/*
    *  Java HTML Tidy - JTidy
    *  HTML parser and pretty printer
    *
    *  Copyright (c) 1998-2000 World Wide Web Consortium (Massachusetts
    *  Institute of Technology, Institut National de Recherche en
    *  Informatique et en Automatique, Keio University). All Rights
    *  Reserved.
    *
   *  Contributing Author(s):
   *
   *     Dave Raggett <dsr@w3.org>
   *     Andy Quick <ac.quick@sympatico.ca> (translation to Java)
   *     Gary L Peskin <garyp@firstech.com> (Java development)
   *     Sami Lempinen <sami@lempinen.net> (release management)
   *     Fabrizio Giustina <fgiust at users.sourceforge.net>
   *     Vlad Skarzhevskyy <vlads at users.sourceforge.net> (JTidy servlet  development)
   *
   *  The contributing author(s) would like to thank all those who
   *  helped with testing, bug fixes, and patience.  This wouldn't
   *  have been possible without all of you.
   *
   *  COPYRIGHT NOTICE:
   *
   *  This software and documentation is provided "as is," and
   *  the copyright holders and contributing author(s) make no
   *  representations or warranties, express or implied, including
   *  but not limited to, warranties of merchantability or fitness
   *  for any particular purpose or that the use of the software or
   *  documentation will not infringe any third party patents,
   *  copyrights, trademarks or other rights.
   *
   *  The copyright holders and contributing author(s) will not be
   *  liable for any direct, indirect, special or consequential damages
   *  arising out of any use of the software or documentation, even if
   *  advised of the possibility of such damage.
   *
   *  Permission is hereby granted to use, copy, modify, and distribute
   *  this source code, or portions hereof, documentation and executables,
   *  for any purpose, without fee, subject to the following restrictions:
   *
   *  1. The origin of this source code must not be misrepresented.
   *  2. Altered versions must be plainly marked as such and must
   *     not be misrepresented as being the original source.
   *  3. This Copyright notice may not be removed or altered from any
   *     source or altered source distribution.
   *
   *  The copyright holders and contributing author(s) specifically
   *  permit, without fee, and encourage the use of this source code
   *  as a component for supporting the Hypertext Markup Language in
   *  commercial products. If you use this source code in a product,
   *  acknowledgment is not required but would be appreciated.
   *
   */
  package org.w3c.tidy.servlet.filter;
  /*
   * Created on 02.10.2004 by vlads
   */
  import java.io.IOException;
  
  import javax.servlet.Filter;
  import javax.servlet.FilterChain;
  import javax.servlet.FilterConfig;
  import javax.servlet.ServletException;
  import javax.servlet.ServletRequest;
  import javax.servlet.ServletResponse;
  import javax.servlet.http.HttpServletRequest;
  import javax.servlet.http.HttpServletResponse;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  
  import org.w3c.tidy.servlet.Consts;
  import org.w3c.tidy.servlet.TidyProcessor;
  import org.w3c.tidy.servlet.properties.JTidyServletProperties;
  
  
  /***
   * Wrapp the Response and creates TidyProcessor who does all the work.
   *
   * Use this filter instead of TidyTag if you don't
   * want to modify your JSP pages or HTML is denerated by non JSP servlets.
   *
   * @author Vlad Skarzhevskyy <a href="mailto:skarzhevskyy@gmail.com">skarzhevskyy@gmail.com</a> 
   * @version $Revision: 1.5 $ ($Author: vlads $)
   */
  public class JTidyFilter implements Filter
  {
      /***
       * name of the parameter <code>properties.filename</code> containing the properties file path.
       */
      public static final String CONFIG_PROPERTIES_FILE_NAME = Consts.CONFIG_PROPERTIES_FILE_NAME;
  
      /***
       * name of the parameter <code>config</code> containing JTidy Parser configutation string.
       * 
       * JTidy Parser configutation string
       * Examples of config string: indent: auto; indent-spaces: 2
       */
     public static final String CONFIG_CONFIG = "config";
 
     /***
      * name of the parameter <code>tee</code>.
      * Do not buffer the output, Preform validation only
      * This may send the responce back to browser while we are still parsing the HTML
      * May solve problem for some applications that are flushing the OutputStream
      */
     public static final String CONFIG_TEE = "tee";
 
