@gramio/i18n/dist/fluent/index.js

i18n plugin for GramIO with type-safety

import { Plugin } from 'gramio';
import fs from 'node:fs';
import path from 'node:path';
import { FluentBundle, FluentResource } from '@fluent/bundle';

function getFluentClient(options) {
  const directory = options?.directory ?? "locales";
  const bundles = /* @__PURE__ */ new Map();
  for (const entry of fs.readdirSync(directory, { withFileTypes: true })) {
    if (!entry.isFile() || !entry.name.endsWith(".ftl")) continue;
    const lang = entry.name.slice(0, -4);
    const source = fs.readFileSync(path.resolve(directory, entry.name)).toString();
    const bundle = new FluentBundle(lang);
    const resource = new FluentResource(source);
    bundle.addResource(resource);
    bundles.set(lang, bundle);
  }
  const defaultLocale = options?.defaultLocale ?? bundles.keys().next().value;
  if (!defaultLocale)
    throw new Error("Please specify one or more translations");
  let currentLanguage = defaultLocale;
  return {
    languages: {
      bundles,
      fallback: defaultLocale,
      all: Array.from(bundles.keys()),
      current: currentLanguage,
      change: (language) => {
        if (!bundles.has(language))
          throw new Error(`No ${language} language found`);
        currentLanguage = language;
      }
    },
    t: (id, args) => {
      const bundle = bundles.get(currentLanguage);
      if (!bundle) throw new Error(`No ${currentLanguage} language found`);
      const message = bundle.getMessage(id);
      if (!message?.value) throw new Error(`No message found for ${id}`);
      return bundle.formatPattern(message.value, args);
    }
  };
}

function i18n(options) {
  const client = options && "t" in options ? options : getFluentClient(options);
  return new Plugin("@gramio/i18n").derive(() => {
    let language = client.languages.current;
    return {
      /** Object with localization utils and settings */
      i18n: {
        /** All languages */
        locales: client.languages.all,
        /** Current user locale */
        locale: language,
        /** Set locale to current user */
        setLocale: (lang, strict = false) => {
          if (!client.languages.all.includes(lang)) {
            if (strict) throw new Error(`No ${language} language found`);
            language = client.languages.fallback;
            return;
          }
          language = lang;
        }
      },
      t: (id, args) => {
        const bundle = client.languages.bundles.get(language);
        if (!bundle) throw new Error(`No ${language} language found`);
        const message = bundle.getMessage(id);
        if (!message?.value) throw new Error(`No message found for ${id}`);
        return bundle.formatPattern(message.value, args);
      }
    };
  });
}

export { getFluentClient, i18n };