import { describe, expect, it } from 'vitest'
import { I18N_NAMESPACES } from '../../src/i18n'
import { APP_LANGUAGES, type AppLanguage } from '../../src/i18n/detectLocale'

function flattenKeys(value: unknown, prefix = ''): string[] {
  if (value === null || typeof value !== 'object' || Array.isArray(value)) {
    return prefix ? [prefix] : []
  }

  const entries = Object.entries(value as Record<string, unknown>)
  if (entries.length === 0) return prefix ? [prefix] : []

  return entries.flatMap(([key, nested]) => {
    const next = prefix ? `${prefix}.${key}` : key
    if (nested !== null && typeof nested === 'object' && !Array.isArray(nested)) {
      const childKeys = flattenKeys(nested, next)
      return childKeys.length > 0 ? childKeys : [next]
    }
    return [next]
  })
}

async function loadLocale(namespace: string, language: AppLanguage) {
  const mod = await import(`../../src/i18n/locales/${language}/${namespace}.json`)
  return mod.default as Record<string, unknown>
}

describe('i18n locale key parity', () => {
  for (const namespace of I18N_NAMESPACES) {
    for (const language of APP_LANGUAGES) {
      it(`${language} keys match en for ${namespace}`, async () => {
        const [locale, en] = await Promise.all([
          loadLocale(namespace, language),
          loadLocale(namespace, 'en'),
        ])

        const localeKeys = flattenKeys(locale).sort()
        const enKeys = flattenKeys(en).sort()

        expect(localeKeys).toEqual(enKeys)
      })
    }
  }
})