import { beforeAll, describe, expect, it } from "vitest";
import {
  buildSignedDeviceManifest,
  canonicalise,
  DeviceManifestError,
  verifyDeviceManifest,
} from "./device-manifest";
import { deriveSyncSigningKeypair } from "./sync-identity";
import {
  DEVICE_MANIFEST_FRESHNESS_MS,
  DEVICE_MANIFEST_VERSION,
  type ManifestDeviceEntry,
} from "./sync-types";

const MASTER_KEY = new Uint8Array(32).fill(0xab);
const ISSUER_DEVICE_ID = "11111111-1111-4111-8111-111111111111";
const PEER_DEVICE_ID = "22222222-2222-4222-8222-222222222222";

function entry(): ManifestDeviceEntry {
  return {
    deviceId: PEER_DEVICE_ID,
    deviceName: "June's Pixel 9",
    deviceType: "android",
    longTermPublicKeyHex: "a".repeat(64),
    signingPublicKeyHex: "b".repeat(64),
    pairedAt: 1_700_000_000_000,
  };
}

describe("canonicalise", () => {
  it("sorts object keys deterministically", () => {
    const a = canonicalise({ b: 2, a: 1 });
    const b = canonicalise({ a: 1, b: 2 });
    expect(a).toBe(b);
    expect(a).toBe('{"a":1,"b":2}');
  });

  it("serialises nested arrays of objects in order", () => {
    expect(canonicalise([{ y: 2, x: 1 }, { z: 3 }])).toBe('[{"x":1,"y":2},{"z":3}]');
  });
});

describe("device manifest sign+verify round trip", () => {
  let signingPrivateKey: CryptoKey;
  let signingPubkey: Uint8Array;

  beforeAll(async () => {
    const kp = await deriveSyncSigningKeypair(MASTER_KEY, ISSUER_DEVICE_ID);
    signingPrivateKey = kp.privateKey;
    signingPubkey = kp.publicKeyRaw;
  });

  it("derives a stable 32-byte Ed25519 public key", () => {
    expect(signingPubkey.length).toBe(32);
  });

  it("signs and verifies a fresh manifest", async () => {
    const m = await buildSignedDeviceManifest(
      ISSUER_DEVICE_ID,
      [entry()],
      signingPrivateKey,
    );
    expect(m.body.manifestVersion).toBe(DEVICE_MANIFEST_VERSION);
    expect(m.body.issuerDeviceId).toBe(ISSUER_DEVICE_ID);
    expect(m.signatureHex).toMatch(/^[0-9a-f]{128}$/);
    const body = await verifyDeviceManifest(m, signingPubkey);
    expect(body.devices).toHaveLength(1);
    expect(body.devices[0].deviceId).toBe(PEER_DEVICE_ID);
  });

  it("rejects a stale manifest", async () => {
    const now = Date.now();
    const m = await buildSignedDeviceManifest(
      ISSUER_DEVICE_ID,
      [entry()],
      signingPrivateKey,
      { now: now - DEVICE_MANIFEST_FRESHNESS_MS - 1_000 },
    );
    await expect(verifyDeviceManifest(m, signingPubkey, { now })).rejects.toMatchObject({
      kind: "freshness",
    } as DeviceManifestError);
  });

  it("rejects a forged signature", async () => {
    const m = await buildSignedDeviceManifest(
      ISSUER_DEVICE_ID,
      [entry()],
      signingPrivateKey,
    );
    // Flip one byte of the signature — must fail verification.
    const sig = m.signatureHex;
    const flipped =
      sig.slice(0, 2) +
      ((parseInt(sig.slice(2, 4), 16) ^ 0xff).toString(16).padStart(2, "0")) +
      sig.slice(4);
    await expect(
      verifyDeviceManifest({ ...m, signatureHex: flipped }, signingPubkey),
    ).rejects.toMatchObject({ kind: "signature" } as DeviceManifestError);
  });

  it("rejects a body tampered after signing", async () => {
    const m = await buildSignedDeviceManifest(
      ISSUER_DEVICE_ID,
      [entry()],
      signingPrivateKey,
    );
    const tampered = {
      ...m,
      body: {
        ...m.body,
        devices: [{ ...entry(), deviceName: "different-name" }],
      },
    };
    await expect(verifyDeviceManifest(tampered, signingPubkey)).rejects.toMatchObject({
      kind: "signature",
    } as DeviceManifestError);
  });

  it("rejects an unknown manifest version", async () => {
    const m = await buildSignedDeviceManifest(
      ISSUER_DEVICE_ID,
      [entry()],
      signingPrivateKey,
    );
    const future = { ...m, body: { ...m.body, manifestVersion: 0x99 } };
    await expect(verifyDeviceManifest(future, signingPubkey)).rejects.toMatchObject({
      kind: "version",
    } as DeviceManifestError);
  });

  it("derives the same keypair across calls (determinism)", async () => {
    const kp2 = await deriveSyncSigningKeypair(MASTER_KEY, ISSUER_DEVICE_ID);
    expect(Array.from(kp2.publicKeyRaw)).toEqual(Array.from(signingPubkey));
  });
});

describe("manifest v0x02 canonical form — cross-platform KAT", () => {
  // Pinned byte-for-byte against peach-android's canonicalDeviceManifestBody.
  // If either side reorders a key, renames a field, or changes number
  // formatting, this string moves and the two stop verifying each other's
  // signatures — the exact silent divergence the manifest version guards.
  const CANONICAL =
    '{"devices":[{"deviceId":"peer-1","deviceName":"Peer One","deviceType":"android",' +
    '"longTermPublicKeyHex":"' + "aa".repeat(32) + '","pairedAt":1700000000001,' +
    '"signingPublicKeyHex":"' + "bb".repeat(32) + '","wsPort":49142}],' +
    '"issuedAt":1700000000000,"issuerDeviceId":"issuer-1","manifestVersion":2,' +
    '"revoked":[{"deviceId":"gone-1","longTermPublicKeyHex":"' + "cc".repeat(32) + '",' +
    '"revokedAt":1700000000002,"revokedByDeviceId":"issuer-1"}]}';

  it("canonicalises a manifest body carrying a revocation to the pinned string", () => {
    expect(
      canonicalise({
        manifestVersion: 2,
        issuerDeviceId: "issuer-1",
        issuedAt: 1_700_000_000_000,
        devices: [
          {
            deviceId: "peer-1",
            deviceName: "Peer One",
            deviceType: "android",
            longTermPublicKeyHex: "aa".repeat(32),
            signingPublicKeyHex: "bb".repeat(32),
            pairedAt: 1_700_000_000_001,
            wsPort: 49142,
          },
        ],
        revoked: [
          {
            deviceId: "gone-1",
            longTermPublicKeyHex: "cc".repeat(32),
            revokedAt: 1_700_000_000_002,
            revokedByDeviceId: "issuer-1",
          },
        ],
      }),
    ).toBe(CANONICAL);
  });
});