/*
    * 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.dialog;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.List;
  import java.util.StringTokenizer;
  
  import javax.faces.component.UIComponent;
  import javax.faces.context.FacesContext;
  import javax.faces.context.ResponseWriter;
  
  import org.apache.myfaces.custom.dojo.DojoUtils;
  import org.apache.myfaces.renderkit.html.util.AddResource;
  import org.apache.myfaces.renderkit.html.util.AddResourceFactory;
  import org.apache.myfaces.shared_tomahawk.renderkit.JSFAttr;
  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.HtmlRenderer;
  import org.apache.myfaces.shared_tomahawk.renderkit.html.HtmlRendererUtils;
  
  /**
   * Renderer for the s:modalDialog component.
   * <p>
   * This component works in one of two different ways:
   * <ul>
   * <li>The component can contain child components, in which case the child components
   * are initially hidden but are displayed in a "popup" modal window when the "show"
   * javascript method is invoked. In this mode, a DIV is rendered to wrap the child
   * components. 
   * <li>The component can have a "viewId" property defined, in which case the specified
   * JSF view will be fetched into a "popup" modal window when the "show" javascript
   * method is invoked. In this mode, a DIV containing an IFrame is rendered into the
   * html page; the iframe is used to load the specified view.
   * </ul>
   * It is the page author's responsibility to have some other HTML control on the
   * page whose "onclick" attribute contains javascript to invoke the "show" method
   * of the modal dialog. Component property "dialogVar" specifies the name of a global
   * javascript variable to be created, and its "show" method can be invoked to display
   * the popup.
   * <p>
   * The Dojo library uses css tricks to make the DIV component act like a modal
   * window.
   * 
   * @JSFRenderer
   *   renderKitId = "HTML_BASIC" 
   *   family = "javax.faces.Panel"
   *   type = "org.apache.myfaces.ModalDialog"
   */
  public class ModalDialogRenderer extends HtmlRenderer
  {
      public static final String RENDERER_TYPE = "org.apache.myfaces.ModalDialog";
  
      public static final String DIV_ID_PREFIX = "_div";
  
      /**
       * Writes a DIV opening tag, plus javascript to make sure that the Dojo
       * library is initialised.
       */
      //@Override
      public void encodeBegin(FacesContext context, UIComponent component)
              throws IOException
      {
          String javascriptLocation = (String) component.getAttributes().get(JSFAttr.JAVASCRIPT_LOCATION);
          DojoUtils.addMainInclude(context, component, javascriptLocation,
                                   DojoUtils.getDjConfigInstance(context));
          DojoUtils.addRequire(context, component, "dojo.widget.Dialog");
  
          writeModalDialogBegin(context, (ModalDialog) component, context.getResponseWriter());
      }
  
      //@Override
      /**
       * Writes a DIV closing tag, plus javascript to declare the global "dialogVar"
       * object that can be invoked to show the modal dialog.
       */
      public void encodeEnd(FacesContext context, UIComponent component) throws IOException
      {
          ModalDialog dlg = (ModalDialog) component;
  
         StringBuffer buf = new StringBuffer();
 
         buf.append("</div>");
 
         writeDialogLoader(context, dlg, buf);
 
         context.getResponseWriter().write(buf.toString());
 
         if (dlg.getViewId() != null)
         {
             // when getViewId is set, we did not render the children in the
             // encodeChildren method, so instead do it now.
             RendererUtils.renderChildren(context, component);
             HtmlRendererUtils.writePrettyLineSeparator(context);
         }
     }
 
     private void appendHiderIds(StringBuffer buf, ModalDialog dlg)
     {
         List hiders = new ArrayList();
 
         if (dlg.getHiderIds() != null)
         {
             hiders.addAll(Arrays.asList(dlg.getHiderIds().split(",")));
         }
 
         if (isRenderCloseButton(dlg) && dlg.getDialogTitle() != null)
         {
             hiders.add(dlg.getDialogVar() + "Closer");
         }
 
         for (int i = 0; i < hiders.size(); i++)
         {
             String varName = "btn" + i;
             buf
                 .append("var ")
                 .append(varName)
                 .append(" = document.getElementById(\"")
                 .append(((String) hiders.get(i)).trim())
                 .append("\");")
 
