(() => {
  const root = document.documentElement;
  let storedTheme = null;
  try {
    storedTheme = localStorage.getItem("vacatureradar-theme");
  } catch {
    // Private or embedded browser contexts may disable persistent storage.
  }
  if (storedTheme === "light" || storedTheme === "dark") root.dataset.theme = storedTheme;

  const themeToggle = document.querySelector("[data-theme-toggle]");
  themeToggle?.addEventListener("click", () => {
    const theme = root.dataset.theme === "light" ? "dark" : "light";
    root.dataset.theme = theme;
    try {
      localStorage.setItem("vacatureradar-theme", theme);
    } catch {
      // The selected theme still applies for the current page.
    }
    themeToggle.setAttribute("aria-label", theme === "light" ? "Donker thema activeren" : "Licht thema activeren");
  });

  const frame = document.querySelector("[data-app-frame]");
  const sidebar = document.querySelector("[data-sidebar]");
  const toggle = document.querySelector("[data-nav-toggle]");
  const closeButtons = document.querySelectorAll("[data-nav-close], [data-nav-scrim]");
  let returnFocus = null;

  const closeNavigation = () => {
    frame?.classList.remove("nav-open");
    toggle?.setAttribute("aria-expanded", "false");
    if (returnFocus instanceof HTMLElement) returnFocus.focus();
  };
  toggle?.addEventListener("click", () => {
    returnFocus = document.activeElement;
    frame?.classList.add("nav-open");
    toggle.setAttribute("aria-expanded", "true");
    sidebar?.querySelector("a, button")?.focus();
  });
  closeButtons.forEach((button) => button.addEventListener("click", closeNavigation));
  document.addEventListener("keydown", (event) => {
    if (event.key === "Escape") closeNavigation();
  });

  document.querySelectorAll("[data-disclosure]").forEach((button) => {
    button.addEventListener("click", () => {
      const target = document.getElementById(button.getAttribute("aria-controls"));
      if (!target) return;
      const expanded = button.getAttribute("aria-expanded") === "true";
      button.setAttribute("aria-expanded", String(!expanded));
      target.hidden = expanded;
    });
  });
})();