/*
    * Copyright 2000-2001,2004 The Apache Software Foundation.
    * 
    * Licensed 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.jetspeed.util;
  
  import org.apache.turbine.util.RunData;
  
  import org.apache.jetspeed.portal.portlets.VelocityPortlet;
  import org.apache.jetspeed.portal.Portlet;
  import org.apache.jetspeed.services.logging.JetspeedLogFactoryService;
  import org.apache.jetspeed.services.logging.JetspeedLogger;
  import org.apache.jetspeed.services.persistence.PersistenceManager;
  import org.apache.jetspeed.portal.PortletInstance;
  
  /***
   * Defines standard utility functions on session attributes
   *
   * @author <a href="mailto:david@apache.org">David Sean Taylor</a>
   * @author <a href="mailto:morciuch@apache.org">Mark Orciuch</a> 
   * @version $Id: PortletSessionState.java,v 1.9 2004/02/23 03:23:42 jford Exp $
   */
  public class PortletSessionState
  {
      /***
       * Static initialization of the logger for this class
       */    
      private static final JetspeedLogger logger = JetspeedLogFactoryService.getLogger(PortletSessionState.class.getName());    
  
      /***
       * Portlet attribute to save config state.
       */
      public static final String CONFIG_CHANGED = "config_changed";
  
      /***
      Returns the parameter for this name from the Temp - session object
      */
      public static Object getAttribute(RunData rundata, String attrName)
      {
          return rundata.getUser().getTemp(attrName);
      }
  
      public static Object getAttribute(RunData rundata, String attrName, Object defValue)
      {
          Object o = rundata.getUser().getTemp(attrName, defValue);
          if (o instanceof java.lang.String && !(defValue instanceof java.lang.String))
          {
              return defValue;
          }
          return o;
      }
  
      /***
       * Sets the parameter for this name in Temp
       * Uses the portlet parameter to generate a unique key.
       */
      public static void setAttribute(RunData rundata, String attrName, Object attrValue)
      {
          rundata.getUser().setTemp(attrName, attrValue);
      }
  
      /***
       * Clears the parameter for this name from Temp
       * Uses the portlet parameter to generate a unique key.
       */
      public static void clearAttribute(RunData rundata, String attrName)
      {
          rundata.getUser().removeTemp(attrName);
      }
      
      /***
       * Returns the parameter for this name from the Temp - session object
       * Uses the portlet parameter to generate a unique key.
       */
      public static Object getAttribute(Portlet portlet, RunData rundata, String attrName)
      {
          return rundata.getUser().getTemp(generateKey(portlet, attrName));
      }
  
      /***
       * Returns the attribute for this name using the following search path:
       * <ul>
       * <li>request parameter</li>
       * <li>session attribute</li>
       * <li>instance attribute</li>     
       * <li>config parameter</li>
       * <ul>
      * Uses the portlet parameter to generate a unique key.
      * 
      * @param portlet
      * @param rundata
      * @param attrName
      * @return attribute value
      */
     public static Object getAttributeWithFallback(Portlet portlet, RunData rundata, String attrName)
     {
         Object result = null;
 
         // Look in the request first
         if(isMyRequest(rundata, portlet)) 
         {
             result =  rundata.getParameters().getString(attrName);
             if (result != null) 
             {
                 if (result.toString().trim().equalsIgnoreCase("")) 
                 {
                     clearAttribute(portlet, rundata, attrName);
                     result = null;
                 } 
                 else 
                 {
                     setAttribute(portlet, rundata, attrName, result);
                 }
             }
         }
 
         // Look in the session attributes
         if (result == null) 
         {
             result = getAttribute(portlet, rundata, attrName);
         }
 
         // Look in the instance attributes
         if (result == null)
         {
             result = portlet.getAttribute(attrName, null, rundata);
         }
         
         // Finally, look in the config
         if (result == null) 
         {
             result = portlet.getPortletConfig().getInitParameter(attrName);
         }
 
         return result;
 
