#!/usr/bin/env node
import { createHash } from "node:crypto";
import { spawnSync } from "node:child_process";
import {
  copyFile,
  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 engineRoot = resolve(
  process.env.NODEDC_ENGINE_SOURCE_ROOT || resolve(platformRoot, "../NODEDC_ENGINE_INFRA"),
);
const artifactRoot = resolve(
  process.env.NODEDC_DEPLOY_ARTIFACT_DIR || resolve(here, "../deploy-artifacts"),
);
const baselineArtifact = resolve(
  here,
  "../deploy-artifacts/nodedc-engine-provider-authority-diagnostics-20260723-029.tgz",
);
const baselineArtifactSha256 =
  "b4a0a1f707bf9814a4decc3f7f261b8afffe5727af2129c14bcdc76f81675e38";
const descriptorRel =
  "nodedc-source/services/node-intelligence/activation.json";
const baselineDescriptorSha256 =
  "84b0e15a10cedf334ad04d6f31c908da2dc155503c9974f0eeb75b01e20fb884";
const predecessorGatewaySha256 =
  "5331f6dc8dc306f641370a2968eb025ee3e278e27ae9a217e4cfc2901fec369c";
const targetGatewaySha256 =
  "4f600a2781be9118bec891fa2a6f20d7f55e0892ef2f06af24059193cebd28f4";
const targetDescriptorSha256 =
  "63e7619c6971d02102583bb5d80d33ece293b952f113200fa0b76f0e88c2dd32";
const [patchId = "", ...extra] = process.argv.slice(2);
if (extra.length || !/^engine-l2-closed-loop-\d{8}-\d{3}$/.test(patchId)) {
  throw new Error(
    "usage: build-engine-l2-closed-loop-artifact.mjs " +
    "<engine-l2-closed-loop-YYYYMMDD-NNN>",
  );
}

const sourceCommit = "dda405cff27977622af0c218abb4d4420c408536";
const entries = Object.freeze([
  "nodedc-source/server/index.js",
  "nodedc-source/server/l2/graphRepository.js",
  "nodedc-source/server/realtime/ws.js",
  "nodedc-source/server/routes/engineAgentGateway.js",
  "nodedc-source/server/routes/n8n.js",
  "nodedc-source/server/routes/ndcAgentMcp.js",
  "nodedc-source/src/App.tsx",
  "nodedc-source/src/n8n/N8nSubworkflowHost.tsx",
  "nodedc-source/src/realtime/useMultiplayer.ts",
  "nodedc-source/src/utils/n8nApi.ts",
  "nodedc-source/dist/index.html",
  "nodedc-source/dist/assets",
  descriptorRel,
]);
const targetSha256 = Object.freeze({
  "nodedc-source/server/index.js":
    "1896e1cade61579863c50ff3f52f2e81ff27f2a511a9d362db81925ee21cefad",
  "nodedc-source/server/l2/graphRepository.js":
    "94ad08e1bb7e7be04854f1f911e06ee1acd6e09631f33f4c01e42e230665ac33",
  "nodedc-source/server/realtime/ws.js":
    "82cfa833e05c2fc6d6049dd4564af06164b5c784fdfb82c243ca67519f4509c2",
  "nodedc-source/server/routes/engineAgentGateway.js":
    "4f600a2781be9118bec891fa2a6f20d7f55e0892ef2f06af24059193cebd28f4",
  "nodedc-source/server/routes/n8n.js":
    "752cb1524160adc1c95163c34e139b615c063d2ce8980f2a63879bddbd0f1e08",
  "nodedc-source/server/routes/ndcAgentMcp.js":
    "353a10291ceb93c3641ece60ec6e809a394be86f5ceb97cb44755178940409dd",
  "nodedc-source/src/App.tsx":
    "b3e61a89330b774f309660208d05143d299ab582f18765c1c14e2122a62c4d5e",
  "nodedc-source/src/n8n/N8nSubworkflowHost.tsx":
    "683aa44ba92aeac4879889e2bdb5319282976d7680d620701578830ce9677087",
  "nodedc-source/src/realtime/useMultiplayer.ts":
    "a4d001d9914098e50a78d8abe0a66344d23680b7a19b3573aa7b6f48c8bb9c35",
  "nodedc-source/src/utils/n8nApi.ts":
    "6f16d4992c51ffcc1e71a7bd172fd9ceb440d6e1a74d69ef1db62e0ac4230b3c",
  "nodedc-source/dist/index.html":
    "90d72f8790dc8cf951066b1210447c84d640373117bae23f3a4cb3227fb96d6d",
  "nodedc-source/dist/assets/index-Bim2pv1P.css":
    "18322addd45c126a7b8396f36b005f3085fddba3e9b346dd2c910f6fa6987ebf",
  "nodedc-source/dist/assets/index-CqvJfRRS.js":
    "06e6c23b03ea2ba8a4890e1f1714fd08ebaf18d735834200af6ab430af360ca8",
  [descriptorRel]: targetDescriptorSha256,
});
const artifact = join(artifactRoot, `nodedc-${patchId}.tgz`);

