/*

  * Copyright 2007 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.kns.web.spring;

 import java.util.HashMap;

 import java.util.Map;

 import javax.servlet.ServletRequest;

 import javax.servlet.http.HttpServletRequest;

 import org.apache.commons.lang.StringUtils;

 import org.kuali.rice.kns.datadictionary.DataDictionaryException;

 import org.kuali.rice.kns.service.KNSServiceLocatorWeb;

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

 import org.kuali.rice.kns.uif.container.View;

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

 import org.kuali.rice.kns.util.WebUtils;

 import org.kuali.rice.kns.web.spring.form.UifFormBase;

 import org.springframework.core.convert.ConversionService;

 import org.springframework.util.Assert;

 import org.springframework.validation.AbstractPropertyBindingResult;

 import org.springframework.web.bind.ServletRequestDataBinder;

 /**

  * This is class is overridden in order to hook in the UifBeanPropertyBindingResult

  * which instantiates a custom BeanWrapperImpl. 

  * 

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

  *

  */

 public class UifServletRequestDataBinder extends ServletRequestDataBinder {

     protected static final org.apache.log4j.Logger LOG = org.apache.log4j.Logger.getLogger(UifServletRequestDataBinder.class);

         private UifBeanPropertyBindingResult bindingResult;

         private ConversionService conversionService;

         protected ViewService viewService;

         public UifServletRequestDataBinder(Object target) {

         super(target);

     }

         public UifServletRequestDataBinder(Object target, String name) {

         super(target, name);

     }

     /**

      * This overridden method allows for a custom binding result class.

      * 

      * @see org.springframework.validation.DataBinder#initBeanPropertyAccess()

      */

     @Override

         public void initBeanPropertyAccess() {

                 Assert.state(this.bindingResult == null,

                                 "DataBinder is already initialized - call initBeanPropertyAccess before other configuration methods");

                 this.bindingResult = new UifBeanPropertyBindingResult(getTarget(), getObjectName(), isAutoGrowNestedPaths());

                 if (this.conversionService != null) {

                         this.bindingResult.initConversion(this.conversionService);

                 }

         }

     /**

      * This overridden method allows for the setting attributes to use to find the data dictionary data from Kuali

      * 

      * @see org.springframework.validation.DataBinder#getInternalBindingResult()

      */

     @Override

         protected AbstractPropertyBindingResult getInternalBindingResult() {

                 if (this.bindingResult == null) {

                         initBeanPropertyAccess();

                 }

                 return this.bindingResult;

         }

         /**

      * This overridden method disallows direct field access for Kuali.

      * 

      * @see org.springframework.validation.DataBinder#initDirectFieldAccess()

      */

     @Override

         public void initDirectFieldAccess() {

             LOG.error("Direct Field access is not allowed in UifServletRequestDataBinder.");

                 throw new RuntimeException("Direct Field access is not allowed in Kuali");

         }

         @Override

         @SuppressWarnings("unchecked")

         public void bind(ServletRequest request) {

                 super.bind(request);

                 UifFormBase form = (UifFormBase) this.getTarget();

                 // back up previous view instance

                 View previousView = form.getView();

                 form.setPreviousView(previousView);

         Map<String, String> viewRequestParameters = new HashMap<String, String>();

         if (previousView != null) {

             viewRequestParameters = previousView.getViewRequestParameters();

         }

         // initialize new view for request

         View view = null;

         // we are going to need this no matter how we get the view, so do it

         // once

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

         // determine whether full view should be rendered or just page

         // if not specified on the request and previous is not null, default to

         // just page

         // TODO: revisit and see if we can have a general pattern

 //        if ((previousView != null) && !parameterMap.containsKey(UifParameters.RENDER_FULL_VIEW)) {

 //            form.setRenderFullView(false);

 //        }

         // add/override view request parameters

         parameterMap.putAll(viewRequestParameters);

         String viewId = request.getParameter(UifParameters.VIEW_ID);

         if (viewId != null) {

             view = getViewService().getView(viewId, parameterMap);

         }

         else {

             String viewTypeName = request.getParameter(UifParameters.VIEW_TYPE_NAME);

             if (viewTypeName == null) {

                 viewTypeName = form.getViewTypeName();

             }

             if (StringUtils.isBlank(viewTypeName)) {

                     view = getViewFromPreviousModel(form, parameterMap);

                     if (view == null) {

                             throw new RuntimeException("Could not find enough information to fetch the required view. Checked the model retrieved from session for both viewTypeName and viewId");

                     }

             } else {

                     try {

                         view = getViewService().getViewByType(viewTypeName, parameterMap);

                     }

                     catch(DataDictionaryException ddex) {

                             view = getViewFromPreviousModel(form, parameterMap);

                         // if we didn't find one, just re-throw

                         if(view == null) {

                             throw ddex;

                         }

                         LOG.warn("Obtained viewId from cached form, this may not be safe!");

                     }

             }

         }

         form.setViewRequestParameters(view.getViewRequestParameters());

         form.setViewId(view.getId());

         form.setView(view);

                 form.postBind((HttpServletRequest) request);

         }

         protected View getViewFromPreviousModel(UifFormBase form, Map<String, String> parameterMap) {

         // maybe we have a view id from the session form

         if(form.getViewId() != null) {

             return getViewService().getView(form.getViewId(), parameterMap);

         }

         return null;

         }

         public ViewService getViewService() {

         if(viewService == null) {

             viewService = KNSServiceLocatorWeb.getViewService();

         }

         return this.viewService;

     }

     public void setViewService(ViewService viewService) {

         this.viewService = viewService;

     }

 }