     /***
      * name of the parameter <code>validateOnly</code>.
      * 
      * validateOnly only do not change output.
      */
     public static final String CONFIG_VALIDATE_ONLY = "validateOnly";
 
     /***
      * name of the parameter <code>doubleValidation</code>.
      * 
      * Performs validation of html processed by &lt;jtidy:tidy&gt; jsp tag
      * By default this is not done. Only Usefull for testing JTidy
      * This will create second requestID to store the data
      */
     public static final String CONFIG_DOUBLE_VALIDATION = "doubleValidation";
 
     /***
      * name of the parameter <code>commentsSubst</code>.
      * Special html comments:
      * &lt;!--jtidy:requestID--&gt;
      * &lt;!--jtidy:validationImage--&gt;
      * 
      */
     public static final String CONFIG_COMMENTS_SUBST = "commentsSubst";
     /***
      * Logger.
      */
     private Log log;
 
     /***
      * @see #CONFIG_CONFIG.
      */
     private String config;
 
     /***
      * @see #CONFIG_VALIDATE_ONLY
      */
     private boolean validateOnly;
 
     /***
      * @see #CONFIG_TEE.
      */
     private boolean tee;
 
     /***
      * @see #CONFIG_DOUBLE_VALIDATION.
      */
     private boolean doubleValidation;
 
     /***
      * @see #CONFIG_COMMENTS_SUBST.
      */
     private boolean commentsSubst;
     
     /***
      * Convert String to beelean.
      * @param value "true"
      * @param defaultValue if value anything else but true.
      * @return Returns boolean value
      */
     private boolean getBoolean(String value, boolean defaultValue)
     {
         if (value != null)
         {
             return value.equalsIgnoreCase("true");
         }
         else
         {
             return defaultValue;
         }
     }
 
     /***
      * {@inheritDoc}
      */
     public void init(FilterConfig filterConfig)
     {
         log = LogFactory.getLog(JTidyFilter.class);
 
         JTidyServletProperties.getInstance().loadFile(filterConfig.getInitParameter(CONFIG_PROPERTIES_FILE_NAME));
 
         tee = getBoolean(filterConfig.getInitParameter(CONFIG_TEE), false);
         doubleValidation = getBoolean(filterConfig.getInitParameter(CONFIG_DOUBLE_VALIDATION), false);
         validateOnly = getBoolean(filterConfig.getInitParameter(CONFIG_VALIDATE_ONLY), false);
         config = filterConfig.getInitParameter(CONFIG_CONFIG);
         commentsSubst = getBoolean(filterConfig.getInitParameter(CONFIG_COMMENTS_SUBST), false);
     }
 
     /***
      * {@inheritDoc}
      */
     public void destroy()
     {
         // nothing to destroy
     }
 
     /***
      * Buffer the Response.
      * {@inheritDoc}
      */
     public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain)
         throws IOException, ServletException
     {
         if (!(servletRequest instanceof HttpServletRequest))
         {
             log.debug("Filter has been called, Request is not HTML");
             // don't filter!
             filterChain.doFilter(servletRequest, servletResponse);
             return;
         }
 
         TidyProcessor tidyProcessor = new TidyProcessor(
             ((HttpServletRequest) servletRequest).getSession(),
             (HttpServletRequest) servletRequest,
             (HttpServletResponse) servletResponse);
         tidyProcessor.setValidateOnly(validateOnly);
         tidyProcessor.setDoubleValidation(doubleValidation);
         tidyProcessor.setConfig(config);
         tidyProcessor.setCommentsSubst(commentsSubst);
 
         log.debug(((HttpServletRequest) servletRequest).getRequestURI());
 
         BufferedServletResponse wrappedResponse = new BufferedServletResponse(
             (HttpServletResponse) servletResponse,
             tidyProcessor);
         wrappedResponse.setTee(tee);
 
         try
         {
             filterChain.doFilter(servletRequest, wrappedResponse);
             log.debug("Filter finished"); 
         }
         finally
         {
             wrappedResponse.finishResponse();
         }
     }
 
 }