#!/usr/bin/env node

import { createHash } from "node:crypto";
import { spawnSync } from "node:child_process";
import { copyFile, 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 scriptDir = dirname(fileURLToPath(import.meta.url));
const workspaceRoot = resolve(scriptDir, "../../..");
const engineRoot = resolve(
  process.env.NODEDC_ENGINE_SOURCE_ROOT
    || join(workspaceRoot, "NODEDC_ENGINE_INFRA"),
);
const artifactDir = resolve(
  process.env.NODEDC_DEPLOY_ARTIFACT_DIR || resolve(scriptDir, "../deploy-artifacts"),
);
const [patchId = "engine-mcp-classified-aspects-20260724-039", ...extra] =
  process.argv.slice(2);

if (extra.length || !/^engine-mcp-classified-aspects-\d{8}-\d{3}$/.test(patchId)) {
  throw new Error(
    "usage: build-engine-mcp-classified-aspects-artifact.mjs "
      + "[engine-mcp-classified-aspects-YYYYMMDD-NNN]",
  );
}

const files = Object.freeze([
  "nodedc-source/server/l2ExecutionPlan/compiler.js",
  "nodedc-source/server/assets/execution-plans/v1/catalog.json",
  "nodedc-source/server/assets/provider-packages/v1/catalog.json",
]);
const expectedSha256 = Object.freeze({
  "nodedc-source/server/l2ExecutionPlan/compiler.js":
    "4854a62fb44cb3dd715f2cb8728740575453a666f5c31abe9d41bc2562be5e95",
  "nodedc-source/server/assets/execution-plans/v1/catalog.json":
    "2e70b607b4a347592ce2f4732f6da0781ac94ec4829ac336021cb501fdafe9aa",
  "nodedc-source/server/assets/provider-packages/v1/catalog.json":
    "2fce1c623a8acf9c01a43463e6d38eda71ad28379a2d91b2ca40f31f8dccf3c6",
});
const artifact = join(artifactDir, `nodedc-${patchId}.tgz`);
const checksum = `${artifact}.sha256`;
const stage = await mkdtemp(join(tmpdir(), "nodedc-engine-classified-aspects-"));

await assertFresh(artifact);
await assertEngineBoundary();

try {
  for (const relativePath of files) {
    const source = join(engineRoot, relativePath);
    const info = await lstat(source);
    if (!info.isFile() || info.isSymbolicLink()) {
      throw new Error(`source_file_rejected:${relativePath}`);
    }
    const destination = join(stage, "payload", relativePath);
    await mkdir(dirname(destination), { recursive: true });
    await copyFile(source, destination);
  }
  await writeFile(
    join(stage, "manifest.env"),
    `id=${patchId}\ncomponent=engine\ntype=app-overlay\n`,
    "utf8",
  );
  await writeFile(join(stage, "files.txt"), `${files.join("\n")}\n`, "utf8");
  await mkdir(artifactDir, { recursive: true });
  run("python3", ["-c", canonicalTarScript(), artifact, stage]);
  const sha256 = digest(await readFile(artifact));
  await writeFile(checksum, `${sha256}  ${artifact.split("/").at(-1)}\n`, "utf8");
  console.log(JSON.stringify({
    ok: true,
    patchId,
    artifact,
    checksum,
    sha256,
    services: ["nodedc-backend", "app"],
    engineCorePolicy: "provider-neutral-scalar-visibility-guards",
    providerPackage: "gelios.provider.v10",
    files,
    expectedSha256,
    untouched: [
      "live L2 graphs",
      "n8n L1",
      "Engine UI source and dist",
      "node-intelligence",
      "databases",
      "credentials",
      "embedded Codex",
    ],
  }, null, 2));
} finally {
  await rm(stage, { recursive: true, force: true });
}

async function assertEngineBoundary() {
  for (const relativePath of files) {
    const actual = digest(await readFile(join(engineRoot, relativePath)));
    if (actual !== expectedSha256[relativePath]) {
      throw new Error(
        `classified_aspect_target_mismatch:${relativePath}:`
          + `expected=${expectedSha256[relativePath]}:actual=${actual}`,
      );
    }
  }

  const compiler = await readFile(join(engineRoot, files[0]), "utf8");
  if (
    !compiler.includes("guardMatches")
    || !compiler.includes("'1.3.0'")
    || /gelios|fleet\.units\.contacts/i.test(compiler)
  ) {
    throw new Error("classified_aspect_compiler_boundary_invalid");
  }

  const executionCatalog = JSON.parse(
    await readFile(join(engineRoot, files[1]), "utf8"),
  );
  const providerPackage = executionCatalog?.packages?.find(
    (entry) => entry?.id === "gelios.provider.v10",
  );
  if (
    providerPackage?.version !== "10.0.0"
    || !executionCatalog?.runtime?.compilerVersions?.includes("1.3.0")
    || !providerPackage?.profiles?.some(
      (profile) =>
        profile?.dataProductId === "fleet.units.contacts.current.v1",
    )
  ) {
    throw new Error("classified_aspect_execution_catalog_invalid");
  }

  const securityCatalog = JSON.parse(
    await readFile(join(engineRoot, files[2]), "utf8"),
  );
  const securityPackage = securityCatalog?.packages?.find(
    (entry) => entry?.id === "gelios.provider.v10",
  );
  if (
    securityPackage?.version !== "10.0.0"
    || securityPackage?.capabilities?.length !== 1
    || JSON.stringify(securityPackage.capabilities[0]?.dataProductIds)
      !== JSON.stringify(["fleet.units.contacts.current.v1"])
  ) {
    throw new Error("classified_aspect_security_catalog_invalid");
  }
}

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 digest(value) {
  return createHash("sha256").update(value).digest("hex");
}

function run(command, args) {
  const result = spawnSync(command, args, {
    encoding: "utf8",
    maxBuffer: 64 * 1024 * 1024,
  });
  if (result.status !== 0) {
    throw new Error(`${command}_failed:${result.stderr || result.stdout}`);
  }
}