package com.thebrokenrail.freshcoffee.util;

import org.apache.commons.compress.archivers.ArchiveEntry;
import org.apache.commons.compress.archivers.tar.TarArchiveInputStream;
import org.apache.commons.compress.compressors.gzip.GzipCompressorInputStream;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.UncheckedIOException;
import java.net.URL;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.zip.ZipEntry;
import java.util.zip.ZipInputStream;

public class ExtractUtil {
    private static String stripFirstComponent(String file) {
        String path = new File(file).getPath();
        String[] parts = path.split(File.separator);
        List<String> newParts = new ArrayList<>(Arrays.asList(parts).subList(1, parts.length));
        return String.join(File.separator, newParts);
    }

    public static void extract(URL url, File dir) {
        Util.getLogger().info("Downloading/Extracting: " + url.toString());

        try (InputStream stream = url.openConnection().getInputStream()) {
            if (url.getFile().endsWith(".tar.gz")) {
                extractTarGz(stream, dir);
            } else {
                extractZip(stream, dir);
            }
        } catch (IOException e) {
            throw new UncheckedIOException(e);
        }
    }

    private static void log(File file) {
        Util.getLogger().debug("Extracting: " + file.getAbsolutePath());
    }

    private static void extractTarGz(InputStream stream, File dir) throws IOException {
        try (TarArchiveInputStream tar = new TarArchiveInputStream(new GzipCompressorInputStream(stream))) {
            byte[] buffer = new byte[1024];

            ArchiveEntry entry = tar.getNextEntry();
            while (entry != null) {
                String fileName = entry.getName();
                File newFile = new File(dir, stripFirstComponent(fileName));

                if (newFile.getParentFile() != null) {
                    //noinspection ResultOfMethodCallIgnored
                    newFile.getParentFile().mkdirs();
                }

                log(newFile);

                if (!entry.isDirectory()) {
                    FileOutputStream output = new FileOutputStream(newFile);
                    int len;
                    while ((len = tar.read(buffer)) > 0) {
                        output.write(buffer, 0, len);
                    }
                    output.close();

                    //noinspection ResultOfMethodCallIgnored
                    newFile.setExecutable(true);
                } else {
                    //noinspection ResultOfMethodCallIgnored
                    newFile.mkdir();
                }

                entry = tar.getNextEntry();
            }
        }
    }

    private static void extractZip(InputStream stream, File dir) throws IOException {
        try (ZipInputStream zip = new ZipInputStream(stream)) {
            byte[] buffer = new byte[1024];

            ZipEntry entry = zip.getNextEntry();
            while (entry != null) {
                String fileName = entry.getName();
                File newFile = new File(dir, stripFirstComponent(fileName));

                if (newFile.getParentFile() != null) {
                    //noinspection ResultOfMethodCallIgnored
                    newFile.getParentFile().mkdirs();
                }

                log(newFile);

                if (!entry.isDirectory()) {
                    FileOutputStream output = new FileOutputStream(newFile);
                    int len;
                    while ((len = zip.read(buffer)) > 0) {
                        output.write(buffer, 0, len);
                    }
                    output.close();

                    //noinspection ResultOfMethodCallIgnored
                    newFile.setExecutable(true);
                } else {
                    //noinspection ResultOfMethodCallIgnored
                    newFile.mkdir();
                }

                entry = zip.getNextEntry();
            }
        }
    }
}