function formatRemaining(totalSeconds) {
  const seconds = Math.max(0, Math.ceil(totalSeconds));
  const minutes = Math.floor(seconds / 60);
  const rest = seconds % 60;
  return `${minutes}:${String(rest).padStart(2, "0")}`;
}

function updateTimers() {
  const now = Date.now() / 1000;
  document.querySelectorAll("[data-auto-off-at]").forEach((item) => {
    const target = Number(item.dataset.autoOffAt || 0);
    if (!target) {
      return;
    }
    const remaining = target - now;
    if (remaining <= 0) {
      item.textContent = item.dataset.expiredLabel || "Automatic turn-off pending";
      item.classList.add("timer-expired");
      return;
    }
    item.textContent = `${item.dataset.prefix || "Automatic turn-off in"} ${formatRemaining(remaining)}`;
  });
}

document.addEventListener("submit", (event) => {
  const form = event.target;
  if (!(form instanceof HTMLFormElement) || form.dataset.requiresAck !== "true") {
    return;
  }
  const message = form.dataset.ackMessage || "Confirm this action";
  if (!window.confirm(message)) {
    event.preventDefault();
  }
});

updateTimers();
setInterval(updateTimers, 1000);