/*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache 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.apache.org/licenses/LICENSE-2.0
   *
   * 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.apache.myfaces.custom.toggle;
  
  import java.io.IOException;
  import java.lang.reflect.Method;
  import java.util.Iterator;
  import java.util.List;
  
  import javax.faces.component.UIComponent;
  import javax.faces.context.FacesContext;
  import javax.faces.context.ResponseWriter;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.myfaces.renderkit.html.util.AddResource;
  import org.apache.myfaces.renderkit.html.util.AddResourceFactory;
  import org.apache.myfaces.shared_tomahawk.renderkit.RendererUtils;
  import org.apache.myfaces.shared_tomahawk.renderkit.html.HTML;
  import org.apache.myfaces.shared_tomahawk.renderkit.html.HtmlGroupRendererBase;
  
  /**
   * 
   * @JSFRenderer
   *   renderKitId = "HTML_BASIC" 
   *   family = "javax.faces.Panel"
   *   type = "org.apache.myfaces.TogglePanel"
   * 
   */
  public class TogglePanelRenderer extends HtmlGroupRendererBase {
  
      private static Log log = LogFactory.getLog(TogglePanelRenderer.class);
  
      public void encodeEnd(FacesContext context, UIComponent component) throws IOException {
          RendererUtils.checkParamValidity(context, component, TogglePanel.class);
          addToggleLinkJavascript(context);
          
          TogglePanel togglePanel = (TogglePanel) component;
          boolean toggleMode = togglePanel.isToggled();
          toggleVisibility(togglePanel.getChildren(), toggleMode);
          
          // render the hidden input field
          ResponseWriter writer = context.getResponseWriter();
  
          String hiddenFieldId = getHiddenFieldId(context, togglePanel);
  
          writer.startElement(HTML.INPUT_ELEM, component);
          writer.writeAttribute(HTML.TYPE_ATTR, HTML.INPUT_TYPE_HIDDEN, null);
          writer.writeAttribute(HTML.ID_ATTR, hiddenFieldId, null);
          writer.writeAttribute(HTML.NAME_ATTR, hiddenFieldId, null);
  
          writer.writeAttribute(HTML.VALUE_ATTR, toggleMode ? "1" : "", null);
  
          writer.endElement(HTML.INPUT_ELEM);
  
          super.encodeEnd(context, togglePanel);
      }
  
      private void toggleVisibility(List children, boolean toggleMode) {
          for(Iterator it = children.iterator(); it.hasNext(); ) {
              UIComponent component = (UIComponent) it.next();
              setComponentVisibility( component, toggleMode );
          }
      }
  
      // checks if this component has getStyle/setStyle methods
      public static boolean hasStyleAttribute(UIComponent component) {
          Method[] methods = component.getClass().getMethods();
  
          for (int i = 0; i < methods.length; i++) {
              Method method = methods[i];
              if (method.getName().equals("getStyle")) {
                  return true;
              }
          }
          return false;
      }
  
      // hides component by appending 'display:none' to the 'style' attribute
      public static void setComponentVisibility(UIComponent component, boolean toggleMode) {
          FacesContext context = FacesContext.getCurrentInstance();
  
          if (!hasStyleAttribute(component)) {
             log.info("style attribute expected, not found for component " + component.getClientId(context));
             return;
         }
 
         try {
             Class c = component.getClass();
             Method getStyle = c.getMethod("getStyle", new Class[] {});
             Method setStyle = c.getMethod("setStyle", new Class[] { String.class });
 
             String style = (String) getStyle.invoke(component, new Object[] {});
             
             boolean display = toggleMode != isHiddenWhenToggled(component);
             if( display ){
                 if (style == null || style.length() == 0) {
                     return;
                 } else {
                     int index = style.indexOf(";display:none;");
                     if (index == -1)
                         return;
 
                     if (index == 0) {
                         style = null;
                     } else {
                         style = style.substring(0, index);
                     }
                 }
             }else{ // hide
                 if (style == null) {
                     style = ";display:none;";
                 } else if (style.indexOf("display:none;") == -1) {
                     style = style.concat(";display:none;");
                 }
             }
 
             setStyle.invoke(component, new Object[] { style });
         } catch (Throwable e) {
             log.error("unable to set style attribute on component " + component.getClientId(context));
         }
     }
 
     public static boolean isHiddenWhenToggled(UIComponent component){
         return component instanceof ToggleLink || component instanceof ToggleGroup;
     }
 
     private String getHiddenFieldId(FacesContext context, TogglePanel togglePanel){
         return togglePanel.getClientId(context) + "_hidden";
     }
 
     static public String getToggleJavascriptFunctionName(FacesContext context, TogglePanel togglePanel) {
         return "MyFacesToggleLinkUtils.toggle";
     }
     
     public void addToggleLinkJavascript(FacesContext context)throws IOException {
         AddResource addResource = AddResourceFactory.getInstance(context);
         
         addResource.addJavaScriptAtPosition(context, AddResource.HEADER_BEGIN, AbstractTogglePanel.class, "MyFacesToggleLink.js");
     }
 }