import java.util.List;

public class ProgressMonitor implements Runnable {

    private final String fileName;
    private final int totalSizeMB;
    private final List<ChunkStatus> chunks;
    private final long monitorDelayMs;

    public ProgressMonitor(DownloadConfig config, List<ChunkStatus> chunks) {
        this.fileName = config.getFileName();
        this.totalSizeMB = config.getTotalSizeMB();
        this.chunks = chunks;
        this.monitorDelayMs = 500;
    }

    @Override
    public void run() {
        System.out.println("[Monitor] Started monitoring progress...");

        while (true) {
            double totalDownloadedMB = 0.0;
            int completedChunks = 0;

            for (ChunkStatus chunk : chunks) {
                totalDownloadedMB += chunk.getDownloadedMB();

                if (chunk.isCompleted()) {
                    completedChunks++;
                }
            }

            double percent = 0.0;
            if (totalSizeMB > 0) {
                percent = (totalDownloadedMB * 100.0) / totalSizeMB;
            }

            System.out.printf(
                    "Progress for %s: %.1f/%.1f MB (%.2f%%), completed chunks: %d/%d%n",
                    fileName,
                    totalDownloadedMB,
                    (double) totalSizeMB,
                    percent,
                    completedChunks,
                    chunks.size()
            );

            if (completedChunks == chunks.size())
            {
                System.out.println("[Monitor] All chunks downloaded successfully!");
                break;
            }

            try {
                Thread.sleep(monitorDelayMs);
            } catch (InterruptedException e) {
                System.out.println("Progress monitor interrupted.");
                return;
            }
        }
    }
}