fluxer/packages/geo_utils/src/RegionDisplayNameResolver.tsx
2026-02-17 12:22:36 +00:00

76 lines
2.5 KiB
TypeScript

/*
* Copyright (C) 2026 Fluxer Contributors
*
* This file is part of Fluxer.
*
* Fluxer is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Fluxer is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with Fluxer. If not, see <https://www.gnu.org/licenses/>.
*/
import {Locales} from '@fluxer/constants/src/Locales';
import {normalizeRegionCode} from '@fluxer/geo_utils/src/RegionCodeValidation';
const DISPLAY_NAME_TYPE: Intl.DisplayNamesOptions['type'] = 'region';
const DISPLAY_NAME_FALLBACK: Intl.DisplayNamesOptions['fallback'] = 'none';
const displayNamesByLocale = new Map<string, Intl.DisplayNames>();
function resolveLocale(locale?: string): string {
const trimmedLocale = locale?.trim();
if (trimmedLocale && trimmedLocale.length > 0) {
return trimmedLocale;
}
return Locales.EN_US;
}
function getDisplayNames(locale?: string): Intl.DisplayNames {
const localeCode = resolveLocale(locale);
const cachedDisplayNames = displayNamesByLocale.get(localeCode);
if (cachedDisplayNames) {
return cachedDisplayNames;
}
const displayNames = new Intl.DisplayNames([localeCode], {
type: DISPLAY_NAME_TYPE,
fallback: DISPLAY_NAME_FALLBACK,
});
displayNamesByLocale.set(localeCode, displayNames);
return displayNames;
}
function resolveRegionDisplayNameFromFormatter(
regionCode: string,
displayNames: Intl.DisplayNames,
): string | undefined {
const normalizedRegionCode = normalizeRegionCode(regionCode);
if (!normalizedRegionCode) {
return undefined;
}
return displayNames.of(normalizedRegionCode) ?? undefined;
}
export function resolveRegionDisplayName(regionCode: string, locale?: string): string | undefined {
const displayNames = getDisplayNames(locale);
return resolveRegionDisplayNameFromFormatter(regionCode, displayNames);
}
export function resolveRegionDisplayNames(
regionCodes: ReadonlyArray<string>,
locale?: string,
): Array<string | undefined> {
const displayNames = getDisplayNames(locale);
return regionCodes.map((regionCode) => resolveRegionDisplayNameFromFormatter(regionCode, displayNames));
}