/**
    * Copyright 2005-2006 the original author or authors.
    *
    * Licensed under the Gnu General Pubic 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.opensource.org/licenses/gpl-license.php
    *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   * See the Gnu General Public License for more details.
   */
  package org.figure8.join.control.taglib;
  
  import org.figure8.join.core.ContainerContextHandler;
  import org.figure8.join.services.cache.Cache;
  import org.figure8.join.services.cache.CacheKeys;
  import org.figure8.join.services.cache.EternalCacheAccessor;
  import org.figure8.join.businessfacades.security.UserManager;
  import org.figure8.join.businessobjects.security.User;
  
  import org.apache.commons.beanutils.PropertyUtils;
  
  import javax.servlet.jsp.JspWriter;
  import javax.servlet.jsp.PageContext;
  import javax.servlet.jsp.JspException;
  import javax.servlet.jsp.JspTagException;
  import javax.servlet.http.HttpServletRequest;
  /**
   * Retrieve a user's summary from the users cache using its identifier.<br/>
   * This tag operates in one of two major modes, depending on whether or not the
   * <code>userId</code> attribute is specified. If it is included, this attribute is
   * used as the identifier for retrieving a user's summary. If it is not included,
   * <code>name</code> and <code>property</code> attributes must be provided.<br/>
   * <code>name</code> must be the name of the JSP bean (in page scope) containing
   * the user's identifier. <code>property</code> must be the propery of this bean
   * used to access identifier.
   * <br/>
   * The additional <code>link</code> boolean attribute can be set in order to display
   * (or not) a link to the page displaying user's details. Default is true.
   * @author <a href="mailto:laurent.broudoux@free.fr">Laurent Broudoux</a>
   * @version $Revision: 1.2 $
   */
  public class ResolveUserTag extends ContextTag{
  
     // Attributes ---------------------------------------------------------------
  
     /** User to resolve id */
     private String userId;
  
     /** Name of the bean to use (in some scope) */
     private String name;
     /** Property to call on bean in order to get user's id */
     private String property;
  
     /** Flag telling if user's details page should be linked. */
     private boolean link = true;
  
  
     // Public -------------------------------------------------------------------
  
     /** @return The user to resolve identifier */
     public String getUserId(){
        return userId;
     }
     /** @param userId The user to resolve identifier */
     public void setUserId(String userId){
        this.userId = userId;
     }
  
     /** @return The name of the bean containing userId */
     public String getName(){
        return name;
     }
     /** @param name The name of the bean containing userId */
     public void setName(String name){
        this.name = name;
     }
     /** @return The property to apply on bean <b>name</b> */
     public String getProperty(){
        return property;
     }
     /** @param property The property to apply on bean <b>name</b> */
     public void setProperty(String property){
        this.property = property;
     }
  
     /** @return */
     public boolean getLink(){
        return link;
     }
     /** @param link */
     public void setLink(boolean link){
        this.link = link;
     }
  
  
    // Override of TagSupport ---------------------------------------------------
 
    /**
     * Get the user's summary from Users Cache and write it on output using
     * the page JspWriter. Do not throw exception, if error occurs cause not
     * having the user's summary is not lethal ...
     */
    public int doStartTag() throws JspException{
       try{
          // First, retrieve user's identifier.
          if (userId == null){
             // Lookup bean.
             Object bean = findBeanInScope(name, "page");
             if (bean == null)
                throw new JspTagException("Unable to find bean '" + name + "' into page scope !");
             // Is it bean or property of bean ?
             if (property == null)
                userId = bean.toString();
             else{
                Object result = PropertyUtils.getProperty(bean, property);
                if (result != null)
                   userId = result.toString();
             }
          }
          // Try retrieving user from cache.
          User user = null;
          Cache userCache = getUserIdToUserCache();
          if (userCache != null)
             user = (User)userCache.get(userId);
          // If no cache or not in cache, try UserManager.
          if (user == null){
             ContainerContextHandler ctxHandler = ContainerContextHandler.getInstance();
             UserManager manager = (UserManager)ctxHandler.getComponent("userManager");
             user = manager.getUser(userId);
             if (user != null && userCache != null)
                userCache.put(user.getLogin(), user);
          }
 
          // Finally, write ouput depending on user and link.
          JspWriter writer = pageContext.getOut();
          if (link){
             HttpServletRequest request = (HttpServletRequest)pageContext.getRequest();
             StringBuffer buffer = new StringBuffer("<a href='");
             buffer.append(request.getContextPath());
             buffer.append("/action/user?op=details&amp;login=");
             buffer.append(userId).append("'>");
             writer.write(buffer.toString());
          }
          // Write user id or user summary.
          if (user == null) writer.write(userId);
          else writer.write(user.getLastname() + " " + user.getFirstname());
          // Close link.
          if (link)
             writer.write("</a>");
       }
       catch (Exception e){
          System.err.println("Exception in doStartTag() handling ResolveUserTag: " + e);
       }
       // Continue processing this page
       return (SKIP_BODY);
    }
 
    /** Release any acquired resources. */
    public int doEndTag() throws JspException{
       release();
       return (SKIP_BODY);
    }
 
    /** Release any acquired resource. */
    public void release(){
       super.release();
       userId = null;
       name = null;
       property = null;
       link = true;
    }
 
 
    // Private ------------------------------------------------------------------
 
    /** Get the cache for users or null if it is not available */
    private Cache getUserIdToUserCache(){
       // First, get the cacheAccessor.
       EternalCacheAccessor cacheAccessor = (EternalCacheAccessor)pageContext.getAttribute(
               EternalCacheAccessor.CONTEXT_KEY, PageContext.APPLICATION_SCOPE);
       // Return cache or null if no accessor.
       if (cacheAccessor != null){
          return cacheAccessor.getCache(CacheKeys.USER_ID_TO_USER_KEY);
       }
       return null;
    }
 }