Files
fx-test/fluxer_api/src/infrastructure/EmailI18nService.ts
Hampus Kraft 2f557eda8c initial commit
2026-01-01 21:05:54 +00:00

89 lines
2.9 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 MessageFormat from '@messageformat/core';
import {Logger} from '~/Logger';
import {type EmailTemplateKey, type EmailTemplateVariables, getLocaleTranslations, hasLocale} from './email_i18n';
export interface LocalizedEmailTemplate {
subject: string;
body: string;
}
export class EmailI18nService {
private readonly defaultLocale = 'en-US';
private readonly messageFormatCache: Map<string, MessageFormat> = new Map();
getTemplate<T extends EmailTemplateKey>(
templateKey: T,
locale: string | null,
variables: EmailTemplateVariables[T],
): LocalizedEmailTemplate {
const effectiveLocale = this.getEffectiveLocale(locale);
const translations = getLocaleTranslations(effectiveLocale);
const fallbackTranslations = getLocaleTranslations(this.defaultLocale);
const template = translations[templateKey] ?? fallbackTranslations[templateKey];
if (!template) {
throw new Error(`Missing email template ${templateKey} for locale ${effectiveLocale}`);
}
const subjectMf = this.getMessageFormat(effectiveLocale);
const subject = subjectMf.compile(template.subject)(variables);
const bodyMf = this.getMessageFormat(effectiveLocale);
const body = bodyMf.compile(template.body)(variables);
return {subject, body};
}
formatDate(
date: Date,
locale: string | null,
options: Intl.DateTimeFormatOptions = {dateStyle: 'full', timeStyle: 'short'},
): string {
const effectiveLocale = this.getEffectiveLocale(locale);
return date.toLocaleString(effectiveLocale, options);
}
formatNumber(num: number, locale: string | null): string {
const effectiveLocale = this.getEffectiveLocale(locale);
return num.toLocaleString(effectiveLocale);
}
private getMessageFormat(locale: string): MessageFormat {
if (!this.messageFormatCache.has(locale)) {
this.messageFormatCache.set(locale, new MessageFormat(locale));
}
return this.messageFormatCache.get(locale)!;
}
private getEffectiveLocale(locale: string | null): string {
if (!locale) {
return this.defaultLocale;
}
if (!hasLocale(locale)) {
Logger.warn({locale}, 'Unsupported locale for email, falling back to en-US');
return this.defaultLocale;
}
return locale;
}
}