// same as in renderer

import { IntlMessageFormat } from 'intl-messageformat';
import * as en from '../../../shared/translation/en.json';

const localeData = {
  [Locale.EN]: en as TranslationData,
};

function getDeep(deepKey: string, data: TranslationData): string {
  const keyChain = deepKey.split('.');
  if (!keyChain.length) {
    return deepKey;
  }
  let index = 0;
  let curr: TranslationData | string = data;
  do {
    const key = keyChain[index];
    curr = curr[key];
    index++;
  } while (typeof curr !== 'string' && index < keyChain.length);
  if (typeof curr === 'string') {
    return curr;
  }
  return deepKey;
}

const intlMessageFormatCache: Record<Locale, Record<string, IntlMessageFormat>> = {
  [Locale.EN]: {},
};

/**
 * translates a message
 *
 * @param key - a deep key of the format "labels.actions.save"
 * @param values - arguments for the message
 * @param locale - see {@link Locale} for implemented locales
 */
export function t(key: string, values?: Record<string, string | number | boolean>, locale: Locale = Locale.EN): string {
  if (!intlMessageFormatCache[locale][key]) {
    const message = getDeep(key, localeData[locale]);
    intlMessageFormatCache[locale][key] = new IntlMessageFormat(message, locale);
  }
  const intlMessageFormat = intlMessageFormatCache[locale][key];
  const formatted = intlMessageFormat.format(values);
  if (typeof formatted === 'string') {
    return formatted;
  }
  return key;
}