/**

  * 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.krad.uif.util;

 import org.apache.commons.lang.StringUtils;

 import org.apache.log4j.Logger;

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

 import org.kuali.rice.krad.UserSession;

 import org.kuali.rice.krad.service.KRADServiceLocatorWeb;

 import org.kuali.rice.krad.service.SessionDocumentService;

 import org.kuali.rice.krad.uif.UifConstants;

 import org.kuali.rice.krad.uif.UifParameters;

 import org.kuali.rice.krad.uif.view.History;

 import org.kuali.rice.krad.uif.view.View;

 import org.kuali.rice.krad.uif.component.Component;

 import org.kuali.rice.krad.uif.service.ViewService;

 import org.kuali.rice.krad.util.KRADConstants;

 import org.kuali.rice.krad.util.KRADUtils;

 import org.kuali.rice.krad.web.controller.UifControllerBase;

 import org.kuali.rice.krad.web.form.DocumentFormBase;

 import org.kuali.rice.krad.web.form.UifFormBase;

 import org.kuali.rice.krad.uif.UifConstants.ViewType;

 import org.springframework.web.servlet.ModelAndView;

 import javax.servlet.http.HttpServletRequest;

 import javax.servlet.http.HttpServletResponse;

 import java.util.Map;

 /**

  * Provides helper methods that will be used during the request lifecycle

  *

  * <p>

  * Created to avoid duplication of the methods used by the UifHandlerExceptionResolver

  * </p>

  *

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

  */

 public class UifWebUtils {

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

     /**

      * Gets the form from the request

      *

      * <p>

      * Looks for the form on the session by using the form key. If the form is not

      * on the session it will attempt to get it from the database.

      * </p>

      *

      * @param request the http request

      * @return the form from request

      */

     public static UifFormBase getFormFromRequest(HttpServletRequest request) {

         UifFormBase form = null;

         String formKeyParam = request.getParameter(UifParameters.FORM_KEY);

         if (StringUtils.isBlank(formKeyParam)) {

             formKeyParam = (String) request.getAttribute(UifParameters.FORM_KEY);

         }

         String docId = request.getParameter(KRADConstants.DOCUMENT_DOCUMENT_NUMBER);

         if (StringUtils.isNotBlank(formKeyParam)) {

             form = (UifFormBase) request.getSession().getAttribute(formKeyParam);

             // retrieve from db if form not in session

             if (form == null) {

                 UserSession userSession = (UserSession) request.getSession().getAttribute(

                         KRADConstants.USER_SESSION_KEY);

                 form = KRADServiceLocatorWeb.getSessionDocumentService().getDocumentForm(docId, formKeyParam,

                         userSession, request.getRemoteAddr());

             }

         }

         return form;

     }

     /**

      * Configures the <code>ModelAndView</code> instance containing the form

      * data and pointing to the UIF generic spring view

      *

      * @param form - Form instance containing the model data

      * @param pageId - Id of the page within the view that should be rendered, can

      * be left blank in which the current or default page is rendered

      * @return ModelAndView object with the contained form

      */

     public static ModelAndView getUIFModelAndView(UifFormBase form, String pageId) {

         if (StringUtils.isNotBlank(pageId)) {

             form.setPageId(pageId);

         }

         // create the spring return object pointing to View.jsp

         ModelAndView modelAndView = new ModelAndView();

         modelAndView.addObject(UifConstants.DEFAULT_MODEL_NAME, form);

         modelAndView.setViewName(UifConstants.SPRING_VIEW_ID);

         return modelAndView;

     }

     public static ModelAndView getComponentModelAndView(Component component, Object model) {

         ModelAndView modelAndView = new ModelAndView();

         modelAndView.addObject(UifConstants.DEFAULT_MODEL_NAME, model);

         modelAndView.addObject("Component", component);

         modelAndView.setViewName("ComponentUpdate");

         return modelAndView;

     }

     /**

      * After the controller logic is executed, the form is placed into session

      * and the corresponding view is prepared for rendering

      */

     public static void postControllerHandle(HttpServletRequest request, HttpServletResponse response, Object handler,

             ModelAndView modelAndView) throws Exception {

         if (handler instanceof UifControllerBase && (modelAndView != null)) {

             UifControllerBase controller = (UifControllerBase) handler;

             UifFormBase form = null;

             // check to see if this is a full view request

             if (modelAndView.getViewName().equals(UifConstants.SPRING_VIEW_ID)) {

                 Object model = modelAndView.getModelMap().get(UifConstants.DEFAULT_MODEL_NAME);

                 if (model instanceof UifFormBase) {

                     form = (UifFormBase) model;

                     form.setPreviousView(null);

