/**
    * This file Copyright (c) 2003-2010 Magnolia International
    * Ltd.  (http://www.magnolia-cms.com). All rights reserved.
    *
    *
    * This file is dual-licensed under both the Magnolia
    * Network Agreement and the GNU General Public License.
    * You may elect to use one or the other of these licenses.
    *
   * This file is distributed in the hope that it will be
   * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
   * implied warranty of MERCHANTABILITY or FITNESS FOR A
   * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
   * Redistribution, except as permitted by whichever of the GPL
   * or MNA you select, is prohibited.
   *
   * 1. For the GPL license (GPL), you can redistribute and/or
   * modify this file under the terms of the GNU General
   * Public License, Version 3, as published by the Free Software
   * Foundation.  You should have received a copy of the GNU
   * General Public License, Version 3 along with this program;
   * if not, write to the Free Software Foundation, Inc., 51
   * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * 2. For the Magnolia Network Agreement (MNA), this file
   * and the accompanying materials are made available under the
   * terms of the MNA which accompanies this distribution, and
   * is available at http://www.magnolia-cms.com/mna.html
   *
   * Any modifications to this file must keep this entire header
   * intact.
   *
   */
  package info.magnolia.cms.filters;
  
  import info.magnolia.cms.beans.config.MIMEMapping;
  import info.magnolia.cms.core.AggregationState;
  import info.magnolia.context.MgnlContext;
  
  import java.io.IOException;
  import java.io.UnsupportedEncodingException;
  import java.net.URLDecoder;
  
  import javax.servlet.FilterChain;
  import javax.servlet.ServletException;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.commons.lang.StringUtils;
  
  
  /**
   * TODO : rename this filter. What it really does is initialize and setup the basic,
   * non-content related attributes of the AggregationState. ContentType could become an
   * attribute of the AggregationState too and could be set later.
   *
   * FIXME: the original uri should not be reset, MAGNOLIA-3204
   *
   * @author Sameer Charles
   * @author Fabrizio Giustina
   * @author gjoseph
   * @version $Id: ContentTypeFilter.java 34573 2010-05-20 07:49:54Z had $
   */
  public class ContentTypeFilter extends AbstractMgnlFilter {
  
      private static final org.slf4j.Logger log = org.slf4j.LoggerFactory.getLogger(ContentTypeFilter.class);
  
      /**
       * If set we have to reset the aggregation state before setting the original URI/URL with new values
       */
      private static final String AGGREGATION_STATE_INITIALIZED = ContentTypeFilter.class.getName() + ".aggregationStateInitialized";
  
      public void doFilter(HttpServletRequest request, HttpServletResponse response, FilterChain chain) throws IOException, ServletException {
          // we will set the original uri, to avoid conflicts we have to reset the aggregation state
          // this will mainly reset the original uri and keep all other information
          if(request.getAttribute(AGGREGATION_STATE_INITIALIZED) != null){
              MgnlContext.resetAggregationState();
          }
          else{
              request.setAttribute(AGGREGATION_STATE_INITIALIZED, Boolean.TRUE);
          }
  
          final String originalUri = request.getRequestURI();
          final String ext = getUriExtension(originalUri);
          StringBuffer url = request.getRequestURL();
          String query = request.getQueryString();
          if (!StringUtils.isEmpty(query))
          {
              url.append("?").append(query);
          }
  
          final String characterEncoding = setupContentTypeAndCharacterEncoding(ext, request, response);
          final AggregationState aggregationState = MgnlContext.getAggregationState();
          aggregationState.setCharacterEncoding(characterEncoding);
  
          aggregationState.setOriginalURI(URLDecoder.decode(originalUri, characterEncoding));
          aggregationState.setOriginalURL(URLDecoder.decode(url.toString(), characterEncoding));
          aggregationState.setOriginalBrowserURI(originalUri);
          aggregationState.setOriginalBrowserURL(url.toString());
         aggregationState.setExtension(ext);
 
         chain.doFilter(request, response);
     }
 
     // TODO : test + simplification (substringAfterLast(uri, ".") probably does the trick !?
     protected String getUriExtension(String originalUri) {
         final String fileName = StringUtils.substringAfterLast(originalUri, "/");
         return StringUtils.substringAfterLast(fileName, ".");
     }
 
     protected String setupContentTypeAndCharacterEncoding(String extension, HttpServletRequest req, HttpServletResponse resp) {
         final String mimeType = MIMEMapping.getMIMETypeOrDefault(extension);
         final String characterEncoding = MIMEMapping.getContentEncodingOrDefault(mimeType);
 
         try {
             // let's not override the request encoding if set by the app server
             if (req.getCharacterEncoding() == null) {
                 req.setCharacterEncoding(characterEncoding);
             }
         } catch (UnsupportedEncodingException e) {
             log.error("Can't set character encoding for the request (extension=" + extension + ",mimetype=" + mimeType + ")", e);
         }
 
         resp.setContentType(mimeType);
         resp.setCharacterEncoding(characterEncoding);
 
         return characterEncoding;
     }
 
 }