await assertFresh(artifact);
assertSourceCommit();
await assertExactSources();
const targetDescriptor = await buildTargetDescriptor();

const stage = await mkdtemp(join(tmpdir(), "nodedc-engine-l2-closed-loop-"));
try {
  const payload = join(stage, "payload");
  for (const relativePath of entries) {
    const destination = join(payload, relativePath);
    await mkdir(dirname(destination), { recursive: true });
    if (relativePath === descriptorRel) {
      await writeFile(destination, targetDescriptor, {
        encoding: "utf8",
        flag: "wx",
        mode: 0o644,
      });
      continue;
    }
    const source = join(engineRoot, relativePath);
    const info = await lstat(source);
    if (info.isSymbolicLink()) {
      throw new Error(`engine_l2_closed_loop_source_symlink:${relativePath}`);
    }
    if (info.isDirectory()) {
      await cp(source, destination, {
        recursive: true,
        force: false,
        errorOnExist: true,
      });
    } else if (info.isFile()) {
      await copyFile(source, destination);
    } else {
      throw new Error(`engine_l2_closed_loop_source_unsafe:${relativePath}`);
    }
  }
  await writeFile(
    join(stage, "manifest.env"),
    `id=${patchId}\ncomponent=engine\ntype=app-overlay\n`,
    { encoding: "utf8", flag: "wx", mode: 0o644 },
  );
  await writeFile(join(stage, "files.txt"), `${entries.join("\n")}\n`, {
    encoding: "utf8",
    flag: "wx",
    mode: 0o644,
  });
  await mkdir(artifactRoot, { recursive: true });
  run("python3", ["-c", canonicalTarScript(), artifact, stage]);
  console.log(JSON.stringify({
    ok: true,
    patchId,
    artifact,
    sha256: digest(await readFile(artifact)),
    sourceCommit,
    entries,
    targetSha256,
    services: ["nodedc-backend", "app"],
    healthchecks: [
      "http://127.0.0.1:8080/",
      "http://127.0.0.1:3001/health",
    ],
    mcpVersion: "0.7.0",
    graphContract: "semantic-revision-cas-v1",
    transition: "failed-030-partial-source-reconciliation",
    predecessorDescriptorSha256: baselineDescriptorSha256,
    targetDescriptorSha256,
    predecessorGatewaySha256,
    targetGatewaySha256,
    recoveryArtifact: "nodedc-engine-l2-closed-loop-20260723-030.tgz",
    actorPlanes: ["external_codex_mcp", "ai_workspace", "engine_ui"],
    untouched: [
      "L2 graph data",
      "credentials",
      "databases",
      "n8n runtime",
      "AI Workspace connector",
    ],
  }, null, 2));
} finally {
  await rm(stage, { recursive: true, force: true });
}

