/*
 * Copyright (C) 2026 - present Instructure, Inc.
 *
 * This file is part of Canvas.
 *
 * Canvas is free software: you can redistribute it and/or modify it under
 * the terms of the GNU Affero General Public License as published by the Free
 * Software Foundation, version 3 of the License.
 *
 * Canvas is distributed in the hope that it will be useful, but WITHOUT ANY
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
 * A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Affero General Public License along
 * with this program. If not, see <http://www.gnu.org/licenses/>.
 */

export function documentLocale(): string {
  return (typeof document !== 'undefined' && document.documentElement.lang) || 'en'
}

// Uses the browser's own locale data instead of a bundled translation catalog.
export function languageDisplayName(
  languageId: string,
  displayLocale: string = documentLocale(),
): string {
  try {
    return new Intl.DisplayNames([displayLocale], {type: 'language'}).of(languageId) ?? languageId
  } catch {
    return languageId
  }
}