import { describe, expect, it, vi } from "vitest";

import {
  DEFAULT_RELAY_URL,
  buildRendezvousUrl,
  bytesToHex,
  deriveMeshRendezvousSecret,
  deriveRendezvousId,
  deriveRendezvousSecret,
  dialingRendezvousIds,
  generatePairingRendezvousToken,
  normalizeRelayUrl,
  rendezvousSecretFromHex,
  rendezvousWindowIndex,
  waitingRendezvousIds,
} from "./rendezvous";

const HANDSHAKE_HASH = rendezvousSecretFromHex(
  "0fbab8cd1782bf4b17d69beb69f5b80b0bf24d93da4924959c76ee701c32e655",
);

describe("relay rendezvous contract", () => {
  it("derives the symmetric cross-client mesh capability vector", () => {
    const root = Uint8Array.from({ length: 32 }, (_, i) => i);
    const low = Uint8Array.from({ length: 32 }, (_, i) => i + 32);
    const high = Uint8Array.from({ length: 32 }, (_, i) => i + 64);
    const forward = deriveMeshRendezvousSecret(root, low, high);
    const reverse = deriveMeshRendezvousSecret(root, high, low);

    expect(bytesToHex(forward)).toBe(
      "ad0359be7dc8fbb7df19ed027354b5029133a23a6023f43c2b3500b43addae7b",
    );
    expect(reverse).toEqual(forward);
  });

  it("derives the cross-platform secret and hourly id KATs", () => {
    const secret = deriveRendezvousSecret(HANDSHAKE_HASH);
    expect(bytesToHex(secret)).toBe(
      "0803691c8ac7330883c0987e33cea4a171992366ce4b06b88691e84ca689773d",
    );
    expect(deriveRendezvousId(secret, 500_000)).toBe(
      "9UY3j5AHnwYSApvymtY965su9n60rQOv8QZ2PZzHuKI",
    );
  });

  it("uses one-hour windows with mandatory skew tolerance order", () => {
    const secret = deriveRendezvousSecret(HANDSHAKE_HASH);
    const now = 500_000 * 3600 + 3599;
    expect(rendezvousWindowIndex(now)).toBe(500_000);
    expect(waitingRendezvousIds(secret, now)).toEqual([
      deriveRendezvousId(secret, 500_000),
      deriveRendezvousId(secret, 499_999),
    ]);
    expect(dialingRendezvousIds(secret, now)).toEqual([
      deriveRendezvousId(secret, 500_000),
      deriveRendezvousId(secret, 499_999),
      deriveRendezvousId(secret, 500_001),
    ]);
  });

  it("generates a fresh 128-bit base64url first-pair token", () => {
    vi.spyOn(crypto, "getRandomValues").mockImplementation((array) => {
      (array as Uint8Array).set(Array.from({ length: 16 }, (_, i) => i));
      return array;
    });
    expect(generatePairingRendezvousToken()).toBe("AAECAwQFBgcICQoLDA0ODw");
  });

  it("accepts only credential-free wss relay URLs", () => {
    expect(normalizeRelayUrl(`${DEFAULT_RELAY_URL}/`)).toBe(DEFAULT_RELAY_URL);
    expect(normalizeRelayUrl("wss://relay.example.test/base/")).toBe(
      "wss://relay.example.test/base",
    );
    expect(() => normalizeRelayUrl("ws://relay.example.test")).toThrow(/wss/);
    expect(() => normalizeRelayUrl("wss://user:pass@relay.example.test")).toThrow();
    expect(() => normalizeRelayUrl("wss://relay.example.test?token=x")).toThrow();
  });

  it("builds the relay path without exposing identity", () => {
    const id = "AAECAwQFBgcICQoLDA0ODw";
    expect(buildRendezvousUrl(DEFAULT_RELAY_URL, id)).toBe(
      `${DEFAULT_RELAY_URL}/r/${id}`,
    );
    expect(() => buildRendezvousUrl(DEFAULT_RELAY_URL, "short")).toThrow();
  });
});