/**
 *
 * Copyright 2004 The Apache Software Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.codehaus.plexus.archiver.util;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import org.codehaus.plexus.archiver.ArchiverException;
import org.codehaus.plexus.components.io.resources.PlexusIoResource;
import org.codehaus.plexus.logging.AbstractLogEnabled;
import org.codehaus.plexus.util.IOUtil;

public abstract class Compressor
    extends AbstractLogEnabled
{

    private File destFile;

    private PlexusIoResource source;

    /**
     * the required destination file.
     *
     * @param compressFile
     */
    public void setDestFile( File compressFile )
    {
        this.destFile = compressFile;
    }

    public File getDestFile()
    {
        return destFile;
    }

    /**
     * The resource to compress; required.
     */
    public void setSource( PlexusIoResource source )
    {
        this.source = source;
    }

    /**
     * The resource to compress; required.
     */
    public PlexusIoResource getSource()
    {
        return source;
    }

    /**
     * compress a stream to an output stream
     *
     * @param in
     * @param zOut
     *
     * @throws IOException
     */
    private void compressFile( InputStream in, OutputStream 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 );
    }

    /**
     * compress a resource to an output stream
     */
    protected void compress( PlexusIoResource resource, OutputStream zOut )
        throws IOException
    {
        InputStream in = null;
        try
        {
            in = Streams.bufferedInputStream( resource.getContents() );
            compressFile( in, zOut );
            in.close();
            in = null;
        }
        finally
        {
            IOUtil.close( in );
        }
    }

    /**
     * subclasses must implement this method to do their compression
     *
     * this is public so the process of compression and closing can be dealt with separately.
     */
    public abstract void compress()
        throws ArchiverException;

    /**
     * subclasses must implement this method to cleanup after compression
     *
     * this is public so the process of compression and closing can be dealt with separately.
     */
    public abstract void close()
        throws ArchiverException;

}
