/*
    * 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.captcha;
  
  import java.awt.Color;
  import java.io.IOException;
  import java.util.Map;
  
  import javax.faces.FacesException;
  import javax.faces.FactoryFinder;
  import javax.faces.component.UIComponent;
  import javax.faces.context.FacesContext;
  import javax.faces.context.FacesContextFactory;
  import javax.faces.context.ResponseStream;
  import javax.faces.context.ResponseWriter;
  import javax.faces.lifecycle.Lifecycle;
  import javax.faces.lifecycle.LifecycleFactory;
  import javax.faces.render.Renderer;
  import javax.servlet.ServletContext;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.myfaces.component.html.util.HtmlComponentUtils;
  import org.apache.myfaces.component.html.util.ParameterResourceHandler;
  import org.apache.myfaces.custom.captcha.util.CAPTCHAConstants;
  import org.apache.myfaces.custom.captcha.util.CAPTCHAImageGenerator;
  import org.apache.myfaces.custom.captcha.util.CAPTCHAResponseStream;
  import org.apache.myfaces.custom.captcha.util.CAPTCHATextGenerator;
  import org.apache.myfaces.custom.captcha.util.ColorGenerator;
  import org.apache.myfaces.renderkit.html.util.AddResource;
  import org.apache.myfaces.renderkit.html.util.AddResourceFactory;
  import org.apache.myfaces.renderkit.html.util.ResourceLoader;
  
  import org.apache.myfaces.shared_tomahawk.renderkit.html.HTML;
  
  /**
   *
   * @JSFRenderer
   *   renderKitId = "HTML_BASIC"
   *   family = "org.apache.myfaces.CAPTCHA"
   *   type = "org.apache.myfaces.CAPTCHA"
   * @since 1.1.7
   * @author Hazem Saleh
   *
   */
  public class CAPTCHARenderer extends Renderer implements ResourceLoader
  {
  
      public void encodeBegin(FacesContext context, UIComponent component)
              throws IOException
      {
  
          CAPTCHAComponent captchaComponent = (CAPTCHAComponent) component;
  
          generateImageTag(context, captchaComponent);
      }
  
      public void encodeEnd(FacesContext context, UIComponent component)
              throws IOException
      {
          super.encodeEnd(context, component);
      }
  
      /*
       * This helper method is used for generating the img tag that will
       * use the (AddResource) to generate the url of the generated image.
       */
      private void generateImageTag(FacesContext context,
              CAPTCHAComponent component) throws IOException
      {
  
          AddResource addResource;
          ResponseWriter writer = context.getResponseWriter();
          Map params = HtmlComponentUtils.getParameterMap(component);
          String url;
          String captchaSessionKeyName = component.getCaptchaSessionKeyName();
          String width = component.getImageWidth();
          String height = component.getImageHeight();
  
          // determine width and height of the generated image.
          if (width == null)
          {
              width = CAPTCHAConstants.DEFAULT_CAPTCHA_WIDTH + "";
         }
 
         if (height == null)
         {
             height = CAPTCHAConstants.DEFAULT_CAPTCHA_HEIGHT + "";
         }
 
         writer.startElement(HTML.IMG_ELEM, component);
 
         // constructing the parameter map to be passed to the (AddResource).
         if (captchaSessionKeyName != null)
         {
             params.put(CAPTCHAComponent.ATTRIBUTE_CAPTCHA_SESSION_KEY_NAME,
                     captchaSessionKeyName);
         }
 
         // write the url to trigger the (AddResource).
         addResource = AddResourceFactory.getInstance(context);
 
         url = context.getExternalContext().encodeResourceURL(
                 addResource.getResourceUri(context,
                         new ParameterResourceHandler(this.getClass(), params)));
 
         // adding dummy parameter to prevent caching.
         writer.writeAttribute(HTML.SRC_ATTR, url + "&dummyParameter="
                 + System.currentTimeMillis(), null);
 
         // write rest of attributes.
         writer.writeAttribute(HTML.WIDTH_ATTR, width, null);
 
         writer.writeAttribute(HTML.HEIGHT_ATTR, height, null);
 
         writer.endElement(HTML.IMG_ELEM);
     }
 
     /*
      * This method is implemented to be called from the (AddResource).
      * It wraps the CAPTCHA image generation.
      */
     public void serveResource(ServletContext servletContext,
             HttpServletRequest request, HttpServletResponse response,
             String resourceUri) throws IOException
     {
 
         // get the FacesContext from the ServletContext.
         FacesContextFactory facesContextFactory = (FacesContextFactory) FactoryFinder
                 .getFactory(FactoryFinder.FACES_CONTEXT_FACTORY);
         LifecycleFactory lifecycleFactory = (LifecycleFactory) FactoryFinder
                 .getFactory(FactoryFinder.LIFECYCLE_FACTORY);
         Lifecycle lifecycle = lifecycleFactory.getLifecycle(HtmlComponentUtils
                 .getLifecycleId(servletContext));
         FacesContext facesContext = facesContextFactory.getFacesContext(
                 servletContext, request, response, lifecycle);
         facesContext.setResponseStream(new CAPTCHAResponseStream(response
                 .getOutputStream()));
 
         // render the CAPTCHA.
         try
         {
             try
             {
                 renderCAPTCHA(facesContext);
             }
             catch (IOException e)
             {
                 throw new FacesException("Could not render the CAPTCHA : "
                         + e.getMessage(), e);
             }
             facesContext.getResponseStream().close();
         }
         finally
         {
             facesContext.release();
         }
     }
 
     /*
      * This method is used for rendering the CAPTCHA component.
      */
     protected void renderCAPTCHA(FacesContext facesContext) throws IOException
     {
 
         // getting CAPTCHA attributes.
         HttpServletResponse response = (HttpServletResponse) facesContext
                 .getExternalContext().getResponse();
         ResponseStream out = facesContext.getResponseStream();
         Map requestMap = facesContext.getExternalContext()
                 .getRequestParameterMap();
         String captchaSessionKeyName = requestMap.get(
                 CAPTCHAComponent.ATTRIBUTE_CAPTCHA_SESSION_KEY_NAME).toString();
 
         // construct the CAPTCHA image generator object.
         CAPTCHAImageGenerator captchaImageGenerator = new CAPTCHAImageGenerator();
 
         try
         {
             String captchaText;
             Color endingColor = ColorGenerator.generateRandomColor(null);
             Color startingColor = ColorGenerator
                     .generateRandomColor(endingColor);
 
             // Generate random CAPTCHA text.
             captchaText = CAPTCHATextGenerator.generateRandomText();
 
             // Set the generated text in the user session.
             facesContext.getExternalContext().getSessionMap().put(
                     captchaSessionKeyName, captchaText);
 
             // Generate the image, the BG color is randomized from starting to ending colors.
             captchaImageGenerator.generateImage(response, captchaText,
                     startingColor, endingColor);
         }
         finally
         {
             out.close();
             facesContext.responseComplete();
         }
     }
 }