const path = require('path')
const fs = require('fs')
const { promisify } = require('util')

const log = require('loglevel')

const readFile = promisify(fs.readFile)

function getLocalePath(code) {
  return path.resolve(
    __dirname,
    '..',
    '..',
    'app',
    '_locales',
    code,
    'messages.json',
  )
}

async function getLocale(code) {
  try {
    const localeFilePath = getLocalePath(code)
    const fileContents = await readFile(localeFilePath, 'utf8')
    return JSON.parse(fileContents)
  } catch (e) {
    if (e.code === 'ENOENT') {
      log.error('Locale file not found')
    } else {
      log.error(`Error opening your locale ("${code}") file: `, e)
    }
    process.exit(1)
  }
}

function compareLocalesForMissingItems({ base, subject }) {
  return Object.keys(base).filter((key) => !subject[key])
}

function compareLocalesForMissingDescriptions({ englishLocale, targetLocale }) {
  return Object.keys(englishLocale).filter(
    (key) =>
      targetLocale[key] !== undefined &&
      englishLocale[key].description !== undefined &&
      englishLocale[key].description !== targetLocale[key].description,
  )
}

module.exports = {
  compareLocalesForMissingDescriptions,
  compareLocalesForMissingItems,
  getLocale,
  getLocalePath,
}