#!/usr/bin/env node
import { createHash } from 'node:crypto'
import { spawnSync } from 'node:child_process'
import { cp, lstat, mkdir, mkdtemp, readFile, rm, writeFile } from 'node:fs/promises'
import { tmpdir } from 'node:os'
import { dirname, join, resolve } from 'node:path'
import { fileURLToPath } from 'node:url'

const here = dirname(fileURLToPath(import.meta.url))
const platformRoot = resolve(here, '../..')
const artifactRoot = resolve(process.env.NODEDC_DEPLOY_ARTIFACT_DIR || resolve(here, '../deploy-artifacts'))
const [transitionId = '20260718-005', ...extra] = process.argv.slice(2)
if (extra.length || !/^\d{8}-[0-9]{3}$/.test(transitionId)) {
  throw new Error('usage: build-platform-gelios-provider-v2-artifact.mjs [YYYYMMDD-NNN]')
}

const id = `platform-gelios-provider-v2-${transitionId}`
const target = join(artifactRoot, `nodedc-${id}.tgz`)
const files = [
  'platform/packages/external-provider-contract/providers/gelios/v2/README.md',
  'platform/packages/external-provider-contract/providers/gelios/v2/index.mjs',
  'platform/packages/external-provider-contract/providers/gelios/v2/package.mjs',
]
const expectedSha256 = new Map([
  [files[0], '82b56e484370b5dd99d281a4b91a6f8f4ac7e3e98ce75c15be1f2f23b556d21d'],
  [files[1], '405d2d9894b6b9f53c6522f675740b32355628b63dc2215dac7729033e8ef242'],
  [files[2], 'eca88d359a422162f261c449a4c1547d80bdb7029b6111621a82c99e073218c5'],
])

await assertFresh(target)
const stage = await mkdtemp(join(tmpdir(), 'nodedc-platform-gelios-provider-v2-'))
const payload = join(stage, 'payload')
try {
  await mkdir(payload, { recursive: true })
  for (const rel of files) {
    const source = join(platformRoot, rel.replace(/^platform\//, ''))
    const stat = await lstat(source)
    if (!stat.isFile() || stat.isSymbolicLink()) throw new Error(`source_boundary_invalid:${rel}`)
    const bytes = await readFile(source)
    if (sha(bytes) !== expectedSha256.get(rel)) throw new Error(`source_sha256_mismatch:${rel}`)
    await mkdir(dirname(join(payload, rel)), { recursive: true })
    await cp(source, join(payload, rel), { force: false })
  }
  await writeFile(join(stage, 'manifest.env'), `id=${id}\ncomponent=platform\ntype=app-overlay\n`, 'utf8')
  await writeFile(join(stage, 'files.txt'), `${files.join('\n')}\n`, 'utf8')
  await mkdir(artifactRoot, { recursive: true })
  run('python3', ['-c', canonicalTarScript(), target, stage])
  console.log(JSON.stringify({
    ok: true,
    id,
    artifact: target,
    artifactSha256: sha(await readFile(target)),
    services: [],
    providerPackage: 'gelios.provider.v2',
    authentication: 'SDK query token',
    runtimeEffect: 'catalog-only; no service restart',
    files,
  }, null, 2))
} finally {
  await rm(stage, { recursive: true, force: true })
}

async function assertFresh(path) {
  try {
    await lstat(path)
  } catch (error) {
    if (error?.code === 'ENOENT') return
    throw error
  }
  throw new Error('artifact_already_exists')
}

function canonicalTarScript() {
  return [
    'import gzip,io,pathlib,sys,tarfile',
    'root=pathlib.Path(sys.argv[2])',
    "with open(sys.argv[1],'wb') as out:",
    " with gzip.GzipFile(filename='',mode='wb',fileobj=out,compresslevel=9,mtime=0) as gz:",
    "  with tarfile.open(fileobj=gz,mode='w',format=tarfile.PAX_FORMAT) as tar:",
    "   for top in ('manifest.env','files.txt','payload'):",
    "    p=root/top; paths=[p]+(sorted(p.rglob('*')) if p.is_dir() else [])",
    '    for x in paths:',
    '     info=tar.gettarinfo(str(x),arcname=x.relative_to(root).as_posix())',
    "     info.uid=info.gid=0; info.uname=info.gname='root'; info.mtime=0; info.mode=0o755 if info.isdir() else 0o644",
    "     with (open(x,'rb') if info.isfile() else io.BytesIO()) as src: tar.addfile(info,src if info.isfile() else None)",
  ].join('\n')
}

function sha(bytes) {
  return createHash('sha256').update(bytes).digest('hex')
}

function run(command, args) {
  const result = spawnSync(command, args, {
    encoding: 'utf8',
    maxBuffer: 128 * 1024 * 1024,
    stdio: ['ignore', 'pipe', 'pipe'],
  })
  if (result.status !== 0) throw new Error(`${command}_failed:${result.stderr || result.stdout}`)
  return result
}