                 .append(dlg.getDialogVar())
                 .append(".setCloseControl(")
                 .append(varName)
                 .append(");");
         }
     }
 
     private void appendDialogAttributes(StringBuffer buf, ModalDialog dlg)
     {
         if(dlg.getDialogAttr() == null)
         {
             return;
         }
 
         StringTokenizer it = new StringTokenizer(dlg.getDialogAttr(), " ");
         while(it.hasMoreElements())
         {
             String[] pair = it.nextToken().split("=");
             String attribute = pair[0];
             String value = pair[1].replaceAll("'", "");
             try
             {
                 // try to parse a double from the attribute value
                 new Double(value);
             }
             catch(NumberFormatException e)
             {
                 // parsing failed - attribute is not numeric
                 value = new StringBuffer("\"").append(value).append("\"").toString();
             }
             buf
                 .append(", ")
                 .append(attribute)
                 .append(":")
                 .append(value);
         }
     }
 
     /**
      * Write an html DIV whose css style the Dojo library will manipulate to make it
      * look like a popup window. 
      * <p>
      * The child components (or the nested iframe) will be rendered inside this div.
      */
     private void writeModalDialogBegin(FacesContext context, ModalDialog dlg, ResponseWriter writer)
     throws IOException
     {
         StringBuffer buf = new StringBuffer();
 
         String dlgId = getDialogWrapperId(dlg);
         buf.append("<div id=\"").append(dlgId).append("\"");
         if(dlg.getStyle() != null)
         {
             buf.append(" style=\"").append(dlg.getStyle()).append("\"");
         }
         if(dlg.getStyleClass() != null)
         {
             buf.append(" class=\"").append(dlg.getStyleClass()).append("\"");
         }
         buf.append(">");
 
         writer.write(buf.toString());
     }
 
     /**
      * Gets the id for the HTML wrapper of the dialog.
      * @param dlg
      * @return
      */
     private String getDialogWrapperId(ModalDialog dlg)
     {
         // use dlg.getDialogId() with prefix if it is non-null,
         // otherwise use the component id.
         
         String dlgId = dlg.getDialogId() != null ?
                        new StringBuffer(dlg.getDialogId()).append(DIV_ID_PREFIX).toString() :
                        dlg.getId();
         return dlgId;
     }
 
     /**
      * Write a javascript block that declares a single global variable of type Object that
      * provides methods for showing and hiding the modal dialog.
      * <p>
      * The name of the javascript variable is specified by component property "dialogVar".
      */
     private String writeDialogLoader(FacesContext context, ModalDialog dlg, StringBuffer buf)
     {
         String dlgWrapperId = getDialogWrapperId(dlg);
         String dialogVar = dlg.getDialogVar();
         buf.append("<script type=\"text/javascript\">");
 
         // Declare a global variable whose name is specified by dialogVar.
         // This variable will be initialized to point to a Dojo Widget object
         // when page load is complete.
         buf.append("var ").append(dialogVar).append(";");
 
         // Declare a function that will be called on page load to initialize dialogVar
         buf .append("function " + dialogVar + "_loader(e) {")
             .append(dialogVar)
             .append(" = dojo.widget.createWidget(\"dialog\", {id:")
             .append("\"")
             .append(dlg.getDialogId()) // use the dialogId from the component attribute
             .append("\"");
 
         appendDialogAttributes(buf, dlg);
 
         buf.append("}, dojo.byId(\"").append(dlgWrapperId).append("\"));");
 
         appendHiderIds(buf, dlg);
 
         String viewId = dlg.getViewId();
         String contentURL = dlg.getContentURL();
         if (viewId != null)
         {
             StringBuffer sbUrl = new StringBuffer();
             sbUrl.append(context.getExternalContext().getRequestContextPath());
             sbUrl.append("/");
             sbUrl.append(viewId);
             String encodedUrl = context.getExternalContext().encodeActionURL(sbUrl.toString());
             appendShowHideView(context, buf, dialogVar, encodedUrl);
         }
         else if (contentURL != null)
         {
             String encodedUrl = context.getExternalContext().encodeActionURL(contentURL);
             appendShowHideView(context, buf, dialogVar, encodedUrl);
         }
 
         buf.append("}");
 
