import { CanonicalizeLocaleList } from '../CanonicalizeLocaleList';
import { invariant } from '../utils';
import { IsWellFormedCurrencyCode } from '../IsWellFormedCurrencyCode';
var UNICODE_REGION_SUBTAG_REGEX = /^([a-z]{2}|[0-9]{3})$/i;
var ALPHA_4 = /^[a-z]{4}$/i;
function isUnicodeRegionSubtag(region) {
    return UNICODE_REGION_SUBTAG_REGEX.test(region);
}
function isUnicodeScriptSubtag(script) {
    return ALPHA_4.test(script);
}
export function CanonicalCodeForDisplayNames(type, code) {
    if (type === 'language') {
        return CanonicalizeLocaleList([code])[0];
    }
    if (type === 'region') {
        if (!isUnicodeRegionSubtag(code)) {
            throw RangeError('invalid region');
        }
        return code.toUpperCase();
    }
    if (type === 'script') {
        if (!isUnicodeScriptSubtag(code)) {
            throw RangeError('invalid script');
        }
        return "" + code[0].toUpperCase() + code.slice(1);
    }
    invariant(type === 'currency', 'invalid type');
    if (!IsWellFormedCurrencyCode(code)) {
        throw RangeError('invalid currency');
    }
    return code.toUpperCase();
}