/** 进程内公开元信息快照：供根 layout 同步 generateMetadata，避免 await 触发标题闪成 localhost */

export type PublicMetaSnapshot = {
  site_name: string;
  site_slogan: string;
  site_description: string;
  site_keywords: string[];
  favicon_url: string;
};

const DEFAULT_SNAP: PublicMetaSnapshot = {
  site_name: "姜十三论坛",
  site_slogan: "",
  site_description: "姜十三论坛 - 技术分享与讨论社区",
  site_keywords: [],
  favicon_url: "",
};

let snap: PublicMetaSnapshot = { ...DEFAULT_SNAP };

export function publishPublicMetaSnapshot(
  s: Partial<PublicMetaSnapshot> | null | undefined,
): void {
  if (!s) return;
  const name = typeof s.site_name === "string" ? s.site_name.trim() : "";
  snap = {
    site_name: name || DEFAULT_SNAP.site_name,
    site_slogan: typeof s.site_slogan === "string" ? s.site_slogan.trim() : snap.site_slogan,
    site_description:
      typeof s.site_description === "string" && s.site_description.trim()
        ? s.site_description.trim()
        : snap.site_description,
    site_keywords: Array.isArray(s.site_keywords) ? s.site_keywords : snap.site_keywords,
    favicon_url: typeof s.favicon_url === "string" ? s.favicon_url.trim() : snap.favicon_url,
  };
}

export function peekPublicMetaSnapshot(): PublicMetaSnapshot {
  return snap;
}