package max.music_cyclon.service;

import android.os.Environment;
import android.util.Log;

import org.apache.commons.io.FileUtils;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.concurrent.CountDownLatch;
import java.util.zip.Adler32;

import max.music_cyclon.SynchronizeConfig;
import max.music_cyclon.tracker.FileTracker;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class DownloadTask implements Runnable {

    private final SynchronizeConfig config;
    private final String url;
    private final String itemPath;

    private final FileTracker tracker;
    private final ProgressUpdater progressUpdater;
    private CountDownLatch itemsLeftLatch;
    public static final OkHttpClient CLIENT = new OkHttpClient();


    public DownloadTask(SynchronizeConfig config, String url, String itemPath,
                        FileTracker tracker, ProgressUpdater progressUpdater) {
        this.config = config;
        this.url = url;
        this.itemPath = itemPath;

        this.tracker = tracker;
        this.progressUpdater = progressUpdater;
    }

    private InputStream prepareConnection() throws IOException {
        Request request = new Request.Builder()
                .url(url)
                .build();

        Response response = CLIENT.newCall(request).execute();

        if (response.code() != 200) {
            Log.e("ERROR", "Server returned HTTP " + response.message());
            return null;
        }

        return response.body().byteStream();
    }

    public void setItemsLeftLatch(CountDownLatch itemsLeftLatch) {
        this.itemsLeftLatch = itemsLeftLatch;
    }

    @Override
    public void run() {
        File root = new File(Environment.getExternalStorageDirectory(), "library");

        try {
            File target = new File(root, itemPath);
            Adler32 checksum = new Adler32();

            InputStream input = prepareConnection();

            if (input != null) {

                FileOutputStream output = FileUtils.openOutputStream(target);

                byte[] buffer = new byte[4 * 1024];
                int n;
                while (-1 != (n = input.read(buffer))) {
                    output.write(buffer, 0, n);
                    checksum.update(buffer, 0, n);
                }

                output.flush();
                output.close();
                input.close();
            }

            tracker.track(config, target, checksum.getValue());
        } catch (IOException e) {
            Log.e("DOWNLOAD", "Failed to download", e);
        }

        progressUpdater.increment();
        itemsLeftLatch.countDown();
    }
}