#!/usr/bin/env node
import { createHash } from "node:crypto";
import { spawnSync } from "node:child_process";
import { cp, 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 scriptDir = dirname(fileURLToPath(import.meta.url));
const platformRoot = resolve(scriptDir, "../..");
const artifactDir = resolve(process.env.NODEDC_DEPLOY_ARTIFACT_DIR || join(scriptDir, "../deploy-artifacts"));
const [patchId = "external-data-plane-replacement-replay-v1-20260721-014", ...extra] = process.argv.slice(2);
const sourceRelative = "services/external-data-plane/src/data-product-delivery.mjs";
const destinationRelative = `platform/${sourceRelative}`;

if (extra.length || !/^[A-Za-z0-9._-]{1,96}$/.test(patchId)) {
  throw new Error("usage: build-external-data-plane-replacement-replay-artifact.mjs [patch-id]");
}

const source = resolve(platformRoot, sourceRelative);
const sourceText = await readFile(source, "utf8");
for (const marker of [
  'replacement.disposition === "replay"',
  "classifyReplacementGeneration",
  'throw deliveryError("data_product_generation_not_newer", 409)',
  'join current_scope using (source_id, semantic_type, fingerprint)',
]) {
  if (!sourceText.includes(marker)) throw new Error(`replacement_replay_boundary_missing:${marker}`);
}

const stage = await mkdtemp(join(tmpdir(), "nodedc-edp-replacement-replay-"));
const payloadPath = join(stage, "payload", destinationRelative);
const target = join(artifactDir, `nodedc-platform-${patchId}.tgz`);

try {
  await mkdir(dirname(payloadPath), { recursive: true });
  await cp(source, payloadPath, { force: false });
  await writeFile(join(stage, "manifest.env"), `id=${patchId}\ncomponent=platform\ntype=app-overlay\n`, "utf8");
  await writeFile(join(stage, "files.txt"), `${destinationRelative}\n`, "utf8");
  await mkdir(artifactDir, { recursive: true });
  const tar = spawnSync("python3", ["-c", canonicalTarScript(), target, stage], {
    encoding: "utf8",
    maxBuffer: 32 * 1024 * 1024,
  });
  if (tar.status !== 0) throw new Error(`tar_failed:${tar.stderr || tar.stdout}`);
  const sha256 = createHash("sha256").update(await readFile(target)).digest("hex");
  console.log(JSON.stringify({
    ok: true,
    patchId,
    artifact: target,
    sha256,
    entries: [destinationRelative],
    service: "external-data-plane",
    database: "preserved",
  }, null, 2));
} finally {
  await rm(stage, { recursive: true, force: true });
}

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");
}
