chill-bundles/src/Bundle/ChillMainBundle/Resources/public/lib/localizationHelper/localizationHelper.ts

import { TranslatableString } from "ChillMainAssets/types";

/**
 * Localizes a translatable string object based on the current locale.
 * A fallback logic is implemented in case no translation is available for the current locale.
 *
 * @param translatableString Object containing translations for different locales
 * @param locale defaults to browser locale
 * @returns The localized string or null if no translation is available
 */
export function localizeString(
  translatableString: TranslatableString | null | undefined,
  locale?: string,
): string {
  if (!translatableString || Object.keys(translatableString).length === 0) {
    return "";
  }

  const currentLocale = locale || navigator.language.split("-")[0] || "fr";

  if (translatableString[currentLocale]) {
    return translatableString[currentLocale];
  }

  // Define fallback locales
  const fallbackLocales: string[] = ["fr", "en"];

  for (const fallbackLocale of fallbackLocales) {
    if (translatableString[fallbackLocale]) {
      return translatableString[fallbackLocale];
    }
  }

  // No fallback translation found, use the first available
  const availableLocales = Object.keys(translatableString);
  if (availableLocales.length > 0) {
    return translatableString[availableLocales[0]];
  }

  return "";
}