the url, stripping off pieces until you match -- this should work for rest too
 			while (qname == null) {
 				qname = servicePathToQName.get(serviceUrlBase);
 
 				int lastSeparatorIndex = serviceUrlBase.lastIndexOf('/');
 				if (lastSeparatorIndex == -1)
 					break;
 				serviceUrlBase = serviceUrlBase.substring(0, lastSeparatorIndex);
 			}
 
 			return qname;
 		}
 
 	}
 
 }