(function () {
  function setLocaleCookie(locale) {
    document.cookie =
      "site_locale=" +
      encodeURIComponent(locale) +
      "; Max-Age=31536000; Path=/; SameSite=Lax; Secure";
  }

  function readLocaleCookie() {
    var parts = document.cookie ? document.cookie.split(";") : [];
    for (var i = 0; i < parts.length; i++) {
      var part = parts[i].trim();
      if (part.indexOf("site_locale=") === 0) {
        try {
          return decodeURIComponent(part.slice("site_locale=".length));
        } catch (e) {
          return part.slice("site_locale=".length);
        }
      }
    }
    return "";
  }

  /** Map a BCP 47 tag to a published locale id present in `available`. */
  function mapBrowserLang(tag, available) {
    if (!tag) return "";
    var raw = String(tag).trim().replace(/_/g, "-");
    if (!raw) return "";
    var lower = raw.toLowerCase();
    var primary = lower.split("-")[0];

    if (
      lower === "zh-tw" ||
      lower === "zh-hk" ||
      lower === "zh-mo" ||
      lower === "zh-hant" ||
      lower.indexOf("zh-hant") === 0 ||
      lower === "zh-trad"
    ) {
      return available["zh-Hant"] ? "zh-Hant" : "";
    }
    if (primary === "zh") {
      return available.zh ? "zh" : available["zh-Hant"] ? "zh-Hant" : "";
    }
    if (primary === "pt") {
      return available["pt-BR"] ? "pt-BR" : available.pt ? "pt" : "";
    }

    // Exact / case-insensitive match against published locale ids
    if (available[raw]) return raw;
    var keys = Object.keys(available);
    for (var i = 0; i < keys.length; i++) {
      if (keys[i].toLowerCase() === lower) return keys[i];
    }
    for (var j = 0; j < keys.length; j++) {
      if (keys[j].toLowerCase().split("-")[0] === primary) return keys[j];
    }
    return "";
  }

  function preferredLocaleIds(available, currentLocale) {
    var ranked = [];
    var seen = {};

    function push(id) {
      if (!id || !available[id] || seen[id]) return;
      seen[id] = true;
      ranked.push(id);
    }

    // Cookie first — explicit prior choice
    push(readLocaleCookie());

    // Then browser language preferences
    var navLangs =
      (typeof navigator !== "undefined" &&
        (navigator.languages ||
          (navigator.language ? [navigator.language] : []))) ||
      [];
    for (var i = 0; i < navLangs.length; i++) {
      push(mapBrowserLang(navLangs[i], available));
    }

    // Current page locale stays easy to find near the top of suggestions
    push(currentLocale);

    return ranked;
  }

  function prioritizeMenuItems(menu, currentLocale) {
    var items = Array.prototype.slice.call(
      menu.querySelectorAll('[role="menuitem"]')
    );
    if (items.length < 2) return items;

    var available = {};
    var byId = {};
    items.forEach(function (item) {
      var id = item.getAttribute("data-locale-target");
      if (!id) return;
      available[id] = true;
      byId[id] = item;
      item.removeAttribute("data-suggested");
    });

    var preferred = preferredLocaleIds(available, currentLocale);
    preferred.forEach(function (id) {
      if (byId[id] && id !== currentLocale) {
        byId[id].setAttribute("data-suggested", "true");
      }
    });

    var ordered = [];
    preferred.forEach(function (id) {
      if (byId[id]) ordered.push(byId[id]);
    });
    items.forEach(function (item) {
      var id = item.getAttribute("data-locale-target");
      if (id && preferred.indexOf(id) === -1) ordered.push(item);
    });

    // Re-append <li> wrappers in the new order (grid follows DOM order)
    ordered.forEach(function (item) {
      var li = item.parentElement;
      if (li && li.parentElement === menu) menu.appendChild(li);
    });

    return ordered;
  }

  function columnCount(menu) {
    var style = window.getComputedStyle(menu);
    var cols = style.gridTemplateColumns;
    if (!cols || cols === "none") return 1;
    // Resolved value looks like "120px 120px 120px"
    return Math.max(1, cols.split(/\s+/).filter(Boolean).length);
  }

  function initSwitcher(root) {
    if (!root) return;

    var toggle = root.querySelector("[data-lang-toggle]");
    var menu = root.querySelector("[data-lang-menu]");
    if (!toggle || !menu) return;

    var pageId = root.getAttribute("data-page-id") || "";
    var fromLocale = root.getAttribute("data-locale") || "";
    var items = prioritizeMenuItems(menu, fromLocale);
    if (!items.length) {
      items = Array.prototype.slice.call(menu.querySelectorAll("a[href]"));
    }

