import fs from 'node:fs'
import path from 'node:path'
import { fileURLToPath } from 'node:url'

const [, , sourceHtmlArg, outputPrefixArg] = process.argv
if (!sourceHtmlArg || !outputPrefixArg) {
  throw new Error(
    'Usage: node scripts/extract-page.mjs <source-html-path> <output-prefix>\n' +
      'Example: npm run extract:page -- ./snapshots/about.html about\n' +
      'Writes src/generated/<prefix>-page-body.html, <prefix>-assets.json, <prefix>-inline-scripts.txt'
  )
}

const currentFile = fileURLToPath(import.meta.url)
const rootDir = path.resolve(path.dirname(currentFile), '..')
const sourceHtmlPath = path.resolve(rootDir, sourceHtmlArg)
const outDir = path.resolve(rootDir, 'src', 'generated')

const html = fs.readFileSync(sourceHtmlPath, 'utf8')
const bodyMatch = html.match(/<body[^>]*>([\s\S]*?)<\/body>/i)
if (!bodyMatch) throw new Error(`Failed to extract <body> from ${sourceHtmlArg}`)

let bodyHtml = bodyMatch[1]
bodyHtml = bodyHtml.replace(/<script\b[^>]*>[\s\S]*?<\/script>/gi, '')

const links = Array.from(html.matchAll(/<link[^>]+href="([^"]+)"[^>]*>/gi)).map((m) => m[1])
const scripts = Array.from(html.matchAll(/<script[^>]+src="([^"]+)"[^>]*><\/script>/gi)).map(
  (m) => m[1]
)
const inlineScripts = Array.from(
  html.matchAll(/<script\b(?![^>]*\bsrc=)[^>]*>([\s\S]*?)<\/script>/gi)
)
  .map((m) => m[1].trim())
  .filter(Boolean)

fs.writeFileSync(path.join(outDir, `${outputPrefixArg}-page-body.html`), bodyHtml, 'utf8')
fs.writeFileSync(
  path.join(outDir, `${outputPrefixArg}-assets.json`),
  JSON.stringify({ scripts, links }, null, 2),
  'utf8'
)
fs.writeFileSync(
  path.join(outDir, `${outputPrefixArg}-inline-scripts.txt`),
  inlineScripts.join('\n/*__INLINE_SPLIT__*/\n'),
  'utf8'
)

console.log(`Generated files for ${outputPrefixArg}`)