/** 中控主题：暗色（默认）/ 亮色，localStorage hub-theme */
(function (global) {
  const KEY = "hub-theme";
  const META = { dark: "#0b0e18", light: "#d4dde8" };

  function normalize(theme) {
    return theme === "light" ? "light" : "dark";
  }

  function get() {
    try {
      return normalize(localStorage.getItem(KEY));
    } catch (_) {
      return "dark";
    }
  }

  function broadcastThemeToInstances() {
    const msg = { type: "hub-theme-sync", theme: get() };
    document.querySelectorAll("iframe#instance-frame, iframe.instance-frame").forEach((frame) => {
      try {
        if (frame.contentWindow) frame.contentWindow.postMessage(msg, "*");
      } catch (_) {}
    });
  }

  function apply(theme) {
    const t = normalize(theme);
    const root = document.documentElement;
    root.setAttribute("data-theme", t);
    try {
      localStorage.setItem(KEY, t);
    } catch (_) {}
    const meta = document.querySelector('meta[name="theme-color"]');
    if (meta) meta.setAttribute("content", META[t]);
    root.style.colorScheme = t;
    document.dispatchEvent(new CustomEvent("hub-theme-change", { detail: { theme: t } }));
    broadcastThemeToInstances();
    return t;
  }

  function toggle() {
    return apply(get() === "dark" ? "light" : "dark");
  }

  function syncToggleUI(root) {
    const scope = root || document;
    scope.querySelectorAll(".theme-toggle-btn[data-theme-value]").forEach((btn) => {
      const on = btn.getAttribute("data-theme-value") === get();
      btn.classList.toggle("is-active", on);
      btn.setAttribute("aria-pressed", on ? "true" : "false");
    });
  }

  function initToggleUI(root) {
    const scope = root || document;
    syncToggleUI(scope);
    scope.querySelectorAll(".theme-toggle-btn[data-theme-value]").forEach((btn) => {
      if (btn.dataset.themeBound === "1") return;
      btn.dataset.themeBound = "1";
      btn.addEventListener("click", () => {
        apply(btn.getAttribute("data-theme-value"));
        syncToggleUI(scope);
      });
    });
    document.addEventListener("hub-theme-change", () => syncToggleUI(scope));
  }

  apply(get());
  global.HubTheme = { KEY, get, apply, toggle, syncToggleUI, initToggleUI };
})(typeof window !== "undefined" ? window : globalThis);