astro/examples/docs/src/languages.ts

export const LANGUAGE_NAMES = {
  English: 'en',
};

export const KNOWN_LANGUAGES = Object.values(LANGUAGE_NAMES);
export const langPathRegex = new RegExp(`\/(${KNOWN_LANGUAGES.join('|')})\/`);
export const getLanguageDetails = () => {
  // @ts-ignore
  let newLangWithRegion = (window.navigator.userLanguage || window.navigator.language || 'en-US').substr(0, 5);
  let newLang = newLangWithRegion.substr(0, 2);

  let actualDest = window.location.pathname.replace(langPathRegex, '/');
  return {
    newLangWithRegion,
    newLang,
    langPathRegex,
    actualDest,
  };
};