import fs from 'node:fs'
import path from 'node:path'

const root = process.cwd()
const localesDir = path.join(root, 'src', 'i18n', 'locales')

const locales = fs.readdirSync(localesDir).filter((entry) => {
  const fullPath = path.join(localesDir, entry)
  return fs.statSync(fullPath).isDirectory()
})

if (!locales.includes('en')) {
  console.error('i18n-check: expected base locale directory "en"')
  process.exit(1)
}

function loadJson(filePath) {
  return JSON.parse(fs.readFileSync(filePath, 'utf8'))
}

function collectKeyPaths(obj, prefix = '') {
  if (!obj || typeof obj !== 'object' || Array.isArray(obj)) {
    return prefix ? [prefix] : []
  }

  const keys = Object.keys(obj)
  if (keys.length === 0) {
    return prefix ? [prefix] : []
  }

  const paths = []
  for (const key of keys) {
    const nextPrefix = prefix ? `${prefix}.${key}` : key
    const value = obj[key]
    if (value && typeof value === 'object' && !Array.isArray(value)) {
      paths.push(...collectKeyPaths(value, nextPrefix))
    } else {
      paths.push(nextPrefix)
    }
  }
  return paths
}

const baseLocaleDir = path.join(localesDir, 'en')
const namespaceFiles = fs.readdirSync(baseLocaleDir).filter((file) => file.endsWith('.json'))

let hasErrors = false

for (const namespaceFile of namespaceFiles) {
  const baseData = loadJson(path.join(baseLocaleDir, namespaceFile))
  const baseKeys = new Set(collectKeyPaths(baseData))

  for (const locale of locales) {
    if (locale === 'en') continue

    const localeFile = path.join(localesDir, locale, namespaceFile)
    if (!fs.existsSync(localeFile)) {
      console.error(`i18n-check: missing namespace file ${locale}/${namespaceFile}`)
      hasErrors = true
      continue
    }

    const localeData = loadJson(localeFile)
    const localeKeys = new Set(collectKeyPaths(localeData))

    for (const key of baseKeys) {
      if (!localeKeys.has(key)) {
        console.error(`i18n-check: missing key ${locale}/${namespaceFile}:${key}`)
        hasErrors = true
      }
    }

    for (const key of localeKeys) {
      if (!baseKeys.has(key)) {
        console.error(`i18n-check: extra key ${locale}/${namespaceFile}:${key}`)
        hasErrors = true
      }
    }
  }
}

if (hasErrors) {
  process.exit(1)
}

console.log('i18n-check: locale files are structurally consistent')