import { describe, expect, it } from "vitest";
import { TOTP } from "otpauth";

import { generateTOTP, parseOtpauthURI } from "./totp";

// PCH-01-019: algorithm/digits/period must be threaded through, with RFC
// defaults (SHA-1 / 6 / 30) when absent so legacy bare-seed entries are stable.

const SECRET = "JBSWY3DPEHPK3PXP";

describe("generateTOTP (PCH-01-019)", () => {
  it("honours SHA256 / 8-digit / 60s params", () => {
    const { code, remaining } = generateTOTP(SECRET, "SHA256", 8, 60);
    const expected = new TOTP({ secret: SECRET, algorithm: "SHA256", digits: 8, period: 60 }).generate();
    expect(code).toBe(expected);
    expect(code.length).toBe(8);
    expect(remaining).toBeGreaterThan(0);
    expect(remaining).toBeLessThanOrEqual(60);
  });

  it("legacy bare seed (no params) generates the SHA-1 / 6 / 30 default", () => {
    const { code, remaining } = generateTOTP(SECRET);
    const expected = new TOTP({ secret: SECRET, algorithm: "SHA1", digits: 6, period: 30 }).generate();
    expect(code).toBe(expected);
    expect(code.length).toBe(6);
    expect(remaining).toBeLessThanOrEqual(30);
  });

  it("undefined optional args fall through to defaults", () => {
    const a = generateTOTP(SECRET, undefined, undefined, undefined);
    const b = generateTOTP(SECRET);
    expect(a.code).toBe(b.code);
  });
});

describe("parseOtpauthURI (PCH-01-019)", () => {
  it("extracts algorithm, digits, and period", () => {
    const parsed = parseOtpauthURI(
      `otpauth://totp/Example:alice?secret=${SECRET}&algorithm=SHA256&digits=8&period=60&issuer=Example`,
    );
    expect(parsed).toMatchObject({
      secret: SECRET,
      algorithm: "SHA256",
      digits: 8,
      period: 60,
    });
  });

  it("defaults a bare otpauth URI to SHA1 / 6 / 30", () => {
    const parsed = parseOtpauthURI(`otpauth://totp/Example:alice?secret=${SECRET}&issuer=Example`);
    expect(parsed).toMatchObject({ secret: SECRET, algorithm: "SHA1", digits: 6, period: 30 });
  });

  it("returns null for non-otpauth input", () => {
    expect(parseOtpauthURI("not-a-uri")).toBeNull();
  });
});