/*
    * Copyright (C) 2013 Google Inc. and others
    *
    * This program and the accompanying materials are made available under the
    * terms of the Eclipse Distribution License v. 1.0 which is available at
    * https://www.eclipse.org/org/documents/edl-v10.php.
    *
    * SPDX-License-Identifier: BSD-3-Clause
    */
  package org.eclipse.jgit.archive;
  
  import java.io.IOException;
  import java.io.OutputStream;
  import java.util.Arrays;
  import java.util.Collections;
  import java.util.List;
  import java.util.Map;
  
  import org.apache.commons.compress.archivers.ArchiveOutputStream;
  import org.apache.commons.compress.compressors.gzip.GzipCompressorOutputStream;
  import org.apache.commons.compress.compressors.gzip.GzipParameters;
  import org.eclipse.jgit.api.ArchiveCommand;
  import org.eclipse.jgit.lib.FileMode;
  import org.eclipse.jgit.lib.ObjectId;
  import org.eclipse.jgit.lib.ObjectLoader;
  
  /**
   * gzip-compressed tarball (tar.gz) format.
   */
  public final class TgzFormat extends BaseFormat implements
  		ArchiveCommand.Format<ArchiveOutputStream> {
  	private static final List<String> SUFFIXES = Collections
  			.unmodifiableList(Arrays.asList(".tar.gz", ".tgz")); //$NON-NLS-1$ //$NON-NLS-2$
  
  	private final ArchiveCommand.Format<ArchiveOutputStream> tarFormat = new TarFormat();
  
  	/** {@inheritDoc} */
  	@Override
  	public ArchiveOutputStream createArchiveOutputStream(OutputStream s)
  			throws IOException {
  		return createArchiveOutputStream(s,
  				Collections.<String, Object> emptyMap());
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public ArchiveOutputStream createArchiveOutputStream(OutputStream s,
  			Map<String, Object> o) throws IOException {
  		GzipCompressorOutputStream out;
  		int compressionLevel = getCompressionLevel(o);
  		if (compressionLevel != -1) {
  			GzipParameters parameters = new GzipParameters();
  			parameters.setCompressionLevel(compressionLevel);
  			out = new GzipCompressorOutputStream(s, parameters);
  		} else {
  			out = new GzipCompressorOutputStream(s);
  		}
  		return tarFormat.createArchiveOutputStream(out, o);
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public void putEntry(ArchiveOutputStream out,
  			ObjectId tree, String path, FileMode mode, ObjectLoader loader)
  			throws IOException {
  		tarFormat.putEntry(out, tree, path, mode, loader);
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public Iterable<String> suffixes() {
  		return SUFFIXES;
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public boolean equals(Object other) {
  		return (other instanceof TgzFormat);
  	}
  
  	/** {@inheritDoc} */
  	@Override
  	public int hashCode() {
  		return getClass().hashCode();
  	}
  }