/**
    * Copyright 2005-2015 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.widget;
  
  import java.text.MessageFormat;
  
  import org.apache.commons.lang.StringUtils;
  import org.kuali.rice.core.api.CoreApiServiceLocator;
  import org.kuali.rice.coreservice.framework.CoreFrameworkServiceLocator;
  import org.kuali.rice.coreservice.framework.parameter.ParameterService;
  import org.kuali.rice.krad.datadictionary.HelpDefinition;
  import org.kuali.rice.krad.datadictionary.parse.BeanTag;
  import org.kuali.rice.krad.datadictionary.parse.BeanTagAttribute;
  import org.kuali.rice.krad.datadictionary.uif.UifDictionaryBean;
  import org.kuali.rice.krad.uif.CssConstants;
  import org.kuali.rice.krad.uif.UifConstants;
  import org.kuali.rice.krad.uif.element.Action;
  import org.kuali.rice.krad.uif.field.InputField;
  import org.kuali.rice.krad.uif.lifecycle.ViewLifecycle;
  import org.kuali.rice.krad.uif.util.ComponentFactory;
  import org.kuali.rice.krad.uif.util.LifecycleElement;
  import org.kuali.rice.krad.uif.view.ExpressionEvaluator;
  
  /**
   * Widget that renders help on a component
   *
   * <p>
   * If help URL is specified then display help icon and/or if help summary is specified then display help tooltip.
   * </p>
   *
   * @author Kuali Rice Team (rice.collab@kuali.org)
   */
  @BeanTag(name = "help", parent = "Uif-Help")
  public class Help extends WidgetBase {
  	private static final long serialVersionUID = -1514436681476297241L;
  
      private static final org.apache.log4j.Logger LOG = org.apache.log4j.Logger.getLogger(Help.class);
  
      private Action helpAction;
      private HelpDefinition helpDefinition;
      private String externalHelpUrl;
  
      private String tooltipHelpContent;
  
      /**
       * The following initialization is performed:
       *
       * <ul>
       * <li>If help action not initialized and external help is configured, get the default
       * help action component</li>
       * </ul>
       *
       * {@inheritDoc}
       */
      @Override
      public void performInitialization(Object model) {
          super.performInitialization(model);
  
          if (helpAction == null) {
              if(hasValueOrPropertyExpression(externalHelpUrl, this, "externalHelpUrl") ||  (
                      helpDefinition != null &&
                              hasValueOrPropertyExpression(helpDefinition.getParameterName(), helpDefinition, "parameterName") &&
                              hasValueOrPropertyExpression(helpDefinition.getParameterDetailType(), helpDefinition, "parameterDetailType")
              )){
                  helpAction = ComponentFactory.getHelpAction();
                  helpAction.addDataAttribute(UifConstants.DataAttributes.ROLE, "help");
              }
          }
          else{
              helpAction.addDataAttribute(UifConstants.DataAttributes.ROLE, "help");
          }
      }
  
      /**
       * Helper function to check if value or property expression exists
       *
       * @param defaultValue
       * @param dictionaryBean
       * @param expressionName
       * @return
       */
      private boolean hasValueOrPropertyExpression(String defaultValue, UifDictionaryBean dictionaryBean, String expressionName) {
          return StringUtils.isNotBlank(defaultValue) || (dictionaryBean != null && dictionaryBean.getPropertyExpressions() != null &&
                  StringUtils.isNotBlank(dictionaryBean.getPropertyExpression(expressionName)));
      }
  
     /**
      * Finalize the help widget for usage
      *
      * <p>
      * In addition to the standard finalization the following tasks are performed:
      * <li>Build the external help Url</li>
      * <li>Set the javascript action which opens the external help in window</li>
      * <li>Set render to false if help not configured</li>
      * </p>
      *
      * {@inheritDoc}
      */
     @Override
     public void performFinalize(Object model, LifecycleElement parent) {
         super.performFinalize(model, parent);
 
         buildExternalHelp(parent);
         buildTooltipHelp(parent);
 
         // if help is not configured don't render the component
         if (StringUtils.isBlank(this.externalHelpUrl) && StringUtils.isBlank(this.tooltipHelpContent)) {
             setRender(false);
         }
 
         // Change to icon only look and feel if not associated with an input
         if (parent != null && !(parent instanceof InputField) && helpAction != null) {
             helpAction.getLibraryCssClasses().remove(CssConstants.Classes.BTN);
             helpAction.getLibraryCssClasses().remove(CssConstants.Classes.BTN_DEFAULT);
             helpAction.getLibraryCssClasses().add(CssConstants.Classes.ICON_ONLY_BUTTON);
         }
     }
 
     /**
      * Build the external help
      *
      * <p>
      * When the externalHelpUrl is blank and the helpDefinition is specified then the external help URL is
      * looked up via the helpDefinition from the system parameters.  The namespace in the helpDefinition
      * does not need to be specified and will default to the namespace of the view.
      * </p>
      *
      * <p>
      * Set the javascript action to open the external help in a window.
      * </p>
      *
      * <p>
      * Set the html title attribute of the help icon.
      * </p>
      *
      * @param parent used to get the help title text used in the html title attribute of the help icon
      */
     protected void buildExternalHelp(LifecycleElement parent) {
         if (StringUtils.isBlank(externalHelpUrl) && (helpDefinition != null)) {
             if (StringUtils.isBlank(helpDefinition.getParameterNamespace())) {
                 helpDefinition.setParameterNamespace(ViewLifecycle.getView().getNamespaceCode());
             }
 
