Source Code

// Background Worker Function
async function performCheck() {
  const now = Date.now();
  const timestamp = new Date(now).toISOString();
  try {
    // Accept any response < 500 as "up" since Cloudflare bot detection
    // may return 403/challenge pages even when the site is operational
    const response = await axios.get(CHECK_URL, {
      timeout: 10000,
      validateStatus: (status) => status < 500
    });

    currentStatus = {
      status: 'up',
      timestamp,
      lastCheckAt: now
    };
    console.log(`[${timestamp}] Check performed: UP`);
  } catch (error) {
    currentStatus = {
      status: 'down',
      timestamp,
      lastCheckAt: now
    };
    console.log(`[${timestamp}] Check performed: DOWN`);
  }
}

// Start the background worker
performCheck();
checkInterval = setInterval(performCheck, 30000);

// Status checking - syncs with server's check time
const CHECK_INTERVAL_MS = 30000;
let lastServerCheck = null;

function updateCountdown() {
  const countdownEl = document.getElementById('countdown');

  if (!lastServerCheck) {
    countdownEl.textContent = 'Waiting...';
    return;
  }

  const elapsed = Date.now() - lastServerCheck;
  const remaining = Math.max(0, Math.ceil(
    (CHECK_INTERVAL_MS - elapsed) / 1000
  ));

  countdownEl.textContent = remaining === 0
    ? 'Now...'
    : `${remaining}s`;
}

// Poll server every 5 seconds to stay in sync
checkStatus();
setInterval(checkStatus, 5000);
setInterval(updateCountdown, 1000);