// Global-nav flyouts and the home gallery.
//
// Progressive enhancement only: every flyout destination is a real anchor and
// every gallery slide is in the document, so both work with JavaScript off.
(function () {
  "use strict";

  var OPEN_DELAY = 120;
  var CLOSE_DELAY = 260;

  function initNav() {
    var nav = document.querySelector(".globalnav");
    if (!nav) return;

    var items = Array.prototype.slice.call(nav.querySelectorAll(".globalnav-item"));
    var openTimer = null;
    var closeTimer = null;

    function setOpen(item, open) {
      item.setAttribute("data-open", open ? "true" : "false");
      var trigger = item.querySelector(".globalnav-trigger");
      if (trigger) trigger.setAttribute("aria-expanded", open ? "true" : "false");
      if (open) nav.setAttribute("data-flyout", "open");
    }

    function closeAll(except) {
      var anyOpen = false;
      items.forEach(function (item) {
        if (item === except) {
          anyOpen = true;
          return;
        }
        setOpen(item, false);
      });
      if (!anyOpen) nav.setAttribute("data-flyout", "closed");
    }

    function scheduleOpen(item) {
      window.clearTimeout(closeTimer);
      window.clearTimeout(openTimer);
      // An already-open menu swaps instantly, the way the source nav does.
      var immediate = nav.getAttribute("data-flyout") === "open";
      openTimer = window.setTimeout(
        function () {
          closeAll(item);
          setOpen(item, true);
        },
        immediate ? 0 : OPEN_DELAY
      );
    }

    function scheduleClose() {
      window.clearTimeout(openTimer);
      window.clearTimeout(closeTimer);
      closeTimer = window.setTimeout(function () {
        closeAll(null);
      }, CLOSE_DELAY);
    }

    items.forEach(function (item) {
      var trigger = item.querySelector(".globalnav-trigger");
      if (!trigger) return;

      item.addEventListener("mouseenter", function () {
        if (window.matchMedia("(hover: none)").matches) return;
        scheduleOpen(item);
      });
      item.addEventListener("mouseleave", function () {
        if (window.matchMedia("(hover: none)").matches) return;
        scheduleClose();
      });

      // Keyboard and touch still need an explicit activation.
      trigger.addEventListener("click", function (event) {
        event.preventDefault();
        window.clearTimeout(openTimer);
        window.clearTimeout(closeTimer);
        var open = item.getAttribute("data-open") === "true";
        closeAll(open ? null : item);
        setOpen(item, !open);
        if (open) nav.setAttribute("data-flyout", "closed");
      });
      trigger.addEventListener("focus", function () {
        if (nav.getAttribute("data-flyout") === "open") {
          closeAll(item);
          setOpen(item, true);
        }
      });
    });

    document.addEventListener("keydown", function (event) {
      if (event.key !== "Escape") return;
      closeAll(null);
      nav.setAttribute("data-flyout", "closed");
    });

    document.addEventListener("click", function (event) {
      if (nav.contains(event.target)) return;
      closeAll(null);
      nav.setAttribute("data-flyout", "closed");
    });

    var toggle = nav.querySelector(".menu-toggle");
    if (toggle) {
      toggle.addEventListener("click", function () {
        var open = nav.getAttribute("data-menu") === "open";
        nav.setAttribute("data-menu", open ? "closed" : "open");
        toggle.setAttribute("aria-expanded", open ? "false" : "true");
        if (open) closeAll(null);
      });
    }
  }

  function initGallery() {
    var gallery = document.querySelector("[data-gallery]");
    if (!gallery) return;

    var slides = Array.prototype.slice.call(gallery.querySelectorAll(".gallery-item"));
    var dots = Array.prototype.slice.call(gallery.querySelectorAll(".gallery-dot"));
    if (slides.length < 2) return;

    var index = 0;
    var timer = null;
    var interval = 5000;

    function show(next) {
      index = (next + slides.length) % slides.length;
      slides.forEach(function (slide, position) {
        slide.setAttribute("data-active", position === index ? "true" : "false");
        slide.setAttribute("aria-hidden", position === index ? "false" : "true");
      });
      dots.forEach(function (dot, position) {
        dot.setAttribute("aria-selected", position === index ? "true" : "false");
      });
    }

    function play() {
      stop();
      if (window.matchMedia("(prefers-reduced-motion: reduce)").matches) return;
      timer = window.setInterval(function () {
        show(index + 1);
      }, interval);
      gallery.setAttribute("data-playing", "true");
    }

    function stop() {
      window.clearInterval(timer);
      timer = null;
      gallery.setAttribute("data-playing", "false");
    }

    dots.forEach(function (dot, position) {
      dot.addEventListener("click", function () {
        show(position);
        play();
      });
    });

    var previous = gallery.querySelector("[data-gallery-previous]");
    var next = gallery.querySelector("[data-gallery-next]");
    if (previous) {
      previous.addEventListener("click", function () {
        show(index - 1);
        play();
      });
    }
    if (next) {
      next.addEventListener("click", function () {
        show(index + 1);
        play();
      });
    }

    var toggle = gallery.querySelector("[data-gallery-toggle]");
    if (toggle) {
      toggle.addEventListener("click", function () {
        if (timer) {
          stop();
          toggle.textContent = "Play";
          toggle.setAttribute("aria-label", "Play endless entertainment gallery");
        } else {
          play();
          toggle.textContent = "Pause";
          toggle.setAttribute("aria-label", "Pause endless entertainment gallery");
        }
      });
    }

    gallery.addEventListener("mouseenter", stop);
    gallery.addEventListener("mouseleave", play);
    gallery.addEventListener("focusin", stop);

    show(0);
    play();
  }

  initNav();
  initGallery();
})();