     }
 
     /***
      * Returns true if the request pertains to current portlet instance. It assumes that the portlet interested in
      * recognizing its own requests, has a hidden input "js_peid". For backwards compatibility, if "js_peid" was
      * not set, this method will return TRUE.
      * 
      * @param rundata
      * @return boolean
      */
     public static boolean isMyRequest(RunData rundata, Portlet portlet) {
 
         // If the request does not contain "js_peid", assume that the portlet is not interested 
         // in isMyRequest functionality and return TRUE.
         String requestPeid = rundata.getParameters().getString("js_peid");
         if (requestPeid == null || requestPeid.equalsIgnoreCase(""))
         {
             return true;
         }
 
         // If the portlet does not have its id set, assume that the portlet is not interested
         // in isMyRequest functionality and return TRUE.
         if (portlet == null || portlet.getID() == null)
         {
             return true;
         }
 
         // Retrieve portlet instance
         String peId = null;
         PortletInstance instance = PersistenceManager.getInstance(portlet, rundata);
         if (instance != null)
         {
             peId = instance.getPortlet().getID();
         }
 
         // Compare the ids
         if (peId != null && peId.equals(requestPeid))
         {
             return true;
         }
         else
         {
             return false;
         }
     }
 
     /***
      * Sets the parameter for this name in Temp
      * Uses the portlet parameter to generate a unique key.
      */
     public static void setAttribute(Portlet portlet,
                              RunData rundata,
                              String attrName,
                              Object attrValue)
     {
         rundata.getUser().setTemp(generateKey(portlet, attrName), attrValue);
     }
 
     /***
      * Clears the parameter for this name from Temp
      * Uses the portlet parameter to generate a unique key.
      */
     public static void clearAttribute(Portlet portlet, RunData rundata, String attrName)
     {
         rundata.getUser().removeTemp(generateKey(portlet, attrName));
     }
 
     /***
      * Uses the portlet parameter to generate a unique key, using the portlet.getId.
      */
     protected static String generateKey(Portlet portlet, String name)
     {
         if (portlet != null)
         {
             return (portlet.getID()+"."+name);
         }
         else
         {
             logger.error("PortletSessionState: Passed null Velocity Portlet for name: " + name);
             return name;
         }
     }
 
     /***
      * Returns the parameter for this name from the Temp - session object
      * Uses the portlet parameter to generate a unique key.
      */
     public static Object getAttribute(VelocityPortlet portlet, RunData rundata, String attrName)
     {
         return getAttribute((Portlet) portlet, rundata, attrName);
     }
 
     /***
      * Sets the parameter for this name in Temp
      * Uses the portlet parameter to generate a unique key.
      */
     public static void setAttribute(VelocityPortlet portlet,
                              RunData rundata,
                              String attrName,
                              Object attrValue)
     {
         setAttribute((Portlet) portlet, rundata, attrName, attrValue);
     }
 
     /***
      * Clears the parameter for this name from Temp
      * Uses the portlet parameter to generate a unique key.
      */
     public static void clearAttribute(VelocityPortlet portlet, RunData rundata, String attrName)
     {
         clearAttribute((Portlet) portlet, rundata, attrName);
     }
 
     /***
      * The portlet config has changed. Calling getPortletConfigChanged returns the current state
      * and resets it.
      * 
      * @param portlet
      * @param rundata
      */
     public static void setPortletConfigChanged(Portlet portlet, RunData rundata)
     {
         setAttribute(portlet, rundata, CONFIG_CHANGED, "true");
     }
 
     /***
      * Returns current state of portlet config and resets it if set.
      * 
      * @param portlet
      * @param rundata
      * @return TRUE if portlet config has changed
      */
     public static boolean getPortletConfigChanged(Portlet portlet, RunData rundata)
     {
         String state = (String) getAttribute(portlet, rundata, CONFIG_CHANGED);
         if (state != null)
         {
             clearAttribute(portlet, rundata, CONFIG_CHANGED);
         }
 
         return state != null;
     }
 
 }