/*
 * 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", "Ant", 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"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * 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
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * 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.zip.*;

/**
 * Compresses a file with the GZIP algorightm. Normally used to compress
 * non-compressed archives such as TAR files.
 *
 * @author James Davidson <a href="mailto:duncan@x180.com">duncan@x180.com</a>
 * @author Jon S. Stevens <a href="mailto:jon@clearink.com">jon@clearink.com</a>
 */
 
public class GZip extends Task {

    private File zipFile;
    private File source;
    
    public void setZipfile(String zipFilename) {
        zipFile = project.resolveFile(zipFilename);
    }

    public void setSrc(String src) {
        source = project.resolveFile(src);
    }

    public void execute() throws BuildException {
        if (zipFile == null) {
            throw new BuildException("zipfile attribute is required", location);
        }

        if (source == null) {
            throw new BuildException("src attribute is required", location);
        }

        log("Building gzip: " + zipFile.getAbsolutePath());
    
        GZIPOutputStream zOut = null;
        try {
            zOut = new GZIPOutputStream(new FileOutputStream(zipFile));
        
            if (source.isDirectory()) {
                log ("Cannot Gzip a directory!", Project.MSG_ERR);
            } else {
                zipFile(source, zOut);
            }
        } catch (IOException ioe) {
            String msg = "Problem creating gzip " + ioe.getMessage();
            throw new BuildException(msg, ioe, location);
        } finally {
            if (zOut != null) {
                try {
                    // close up
                    zOut.close();
                }
                catch (IOException e) {}
            }
        }
    }
    
    private void zipFile(InputStream in, GZIPOutputStream zOut)
        throws IOException
    {        
        byte[] buffer = new byte[8 * 1024];
        int count = 0;
        do {
            zOut.write(buffer, 0, count);
            count = in.read(buffer, 0, buffer.length);
        } while (count != -1);
    }
    
    private void zipFile(File file, GZIPOutputStream zOut)
        throws IOException
    {
        FileInputStream fIn = new FileInputStream(file);
        try {
            zipFile(fIn, zOut);
        } finally {
            fIn.close();
        }
    }
}
