/*
 * Copyright (c) 2025  blog-software-java developers
 * blog-software-java is licensed under the GNU General Public License. See the LICENSE.md file
 * in the project root for the full license text.
 */

package eu.m724.blog.compress;

import org.apache.commons.compress.compressors.CompressorException;
import org.apache.commons.compress.compressors.CompressorStreamFactory;

import java.io.IOException;
import java.io.OutputStream;
import java.nio.file.FileAlreadyExistsException;
import java.nio.file.Files;
import java.nio.file.Path;

public class CommonsCompressor extends FileCompressor {
    /**
     * Constructs a {@link FileCompressor} instance using the provided algorithm.
     *
     * @param algorithm The algorithm, for valid names see {@link CompressorStreamFactory}
     * @throws NoSuchAlgorithmException If that algorithm is unavailable or the name is invalid.
     */
    public CommonsCompressor(String algorithm) throws NoSuchAlgorithmException {
        super(algorithm);

        try {
            var os = new CompressorStreamFactory().createCompressorOutputStream(algorithm, OutputStream.nullOutputStream());
            os.close();
        } catch (NoClassDefFoundError | CompressorException e) {
            throw new NoSuchAlgorithmException(algorithm, e);
        } catch (IOException e) {
            throw new RuntimeException("Unexpected IOException closing test output stream", e);
        }
    }

    @Override
    public void compress(Path file) throws IOException, CompressException {
        var destination = file.resolveSibling(file.getFileName() + "." + getAlgorithmName());
        compress(file, destination);
    }

    @Override
    public void compress(Path source, Path destination) throws IOException, CompressException {
        if (Files.exists(destination))
            throw new FileAlreadyExistsException(destination.toString());

        try (
                var outputStream = new CompressorStreamFactory()
                        .createCompressorOutputStream(getAlgorithmName(), Files.newOutputStream(destination))
        ) {
            Files.copy(source, outputStream);
        } catch (CompressorException e) {
            throw new CompressException(e);
        }
    }
}