/** Verify every packed companion through its package self-reference under plain Node. */

import { spawnSync } from 'node:child_process'
import {
  copyFileSync,
  globSync,
  mkdirSync,
  mkdtempSync,
  readFileSync,
  rmSync,
} from 'node:fs'
import { dirname, resolve } from 'node:path'
import { pathToFileURL } from 'node:url'

const root = resolve(import.meta.dirname, '..')
const loaderUrl = pathToFileURL(resolve(root, 'vendor/loader/lib/index.js')).href
const failures = []
const manifests = globSync('packages/*/*/package.json', { cwd: root }).sort()
const packArgs = ['pack', '--dry-run', '--json', '--ignore-scripts']
// Windows cannot spawn npm's .cmd shim directly; setup-node installs this JS
// entrypoint beside node.exe, so the probe stays shell-free on every runner.
const npmInvocation = process.platform === 'win32'
  ? [process.execPath, [resolve(dirname(process.execPath), 'node_modules/npm/bin/npm-cli.js'), ...packArgs]]
  : ['npm', packArgs]

for (const manifestPath of manifests) {
  const packageDir = dirname(resolve(root, manifestPath))
  const manifest = JSON.parse(readFileSync(resolve(root, manifestPath), 'utf8'))
  const packageName = manifest.name
  if (typeof packageName !== 'string' || packageName.length === 0) {
    failures.push(`${manifestPath}: missing package name`)
    continue
  }

  const pack = spawnSync(npmInvocation[0], npmInvocation[1], {
    cwd: packageDir,
    encoding: 'utf8',
  })
  if (pack.status !== 0) {
    const detail = pack.error?.message
      ?? (pack.stderr.trim() || pack.stdout.trim() || `npm pack exited ${pack.status}`)
    failures.push(`${packageName}: ${detail}`)
    continue
  }

  let files
  try {
    const result = JSON.parse(pack.stdout)
    files = result[0]?.files
    if (!Array.isArray(files)) throw new Error('npm pack returned no file inventory')
  } catch (error) {
    failures.push(`${packageName}: cannot parse npm pack inventory: ${String(error)}`)
    continue
  }

  // Keep the packed view below its owning package so Node reaches the real
  // pnpm dependency links. Junctioning node_modules elsewhere breaks pnpm's
  // relative workspace links on Windows.
  const stagedPackageDir = mkdtempSync(resolve(packageDir, '.dsh-packed-invariant-'))
  try {
    for (const file of files) {
      if (typeof file.path !== 'string'
        || (file.path !== 'package.json' && !file.path.startsWith('lib/'))) continue
      const target = resolve(stagedPackageDir, file.path)
      mkdirSync(dirname(target), { recursive: true })
      copyFileSync(resolve(packageDir, file.path), target)
    }

    const probe = `
      const companion = await import(${JSON.stringify(`${packageName}/invariant`)});
      const { default: Loader } = await import(${JSON.stringify(loaderUrl)});
      if ('default' in companion) throw new Error('companion has a default export');
      const loader = Object.create(Loader.prototype);
      const unwrapped = loader.unwrapExports(companion);
      if (unwrapped !== companion) throw new Error('Loader collapsed the companion namespace');
      if (typeof unwrapped.name !== 'string') throw new Error('companion name is missing');
      if (!Array.isArray(unwrapped.inject) || !unwrapped.inject.includes('invariants')) {
        throw new Error('companion does not inject invariants');
      }
      if (typeof unwrapped.apply !== 'function') throw new Error('companion apply is missing');
    `
    const result = spawnSync(process.execPath, ['--input-type=module', '--eval', probe], {
      cwd: stagedPackageDir,
      encoding: 'utf8',
    })
    if (result.status !== 0) {
      const detail = result.error?.message
        ?? (result.stderr.trim() || result.stdout.trim() || `node exited ${result.status}`)
      failures.push(`${packageName}: ${detail}`)
    }
  } finally {
    rmSync(stagedPackageDir, { recursive: true, force: true })
  }
}

if (failures.length > 0) {
  console.error('verify-built-package-invariants: packed companion failures:')
  for (const failure of failures) console.error(`  ${failure}`)
  process.exit(1)
}

console.log(`verify-built-package-invariants: ${manifests.length} packed companion(s) passed plain-Node Loader checks.`)