/**
 * About Us 2 — achievements stats count-up animation.
 */
(function () {
  var SECTION_SELECTOR = "#about-us-2 .au2-stats";
  var VALUE_SELECTOR = ".au2-stats__value[data-au2-count]";
  var DURATION_MS = 1800;

  function easeOutCubic(t) {
    return 1 - Math.pow(1 - t, 3);
  }

  function formatValue(value, useGrouping) {
    if (!useGrouping) return String(value);
    return value.toLocaleString("en-US");
  }

  function parseCountOptions(el) {
    var raw = el.getAttribute("data-au2-count");
    var to = raw ? Number(raw) : NaN;
    if (!Number.isFinite(to)) return null;

    return {
      to: to,
      prefix: el.getAttribute("data-au2-prefix") || "",
      suffix: el.getAttribute("data-au2-suffix") || "",
      grouping: el.getAttribute("data-au2-grouping") === "true",
    };
  }

  function renderValue(el, value, options) {
    el.textContent =
      options.prefix + formatValue(value, options.grouping) + options.suffix;
  }

  function animateValue(el, options) {
    if (el.dataset.au2Counted === "true") return;
    el.dataset.au2Counted = "true";

    if (window.matchMedia("(prefers-reduced-motion: reduce)").matches) {
      renderValue(el, options.to, options);
      return;
    }

    var start = performance.now();

    function tick(now) {
      var progress = Math.min((now - start) / DURATION_MS, 1);
      var current = Math.round(easeOutCubic(progress) * options.to);
      renderValue(el, current, options);

      if (progress < 1) {
        requestAnimationFrame(tick);
      } else {
        renderValue(el, options.to, options);
      }
    }

    renderValue(el, 0, options);
    requestAnimationFrame(tick);
  }

  function initSection(section) {
    var values = section.querySelectorAll(VALUE_SELECTOR);
    if (!values.length) return;

    var observer = new IntersectionObserver(
      function (entries, obs) {
        entries.forEach(function (entry) {
          if (!entry.isIntersecting) return;

          values.forEach(function (el) {
            var options = parseCountOptions(el);
            if (options) animateValue(el, options);
          });

          obs.unobserve(entry.target);
        });
      },
      { threshold: 0.35, rootMargin: "0px 0px -40px 0px" }
    );

    observer.observe(section);
  }

  function init() {
    var section = document.querySelector(SECTION_SELECTOR);
    if (section) initSection(section);
  }

  if (document.readyState === "loading") {
    document.addEventListener("DOMContentLoaded", init);
  } else {
    init();
  }
})();