import { describe, expect, it } from "vitest";
import { utf8ToBytes } from "../../src/crypto/encoding";
import {
  hotp,
  totp,
  totpCounter,
  verifyHotp,
  verifyTotp,
} from "../../src/otp/otp";

describe("HOTP", () => {
  it("matches every RFC 4226 test value", async () => {
    const secret = utf8ToBytes("12345678901234567890");
    const expected = [
      "755224",
      "287082",
      "359152",
      "969429",
      "338314",
      "254676",
      "287922",
      "162583",
      "399871",
      "520489",
    ];
    await expect(
      Promise.all(
        expected.map((_, counter) =>
          hotp({ secret, counter: BigInt(counter) }),
        ),
      ),
    ).resolves.toEqual(expected);
  });

  it("searches forward without losing leading zeroes", async () => {
    const secret = utf8ToBytes("12345678901234567890");
    const match = await verifyHotp("338314", {
      secret,
      counter: 1n,
      lookAhead: 5,
    });
    expect(match).toMatchObject({ counter: 4n, delta: 3 });
  });
});

describe("TOTP", () => {
  const cases = [
    [59, "94287082", "46119246", "90693936"],
    [1_111_111_109, "07081804", "68084774", "25091201"],
    [1_111_111_111, "14050471", "67062674", "99943326"],
    [1_234_567_890, "89005924", "91819424", "93441116"],
    [2_000_000_000, "69279037", "90698825", "38618901"],
    [20_000_000_000, "65353130", "77737706", "47863826"],
  ] as const;

  it("matches RFC 6238 SHA-1, SHA-256 and SHA-512 vectors", async () => {
    const secrets = {
      "SHA-1": utf8ToBytes("12345678901234567890"),
      "SHA-256": utf8ToBytes("12345678901234567890123456789012"),
      "SHA-512": utf8ToBytes(
        "1234567890123456789012345678901234567890123456789012345678901234",
      ),
    } as const;
    for (const [timestamp, sha1, sha256, sha512] of cases) {
      await expect(
        totp({
          secret: secrets["SHA-1"],
          timestamp,
          digits: 8,
          algorithm: "SHA-1",
        }),
      ).resolves.toBe(sha1);
      await expect(
        totp({
          secret: secrets["SHA-256"],
          timestamp,
          digits: 8,
          algorithm: "SHA-256",
        }),
      ).resolves.toBe(sha256);
      await expect(
        totp({
          secret: secrets["SHA-512"],
          timestamp,
          digits: 8,
          algorithm: "SHA-512",
        }),
      ).resolves.toBe(sha512);
    }
  });

  it("uses integer counters beyond 2038", () => {
    expect(totpCounter(20_000_000_000)).toBe(666_666_666n);
  });

  it("diagnoses a bounded clock delta", async () => {
    const secret = utf8ToBytes("12345678901234567890");
    const code = await totp({ secret, timestamp: 1_111_111_109 });
    const match = await verifyTotp(code, {
      secret,
      timestamp: 1_111_111_109 + 60,
      window: 3,
    });
    expect(match?.delta).toBe(-2);
  });
});