// statehandoff v1.0.1 独立复算（Monday / 2026-11-05）
// 腿A：part9 E1 固定向量（三叶 MTH root + node01 + leafHashes + Z-4 乱序 + Z-5 篡改必红）
// 腿B：C-1 实测重跑（part10 R-1：454f9d…i0 registration payload → JCS → SHA-256）
import { createHash } from "node:crypto";
import { readFileSync } from "node:fs";

const sha = (buf) => createHash("sha256").update(buf).digest("hex");
// JCS(RFC 8785) for this payload family: recursively sort object keys by UTF-16 code-unit order,
// then JSON.stringify (minimal escaping — matches JCS for control chars; no numbers in scope).
const jcs = (v) => {
  if (v === null || typeof v !== "object") return JSON.stringify(v);
  if (Array.isArray(v)) return "[" + v.map(jcs).join(",") + "]";
  const keys = Object.keys(v).sort(); // JS default sort = UTF-16 code unit comparison
  return "{" + keys.map((k) => JSON.stringify(k) + ":" + jcs(v[k])).join(",") + "}";
};

// ---------- 腿A：E1 向量（夹具见 statehandoff part9 E1_offer） ----------
const items = [
  { pinId: "35e9c870025e21305a62f8d7c81df71374d636a53a75a9e6201689a277a3add9i0",
    cHash: "sha256:1b49b5ebca7e32394d732cf58e94a9b9204daeba3f341121cbfb9bec0277e43b" },
  { pinId: "0b3321f4f845c5f216ff7cf6a2a6cf0e7da3922f7e3ced18b6cb9493deb00375i0",
    cHash: "sha256:d548f39bc75dddb3ccb046bd7314db7679495fad18eee95027c000c2f8fc3933" },
  { pinId: "d33d43be6968890cefe1accc2299ee7f81bfbf9abffd707cd942a2b909138150i0",
    cHash: "sha256:90bea7928504c5d49a04046e9438c6b796a672660c28ed17a41d4264e1ae4281" },
];
const leaves = (arr) =>
  [...arr] // 输入顺序无关：先规范化（按 pinId UTF-16 码元序）
    .slice()
    .sort((a, b) => (a.pinId < b.pinId ? -1 : a.pinId > b.pinId ? 1 : 0))
    .map((it) => Buffer.from(jcs({ cHash: it.cHash, pinId: it.pinId }), "utf8"));
// RFC 6962 §2.1 MTH：单叶 0x00 前缀；内节点 0x01 || 左 || 右；k = 严格小于 n 的最大 2 的幂
const mth = (leavesArr) => {
  const n = leavesArr.length;
  if (n === 0) return sha(Buffer.alloc(0));
  if (n === 1) return sha(Buffer.concat([Buffer.from([0x00]), leavesArr[0]]));
  let k = 1; while (k * 2 < n) k *= 2; // largest power of two strictly less than n
  return sha(Buffer.concat([Buffer.from([0x01]),
    Buffer.from(mth(leavesArr.slice(0, k)), "hex"),
    Buffer.from(mth(leavesArr.slice(k)), "hex")]));
};
const L = leaves(items);
const hashes = [sha(Buffer.concat([Buffer.from([0x00]), L[0]])),
                sha(Buffer.concat([Buffer.from([0x00]), L[1]])),
                sha(Buffer.concat([Buffer.from([0x00]), L[2]]))];
const node01 = sha(Buffer.concat([Buffer.from([0x01]),
  Buffer.from(hashes[0], "hex"), Buffer.from(hashes[1], "hex")]));
const root = mth(L);
const docLeaf = ["b5a4422a926dcf1326be3e336045ca0ec796bba69496f75687c1dbcdd71564ca",
                 "6fa5241b408ebe947a318bfda11bddc0488317de526481fbd13ce746500dc3d7",
                 "2d2cd4da5ea3b7701bf7c8cfbda31cc79c69b66ad3ed85d3551945bc86c53331"];
const doc = { node01: "12a0d22255122e794c5413b1cf18e74c1e049d24fb00ebd04509f69dc564fec0",
              root: "344e0804d2d79da8f60846c7bbd8bf5c346be8f077c956a685697f3f5db17aca" };
const eq = (a, b) => a === b;
const leafOk = hashes.map((h, i) => eq(h, docLeaf[i]));
const shuffledRoot = mth(leaves([...items].reverse()));
const shuffledRoot2 = mth(leaves([items[2], items[0], items[1]]));
const tampered = mth(leaves(items.map((it, i) => i === 0
  ? { pinId: it.pinId, cHash: "sha256:" + "0" + it.cHash.slice(7) } : it)));
console.log("== A: E1 固定向量 ==");
console.log("leafHash[0..2] match:", leafOk.join(","));
console.log("node01 match:", eq(node01, doc.node01));
console.log("root match:", eq(root, doc.root));
console.log("Z-4 reversed-root == root:", eq(shuffledRoot, doc.root));
console.log("Z-4 rotated-root  == root:", eq(shuffledRoot2, doc.root));
console.log("Z-5 tamper changes root:", !eq(tampered, doc.root));
console.log("root:", root);

// ---------- 腿B：C-1 实测（payload 文件由调用方传入） ----------
const payloadPath = process.argv[2];
if (payloadPath) {
  console.log("== B: C-1 实测重跑（" + payloadPath + "） ==");
  const rawBytes = readFileSync(payloadPath);
  let obj;
  try { obj = JSON.parse(rawBytes.toString("utf8")); }
  catch (e) { console.log("payload parse failed:", e.message); process.exit(1); }
  const hadCHash = Object.prototype.hasOwnProperty.call(obj, "cHash");
  if (hadCHash) delete obj.cHash; // C-1：摘 cHash 键（存在则删，不存在则不动）
  const canon = Buffer.from(jcs(obj), "utf8");
  const chash = "sha256:" + sha(canon);
  const expected = "sha256:8b561c0403a4b3e3c4989429c7aac36cdb4188f588df824455159463b66bd2c9";
  console.log("raw payload bytes:", rawBytes.length, "(doc R-1.bytes: 27024)");
  console.log("payload had cHash key:", hadCHash, "(期望: 不存在则不动)");
  console.log("outer top-level keys:", Object.keys(obj).sort().join(","));
  console.log("JCS bytes:", canon.length);
  console.log("cHash' :", chash);
  console.log("match R-1.cHash:", eq(chash, expected));
}