    var rtl =
      (document.documentElement.getAttribute("dir") || "").toLowerCase() ===
      "rtl";

    function refreshItems() {
      items = Array.prototype.slice.call(
        menu.querySelectorAll('[role="menuitem"]')
      );
      if (!items.length) {
        items = Array.prototype.slice.call(menu.querySelectorAll("a[href]"));
      }
    }

    function isOpen() {
      return root.classList.contains("is-open");
    }

    function close(restoreFocus) {
      if (!isOpen()) return;
      root.classList.remove("is-open");
      toggle.setAttribute("aria-expanded", "false");
      menu.setAttribute("hidden", "");
      var active = document.activeElement;
      if (restoreFocus !== false) {
        toggle.focus();
      } else if (active && menu.contains(active)) {
        // Outside-click / Tab close: don't leave focus on a hidden menuitem
        // (can make the page feel stuck until focus moves elsewhere).
        if (typeof active.blur === "function") active.blur();
      }
    }

    function open(focusTarget) {
      root.classList.add("is-open");
      toggle.setAttribute("aria-expanded", "true");
      menu.removeAttribute("hidden");
      refreshItems();
      var target = focusTarget;
      if (!target) {
        target =
          menu.querySelector('[role="menuitem"][aria-current="true"]') ||
          items[0];
      }
      if (target) target.focus();
    }

    function focusItem(index) {
      refreshItems();
      if (!items.length) return;
      var i = index % items.length;
      if (i < 0) i += items.length;
      items[i].focus();
    }

    function itemIndex(el) {
      refreshItems();
      return items.indexOf(el);
    }

    toggle.addEventListener("click", function (e) {
      e.stopPropagation();
      if (isOpen()) close(false);
      else open();
    });

    toggle.addEventListener("keydown", function (e) {
      if (e.key === "Escape") {
        close();
        return;
      }
      // Enter/Space: let the button click handler toggle (avoids double-fire).
      if (e.key === "ArrowDown") {
        e.preventDefault();
        if (!isOpen()) open(items[0]);
        else focusItem(0);
      } else if (e.key === "ArrowUp") {
        e.preventDefault();
        if (!isOpen()) open(items[items.length - 1]);
        else focusItem(items.length - 1);
      } else if (e.key === "Home") {
        e.preventDefault();
        if (!isOpen()) open(items[0]);
        else focusItem(0);
      } else if (e.key === "End") {
        e.preventDefault();
        if (!isOpen()) open(items[items.length - 1]);
        else focusItem(items.length - 1);
      }
    });

    menu.addEventListener("keydown", function (e) {
      var current = document.activeElement;
      var idx = itemIndex(current);
      var cols = columnCount(menu);

      if (e.key === "Escape") {
        e.preventDefault();
        close();
        return;
      }
      if (e.key === "ArrowDown") {
        e.preventDefault();
        focusItem(idx < 0 ? 0 : idx + cols);
      } else if (e.key === "ArrowUp") {
        e.preventDefault();
        focusItem(idx < 0 ? items.length - 1 : idx - cols);
      } else if (e.key === "ArrowRight") {
        e.preventDefault();
        focusItem(idx < 0 ? 0 : idx + (rtl ? -1 : 1));
      } else if (e.key === "ArrowLeft") {
        e.preventDefault();
        focusItem(idx < 0 ? 0 : idx + (rtl ? 1 : -1));
      } else if (e.key === "Home") {
        e.preventDefault();
        focusItem(0);
      } else if (e.key === "End") {
        e.preventDefault();
        focusItem(items.length - 1);
      } else if (e.key === "Tab") {
        close(false);
      }
    });

    items.forEach(function (item) {
      item.addEventListener("click", function (e) {
        var toLocale = item.getAttribute("data-locale-target");
        var href = item.getAttribute("href");
        if (!toLocale || !href) return;

        setLocaleCookie(toLocale);

        if (typeof gtag === "function") {
          gtag("event", "language_switch", {
            from_locale: fromLocale,
            to_locale: toLocale,
            page_id: pageId,
          });
        }

        if (toLocale === fromLocale) {
          e.preventDefault();
          close();
        }
      });
    });

    document.addEventListener("click", function (e) {
      if (!root.contains(e.target)) close(false);
    });
  }

  document.addEventListener("DOMContentLoaded", function () {
    document.querySelectorAll("[data-lang-switcher]").forEach(initSwitcher);
  });
})();