const _cache: Record<string, any> = {};

function IntlInfo(lang = 'en', includeCurrencies = true) {
	if (_cache[lang]) {
		return _cache[lang];
	}

	const countryNames = new Intl.DisplayNames([lang], { type: 'region', fallback: 'none' });
	const languageNames = new Intl.DisplayNames([lang], { type: 'language', fallback: 'none' });
	const currencyNames = new Intl.DisplayNames([lang], { type: 'currency', fallback: 'none' });

	const countries: Record<string, any> = {};
	const languages: Record<string, any> = {};
	const currencies: Record<string, any> = {};

	let i, j, k, codeU, codeL, codeC, country, language, currency;

	if (!_cache.$) {
		_cache.$ = {
			U: [],
			L: [],
			C: [],
		};

		const alpha: string[] = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.split('');

		for (i = 0; i < 26; ++i) {
			for (j = 0; j < 26; ++j) {
				if (alpha[i] && alpha[j]) {
					codeU = alpha[i] + alpha[j]!;

					country = countryNames.of(codeU);
					if (country) {
						_cache.$.U.push(codeU);
						countries[codeU] = country;
					}

					codeL = codeU.toLowerCase();
					language = languageNames.of(codeL);
					if (language) {
						_cache.$.L.push(codeL);
						languages[codeL] = language;
					}

					if (includeCurrencies) {
						for (k = 0; k < 26; ++k) {
							codeC = codeU + alpha[k];
							currency = currencyNames.of(codeC);
							if (currency) {
								_cache.$.C.push(codeC);
								currencies[codeC] = currency;
							}
						}
					}
				}
			}
		}
	} else {
		for (i = 0; i < _cache.$.U.length; ++i) {
			codeU = _cache.$.U[i];
			countries[codeU] = countryNames.of(codeU);
		}
		for (j = 0; j < _cache.$.L.length; ++j) {
			codeL = _cache.$.L[j];
			languages[codeL] = languageNames.of(codeL);
		}
		for (k = 0; k < _cache.$.C.length; ++k) {
			codeC = _cache.$.C[k];
			currencies[codeC] = currencyNames.of(codeC);
		}
	}

	return (_cache[lang] = {
		countries,
		languages,
		currencies,
	});
}

IntlInfo._cache = _cache;
export default IntlInfo;