package org.apache.maven.util;

/* ====================================================================
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 2002 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
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 *    distribution.
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 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
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 * 4. The names "Apache" and "Apache Software Foundation" and
 *    "Apache Maven" must not be used to endorse or promote products
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 * 5. Products derived from this software may not be called "Apache",
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 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

import java.util.*;
import java.io.*;

/**
 * Path transformation utilities.
 *
 * @author <a href="vmassol@apache.org">Vincent Massol</a>
 * @version $Id: ProjectProperties.java,v 1.33 2002/05/23 01:17:01 dion Exp $
 */
public class PathUtil
{
    /**
     * Transform an absolute file name into a relative file name, looking for
     * path prefix in a list of possible prefix. For example if the list
     * contains {"e:\tmp\dir1\myfile", "e:\tmp\dir1\dir2"} and the file is
     * "e:\tmp\dir1\dir2\test.java" then the result is "test.java".
     *
     * Note: The first path that matches is used to shorten the file name even
     * if other longer paths were matching.
     *
     * @param absoluteFileName the absolute file name to transform
     * @param pathList list of path prefix (separated by the OS File Separator
     *        char) to look for in the absolute file name
     * @return the shortened file name or the original file name if not path
     *         prefix matches the start of the file name
     */
    public String getRelativePath(String absoluteFileName, String pathList)
    {
        StringTokenizer st = new StringTokenizer(pathList, File.pathSeparator);
        while (st.hasMoreTokens())
        {
            String path = st.nextToken();

            // Add trailing dir separator character if missing
            if (!path.endsWith(File.separator)) {
                path = path + File.separator;
            }

            if (absoluteFileName.startsWith(path))
            {
                return absoluteFileName.substring(path.length());
            }
        }
        return absoluteFileName;
    }

}