/*

  * 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.view.facelets.tag.ui;

 import java.io.IOException;

 import java.util.ArrayList;

 import java.util.LinkedHashMap;

 import java.util.List;

 import java.util.Map;

 import java.util.Map.Entry;

 import javax.faces.component.UIComponent;

 import javax.faces.component.UIComponentBase;

 import javax.faces.context.FacesContext;

 import javax.faces.context.ResponseWriter;

 import javax.servlet.http.HttpServletResponse;

 import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFComponent;

 import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFJspProperty;

 import org.apache.myfaces.buildtools.maven2.plugin.builder.annotation.JSFProperty;

 import org.apache.myfaces.renderkit.ErrorPageWriter;

 import org.apache.myfaces.view.facelets.util.FastWriter;

 /**

  * The debug tag will capture the component tree and variables when it is encoded, 

  * storing the data for retrieval later. You may launch the debug window at any time 

  * from your browser by pressing 'CTRL' + 'SHIFT' + 'D' (by default).

  * 

  * The debug tag doesn't need to be used with the facelet.DEVELOPMENT parameter.

  * The best place to put this tag is in your site's main template where it can be 

  * enabled/disabled across your whole application. 

  * 

  * If your application uses multiple windows, you might want to assign different 

  * hot keys to each one.

  * 

  * @author Jacob Hookom

  * @version $Id$

  */

 @JSFComponent(name="ui:debug")

 @JSFJspProperty(name = "binding", tagExcluded=true)

 public final class UIDebug extends UIComponentBase

 {

     public static final String COMPONENT_TYPE = "facelets.ui.Debug";

     public static final String COMPONENT_FAMILY = "facelets";

     public static final String DEFAULT_HOTKEY = "D";

     private static final String KEY = "facelets.ui.DebugOutput";

     private static long nextId = System.currentTimeMillis();

     private String _hotkey = DEFAULT_HOTKEY;

     public UIDebug()

     {

         setTransient(true);

         setRendererType(null);

     }

     public String getFamily()

     {

         return COMPONENT_FAMILY;

     }

     public List<UIComponent> getChildren()

     {

         return new ArrayList<UIComponent>()

         {

             public boolean add(UIComponent o)

             {

                 throw new IllegalStateException("<ui:debug> does not support children");

             }

             public void add(int index, UIComponent o)

             {

                 throw new IllegalStateException("<ui:debug> does not support children");

             }

         };

     }

     public void encodeBegin(FacesContext faces) throws IOException

     {

         boolean partialRequest = faces.getPartialViewContext().isPartialRequest();

         String actionId = faces.getApplication().getViewHandler()

                 .getActionURL(faces, faces.getViewRoot().getViewId());

         StringBuilder sb = new StringBuilder(512);

         sb.append("<script language=\"javascript\" type=\"text/javascript\">\n");

         if (!partialRequest)

         {

             sb.append("//<![CDATA[\n");

         }

         sb.append("function faceletsDebug(URL) { day = new Date(); id = day.getTime(); eval(\"page\" + id + \" "

                   + "= window.open(URL, '\" + id + \"', 'toolbar=0,scrollbars=1,location=0,statusbar=0,menubar=0,"

                   + "resizable=1,width=800,height=600,left = 240,top = 212');\"); };");

         sb.append("var faceletsOrigKeyup = document.onkeyup; document.onkeyup = function(e) { "

                   + "if (window.event) e = window.event; if (String.fromCharCode(e.keyCode) == '"

                   + this.getHotkey() + "' & e.shiftKey & e.ctrlKey) faceletsDebug('");

         sb.append(actionId);

         int index = actionId.indexOf('?');

         if (index != -1)

         {

             sb.append('&');

         }

         else

         {

             sb.append('?');

         }

         sb.append(KEY);

         sb.append('=');

         sb.append(writeDebugOutput(faces));

         sb.append("'); else if (faceletsOrigKeyup) faceletsOrigKeyup(e); };\n");

         if (!partialRequest)

         {

             sb.append("//]]>\n");

         }

         sb.append("</script>\n");

         ResponseWriter writer = faces.getResponseWriter();

         writer.write(sb.toString());

     }

     @SuppressWarnings("unchecked")

     private static String writeDebugOutput(FacesContext faces) throws IOException

     {

         FastWriter fw = new FastWriter();

         ErrorPageWriter.debugHtml(fw, faces);

         Map<String, Object> session = faces.getExternalContext().getSessionMap();

         Map<String, String> debugs = (Map<String, String>) session.get(KEY);

         if (debugs == null)

         {

             debugs = new LinkedHashMap<String, String>()

             {

                 protected boolean removeEldestEntry(Entry<String, String> eldest)

                 {

                     return (this.size() > 5);

                 }

             };

             session.put(KEY, debugs);

         }

         String id = String.valueOf(nextId++);

         debugs.put(id, fw.toString());

         return id;

     }

     @SuppressWarnings("unchecked")

     private static String fetchDebugOutput(FacesContext faces, String id)

     {

         Map<String, Object> session = faces.getExternalContext().getSessionMap();

         Map<String, String> debugs = (Map<String, String>) session.get(KEY);

         if (debugs != null)

         {

             return debugs.get(id);

         }

         return null;

     }

     public static boolean debugRequest(FacesContext faces)

     {

         String id = (String) faces.getExternalContext().getRequestParameterMap().get(KEY);

         if (id != null)

         {

             Object resp = faces.getExternalContext().getResponse();

             if (!faces.getResponseComplete() && resp instanceof HttpServletResponse)

             {

                 try

                 {

                     HttpServletResponse httpResp = (HttpServletResponse) resp;

                     String page = fetchDebugOutput(faces, id);

                     if (page != null)

                     {

                         httpResp.setContentType("text/html");

                         httpResp.getWriter().write(page);

                     }

                     else

                     {

                         httpResp.setContentType("text/plain");

                         httpResp.getWriter().write("No Debug Output Available");

                     }

                     httpResp.flushBuffer();

                     faces.responseComplete();

                 }

                 catch (IOException e)

                 {

                     return false;

                 }

                 return true;

             }

         }

         return false;

     }

     @JSFProperty(tagExcluded=true)

     @Override

     public String getId()

     {

         // TODO Auto-generated method stub

         return super.getId();

     }

     /**

      * The hot key to use in combination with 'CTRL' + 'SHIFT' to launch the debug window. 

      * By default, when the debug tag is used, you may launch the debug window with 

      * 'CTRL' + 'SHIFT' + 'D'. This value cannot be an EL expression.

      * 

      * @return

      */

     @JSFProperty

     public String getHotkey()

     {

         return _hotkey;

     }

     public void setHotkey(String hotkey)

     {

         _hotkey = (hotkey != null) ? hotkey.toUpperCase() : "";

     }

 }