#!/usr/bin/env node
import { createHash } from 'node:crypto'
import { spawnSync } from 'node:child_process'
import { 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 workspaceRoot = resolve(platformRoot, '..')
const engineRoot = resolve(workspaceRoot, 'NODEDC_ENGINE_INFRA')
const artifactRoot = resolve(process.env.NODEDC_DEPLOY_ARTIFACT_DIR || join(workspaceRoot, 'deploy-artifacts'))
const [patchId = '', ...extra] = process.argv.slice(2)
const storeRelativePath = 'nodedc-source/server/engineAgents/store.js'
const predecessorSha256 = '52daa43499d6d9a97fe7ffa891edb9212b7791e733f91dd3ca686d42739b7e9a'
const targetSha256 = '2e62654c2dc12905efcc83a9dff45a818dd7b47924a10600160835c4416540e9'
const readerExtendedSourceSha256 = 'debd351fe0b8c72b33b8c79909b8f339cbaf061b970576f3ae72df52ebaa211f'
const ontologyExtendedSourceSha256 = '4cd4bdd5958cfafee184e98a04fe12aa0c1cbe884326beaec63c99f9fff61285'
const frozenTargetArtifact = join(
  workspaceRoot,
  'deploy-artifacts/nodedc-engine-agent-full-grant-migration-20260717-002.tgz',
)
const frozenTargetArtifactSha256 = 'd104ee6e63d1fccb9069e2b3db5e0446907ee9bf9cb04f2387636c272f803d68'
const previouslyIssuedPatchIds = new Set([
  'engine-agent-full-grant-migration-20260717-001',
])

if (extra.length || !/^engine-agent-full-grant-migration-\d{8}-\d{3}$/.test(patchId)) {
  throw new Error('usage: build-engine-agent-full-grant-migration-artifact.mjs <fresh-patch-id>')
}
if (previouslyIssuedPatchIds.has(patchId)) {
  throw new Error('engine_agent_full_grant_migration_patch_id_already_issued')
}

const source = join(engineRoot, storeRelativePath)
const sourceInfo = await lstat(source)
if (sourceInfo.isSymbolicLink() || !sourceInfo.isFile()) throw new Error('engine_agent_store_source_unsafe')
const sourceBytes = await materializeFrozenTarget(await readFile(source))
if (digest(sourceBytes) !== targetSha256) throw new Error('engine_agent_store_target_sha256_mismatch')
const sourceText = sourceBytes.toString('utf8')
for (const required of [
  'const STORE_VERSION = 2',
  "export const ENGINE_AGENT_FULL_DEVELOPER_PROFILE = 'full-developer'",
  "export const ENGINE_AGENT_CUSTOM_PROFILE = 'custom'",
  'const LEGACY_FULL_DEVELOPER_SCOPES = Object.freeze([',
  "'engine:l2:data-product-publish-grant:plan'",
  "'engine:l2:data-product-publish-grant:write'",
  'const migrateLegacyFullDeveloper = sourceVersion === 1',
  'LEGACY_FULL_DEVELOPER_SCOPES.every((scope) => scopes.includes(scope))',
  'profile === ENGINE_AGENT_FULL_DEVELOPER_PROFILE ? [...ENGINE_AGENT_SCOPES] : scopes',
  "throw new Error('engine_agent_store_version_unsupported')",
]) {
  if (!sourceText.includes(required)) throw new Error(`engine_agent_store_contract_missing:${required}`)
}
if (/gelios|robot2b/i.test(sourceText)) throw new Error('engine_agent_store_provider_logic_forbidden')
run('node', ['--check', source])

await mkdir(artifactRoot, { recursive: true })
const artifact = join(artifactRoot, `nodedc-${patchId}.tgz`)
await assertFresh(artifact)
const stage = await mkdtemp(join(tmpdir(), 'nodedc-engine-agent-grant-migration-'))
try {
  const destination = join(stage, 'payload', storeRelativePath)
  await mkdir(dirname(destination), { recursive: true })
  await writeFile(destination, sourceBytes)
  await writeFile(
    join(stage, 'manifest.env'),
    `id=${patchId}\ncomponent=engine\ntype=app-overlay\n`,
    'utf8',
  )
  await writeFile(join(stage, 'files.txt'), `${storeRelativePath}\n`, 'utf8')
  run('python3', ['-c', canonicalTarScript(), artifact, stage])
  const artifactBytes = await readFile(artifact)
  console.log(JSON.stringify({
    ok: true,
    patchId,
    artifact,
    sha256: digest(artifactBytes),
    entries: [storeRelativePath],
    predecessorSha256,
    targetSha256,
    services: ['nodedc-backend'],
    excluded: ['n8n', 'app', 'databases', 'credentials', 'runtime-data'],
  }, null, 2))
} finally {
  await rm(stage, { recursive: true, force: true })
}

async function assertFresh(target) {
  try {
    await lstat(target)
  } catch (error) {
    if (error?.code === 'ENOENT') return
    throw error
  }
  throw new Error('engine_agent_full_grant_migration_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 run(command, args) {
  const result = spawnSync(command, args, {
    encoding: 'utf8',
    stdio: ['ignore', 'pipe', 'pipe'],
    maxBuffer: 16 * 1024 * 1024,
  })
  if (result.status !== 0) throw new Error(`${command}_failed:${result.stderr || result.stdout}`)
  return result
}

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

async function materializeFrozenTarget(bytes) {
  const sourceSha256 = digest(bytes)
  if (sourceSha256 === targetSha256) return bytes
  if (sourceSha256 === ontologyExtendedSourceSha256) {
    const artifactBytes = await readFile(frozenTargetArtifact)
    if (digest(artifactBytes) !== frozenTargetArtifactSha256) {
      throw new Error('engine_agent_store_frozen_target_artifact_sha256_mismatch')
    }
    const script = [
      'import pathlib,sys,tarfile',
      'p=pathlib.Path(sys.argv[1])',
      "with tarfile.open(p,'r:gz') as t:",
      " f=t.extractfile('payload/nodedc-source/server/engineAgents/store.js')",
      " if f is None: raise SystemExit('member-unreadable')",
      ' sys.stdout.buffer.write(f.read())',
    ].join('\n')
    const frozen = Buffer.from(run('python3', ['-c', script, frozenTargetArtifact]).stdout, 'utf8')
    if (digest(frozen) !== targetSha256) {
      throw new Error('engine_agent_store_frozen_target_sha256_mismatch')
    }
    return frozen
  }
  if (sourceSha256 !== readerExtendedSourceSha256) {
    throw new Error('engine_agent_store_target_sha256_mismatch')
  }
  const text = bytes.toString('utf8')
  const readerScopes = [
    "  'engine:l2:data-product-read-grant:plan',\n",
    "  'engine:l2:data-product-read-grant:write',\n",
  ]
  let frozen = text
  for (const scope of readerScopes) {
    if (!frozen.includes(scope)) throw new Error('engine_agent_store_reader_scope_boundary_missing')
    frozen = frozen.replace(scope, '')
  }
  return Buffer.from(frozen, 'utf8')
}