import assert from 'node:assert/strict'
import fs from 'node:fs'
import path from 'node:path'
import test from 'node:test'
import { createI18n } from 'vue-i18n'

const repoRoot = path.resolve(import.meta.dirname, '../..')
const read = relativePath => fs.readFileSync(path.join(repoRoot, relativePath), 'utf8')
const parseJson = relativePath => JSON.parse(read(relativePath))

const flattenKeys = (value, prefix = '') => {
  const keys = []
  for (const [key, child] of Object.entries(value)) {
    const fullKey = prefix ? `${prefix}.${key}` : key
    if (child && typeof child === 'object' && !Array.isArray(child)) {
      keys.push(...flattenKeys(child, fullKey))
    } else {
      keys.push(fullKey)
    }
  }
  return keys.sort()
}

const flattenStringKeys = (value, prefix = '') => {
  const keys = []
  for (const [key, child] of Object.entries(value)) {
    const fullKey = prefix ? `${prefix}.${key}` : key
    if (child && typeof child === 'object') {
      keys.push(...flattenStringKeys(child, fullKey))
    } else if (typeof child === 'string') {
      keys.push(fullKey)
    }
  }
  return keys.sort()
}

test('locale registry exposes only Thai and English', () => {
  const languages = parseJson('locales/languages.json')
  assert.deepEqual(Object.keys(languages).sort(), ['en', 'th'])
  assert.equal(languages.en.label, 'English')
  assert.equal(languages.th.label, 'ไทย')
})

test('Thai and English translation dictionaries have the same keys', () => {
  assert.deepEqual(
    flattenKeys(parseJson('locales/en.json')),
    flattenKeys(parseJson('locales/th.json')),
  )
})

test('every translation message compiles through the vue-i18n public API', () => {
  const messages = {
    th: parseJson('locales/th.json'),
    en: parseJson('locales/en.json'),
  }
  const i18n = createI18n({ legacy: false, locale: 'th', messages })

  for (const locale of ['th', 'en']) {
    i18n.global.locale.value = locale
    for (const keyPath of flattenStringKeys(messages[locale])) {
      assert.doesNotThrow(
        () => i18n.global.t(keyPath),
        `${locale}:${keyPath} is not valid vue-i18n syntax`,
      )
    }
    // The visible email placeholder must render as a literal email in both
    // locales; vue-i18n must not misparse it as linked-message syntax.
    assert.equal(
      i18n.global.t('auth.emailPlaceholder'),
      'name@company.com',
      `${locale}:auth.emailPlaceholder`,
    )
  }
})

test('frontend i18n uses Thai as the safe default and fallback', () => {
  const source = read('frontend/src/i18n/index.js')
  assert.match(source, /DEFAULT_LOCALE\s*=\s*['"]th['"]/)
  assert.match(source, /fallbackLocale:\s*DEFAULT_LOCALE/)
  assert.doesNotMatch(source, /\|\|\s*['"]zh['"]|fallbackLocale:\s*['"]zh['"]/)
})

test('HTML metadata has no Chinese locale or font dependency', () => {
  const html = read('frontend/index.html')
  assert.match(html, /<html\s+lang=["']th["']/)
  assert.doesNotMatch(html, /lang=["']zh|Noto Sans SC|预测|社交媒体|中文/)
})

test('production build text artifacts contain no CJK code points', () => {
  const distRoot = path.join(repoRoot, 'frontend/dist')
  const binaryExtensions = new Set(['.png', '.jpg', '.jpeg', '.gif', '.webp', '.ico'])
  const textFiles = []

  const visit = directory => {
    for (const entry of fs.readdirSync(directory, { withFileTypes: true })) {
      const entryPath = path.join(directory, entry.name)
      if (entry.isDirectory()) {
        visit(entryPath)
      } else if (!binaryExtensions.has(path.extname(entry.name).toLowerCase())) {
        textFiles.push(entryPath)
      }
    }
  }

  visit(distRoot)
  for (const filePath of textFiles) {
    const content = fs.readFileSync(filePath, 'utf8')
    assert.doesNotMatch(content, /[\u3400-\u4dbf\u4e00-\u9fff\uf900-\ufaff]/, filePath)
  }
})