/* CVS ID: $Id: JavaScriptFilter.java,v 1.1.1.1 2002/10/02 18:42:54 wastl Exp $ */
package net.wastl.webmail.ui.html;

import java.util.regex.*;

/*
 * JavaScriptFilter.java
 *
 * Created: Thu Oct 14 12:08:28 1999
 *
 * Copyright (C) 1999-2000 Sebastian Schaffert
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program 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 General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

/**
 * Filter JavaScript content from HTML messages to avoid security problems.
 *
 * @author Sebastian Schaffert
 * @version
 */

public class JavaScriptFilter  {

    private static Pattern[] filter = new Pattern[3]; 
    private static String[] substitution = new String[3];

    private static boolean initialized=false;
    
    public JavaScriptFilter() {
	
    }

    public static void init() {
	try {
	    filter[0]=Pattern.compile("<\\s*SCRIPT[^>]*>",Pattern.CASE_INSENSITIVE);
	    filter[1]=Pattern.compile("<\\s*\\/SCRIPT[^>]*>",Pattern.CASE_INSENSITIVE);
	    filter[2]=Pattern.compile("<\\s*A +HREF *=.*\"(javascript:[^\"]*)\"[^>]*>([^<]+)",Pattern.CASE_INSENSITIVE);

	    substitution[0]="<P>WebMail security: JavaScript filtered:
\n
\n
";
	    substitution[1]="</PRE>
JavaScript end
";
	    substitution[2]="<FONT COLOR=\"red\">WebMail security: JavaScript link filtered: $1 $2 ";
	    // Link highlighting
	    //uri=new RE("http\\:\\/\\/(.+)(html|\\/)(\\S|\\-|\\+|\\.|\\\|\\:)");
	    initialized=true;
	} catch(Exception e) {
	    e.printStackTrace();
	}
    }

    public static String apply(String s) {
	if(!initialized) {
	    init();
	}
	String retval=s;
	for(int i=0;i<filter.length;i++) {
	    Matcher m = filter[i].matcher(retval);
	    retval=m.replaceAll(substitution[i]);
	}
	return retval;
    }
    
} // JavaScriptFilter