/*
    * 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.krad.web.bind;
  
  import org.apache.commons.lang.StringUtils;
  import org.kuali.rice.krad.datadictionary.DataDictionaryException;
  import org.kuali.rice.krad.service.KRADServiceLocatorWeb;
  import org.kuali.rice.krad.uif.UifParameters;
  import org.kuali.rice.krad.uif.container.View;
  import org.kuali.rice.krad.uif.service.ViewService;
  import org.kuali.rice.krad.util.KRADUtils;
  import org.kuali.rice.krad.web.form.UifFormBase;
  import org.springframework.core.convert.ConversionService;
  import org.springframework.util.Assert;
  import org.springframework.validation.AbstractPropertyBindingResult;
  import org.springframework.web.bind.ServletRequestDataBinder;
  
  import javax.servlet.ServletRequest;
  import javax.servlet.http.HttpServletRequest;
  import java.util.HashMap;
  import java.util.Map;
  
  /**
   * Override of ServletRequestDataBinder 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);
          setBindingErrorProcessor(new UifBindingErrorProcessor());
      }
  	
  	public UifServletRequestDataBinder(Object target, String name) {
          super(target, name);
          setBindingErrorProcessor(new UifBindingErrorProcessor());
      }
  	
      /**
       * 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);
  		}
  	}
  
      /**
       * 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;
  	}
  
  	/**
       * 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();
         
         // check for request param that indicates to skip view initialize
         Boolean skipViewInit = KRADUtils.getRequestParameterAsBoolean(request, UifParameters.SKIP_VIEW_INIT);
         if ((skipViewInit != null) && skipViewInit.booleanValue()) {
             // just invoke post bind on form and return
             form.postBind((HttpServletRequest) request);
             return;
         }
 
         // back up previous view instance
         View previousView = form.getView();
         form.setPreviousView(previousView);
 
         Map<String, String> viewRequestParameters = new HashMap<String, String>();
         // TODO: this should get from form not previous view, test
         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 = KRADUtils.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!");
                 }
             }
         }
 
         // apply default values to form if needed
         if (!form.isDefaultsApplied()) {
             view.getViewHelperService().applyDefaultValues(view, form);
         }
 
         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 = KRADServiceLocatorWeb.getViewService();
         }
         return this.viewService;
     }
 
     public void setViewService(ViewService viewService) {
         this.viewService = viewService;
     }
 
 }