/*
  Copyright (C) 2006 Helge Hess

  This file is part of JOPE.

  JOPE is free software; you can redistribute it and/or modify it under
  the terms of the GNU Lesser General Public License as published by the
  Free Software Foundation; either version 2, or (at your option) any
  later version.

  JOPE 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 Lesser General Public
  License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with JOPE; see the file COPYING.  If not, write to the
  Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  02111-1307, USA.
*/

package org.opengroupware.jope.appserver.core;

import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

/*
 * WOResourceRequestHandler
 * 
 * TODO: document
 */
public class WOResourceRequestHandler extends WORequestHandler {

  public WOResourceRequestHandler(WOApplication _app) {
    super(_app);
  }

  @Override
  public WOResponse handleRequest(WORequest _rq, WOContext _ctx, WOSession _s) {
    boolean isFavIcon = "/favicon.ico".equals(_rq.uri());
    
    /* decode URL */
    
    String[] handlerPath = _rq.requestHandlerPathArray();
    if (!isFavIcon && (handlerPath == null || handlerPath.length < 1)) {
      log.error("URL resource path too short / missing.");
      return null;
    }
    
    List<String> langList = _ctx.languages();
    String[] langs = null;
    String   resourceName;
    
    if (isFavIcon)
      resourceName = "favicon.ic";
    else if (handlerPath.length > 1) {
      resourceName = handlerPath[1];
      langList     = new ArrayList<String>(langList);
      langList.add(0, handlerPath[0]);
    }
    else
      resourceName = handlerPath[0];
    
    resourceName = "www/" + resourceName;
    langs        = langList.toArray(new String[0]);

    if (log.isDebugEnabled())
      log.debug("lookup resource: " + resourceName);
    
    /* find resource manager and deliver */
    
    WOResourceManager rm = _ctx.application().resourceManager();
    WOResponse        r  = _ctx.response();

    if (log.isDebugEnabled())
      log.debug("lookup resource using manager: " + rm);
    
    InputStream is = rm.inputStreamForResourceNamed(resourceName, langs);
    if (is == null) {
      log.error("did not find resource: " + resourceName);
      r.setStatus(WOMessage.HTTP_STATUS_NOT_FOUND);
      return r;
    }
    
    // TODO: retrieve resource metadata (content-type, length)
    
    r.enableStreaming();
    try {
      byte[] buffer = new byte[4096]; // TODO: adjust buffer size?
      
      while (true) {
        int len = is.read(buffer);
        if (len == -1)
          break;
        
        if (r.appendContentData(buffer, len) != null) {
          log.error("failed to write resource data", r.lastException());
          break;
        }
      }
    }
    catch (IOException e) {
      log.error("failed to read resource data", e);
    }
    
    return r;
  }

}