/*
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 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.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
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 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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 * SUCH DAMAGE.
 * ====================================================================
 *
 * 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/>.
 */

package org.apache.tools.ant.taskdefs;

import org.apache.tools.ant.*;
import java.io.*;
import java.util.*;

/**
 * Will set the given property if the specified target has a timestamp greater
 * than all of the source files.
 *
 * @author William Ferguson <a href="mailto:williamf@mincom.com">williamf@mincom.com</a>
 */

public class UpToDate extends Task {

    private String _property;
    private String _targetFileName;
    private String _sourceFileNames;

    /**
     * The property to set if the target file is more up to date than each of
     * the source files.
     */
    public void setProperty(String property) {
        _property = property;
    }

    /**
     * The file which must be more up to date than each of the source files
     * if the property is to be set.
     */
    public void setTargetFileName(String filename) {
        _targetFileName = filename;
    }

    /**
     * Comma separated list of files for which the target file must have a more
     * recent timestamp if the property is to be set.
     */
    public void setSourceFileNames(String filenames) {
        _sourceFileNames = filenames;
    }


    /**
     * Sets property to true if target file has a more recent timestamp than
     * each of the source files.
     */
    public void init() throws BuildException {

        // get file for target file name
        File targetFile = new File(_targetFileName);
        if (!targetFile.exists()) return; // if not there then it can't be up to date

        // get collection of source files
        Set sourcefiles = getFiles(_sourceFileNames);
        Iterator iterator = sourcefiles.iterator();

        while(iterator.hasNext()) {
          File sourceFile = (File) iterator.next();
          if (sourceFile.lastModified() > targetFile.lastModified()) return; // sourceFile is more recent - so targtet is not up to date
        }

        this.project.setProperty(_property, "true");
    }

    /**
     * tokenizes filenames and returns a collection of file retrieved from
     * the tokens.
     */
    private Set getFiles(String filenames) {
      Set files = new HashSet();
      StringTokenizer tokenizer = new StringTokenizer(filenames, ",");
      while (tokenizer.hasMoreTokens()) {
        File file = new File(tokenizer.nextToken());
        if (file.exists()) {
          files.add(file);
        }
      }
      return files;
    }
}