         // Emit some global javascript that causes the initialization function
         // defined above.
         //
         // We cannot use a standard javascript setTimeout call, as this breaks the
         // submitOnEvent component.
         //
         // We cannot call the loader function immediately, as it appears that this
         // breaks IE sometimes (always?).
         //
         // So it looks like using dojo's addOnLoad function is the best solution.. 
         buf.append("dojo.addOnLoad(function() {" + dialogVar + "_loader();});");
 
         buf.append("</script>");
         return dlgWrapperId;
     }
 
     /**
      * This is invoked only when the ModalDialog component has a viewId property
      * defined, ie the dialog should automatically load a specific JSF view when
      * it is shown.
      * <p>
      * Javascript is generated which override the standard Dojo modal dialog
      * show and hide methods to do some initialisation, including loading the
      * required view into the iframe.
      */
     private void appendShowHideView(
             FacesContext context,
             StringBuffer buf,
             String dialogVar,
             String url)
     {
         // save original onShow function (the standard dojo widget implementation)
         buf .append(dialogVar)
             .append(".oldOnShow=")
             .append(dialogVar)
             .append(".onShow;");
 
         // Define a new onShow function which first shows the modal window then
         // causes it to do a GET to the server to fetch a specific page that is
         // defined by the "url" parameter (which is defined via property viewId
         // or contentURL on the JSF component).
         //
         // TODO: What is the purpose of variable window._myfaces_currentModal?
         // There doesn't appear to be anything that *reads* it...
         //
         // TODO: What is the purpose of ${dialogVar}._myfaces_ok? Nothing appears
         // to read it. 
         buf .append(dialogVar)
             .append(".onShow = function() {")
             .append("this.oldOnShow();")
             .append("var content = document.getElementById(\"modalDialogContent")
             .append(dialogVar)
             .append("\"); ")
             .append("window._myfaces_currentModal=")
             .append(dialogVar)
             .append("; ")
             .append(dialogVar)
             .append("._myfaces_ok=false; ")
             .append("content.contentWindow.location.replace('")
             .append(url)
             .append("'); ")
             .append("}; ");
 
         // save original onHide function (the standard dojo widget implementation)
         buf .append(dialogVar)
             .append(".oldOnHide=")
             .append(dialogVar)
             .append(".onHide;");
 
         // Define a new onHide function which first shows the modal window then
         // causes it to do a GET to the server to fetch a specific page that is
         // defined by the "viewId" property on the JSF component.
         buf .append(dialogVar)
             .append(".onHide = function() {")
             .append("this.oldOnHide();")
             .append("window._myfaces_currentModal=null;")
             .append("var content = document.getElementById(\"modalDialogContent")
             .append(dialogVar)
             .append("\"); ")
             .append("content.contentWindow.location.replace('javascript:false;'); ")
             .append("}; ");
     }
 
     public boolean getRendersChildren()
     {
         return true;
     }
 
     /**
      * Override normal "encodeChildren" method to render the necessary dynamic
      * parts of this component as well as the children.
      * <p>
      * If the user specified a titleBar facet, then that is rendered as the
      * "window decoration" for the popup window. Otherwise if the user specified
      * a dialogTitle, then a standard "window decoration" is rendered.
      * <p>
      * Then if the user did NOT specify a content page to be loaded into the popup,
      * then the rest of the child components are rendered as normal.
      * <p>
      * But if the user DID specify a content page to be loaded, then an empty
      * IFrame is rendered (javascript will be used to load it later), and the
      * rendering of the child components is delayed until the encodeEnd method.
      * TODO: why is child component rendering delayed?
      *
      * @see javax.faces.render.Renderer#encodeChildren(javax.faces.context.FacesContext,
      *      javax.faces.component.UIComponent)
      */
     public void encodeChildren(FacesContext facesContext, UIComponent uiComponent) throws IOException
     {
         ModalDialog dlg = (ModalDialog) uiComponent;
         ResponseWriter writer = facesContext.getResponseWriter();
 
