/*
    * Copyright (C) 1998-2000 Semiotek Inc.  All Rights Reserved.
    *
    * Redistribution and use in source and binary forms, with or without
    * modification, are permitted under the terms of either of the following
    * Open Source licenses:
    *
    * The GNU General Public License, version 2, or any later version, as
    * published by the Free Software Foundation
   * (http://www.fsf.org/copyleft/gpl.html);
   *
   *  or
   *
   * The Semiotek Public License (http://webmacro.org/LICENSE.)
   *
   * This software is provided "as is", with NO WARRANTY, not even the
   * implied warranties of fitness to purpose, or merchantability. You
   * assume all risks and liabilities associated with its use.
   *
   * See www.webmacro.org for more information on the WebMacro project.
   */
  
  
  package org.webmacro.servlet;
  
  import org.webmacro.Broker;
  import org.webmacro.InitException;
  import org.webmacro.Log;
  import org.webmacro.util.LogSystem;
  
  import javax.servlet.Servlet;
  import javax.servlet.ServletContext;
  import java.io.InputStream;
  import java.net.URL;
  import java.util.Properties;
  
  /***
   * An implementation of Broker tailored for Servlet 2.0/2.1
   * environments.
   * <p>
   * Loads templates and other resources from:
   * <ol>
   * <li> the class path,
   * </p>
   * writes log messages to the servlet log.
   * @author Brian Goetz
   * @author Marc Palmer (wj5@wangjammers.org)
   * @since 0.96
   */
  
  public class Servlet20Broker extends ServletBroker
  {
  
      protected ClassLoader _servletClassLoader;
  
      protected Servlet20Broker (ServletContext sc,
                               ClassLoader cl,
                               Properties additionalProperties) throws InitException
      {
          super(sc);
          _servletClassLoader = cl;
  
          String propertySource = WEBMACRO_DEFAULTS + ", " + WEBMACRO_PROPERTIES;
          loadDefaultSettings();
          loadSettings(WEBMACRO_PROPERTIES, true);
          if (additionalProperties != null && additionalProperties.keySet().size() > 0)
          {
              propertySource += ", (additional Properties)";
              loadSettings(additionalProperties);
          }
          propertySource += ", (System Properties)";
          loadSystemSettings();
          initLog(_config);
  
          _log.notice("Loaded settings from " + propertySource);
          init();
      }
  
      /***
       * Get a Servlet API 2.0 compatible broker for the Servlet specified
       * @param s The servlet
       * @param additionalProperties
       * @return The broker for the servlet context.
       * @throws InitException
       */
      public static Broker getBroker (Servlet s, Properties additionalProperties) throws InitException
      {
          ServletContext sc = s.getServletConfig().getServletContext();
          ClassLoader cl = s.getClass().getClassLoader();
          return _getBroker(sc, cl, additionalProperties, true,
                  s.getClass().getName());
      }
  
      /***
       * Get a Servlet API 2.0 compatible broker for the ServletContext specified
       * @param sc The Servlet context
       * @param cl A ClassLoader to use, presumably the webapp classloader
       * @param additionalProperties
       * @return The broker for the servlet context
      * @throws InitException
      * @since 2.1 JSDK
      */
     public static Broker getBroker (ServletContext sc, ClassLoader cl,
         Properties additionalProperties) throws InitException
     {
         return _getBroker(sc, cl, additionalProperties, false, sc.toString() );
     }
 
     /***
      * Get an existing instance of the Servlet 2.0/2.1 broker or create a new one.
      * Templates will be retrieved relative to the ServletContext root
      * and classes loaded from the ClassLoader passed in. NOTE: Templates
      * will <b>not</b> be loaded from the classpath.
      * @param sc The ServletContext to template access
      * @param cl The ClassLoader for class loading, typically servlet or
      * JSP page's class loader
      * @param additionalProperties
      * @param fromServlet true if it is actually an initialization derived from
      * a Servlet instance passed in - just for nicer logging output
      * @param servletOrContextName Name of the servlet or context originating this broker,
      * for nicer logging
      * @return The broker for the servlet context
      * @throws org.webmacro.InitException
      * @since 2.1 JSDK
      */
     protected static Broker _getBroker (ServletContext sc,
         ClassLoader cl, Properties additionalProperties, boolean fromServlet,
         String servletOrContextName) throws InitException
     {
         try
         {
             Object key = cl;
             if (additionalProperties != null && additionalProperties.keySet().size() > 0)
                 key = new PropertiesPair(cl, additionalProperties);
 
             Broker b = findBroker(key);
             if (b == null)
             {
                 b = new Servlet20Broker(sc, cl, additionalProperties);
                 register(key, b);
             }
             else
                 b.getLog("broker").notice(
                     (fromServlet ? "Servlet " : "ServletContext ")
                     + servletOrContextName
                     + " joining Broker" + " " + b.getName() );
             return b;
         }
         catch (InitException e)
         {
             Log log = LogSystem.getSystemLog("wm");
             log.error("Failed to initialized WebMacro from "+
                     (fromServlet ? "Servlet " : "ServletContext ")
                     + servletOrContextName);
             throw e;
         }
     }
 
     /***
      * Get a resource (file) from the the Broker's class loader */
     public URL getResource (String name)
     {
         URL u = _servletClassLoader.getResource(name);
         if (u == null)
             u = super.getResource(name);
         return u;
     }
 
     /***
      * Get a resource (file) from the Broker's class loader
      */
     public InputStream getResourceAsStream (String name)
     {
         InputStream is = _servletClassLoader.getResourceAsStream(name);
         if (is == null)
             is = super.getResourceAsStream(name);
         return is;
     }
 
     /***
      * Loads a class by name. Uses the servlet classloader to load the
      * class. If the class is not found uses the Broker classForName
      * implementation.  */
 
     public Class classForName (String name) throws ClassNotFoundException
     {
         Class cls = null;
         try
         {
             cls = _servletClassLoader.loadClass(name);
         }
         catch (ClassNotFoundException e)
         {
         }
 
         if (cls == null)
             cls = super.classForName(name);
 
         return cls;
     }
 
 }