/*

  * 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.servlet;

 import org.apache.cxf.Bus;

 import org.apache.cxf.interceptor.Interceptor;

 import org.apache.cxf.message.Message;

 import org.apache.cxf.transport.servlet.ServletController;

 import org.apache.cxf.transport.servlet.ServletTransportFactory;

 import org.apache.log4j.Logger;

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

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

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

 import org.kuali.rice.ksb.api.KsbApiServiceLocator;

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

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

 import org.kuali.rice.ksb.api.bus.support.SoapServiceConfiguration;

 import org.kuali.rice.ksb.security.SignatureSigningResponseWrapper;

 import org.kuali.rice.ksb.security.SignatureVerifyingRequestWrapper;

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

 import org.springframework.beans.BeansException;

 import org.springframework.web.HttpRequestHandler;

 import org.springframework.web.context.WebApplicationContext;

 import org.springframework.web.servlet.DispatcherServlet;

 import org.springframework.web.servlet.HandlerAdapter;

 import org.springframework.web.servlet.HandlerExecutionChain;

 import org.springframework.web.servlet.ModelAndView;

 import org.springframework.web.servlet.mvc.Controller;

 import org.springframework.web.servlet.mvc.HttpRequestHandlerAdapter;

 import org.springframework.web.servlet.mvc.SimpleControllerHandlerAdapter;

 import javax.servlet.ServletException;

 import javax.servlet.http.HttpServletRequest;

 import javax.servlet.http.HttpServletResponse;

 import javax.xml.namespace.QName;

 import java.io.IOException;

 import java.util.List;

 /**

  * A {@link DispatcherServlet} which dispatches incoming requests to the appropriate

  * service endpoint.

  *

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

  */

 public class KSBDispatcherServlet extends DispatcherServlet {

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

         private static final long serialVersionUID = 6790121225857950019L;

         private KSBHttpInvokerHandler httpInvokerHandler;

         private ServletController cxfServletController;

         /**

          * Instantiate the WebApplicationContext for this servlet, either a default

          * XmlWebApplicationContext or a custom context class if set. This implementation

          * expects custom contexts to implement ConfigurableWebApplicationContext.

          * Can be overridden in subclasses.

          * @param parent the parent ApplicationContext to use, or <code>null</code> if none

          * @return the WebApplicationContext for this servlet

          * @throws BeansException if the context couldn't be initialized

          * @see #setContextClass

          * @see org.springframework.web.context.support.XmlWebApplicationContext

          */

         protected WebApplicationContext initWebApplicationContext() throws BeansException {

                 return null;//we want to start spring all by ourselves

         }

         protected void initFrameworkServlet() throws ServletException, BeansException {

                 this.httpInvokerHandler = new KSBHttpInvokerHandler();

         Bus bus = KSBServiceLocator.getCXFBus();

         List<Interceptor<? extends Message>> inInterceptors = KSBServiceLocator.getInInterceptors();

         if(inInterceptors != null) {

                 List<Interceptor<? extends Message>> busInInterceptors = bus.getInInterceptors();

                 busInInterceptors.addAll(inInterceptors);

         }

         List<Interceptor<? extends Message>> outInterceptors = KSBServiceLocator.getOutInterceptors();

         if(outInterceptors != null) {

                 List<Interceptor<? extends Message>> busOutInterceptors = bus.getOutInterceptors();

                 busOutInterceptors.addAll(outInterceptors);

         }

                 ServletTransportFactory servletTransportFactory = KSBServiceLocator.getCXFServletTransportFactory();

                 this.cxfServletController = new ServletController(servletTransportFactory, this.getServletConfig(), this.getServletContext(), bus);

                 if (!ConfigContext.getCurrentContextConfig().getDevMode()) {

                     // disable handling of URLs ending in /services which display CXF generated service lists

                     this.cxfServletController.setHideServiceList(true);

                 }

                 this.setPublishEvents(false);

         }

         protected HandlerAdapter getHandlerAdapter(Object handler) throws ServletException {

                 if (handler instanceof HttpRequestHandler) {

                         return new HttpRequestHandlerAdapter();

                 } else if (handler instanceof Controller) {

                         Object unwrappedHandler = ClassLoaderUtils.unwrapFromProxy(handler);

                         if (unwrappedHandler instanceof CXFServletControllerAdapter) {

                                 // TODO this just seems weird as this controller is initially null when it's created, does there need to be some synchronization here?

                                 ((CXFServletControllerAdapter)unwrappedHandler).setController(cxfServletController);

                         }                        

                         return new SimpleControllerHandlerAdapter();

                 }

                 throw new RiceRuntimeException("handler of type " + handler.getClass().getName() + " is not known and can't be used by " + KSBDispatcherServlet.class.getName());

         }

         /**

          * Return the HandlerExecutionChain for this request.

          * Try all handler mappings in order.

          * @param request current HTTP request

          * @param cache whether to cache the HandlerExecutionChain in a request attribute

          * @return the HandlerExceutionChain, or <code>null</code> if no handler could be found

          */

         protected HandlerExecutionChain getHandler(HttpServletRequest request, boolean cache) throws Exception {

                 return this.httpInvokerHandler.getHandler(request);

         }

         @Override

         protected ModelAndView processHandlerException(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

                 try {

                         QName serviceName = this.httpInvokerHandler.getServiceNameFromRequest(request);

                         LOG.info("Caught Exception from service " + serviceName, ex);

                 } catch (Throwable throwable) {

                         LOG.warn("Caught exception attempting to log exception thrown from remotely accessed service", throwable);

                 }

                 return null;

         }

         /**

          * Overrides the service method to replace the request and responses with one which will provide input and output streams for

          * verifying and signing the data.

          */

         @Override

         protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

                 if (isSecure(request)) {

                         super.service(new SignatureVerifyingRequestWrapper(request), new SignatureSigningResponseWrapper(response));

                 } else {

                         super.service(request, response);

                 }

         }

         protected boolean isSecure(HttpServletRequest request) {

                 QName serviceName = this.httpInvokerHandler.getServiceNameFromRequest(request);

                 if (LOG.isDebugEnabled()) {

                     LOG.debug("Checking service " + serviceName + " for security enabled");

                 }

                 Endpoint endpoint = KsbApiServiceLocator.getServiceBus().getEndpoint(serviceName);

                 if (endpoint == null) {

                         LOG.error("Attempting to acquire non-existent service " + request.getRequestURI());

                     throw new RiceRuntimeException("Attempting to acquire non-existent service.");

                 }

                 ServiceConfiguration serviceConfiguration = endpoint.getServiceConfiguration();

                 if (serviceConfiguration instanceof SoapServiceConfiguration) {

                     return false;

                 }

                 return serviceConfiguration.getBusSecurity();

         }

 }