First build

src/i18n.js

@@ -0,0 +1,54 @@
+'use strict'
+
+const fsp = require('fs').promises
+const path = require('path')
+const { DIRS } = require('./paths')
+
+const FALLBACK = 'en-us'
+let cache = {}
+
+async function loadLang(code) {
+  const file = path.join(DIRS.TRANSLATIONS, `${code}.json`)
+  try {
+    const raw = await fsp.readFile(file, 'utf8')
+    const parsed = JSON.parse(raw)
+    cache[code] = parsed
+    return parsed
+  } catch {
+    return null
+  }
+}
+
+async function init() {
+  const files = await fsp.readdir(DIRS.TRANSLATIONS).catch(() => [])
+  const langs = []
+  for (const f of files) {
+    if (!f.endsWith('.json')) continue
+    const lang = await loadLang(f.replace(/\.json$/, ''))
+    if (lang && lang.data && lang.texts) langs.push(lang)
+  }
+  return langs
+}
+
+function listLangs() {
+  return Object.entries(cache).map(([code, lang]) => ({
+    code,
+    nameEn: (lang.data && lang.data.nameEn) || code,
+    nameSelf: (lang.data && lang.data.nameSelf) || code
+  }))
+}
+
+function getLang(code) {
+  return cache[code] || cache[FALLBACK] || { texts: {}, data: {} }
+}
+
+function translate(code, key, ...args) {
+  const lang = getLang(code)
+  let text = (lang.texts && lang.texts[key]) ?? (cache[FALLBACK] && cache[FALLBACK].texts && cache[FALLBACK].texts[key]) ?? key
+  args.forEach((v, i) => {
+    text = String(text).split(`{${i}}`).join(String(v))
+  })
+  return text
+}
+
+module.exports = { init, listLangs, getLang, translate, loadLang, FALLBACK }