             String parameterNamespace = helpDefinition.getParameterNamespace();
             String parameterDetailType = helpDefinition.getParameterDetailType();
             String parameterName = helpDefinition.getParameterName();
 
             ExpressionEvaluator expressionEvaluator = ViewLifecycle.getExpressionEvaluator();
             if (parameterNamespace == null && helpDefinition.getPropertyExpression("parameterNamespace") != null) {
                 parameterNamespace = (String) expressionEvaluator.evaluateExpression(this.getContext(),
                         helpDefinition.getPropertyExpression("parameterNamespace"));
             }
 
             if (parameterDetailType == null && helpDefinition.getPropertyExpression("parameterDetailType") != null) {
                 parameterDetailType = (String) expressionEvaluator.evaluateExpression(this.getContext(),
                         helpDefinition.getPropertyExpression("parameterDetailType"));
             }
 
             if (parameterName == null && helpDefinition.getPropertyExpression("parameterName") != null) {
                 parameterName = (String) expressionEvaluator.evaluateExpression(this.getContext(),
                         helpDefinition.getPropertyExpression("parameterName"));
             }
 
             if (StringUtils.isNotBlank(parameterNamespace)
                     && StringUtils.isNotBlank(parameterDetailType)
                     && StringUtils.isNotBlank(parameterName)) {
                 externalHelpUrl = getParameterService().getParameterValueAsFilteredString(
                         parameterNamespace, parameterDetailType, parameterName);
             }
         }
 
         if (StringUtils.isNotBlank(externalHelpUrl)) {
             // set the javascript action for the external help
             getHelpAction().setActionScript("openHelpWindow('" + externalHelpUrl + "')");
 
             // set the alt and title attribute of the image
             String helpTitle;
 
             // make sure that we are the component's native help and not a misconfigured standalone help bean.
             if ((parent instanceof Helpable) && (((Helpable) parent).getHelp() == this)) {
                 helpTitle = MessageFormat.format(
                         CoreApiServiceLocator.getKualiConfigurationService().getPropertyValueAsString(
                                 "help.icon.title.tag.with.field.label"), ((Helpable) parent).getHelpTitle());
             } else {
                 helpTitle = CoreApiServiceLocator.getKualiConfigurationService().getPropertyValueAsString(
                         "help.icon.title.tag");
             }
 
             getHelpAction().setTitle(helpTitle);
         }
     }
 
     /**
      * Build the tooltip help
      *
      * <p>
      * The help tooltip is set on the component.  To use the help tooltip bean definition, the help's tooltip is used
      * as and intermediary for setting up the tooltip widget and then copied to the component.
      * </p>
      *
      * @param parent used for checking misconfigurations
      */
     protected void buildTooltipHelp(LifecycleElement parent) {
         if (StringUtils.isNotBlank(tooltipHelpContent) && this.isRender()) {
             // make sure that we are the component's native help and not a misconfigured standalone help bean.
             if (this.getToolTip() != null && (parent instanceof Helpable) 
                     && (((Helpable) parent).getHelp() == this)) {
                 this.getToolTip().setTooltipContent(tooltipHelpContent);
                 ((Helpable) parent).setTooltipOfComponent(this.getToolTip());
             }
         }
     }
 
     /**
      * HelpActionField is used for rendering external help
      *
      * @return Action for external help
      */
     @BeanTagAttribute
     public Action getHelpAction() {
         return helpAction;
     }
 
     /**
      * Setter for helpAction
      *
      * @param helpAction
      */
     public void setHelpAction(Action helpAction) {
         this.helpAction = helpAction;
     }
 
     /**
      * The help definition is used as the key to retrieve the external help Url from the parameter table of
      * the database
      *
      * @return HelpDefinition
      */
     @BeanTagAttribute(type= BeanTagAttribute.AttributeType.DIRECTORBYTYPE)
     public HelpDefinition getHelpDefinition() {
         return helpDefinition;
     }
 
     /**
      * Setter for the help definition of the database.
      *
      * @param helpDefinition
      */
     public void setHelpDefinition(HelpDefinition helpDefinition) {
         this.helpDefinition = helpDefinition;
     }
 
     /**
      * The external help Url
      *
      * <p>
      * This should contain a valid URL.  When specified this URL takes precedence over the external help URL from
      * the system parameters.
      * </p>
      *
      * @return Url of the external help
      */
     @BeanTagAttribute
     public String getExternalHelpUrl() {
         return this.externalHelpUrl;
     }
 
     /**
      * Setter for externalHelpUrl
      *
      * @param externalHelpUrl
      */
     public void setExternalHelpUrl(String externalHelpUrl) {
         this.externalHelpUrl = externalHelpUrl;
     }
 
     /**
      * TooltipHelpContent
      *
      * @return TooltipHelpContent
      */
     @BeanTagAttribute
     public String getTooltipHelpContent() {
         return this.tooltipHelpContent;
     }
 
     /**
      * Setter for tooltipHelpContent
      *
      * @param tooltipHelpContent
      */
     public void setTooltipHelpContent(String tooltipHelpContent) {
         this.tooltipHelpContent = tooltipHelpContent;
     }
 
     /**
      * Retrieve the parameter service
      *
      * @return ParameterService
      */
     protected ParameterService getParameterService() {
         return CoreFrameworkServiceLocator.getParameterService();
     }
 }