/*
    * 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.portals.bridges.portletfilter;
  
  import java.io.IOException;
  import java.util.Enumeration;
  import java.util.Locale;
  import java.util.ResourceBundle;
  
  import javax.portlet.ActionRequest;
  import javax.portlet.ActionResponse;
  import javax.portlet.GenericPortlet;
  import javax.portlet.Portlet;
  import javax.portlet.PortletConfig;
  import javax.portlet.PortletContext;
  import javax.portlet.PortletException;
  import javax.portlet.RenderRequest;
  import javax.portlet.RenderResponse;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  /***
   * FilterPortlet provides a portlet implementation to filter the 
   * specified portlet. The filtered portlet and filters are defined in 
   * a portlet descriptor(portlet.xml).  The filetered portlet is specified
   * by portlet-class, and the filters are specified by portlet-filters.
   * 
   * Example:
   * <pre>
   * &lt;portlet-app id="example-portlets" version="1.0"&gt;
   *    &lt;portlet id="ExamplePortlet"&gt;
   * ...
   *        &lt;init-param&gt;
   *            &lt;name&gt;portlet-class&lt;/name&gt;
   *            &lt;value&gt;org.apache.myfaces.portlet.MyFacesGenericPortlet&lt;/value&gt;
   *        &lt;/init-param&gt;
   *        &lt;init-param&gt;
   *            &lt;name&gt;portlet-filters&lt;/name&gt;
   *            &lt;value&gt;org.apache.myfaces.portlet.TomahawkPortletFilter&lt;/value&gt;
   *        &lt;/init-param&gt;
   *        &lt;init-param&gt;
   *            &lt;name&gt;org.apache.myfaces.portlet.TomahawkPortletFilter:upload-threshold-size&lt;/name&gt;
   *            &lt;value&gt;1m&lt;/value&gt;
   *        &lt;/init-param&gt;
   *        &lt;init-param&gt;
   *            &lt;name&gt;org.apache.myfaces.portlet.TomahawkPortletFilter:upload-max-file-size&lt;/name&gt;
   *            &lt;value&gt;10m&lt;/value&gt;
   *        &lt;/init-param&gt;
   * ...
   * </pre>
   * 
   * @author <a href="mailto:shinsuke@yahoo.co.jp">Shinsuke Sugaya</a>
   */
  public class FilterPortlet extends GenericPortlet
  {
      private static final Log log = LogFactory.getLog(FilterPortlet.class);
  
      public static final String PORTLET_CLASS = "portlet-class";
  
      private PortletFilterChain portletFilterChain;
  
      private Portlet portlet;
  
      public void init(PortletConfig config) throws PortletException
      {
          super.init(config);
          if (log.isTraceEnabled())
          {
              log.trace("Initializing FilterPortlet.");
          }
  
          // create Portlet
          String portletClassName = config.getInitParameter(PORTLET_CLASS);
          if (portletClassName == null)
          {
              throw new PortletException("Portlet Class Name is null.");
          }
  
          // create PortletFilterChain
          portletFilterChain = new PortletFilterChain(config);
  
          portlet = null;
          try
          {
             Class portletClass = Class.forName(portletClassName);
             Object portletObj = portletClass.newInstance();
             if (portletObj instanceof Portlet)
             {
                 portlet = (Portlet) portletObj;
                 portlet.init(config);
             }
             else
             {
                 throw new PortletException(portletClassName + " is not Portlet instance.");
             }
         }
         catch (ClassNotFoundException e)
         {
             throw new PortletException("Class " + portletClassName + " is not found.", e);
         }
         catch (InstantiationException e)
         {
             throw new PortletException("Could not instantiate " + portletClassName + ".", e);
         }
         catch (IllegalAccessException e)
         {
             throw new PortletException("Illegal Access: " + portletClassName, e);
         }
 
         portletFilterChain.setPortlet(portlet);
     }
 
     public void processAction(ActionRequest request, ActionResponse response) throws PortletException, IOException
     {
         if (log.isTraceEnabled())
         {
             log.trace("called processAction method.");
         }
         portletFilterChain.reset();
         portletFilterChain.processActionFilter(request, response);
     }
 
     public void render(RenderRequest request, RenderResponse response) throws PortletException, IOException
     {
         if (log.isTraceEnabled())
         {
             log.trace("called render method.");
         }
         portletFilterChain.reset();
         portletFilterChain.renderFilter(request, response);
     }
 
     public void destroy()
     {
         if (log.isTraceEnabled())
         {
             log.trace("called destory method.");
         }
         portletFilterChain.release();
         portlet.destroy();
         portlet = null;
         portletFilterChain = null;
     }
 
     /* (non-Javadoc)
      * @see javax.portlet.PortletConfig#getInitParameter(java.lang.String)
      */
     public String getInitParameter(String arg0)
     {
         if (portlet instanceof PortletConfig)
         {
             return ((PortletConfig) portlet).getInitParameter(arg0);
         }
         return super.getInitParameter(arg0);
     }
 
     /* (non-Javadoc)
      * @see javax.portlet.PortletConfig#getInitParameterNames()
      */
     public Enumeration getInitParameterNames()
     {
         if (portlet instanceof PortletConfig)
         {
             return ((PortletConfig) portlet).getInitParameterNames();
         }
         return super.getInitParameterNames();
     }
 
     /* (non-Javadoc)
      * @see javax.portlet.PortletConfig#getPortletContext()
      */
     public PortletContext getPortletContext()
     {
         if (portlet instanceof PortletConfig)
         {
             return ((PortletConfig) portlet).getPortletContext();
         }
         return super.getPortletContext();
     }
 
     /* (non-Javadoc)
      * @see javax.portlet.PortletConfig#getPortletName()
      */
     public String getPortletName()
     {
         if (portlet instanceof PortletConfig)
         {
             return ((PortletConfig) portlet).getPortletName();
         }
         return super.getPortletName();
     }
 
     /* (non-Javadoc)
      * @see javax.portlet.PortletConfig#getResourceBundle(java.util.Locale)
      */
     public ResourceBundle getResourceBundle(Locale arg0)
     {
         if (portlet instanceof PortletConfig)
         {
             return ((PortletConfig) portlet).getResourceBundle(arg0);
         }
         return super.getResourceBundle(arg0);
     }
 }