/*
** Rachel  - Resource Loading Toolkit for Web Start/JNLP
** Copyright (c) 2001, 2002 by Gerald Bauer
**
** This program is free software.
**
** You may redistribute it and/or modify it under the terms of the GNU
** General Public License as published by the Free Software Foundation.
** Version 2 of the license should be included with this distribution in
** the file LICENSE, as well as License.html. If the license is not
** included with this distribution, you may find a copy at the FSF web
** site at 'www.gnu.org' or 'www.fsf.org', or you may write to the
** Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139 USA.
**
** THIS SOFTWARE IS PROVIDED AS-IS WITHOUT WARRANTY OF ANY KIND,
** NOT EVEN THE IMPLIED WARRANTY OF MERCHANTABILITY. THE AUTHOR
** OF THIS SOFTWARE, ASSUMES _NO_ RESPONSIBILITY FOR ANY
** CONSEQUENCE RESULTING FROM THE USE, MODIFICATION, OR
** REDISTRIBUTION OF THIS SOFTWARE.
**
*/

package rachel.http.loader;

import java.util.*;
import houston.*;
import rachel.http.*;
import rachel.http.resource.*;
import rachel.util.*;

public class WebResourceManager implements WebResourceLoader
{
   static Logger T = Logger.getLogger( WebResourceManager.class );

   private static WebResourceManager _instance;

   private static ArrayList _resourceLoaders = new ArrayList();

   /**
    *  WebResourceManager is a singleton, don't allow creation of any instances
    *  outside this class.
    */
   private WebResourceManager() { }

   public static WebResourceManager getInstance()
   {
      if( _instance == null )
         _instance = new WebResourceManager();

      return _instance;
   }

   public WebResource getResource( String name )
   {
      for( int i = 0; i < _resourceLoaders.size(); i++ )
      {
         WebResourceLoader resourceLoader = ( WebResourceLoader ) _resourceLoaders.get( i );
         WebResource res = resourceLoader.getResource( name );
         if( res != null )
            // bingo!
            return res;
      }

      T.error( "*** resource " + name + " not found" );

      // resource not found
      return new ErrorResource( Http.Error.NOT_FOUND_404 );
   }

   public static void addResourceLoader( WebResourceLoader loader )
   {
      getInstance().addResourceLoaderImpl( loader );
   }

   private void addResourceLoaderImpl( WebResourceLoader loader )
   {
      _resourceLoaders.add( loader );
   }

}