/*

         StatCvs - CVS statistics generation 

         Copyright (C) 2002  Lukasz Pekacki <lukasz@pekacki.de>

         http://statcvs.sf.net/

         This library 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 2.1 of the License, or (at your option) any later version.

         This library 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 this library; if not, write to the Free Software

         Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

         $RCSfile: FilePatternMatcher.java,v $

         $Date: 2008/04/02 11:22:15 $

 */

 package net.sf.statcvs.util;

 import java.util.ArrayList;

 import java.util.Iterator;

 import java.util.List;

 import java.util.StringTokenizer;

 import java.util.regex.Pattern;

 /**

  * <p>Matches filenames against an Ant-style wildcard pattern list.</p>

  * 

  * <p>In short, ? matches one character, * matches zero or more characters

  * but no directory changes (it doesn't match / or \), and **

  * matches zero or more directory levels. If the wildcard pattern

  * ends in / or \, an implicit ** is added.</p>

  * 

  * <p>Several patterns can be specified, seperated by : or ;.</p>

  * 

  * <p>Everything is case sensitive. If you need case insensitive pattern

  * matching, use <tt>String.toLower()</tt> on the pattern and on the

  * candidate string.</p>

  *

  * @author Richard Cyganiak <rcyg@gmx.de>

  * @version $Id: FilePatternMatcher.java,v 1.3 2008/04/02 11:22:15 benoitx Exp $

  */

 public class FilePatternMatcher {

     private final String originalPattern;

     private final List patterns = new ArrayList();

     /**

      * Creates a matcher to match filenames against a specified

      * wildcard pattern

      * @param wildcardPattern an Ant-style wildcard pattern

      */

     public FilePatternMatcher(final String wildcardPattern) {

         this.originalPattern = wildcardPattern;

         final StringTokenizer tokenizer = new StringTokenizer(wildcardPattern, ":;");

         while (tokenizer.hasMoreTokens()) {

             patterns.add(Pattern.compile(buildRegex(tokenizer.nextToken())));

         }

     }

     /**

      * Matches a filename against the wildcard pattern.

      * @param filename a filename

      * @return <tt>true</tt> if the filename matches the pattern

      */

     public boolean matches(final String filename) {

         final Iterator it = patterns.iterator();

         while (it.hasNext()) {

             final Pattern regex = (Pattern) it.next();

             if (regex.matcher(filename).matches()) {

                 return true;

             }

         }

         return false;

     }

     private String buildRegex(final String wildcardPattern) {

         String temp = wildcardPattern;

         temp = temp.replace('\\', '/');

         if (temp.endsWith("/")) {

             temp += "**";

         }

         // replace **/** with **

         temp = temp.replaceAll("\\*\\*/\\*\\*", "**");

         if ("**".equals(temp)) {

             return ".*";

         }

         // replace **/ at start with (.*/)? and /** at end with (/.*)?

         if (temp.startsWith("**/") && temp.endsWith("/**")) {

             final String inner = temp.substring(3, temp.length() - 3);

             return "(.*/)?" + buildInnerRegex(inner) + "(/.*)?";

         }

         if (temp.startsWith("**/")) {

             final String inner = temp.substring(3);

             return "(.*/)?" + buildInnerRegex(inner);

         }

         if (temp.endsWith("/**")) {

             final String inner = temp.substring(0, temp.length() - 3);

             return buildInnerRegex(inner) + "(/.*)?";

         }

         return buildInnerRegex(temp);

     }

     private String buildInnerRegex(final String wildcardPattern) {

         // replace /**/ with /(.*/)?

         final int pos = wildcardPattern.indexOf("/**/");

         if (pos > -1) {

             final String before = wildcardPattern.substring(0, pos);

             final String after = wildcardPattern.substring(pos + 4);

             return buildInnerRegex(before) + "/(.*/)?" + buildInnerRegex(after);

         }

         // replace ? with [^/] and * with [^/]*

         return wildcardPattern.replaceAll("\\?", "[^/]").replaceAll("\\*", "[^/]*");

     }

     public String toString() {

         return this.originalPattern;

     }

 }