import java.util.Random;

public class DownloadWorker implements Runnable {

    private final ChunkStatus chunkStatus;
    private final DownloadConfig config;
    private final Random random;

    public DownloadWorker(ChunkStatus chunkStatus, DownloadConfig config) {
        this.chunkStatus = chunkStatus;
        this.config = config;
        this.random = new Random();
    }

    @Override
    public void run() {
        chunkStatus.setStartTimeMs(System.currentTimeMillis());
        System.out.println(Thread.currentThread().getName() + " started downloading.");

        double downloaded = 0.0;
        double chunkSize = chunkStatus.getChunkSizeMB();

        while (downloaded < chunkSize) {
            int delayMs = config.getMinStepDelayMs() + random.nextInt(config.getMaxStepDelayMs() - config.getMinStepDelayMs() + 1);

            try {
                Thread.sleep(delayMs);
            } catch (InterruptedException e) {
                System.out.println(Thread.currentThread().getName() + " was interrupted.");
                return;
            }

            double stepDownload = config.getMinStepDownloadMB() + (config.getMaxStepDownloadMB() - config.getMinStepDownloadMB()) * random.nextDouble();
            downloaded += stepDownload;

            if (downloaded > chunkSize) {
                downloaded = chunkSize;
            }

            chunkStatus.setDownloadedMB(downloaded);
        }

        chunkStatus.setCompleted(true);
        chunkStatus.setEndTimeMs(System.currentTimeMillis());

        System.out.println(Thread.currentThread().getName() + " finished downloading.");
    }

}