import { NextRequest, NextResponse } from "next/server";
import { isLocale } from "@/lib/i18n";

const LOCALE_COOKIE = "site_locale";

export async function POST(req: NextRequest) {
  const body = await req.json().catch(() => null);
  const locale = body?.locale;

  if (typeof locale !== "string" || !isLocale(locale)) {
    return NextResponse.json({ error: "Invalid locale" }, { status: 400 });
  }

  const res = NextResponse.json({ ok: true, locale });

  // Cookie segura (en local no siempre tenés https; en prod sí)
  res.cookies.set(LOCALE_COOKIE, locale, {
    httpOnly: true,
    sameSite: "lax",
    secure: process.env.NODE_ENV === "production",
    path: "/",
    maxAge: 60 * 60 * 24 * 365, // 1 año
  });

  return res;
}