import type { Language } from "../../types/config"; /** Normalize a raw locale string (e.g. `"fr-FR"`) to a supported {@link Language}. */ function normalize(raw: string | undefined | null): Language | undefined { const base = raw?.split("-")[0]?.toLowerCase(); return base === "en" || base === "fr" ? base : undefined; } /** * Best-effort detection of the page's intended content language for SDK copy. * * Precedence: the document's declared `` (the page author's explicit * content language) → the browser UI language (`navigator.language`). Returns * `undefined` when neither resolves to a supported language, letting callers * apply their own fallback (e.g. `"en"`). * * The `` check comes first so a page authored in French renders * French SDK copy even when the visitor's browser is set to another language. */ export function detectPageLanguage(): Language | undefined { const htmlLang = typeof document !== "undefined" ? normalize(document.documentElement.lang) : undefined; if (htmlLang) return htmlLang; return typeof navigator !== "undefined" ? normalize(navigator.language) : undefined; }