/*
    * Copyright 2000-2004 The Apache Software Foundation.
    * 
    * Licensed under the Apache License, Version 2.0 (the "License");
    * you may not use this file except in compliance with the License.
    * You may obtain a copy of the License at
    * 
    *      http://www.apache.org/licenses/LICENSE-2.0
    * 
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.jetspeed.util.rewriter;
  
  // java.io
  import java.io.Reader;
  
  // java.net
  import java.net.MalformedURLException;
  import java.net.URL;
  
  // this makes it dependent on Swing...need an abstraction WTP
  import javax.swing.text.html.HTML;
  import javax.swing.text.MutableAttributeSet;
   
  /***
   *                  
   * Basic Rewriter for rewriting HTML content. 
   *
   * @author <a href="mailto:taylor@apache.org">David Sean Taylor</a>
   * @version $Id: HTMLRewriter.java,v 1.6 2004/02/23 03:18:59 jford Exp $
   * 
   */
  
  public class HTMLRewriter implements Rewriter
  {
      /*
       * Construct a basic HTML Rewriter
       *
       */
      public HTMLRewriter()
      {
      }
  
      protected String baseURL = null;
  
      /*    
       * This callback is called by the HTMLParserAdaptor implementation to write
       * back all rewritten URLs to point to the proxy server.
       * Given the targetURL, rewrites the link as a link back to the proxy server.
       *
       * @return the rewritten URL to the proxy server.
       *
       */
      public String generateNewUrl( String targetURL, HTML.Tag tag, HTML.Attribute attribute)
      {
          String fullPath = "";
          try
          {
  
              if (baseURL != null)
              {
                  URL full = new URL(new URL(baseURL), targetURL);
                  fullPath = full.toString();
              }
              else
              {
                  return targetURL; // leave as is
              }
          }
          catch (Exception e)
          {
              System.err.println(e);
          }
          return fullPath;
  
      }
  
      
      /*
       * Returns true if all rewritten URLs should be sent back to the proxy server.
       *
       * @return true if all URLs are rewritten back to proxy server.
       */
      public boolean proxyAllTags()
      {
          return true; //false;
      }
  
      public String rewrite(Reader input, String baseURL)
                                 throws MalformedURLException
      {
          String rewrittenHTML = "";
          this.baseURL = baseURL;
  
         HTMLParserAdaptor parser = new SwingParserAdaptor(this);
         rewrittenHTML = parser.run(input);
 
         return rewrittenHTML;
     }
 
     /*
      * Simple Tag Events
      */
     public boolean enterSimpleTagEvent(HTML.Tag tag, MutableAttributeSet attrs)
     {
         return true;
     }
 
     public String exitSimpleTagEvent(HTML.Tag tag, MutableAttributeSet attrs)
     {
         return null;
     }
 
     /*
      * Start Tag Events
      */
     public boolean enterStartTagEvent(HTML.Tag tag, MutableAttributeSet attrs)
     {
         return true;
     }
 
     public String exitStartTagEvent(HTML.Tag tag, MutableAttributeSet attrs)
     {
         return null;
     }
 
     /*
      * Exit Tag Events
      */
     public boolean enterEndTagEvent(HTML.Tag tag)
     {
         return true;
     }
 
     public String exitEndTagEvent(HTML.Tag tag)
     {
         return null;
     }
 
     /*
      * Text Event
      */
     public boolean enterText(char[] values, int param)
     {
         return true;
     }
 
     /*
      * Convert Tag Events
      */
     public void convertTagEvent(HTML.Tag tag, MutableAttributeSet attrs)
     {
     }
 
 }