Compass/backend/shared/src/locale.ts

import {defaultLocale} from 'common/constants'
import {getTranslationMethod} from 'common/translate'
import {readFileSync} from 'fs'
import {join} from 'path'

function getMessagesPath(locale: string): string {
  const filePath = join(__dirname, '..', '..', '..', 'common', 'messages', `${locale}.json`)
  return filePath
}

const messageCache: Record<string, Record<string, string>> = {}

export function loadMessages(locale: string): Record<string, string> {
  if (messageCache[locale]) return messageCache[locale]

  try {
    const filePath = getMessagesPath(locale)
    console.log(`Loading messages from ${filePath}.`)
    const raw = readFileSync(filePath, 'utf-8')
    messageCache[locale] = JSON.parse(raw)
  } catch (e) {
    console.error('Failed to load messages for locale', locale, e)
    messageCache[locale] = {}
  }

  return messageCache[locale]
}

export function createT(locale: string | undefined) {
  locale = locale ?? defaultLocale
  const messages = locale === defaultLocale ? {} : loadMessages(locale)
  return getTranslationMethod(locale, messages)
}