package io.github.jshipit;

import me.tongfei.progressbar.ProgressBar;

import java.io.*;
import java.net.*;
import java.nio.file.Files;
import java.nio.file.Path;

public class BlobDownloader extends Thread {

    private final String url;
    private final String digest;
    private final String[][] headers;
    private final String tmpdir;
    private final boolean extract;
    private final String renameTo;

    public BlobDownloader(String url, String digest, String[][] headers, String tmpdir, boolean extract, String renameTo) {
        this.url = url;
        this.digest = digest;
        this.headers = headers;
        this.tmpdir = tmpdir;
        this.extract = extract;
        this.renameTo = renameTo;
    }

    /*
     * Download a blob
     */
    public void run() {
        URL url_obj = null;
        try {
            url_obj = new URI(this.url).toURL();
        } catch(URISyntaxException | MalformedURLException e) {
            System.out.println("URISyntaxException | MalformedURLException");
            e.printStackTrace();
        }

        assert url_obj != null;
        HttpURLConnection con;

        try {
            con = (HttpURLConnection) url_obj.openConnection();
            con.setRequestMethod("GET");
            for (String[] header : this.headers) {
                con.setRequestProperty(header[0], header[1]);
            }
            con.connect();

            if (con.getResponseCode() != 200) {
                System.out.println("Error: " + con.getResponseCode());
                throw new RuntimeException("Failed : HTTP error code : "
                        + con.getResponseCode());
            }
        } catch (IOException e) {
            System.out.println("Failed to connect");
            e.printStackTrace();
            return;
        }


        int fileSize = con.getContentLength(); // We get the file size to display a progress bar

        try (InputStream in = con.getInputStream();
             OutputStream out = new FileOutputStream(tmpdir + "/" + digest.replace("sha256:", "") + ".tar.gz")) {
            byte[] buffer = new byte[4096]; // Always read in chunks of 4096 bytes
            int bytesRead; // How many bytes were read, used to update the progress bar
            try (ProgressBar pb = new ProgressBar("Download blob "+digest.replace("sha256:", ""), fileSize)) {
                while ((bytesRead = in.read(buffer)) != -1) {
                    out.write(buffer, 0, bytesRead);
                    pb.stepBy(bytesRead);
                }
            }
        } catch (IOException e) {
            System.out.println("Failed to download blob "+digest);
            e.printStackTrace();
        }

        if (this.renameTo == null && !extract) {
            return;
        } else if (this.renameTo != null) {
            Path rename = new File(renameTo).toPath();
            Path current = new File(tmpdir + "/" + digest.replace("sha256:", "")+".tar.gz").toPath();
            try {
                Files.move(current, rename);
            } catch (IOException e) {
                System.out.println("Failed to rename file "+digest);
                e.printStackTrace();
            }
            return;
        }


        if (extract) {

            File extracted = new File(tmpdir + "/" + digest.replace("sha256:", ""));
            if (extracted.exists()) {
                extracted.delete();
            }
            SysUtils tarManager = new SysUtils();

            // Extract the downloaded tar.gz
            tarManager.untar(tmpdir + "/" + digest.replace("sha256:", "") + ".tar.gz", tmpdir + "/" + digest.replace("sha256:", ""));

            File tar = new File(tmpdir + "/" + digest.replace("sha256:", "") + ".tar.gz");
            if (tar.exists()) {
                tar.delete();
            }
        }
    }
}