(() => {
  "use strict";

  const root = document.getElementById("conferenceCountdown");
  if (!root) return;

  const targetValue = root.dataset.eventDate;
  const targetTime = Date.parse(targetValue || "");
  if (Number.isNaN(targetTime)) {
    console.warn("Conference countdown date is invalid:", targetValue);
    return;
  }

  const fields = {
    days: document.getElementById("days"),
    hours: document.getElementById("hours"),
    minutes: document.getElementById("minutes"),
    seconds: document.getElementById("seconds")
  };

  const pad = (number, length = 2) => String(Math.max(0, number)).padStart(length, "0");

  const render = () => {
    const remaining = Math.max(0, targetTime - Date.now());
    const totalSeconds = Math.floor(remaining / 1000);
    const days = Math.floor(totalSeconds / 86400);
    const hours = Math.floor((totalSeconds % 86400) / 3600);
    const minutes = Math.floor((totalSeconds % 3600) / 60);
    const seconds = totalSeconds % 60;

    if (fields.days) fields.days.textContent = pad(days);
    if (fields.hours) fields.hours.textContent = pad(hours);
    if (fields.minutes) fields.minutes.textContent = pad(minutes);
    if (fields.seconds) fields.seconds.textContent = pad(seconds);

    root.setAttribute(
      "aria-label",
      remaining > 0
        ? `${days} days, ${hours} hours, ${minutes} minutes and ${seconds} seconds until the conference`
        : "The conference countdown has ended"
    );

    return remaining;
  };

  render();
  const timer = window.setInterval(() => {
    if (render() === 0) window.clearInterval(timer);
  }, 1000);
})();