import i18next, { TOptions, StringMap, TFunction } from 'i18next';
import ChainedBackend from 'i18next-chained-backend';

import { I18nTekoMultiLangBackend } from '@multi-lang/teko-multi-language';
import { initReactI18next } from 'react-i18next';
import resourcesToBackend from 'i18next-resources-to-backend';
import { getCurrentLanguage } from '@tempi/utils';

export type LangType = {
  [key: string]: { [key: string]: string };
};

const { env } = window?.config || {};

const mapEnv = {
  dev: 'development',
  stag: 'staging',
  production: 'production',
};
const { languageServiceCode, defaultLanguage = 'vi' } = window?.config || {};
const lng = getCurrentLanguage();
document.documentElement.lang = lng;

const getDefaultResources = () => {
  return defaultLanguage === 'en'
    ? import('./locales/en/translation.json')
    : import('./locales/vi/translation.json');
};

i18next
  .use(initReactI18next) // passes i18n down to react-i18next
  .use(ChainedBackend) // Use Teko multi language plugin
  .init({
    lng,
    fallbackLng: defaultLanguage,
    interpolation: {
      escapeValue: false,
    },
    initImmediate: false, // Must pass for synchronize init
    backend: languageServiceCode
      ? {
          backends: [
            I18nTekoMultiLangBackend,
            resourcesToBackend(() => getDefaultResources()),
          ],
          backendOptions: [
            {
              env: mapEnv[env], // Environment
              serviceCode: languageServiceCode, // Service ID
              expirationTime: 10000, // TTL of cached languagein milisecond. Default is 10 minutes
            },
          ],
        }
      : {
          backends: [resourcesToBackend(() => getDefaultResources())],
        },
  })
  .then(async () => {
    try {
      const overrideResources = (await getDefaultResources()).default;
      const resources = i18next.getResourceBundle(lng, 'translation');
      i18next.addResourceBundle(
        lng,
        'translation',
        { ...overrideResources, ...resources },
        true,
      );
    } catch (e) {
      console.error(e);
    }
  });

export const t = (
  keys: string | string[],
  options?: TOptions<StringMap>,
): string => {
  const text = i18next.t(keys, {
    ...options,
    interpolation: { escapeValue: false },
  });
  // debugger;
  return text || (keys as string);
};

export const changeLanguage = async (lng: string): Promise<TFunction> => {
  return i18next.changeLanguage(lng);
};