/**
 *
 * 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.gzip;

import javax.inject.Named;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.zip.GZIPInputStream;

import org.codehaus.plexus.archiver.AbstractUnArchiver;
import org.codehaus.plexus.archiver.ArchiverException;
import org.codehaus.plexus.archiver.util.Streams;

import static org.codehaus.plexus.archiver.util.Streams.copyFully;
import static org.codehaus.plexus.archiver.util.Streams.fileInputStream;
import static org.codehaus.plexus.archiver.util.Streams.fileOutputStream;

/**
 * @author <a href="mailto:evenisse@codehaus.org">Emmanuel Venisse</a>
 */
@Named("gzip")
public class GZipUnArchiver extends AbstractUnArchiver {

    private static final String OPERATION_GZIP = "gzip";

    public GZipUnArchiver() {}

    public GZipUnArchiver(File sourceFile) {
        super(sourceFile);
    }

    @Override
    protected void execute() throws ArchiverException {
        if (getSourceFile().lastModified() > getDestFile().lastModified()) {
            getLogger()
                    .info("Expanding " + getSourceFile().getAbsolutePath() + " to "
                            + getDestFile().getAbsolutePath());

            copyFully(
                    getGzipInputStream(fileInputStream(getSourceFile(), OPERATION_GZIP)),
                    fileOutputStream(getDestFile(), OPERATION_GZIP),
                    OPERATION_GZIP);
        }
    }

    private InputStream getGzipInputStream(InputStream in) throws ArchiverException {
        try {
            return Streams.bufferedInputStream(new GZIPInputStream(in));
        } catch (IOException e) {
            throw new ArchiverException("Problem creating GZIP input stream", e);
        }
    }

    @Override
    protected void execute(String path, File outputDirectory) {
        throw new UnsupportedOperationException("Targeted extraction not supported in GZIP format.");
    }
}