                     // persist document form to db

                     if (form instanceof DocumentFormBase) {

                         UserSession userSession = (UserSession) request.getSession().getAttribute(

                                 KRADConstants.USER_SESSION_KEY);

                         getSessionDocumentService().setDocumentForm((DocumentFormBase) form, userSession,

                                 request.getRemoteAddr());

                     }

                     // perform authorization of controller method

                     checkMethodToCallAuthorization(request, controller, form);

                     // prepare view instance

                     prepareViewForRendering(request, form);

                     // update history for view

                     prepareHistory(request, form);

                 }

             }

         }

     }

     /**

      * Verify the user is authorized to invoke the controller method according

      * to the module that owns the functionality. This is done post handle to be

      * able to access the form and whatever processing was done TODO: should

      * this be throwing some exception?

      *

      * @param request - current HTTP request containing method to call parameter

      * @param controller - controller that was invoked

      * @param form - form instance containing the data

      */

     public static void checkMethodToCallAuthorization(HttpServletRequest request, UifControllerBase controller,

             UifFormBase form) {

         // currently methodToCall must be a regularly parseable request

         // parameter, so just get from request

         String methodToCall = request.getParameter(KRADConstants.DISPATCH_REQUEST_PARAMETER);

         if (!controller.getMethodToCallsToNotCheckAuthorization().contains(methodToCall)) {

             if (LOG.isDebugEnabled()) {

                 LOG.debug("'" + methodToCall + "' not in set of excempt methods: " + controller

                         .getMethodToCallsToNotCheckAuthorization());

             }

             controller.checkAuthorization(form, methodToCall);

         } else {

             if (LOG.isDebugEnabled()) {

                 LOG.debug("'" + methodToCall + "' is exempt from auth checks.");

             }

         }

     }

     /**

      * Updates the history object (or constructs a new History) for the view we are getting ready

      * to render

      *

      * @param request - Http request object containing the request parameters

      * @param form - object containing the view data

      */

     public static void prepareHistory(HttpServletRequest request, UifFormBase form) {

         View view = form.getView();

         // main history/breadcrumb tracking support

         History history = form.getFormHistory();

         if (history == null || request.getMethod().equals("GET")) {

             history = new History();

             history.setHomewardPath(view.getBreadcrumbs().getHomewardPathList());

             history.setAppendHomewardPath(view.getBreadcrumbs().isDisplayHomewardPath());

             history.setAppendPassedHistory(view.getBreadcrumbs().isDisplayPassedHistory());

             // passed settings ALWAYS override the defaults

             if (StringUtils.isNotBlank(request.getParameter(UifConstants.UrlParams.SHOW_HOME))) {

                 history.setAppendHomewardPath(Boolean.parseBoolean(request.getParameter(

                         UifConstants.UrlParams.SHOW_HOME)));

             }

             if (StringUtils.isNotBlank(request.getParameter(UifConstants.UrlParams.SHOW_HISTORY))) {

                 history.setAppendPassedHistory(Boolean.parseBoolean(request.getParameter(

                         UifConstants.UrlParams.SHOW_HISTORY)));

             }

             history.setCurrent(form, request);

             history.buildHistoryFromParameterString(request.getParameter(UifConstants.UrlParams.HISTORY));

             form.setFormHistory(history);

         }

     }

     /**

      * Prepares the <code>View</code> instance contained on the form for

      * rendering

      *

      * <p>

      * First

      * </p>

      *

      * @param form - form instance containing the data and view instance

      */

     public static void prepareViewForRendering(HttpServletRequest request, UifFormBase form) {

         View view = form.getView();

         // set view page to page requested on form

         if (StringUtils.isNotBlank(form.getPageId())) {

             view.setCurrentPageId(form.getPageId());

         }

         Map<String, String> parameterMap = KRADUtils.translateRequestParameterMap(request.getParameterMap());

         parameterMap.putAll(form.getViewRequestParameters());

         // build view which will prepare for rendering

         getViewService().buildView(view, form, parameterMap);

         // set dirty flag

         form.setValidateDirty(view.isValidateDirty());

     }

     protected static SessionDocumentService getSessionDocumentService() {

         return KRADServiceLocatorWeb.getSessionDocumentService();

     }

     protected static ViewService getViewService() {

         return KRADServiceLocatorWeb.getViewService();

     }

 }