function assertSourceCommit() {
  const actual = run("git", ["-C", engineRoot, "rev-parse", "HEAD"]).stdout.trim();
  if (actual !== sourceCommit) {
    throw new Error(
      `engine_l2_closed_loop_source_commit_mismatch:expected=${sourceCommit}:actual=${actual}`,
    );
  }
}

async function assertExactSources() {
  const sourceEntries = entries.filter((entry) => entry !== descriptorRel);
  const expectedPaths = Object.keys(targetSha256)
    .filter((entry) => entry !== descriptorRel)
    .sort();
  const actualPaths = [];
  for (const entry of sourceEntries) {
    const source = join(engineRoot, entry);
    const info = await lstat(source);
    if (info.isSymbolicLink() || (!info.isFile() && !info.isDirectory())) {
      throw new Error(`engine_l2_closed_loop_source_unsafe:${entry}`);
    }
    if (info.isDirectory()) {
      const result = run("find", [source, "-type", "f", "-print"]);
      for (const path of result.stdout.split("\n").filter(Boolean)) {
        actualPaths.push(path.slice(engineRoot.length + 1));
      }
    } else {
      actualPaths.push(entry);
    }
  }
  actualPaths.sort();
  if (JSON.stringify(actualPaths) !== JSON.stringify(expectedPaths)) {
    throw new Error(
      `engine_l2_closed_loop_source_set_mismatch:` +
      `expected=${expectedPaths.join(",")}:actual=${actualPaths.join(",")}`,
    );
  }
  for (const relativePath of expectedPaths) {
    const actual = digest(await readFile(join(engineRoot, relativePath)));
    if (actual !== targetSha256[relativePath]) {
      throw new Error(
        `engine_l2_closed_loop_target_mismatch:${relativePath}:` +
        `expected=${targetSha256[relativePath]}:actual=${actual}`,
      );
    }
  }
}

async function buildTargetDescriptor() {
  const baselineBytes = await readFile(baselineArtifact);
  if (digest(baselineBytes) !== baselineArtifactSha256) {
    throw new Error("engine_l2_closed_loop_baseline_artifact_mismatch");
  }
  const baseline = run("tar", [
    "-xOf",
    baselineArtifact,
    `payload/${descriptorRel}`,
  ]).stdout;
  if (digest(Buffer.from(baseline, "utf8")) !== baselineDescriptorSha256) {
    throw new Error("engine_l2_closed_loop_baseline_descriptor_mismatch");
  }
  const descriptor = JSON.parse(baseline);
  if (
    descriptor?.schemaVersion !==
      "nodedc.engine-node-intelligence-transition/v1" ||
    descriptor?.action !== "activate" ||
    descriptor?.releaseId !== "2.33.2-974a9fb3492f" ||
    descriptor?.source?.gatewaySha256 !== predecessorGatewaySha256 ||
    descriptor?.source?.upstreamProjectionSha256 !==
      "2dfa6b4f37d9bfa8b92a8109d4060d02dd2634ceb8f7924504b83ccf3fdd1523"
  ) {
    throw new Error("engine_l2_closed_loop_baseline_descriptor_contract_mismatch");
  }
  descriptor.source.gatewaySha256 = targetGatewaySha256;
  const rendered = `${JSON.stringify(descriptor, null, 2)}\n`;
  if (digest(Buffer.from(rendered, "utf8")) !== targetDescriptorSha256) {
    throw new Error("engine_l2_closed_loop_target_descriptor_mismatch");
  }
  return rendered;
}

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],'xb') 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: 128 * 1024 * 1024,
    stdio: ["ignore", "pipe", "pipe"],
  });
  if (result.status !== 0) {
    throw new Error(`${command}_failed:${result.stderr || result.stdout}`);
  }
  return result;
}