import { headers, cookies } from "next/headers";
import { auth } from "@/lib/auth/server";
import type { Locale } from "@/lib/i18n/provider";
import { MARKETING_LOCALE_COOKIE } from "@/lib/marketing-locale-cookie";

export { MARKETING_LOCALE_COOKIE };

/**
 * Locale for the public marketing pages — cookie-based, not tied to a user
 * account (visitors there have no session). Separate from the authenticated
 * app's locale system (`lib/i18n/provider.tsx`'s `useLocale`/`setLocale`),
 * which persists to `users.locale` via an authenticated PATCH that would
 * just 401 for an anonymous visitor and revert the UI.
 */
export async function getMarketingLocale(): Promise<Locale> {
  const store = await cookies();
  const value = store.get(MARKETING_LOCALE_COOKIE)?.value;
  return value === "fr" ? "fr" : "en";
}

/** A logged-in visitor's own saved locale wins (matches what they see
 * everywhere else in the app); otherwise the marketing cookie. */
export async function getEffectiveMarketingLocale(): Promise<Locale> {
  const session = await auth.api.getSession({ headers: await headers() }).catch(() => null);
  const sessionLocale = (session?.user as { locale?: string } | undefined)?.locale;
  if (sessionLocale === "en" || sessionLocale === "fr") return sessionLocale;
  return getMarketingLocale();
}