         UIComponent titleFacet = dlg.getFacet("titleBar");
         if (titleFacet != null)
         {
             RendererUtils.renderChild(facesContext, titleFacet);
         }
         else if (dlg.getDialogTitle() != null)
         {
             AddResourceFactory.getInstance(facesContext).addStyleSheet(facesContext, AddResource.HEADER_BEGIN,  ModalDialog.class, "modalDialog.css");
 
             writer.startElement(HTML.TABLE_ELEM, dlg);
             writer.writeAttribute(HTML.CLASS_ATTR, "modalDialogDecoration " + getStyleName(dlg, "Decoration") , null);
             writer.writeAttribute(HTML.CELLPADDING_ATTR, "2", null);
             writer.writeAttribute(HTML.CELLSPACING_ATTR, "0", null);
 
             writer.startElement(HTML.TR_ELEM, dlg);
             writer.writeAttribute(HTML.CLASS_ATTR, "modalDialogTitle " + getStyleName(dlg, "Title"), null);
 
             writer.startElement(HTML.TD_ELEM, dlg);
             writer.writeAttribute(HTML.CLASS_ATTR, "modalDialogTitleLeft " + getStyleName(dlg, "TitleLeft"), null);
             writer.writeText(dlg.getDialogTitle(), null);
             writer.endElement(HTML.TD_ELEM);
 
             writer.startElement(HTML.TD_ELEM, dlg);
             writer.writeAttribute(HTML.CLASS_ATTR, "modalDialogTitleRight " + getStyleName(dlg, "TitleRight"), null);
             if (isRenderCloseButton(dlg))
             {
                 String imageUri = AddResourceFactory.getInstance(facesContext).getResourceUri(facesContext, ModalDialog.class, "close.gif");
                 writer.startElement(HTML.IMG_ELEM, dlg);
                 writer.writeAttribute(HTML.ID_ATTR, dlg.getDialogVar() + "Closer", null);
                 writer.writeAttribute(HTML.SRC_ATTR, imageUri, null);
                 writer.writeAttribute(HTML.CLASS_ATTR, "modalDialogCloser " + getStyleName(dlg, "Closer"), null);
                 writer.endElement(HTML.IMG_ELEM);
             }
             writer.endElement(HTML.TD_ELEM);
 
             writer.endElement(HTML.TR_ELEM);
             writer.endElement(HTML.TABLE_ELEM);
         }
 
         if ((dlg.getViewId() != null) || (dlg.getContentURL() != null))
         {
             renderDialogViewFrame(facesContext, dlg);
             // TODO: why are the rest of the child components not rendered here?
             // is it so that subclasses of this component can insert stuff between
             // the iframe and the normal children? 
         }
         else
         {
             RendererUtils.renderChildren(facesContext, uiComponent);
             HtmlRendererUtils.writePrettyLineSeparator(facesContext);
         }
     }
 
     protected boolean isRenderCloseButton(ModalDialog dlg)
     {
         return !Boolean.FALSE.equals(dlg.getCloseButton());
     }
 
     private String getStyleName(ModalDialog dlg, String suffix)
     {
         if (dlg.getStyleClass() != null)
         {
             return dlg.getStyleClass() + suffix;
         }
 
         return "";
     }
 
     /**
      * Invoked only when the ModalDialog component has property viewId or contentURL defined.
      */
     private void renderDialogViewFrame(FacesContext facesContext, ModalDialog dlg) throws IOException
     {
         ResponseWriter writer = facesContext.getResponseWriter();
 
         writer.startElement(HTML.IFRAME_ELEM, dlg);
         writer.writeAttribute(HTML.ID_ATTR, "modalDialogContent" + dlg.getDialogVar(), null);
         writer.writeAttribute(HTML.CLASS_ATTR, "modalDialogContent " + getStyleName(dlg, "Content"), null);
         writer.writeAttribute(HTML.SCROLLING_ATTR, "auto", null);
         writer.writeAttribute(HTML.FRAMEBORDER_ATTR, "0", null);
         writer.endElement(HTML.IFRAME_ELEM);
     }
 }