/**
 * 四所实例主题：默认暗色；单独登录用 instance-theme；中控 iframe/SSO 随 hub-theme 联动。
 */
(function (global) {
  const STANDALONE_KEY = "instance-theme";
  const META = { dark: "#0b0d14", light: "#d8e2ec" };

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

  function isHubLinked() {
    try {
      const p = new URLSearchParams(location.search);
      if (p.get("embed") === "1") return true;
      const ht = p.get("hub_theme");
      if (ht === "light" || ht === "dark") return true;
    } catch (_) {}
    try {
      if (window.self !== window.top) return true;
    } catch (_) {
      return true;
    }
    return false;
  }

  function themeFromUrl() {
    try {
      const t = new URLSearchParams(location.search).get("hub_theme");
      if (t === "light" || t === "dark") return t;
    } catch (_) {}
    return null;
  }

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

  function setStandalone(theme) {
    try {
      localStorage.setItem(STANDALONE_KEY, normalize(theme));
    } catch (_) {}
  }

  function get() {
    if (isHubLinked()) {
      return themeFromUrl() || _linkedTheme || "dark";
    }
    return getStandalone();
  }

  let _linkedTheme = null;

  function apply(theme, opts) {
    const options = opts || {};
    const linked = isHubLinked();
    const t = normalize(theme);
    if (linked) {
      _linkedTheme = t;
    } else if (!options.skipStore) {
      setStandalone(t);
    }
    const root = document.documentElement;
    root.setAttribute("data-theme", t);
    const meta = document.querySelector('meta[name="theme-color"]');
    if (meta) meta.setAttribute("content", META[t]);
    root.style.colorScheme = t;
    syncToggleUI();
    document.dispatchEvent(
      new CustomEvent("instance-theme-change", { detail: { theme: t, hubLinked: linked } })
    );
    return t;
  }

  function syncToggleUI(root) {
    const scope = root || document;
    const linked = isHubLinked();
    const toggle = scope.querySelector(".instance-theme-toggle");
    if (toggle) {
      toggle.classList.toggle("is-hub-linked", linked);
      toggle.setAttribute("aria-hidden", linked ? "true" : "false");
    }
    if (linked) return;
    scope.querySelectorAll(".theme-toggle-btn[data-theme-value]").forEach((btn) => {
      const on = btn.getAttribute("data-theme-value") === getStandalone();
      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", () => {
        if (isHubLinked()) return;
        apply(btn.getAttribute("data-theme-value"));
      });
    });
  }

  function initFromHubMessage(data) {
    if (!data || data.type !== "hub-theme-sync") return;
    if (!isHubLinked()) return;
    apply(data.theme, { skipStore: true });
  }

  function boot() {
    if (isHubLinked()) {
      apply(themeFromUrl() || "dark", { skipStore: true });
      window.addEventListener("message", (ev) => initFromHubMessage(ev.data));
      try {
        window.parent.postMessage({ type: "instance-theme-ready" }, "*");
      } catch (_) {}
    } else {
      apply(getStandalone());
    }
    if (document.readyState === "loading") {
      document.addEventListener("DOMContentLoaded", () => initToggleUI());
    } else {
      initToggleUI();
    }
  }

  boot();

  global.InstanceTheme = {
    STANDALONE_KEY,
    isHubLinked,
    get,
    apply,
    initToggleUI,
    syncToggleUI,
  };
})(typeof window !== "undefined" ? window : globalThis);