#!/usr/bin/env node
/**
 * Generate localized beta flyer HTML from the German master via DeepL.
 * Only visible body text and <title> are translated — CSS/HTML structure stay intact.
 *
 * Usage: node scripts/translate-flyer.mjs [--lang da,sv,nb]
 */

import { readFile, writeFile } from 'node:fs/promises'
import { resolve, dirname } from 'node:path'
import { fileURLToPath } from 'node:url'
import { loadEnvKey, translateTexts } from './lib/deepl-translate.mjs'

const __dirname = dirname(fileURLToPath(import.meta.url))
const repoRoot = resolve(__dirname, '..')
const sourcePath = resolve(repoRoot, 'docs/marketing/beta-flyer.html')

const TARGETS = {
  da: { code: 'DA', htmlLang: 'da', file: 'beta-flyer.da.html' },
  sv: { code: 'SV', htmlLang: 'sv', file: 'beta-flyer.sv.html' },
  nb: { code: 'NB', htmlLang: 'nb', file: 'beta-flyer.nb.html' }
}

const LANG_LIST_BLOCK = `<span class="lang-list"><span class="lang-item"><svg class="feature-flag" viewBox="0 0 5 3" xmlns="http://www.w3.org/2000/svg" aria-hidden="true"><rect width="5" height="1" fill="#000"/><rect y="1" width="5" height="1" fill="#D00"/><rect y="2" width="5" height="1" fill="#FFCE00"/></svg>Deutsch</span><span class="lang-sep">·</span><span class="lang-item"><svg class="feature-flag" viewBox="0 0 60 30" xmlns="http://www.w3.org/2000/svg" aria-hidden="true"><clipPath id="gb-a"><path d="M0 0v30h60V0z"/></clipPath><clipPath id="gb-b"><path d="M30 15h30v15zv15H0z"/></clipPath><g clip-path="url(#gb-a)"><path d="M0 0v30h60V0z" fill="#012169"/><path d="M0 0l60 30m0-30L0 30" stroke="#fff" stroke-width="6"/><path d="M0 0l60 30m0-30L0 30" clip-path="url(#gb-b)" stroke="#C8102E" stroke-width="4"/><path d="M30 0v30M0 15h60" stroke="#fff" stroke-width="10"/><path d="M30 0v30M0 15h60" stroke="#C8102E" stroke-width="6"/></g></svg>English</span><span class="lang-sep">·</span><span class="lang-item"><svg class="feature-flag" viewBox="0 0 37 28" xmlns="http://www.w3.org/2000/svg" aria-hidden="true"><rect width="37" height="28" fill="#C8102E"/><rect x="12" width="4" height="28" fill="#fff"/><rect y="12" width="37" height="4" fill="#fff"/></svg>Dansk</span><span class="lang-sep">·</span><span class="lang-item"><svg class="feature-flag" viewBox="0 0 16 10" xmlns="http://www.w3.org/2000/svg" aria-hidden="true"><rect width="16" height="10" fill="#006AA7"/><rect x="5" width="2" height="10" fill="#FECC00"/><rect y="4" width="16" height="2" fill="#FECC00"/></svg>Svenska</span><span class="lang-sep">·</span><span class="lang-item"><svg class="feature-flag" viewBox="0 0 22 16" xmlns="http://www.w3.org/2000/svg" aria-hidden="true"><rect width="22" height="16" fill="#BA0C2F"/><rect x="6" width="4" height="16" fill="#fff"/><rect y="6" width="22" height="4" fill="#fff"/><rect x="7" width="2" height="16" fill="#00205B"/><rect y="7" width="22" height="2" fill="#00205B"/></svg>Norsk</span></span>`

/** Pull translatable strings from visible content only (never from <style>). */
function collectSegments(html) {
  const segments = []

  const titleMatch = html.match(/<title>([^<]*)<\/title>/i)
  if (titleMatch?.[1]?.trim()) {
    segments.push({ kind: 'title', original: titleMatch[1] })
  }

  const bodyMatch = html.match(/<body[^>]*>([\s\S]*?)<\/body>/i)
  const bodyHtml = bodyMatch?.[1] ?? ''

  const textRe = />([^<]+)</g
  let match
  while ((match = textRe.exec(bodyHtml)) !== null) {
    const text = match[1]
    if (!text.trim()) continue
    // Legal imprint stays identical in all locales
    if (text.includes('KnorrLabs')) continue
    segments.push({ kind: 'text', original: text })
  }

  const ariaRe = /aria-label="([^"]+)"/g
  while ((match = ariaRe.exec(bodyHtml)) !== null) {
    segments.push({ kind: 'aria', original: match[1] })
  }

  const altRe = /alt="([^"]+)"/g
  while ((match = altRe.exec(bodyHtml)) !== null) {
    segments.push({ kind: 'alt', original: match[1] })
  }

  return segments
}

function applySegments(html, segments, translated) {
  let result = html

  segments.forEach((segment, index) => {
    const next = translated[index]
    if (segment.original === next) return

    switch (segment.kind) {
      case 'title':
        result = result.replace(
          `<title>${segment.original}</title>`,
          `<title>${next}</title>`
        )
        break
      case 'text': {
        const needle = `>${segment.original}<`
        const pos = result.indexOf(needle)
        if (pos === -1) return
        result = `${result.slice(0, pos)}>${next}<${result.slice(pos + needle.length)}`
        break
      }
      case 'aria':
        result = result.replace(
          `aria-label="${segment.original}"`,
          `aria-label="${next}"`
        )
        break
      case 'alt':
        result = result.replace(
          `alt="${segment.original}"`,
          `alt="${next}"`
        )
        break
      default:
        break
    }
  })

  return result
}

function patchLanguageFeature(html) {
  return html.replace(
    /(<div class="feature"><span class="feature-icon">✦<\/span>)<span class="lang-list">[\s\S]*?<\/span>(<\/div>)/,
    `$1${LANG_LIST_BLOCK}$2`
  )
}

function parseArgs(argv) {
  let langs = Object.keys(TARGETS)
  for (let i = 2; i < argv.length; i++) {
    if (argv[i] === '--lang' && argv[i + 1]) {
      langs = argv[++i].split(',').map((l) => l.trim())
    }
  }
  return langs
}

async function main() {
  const langs = parseArgs(process.argv)
  const apiKey = loadEnvKey()
  const sourceHtml = await readFile(sourcePath, 'utf8')
  const segments = collectSegments(sourceHtml)
  const texts = segments.map((s) => s.original)

  console.log(`Translating ${texts.length} visible strings per locale…`)

  for (const lang of langs) {
    const target = TARGETS[lang]
    if (!target) {
      console.error(`Unknown language: ${lang}`)
      process.exit(1)
    }

    console.log(`\n→ ${target.file}`)
    const translated = await translateTexts(texts, target.code, {
      sourceLang: 'DE',
      apiKey,
      batchSize: 20
    })

    let html = applySegments(sourceHtml, segments, translated)
    html = html.replace(/<html lang="de">/, `<html lang="${target.htmlLang}">`)
    html = patchLanguageFeature(html)

    const outPath = resolve(repoRoot, 'docs/marketing', target.file)
    await writeFile(outPath, html, 'utf8')
    console.log(`Wrote ${outPath}`)
  }
}

main().catch((err) => {
  console.error(err.message ?? err)
  process.exit(1)
})