import { expect, tap } from '@git.zone/tstest/tapbundle';
import * as crypto from 'node:crypto';
import {
  RadiusAuthenticator,
  RadiusPacket,
  ERadiusCode,
  ERadiusAttributeType,
} from '../../ts_server/index.js';

tap.test('should generate 16-byte random request authenticator', async () => {
  const auth1 = RadiusAuthenticator.generateRequestAuthenticator();
  const auth2 = RadiusAuthenticator.generateRequestAuthenticator();

  expect(auth1.length).toEqual(16);
  expect(auth2.length).toEqual(16);

  // Should be random (different each time)
  expect(auth1.equals(auth2)).toBeFalsy();
});

tap.test('should calculate response authenticator correctly', async () => {
  const code = ERadiusCode.AccessAccept;
  const identifier = 1;
  const requestAuthenticator = crypto.randomBytes(16);
  const attributes = Buffer.from([]);
  const secret = 'testing123';

  const responseAuth = RadiusAuthenticator.calculateResponseAuthenticator(
    code,
    identifier,
    requestAuthenticator,
    attributes,
    secret
  );

  expect(responseAuth.length).toEqual(16);

  // Verify by recalculating
  const verified = RadiusAuthenticator.calculateResponseAuthenticator(
    code,
    identifier,
    requestAuthenticator,
    attributes,
    secret
  );

  expect(responseAuth.equals(verified)).toBeTruthy();
});

tap.test('should calculate accounting request authenticator', async () => {
  const code = ERadiusCode.AccountingRequest;
  const identifier = 1;
  const attributes = Buffer.from([]);
  const secret = 'testing123';

  const acctAuth = RadiusAuthenticator.calculateAccountingRequestAuthenticator(
    code,
    identifier,
    attributes,
    secret
  );

  expect(acctAuth.length).toEqual(16);
});

tap.test('should verify accounting request authenticator', async () => {
  const secret = 'testing123';

  // Create an accounting request packet
  const packet = RadiusPacket.createAccountingRequest(1, secret, [
    { type: ERadiusAttributeType.AcctStatusType, value: 1 },  // Start
    { type: ERadiusAttributeType.AcctSessionId, value: 'session-123' },
  ]);

  // Verify the authenticator
  const isValid = RadiusAuthenticator.verifyAccountingRequestAuthenticator(packet, secret);
  expect(isValid).toBeTruthy();

  // Should fail with wrong secret
  const isInvalid = RadiusAuthenticator.verifyAccountingRequestAuthenticator(packet, 'wrongsecret');
  expect(isInvalid).toBeFalsy();
});

tap.test('should verify response authenticator', async () => {
  const identifier = 1;
  const requestAuthenticator = crypto.randomBytes(16);
  const secret = 'testing123';

  // Create a response packet
  const responsePacket = RadiusPacket.createAccessAccept(
    identifier,
    requestAuthenticator,
    secret,
    [{ type: ERadiusAttributeType.ReplyMessage, value: 'Welcome' }]
  );

  // Verify the authenticator
  const isValid = RadiusAuthenticator.verifyResponseAuthenticator(
    responsePacket,
    requestAuthenticator,
    secret
  );
  expect(isValid).toBeTruthy();

  // Should fail with wrong request authenticator
  const wrongRequestAuth = crypto.randomBytes(16);
  const isInvalid = RadiusAuthenticator.verifyResponseAuthenticator(
    responsePacket,
    wrongRequestAuth,
    secret
  );
  expect(isInvalid).toBeFalsy();

  // Should fail with wrong secret
  const isInvalid2 = RadiusAuthenticator.verifyResponseAuthenticator(
    responsePacket,
    requestAuthenticator,
    'wrongsecret'
  );
  expect(isInvalid2).toBeFalsy();
});

tap.test('should create packet header', async () => {
  const code = ERadiusCode.AccessRequest;
  const identifier = 42;
  const authenticator = crypto.randomBytes(16);
  const attributesLength = 50;

  const header = RadiusAuthenticator.createPacketHeader(
    code,
    identifier,
    authenticator,
    attributesLength
  );

  expect(header.length).toEqual(20);
  expect(header[0]).toEqual(code);
  expect(header[1]).toEqual(identifier);
  expect(header.readUInt16BE(2)).toEqual(20 + attributesLength);
  expect(header.subarray(4, 20).equals(authenticator)).toBeTruthy();
});

tap.test('should calculate CHAP response', async () => {
  const chapId = 1;
  const password = 'testpassword';
  const challenge = crypto.randomBytes(16);

  const response = RadiusAuthenticator.calculateChapResponse(chapId, password, challenge);

  expect(response.length).toEqual(16);

  // Verify the calculation: MD5(CHAP-ID + Password + Challenge)
  const md5 = crypto.createHash('md5');
  md5.update(Buffer.from([chapId]));
  md5.update(Buffer.from(password, 'utf8'));
  md5.update(challenge);
  const expected = md5.digest();

  expect(response.equals(expected)).toBeTruthy();
});

tap.test('should verify CHAP response', async () => {
  const chapId = 1;
  const password = 'testpassword';
  const challenge = crypto.randomBytes(16);

  // Calculate the response
  const response = RadiusAuthenticator.calculateChapResponse(chapId, password, challenge);

  // Create CHAP-Password attribute format: CHAP-ID (1 byte) + Response (16 bytes)
  const chapPassword = Buffer.allocUnsafe(17);
  chapPassword.writeUInt8(chapId, 0);
  response.copy(chapPassword, 1);

  // Verify with correct password
  const isValid = RadiusAuthenticator.verifyChapResponse(chapPassword, challenge, password);
  expect(isValid).toBeTruthy();

  // Verify with wrong password
  const isInvalid = RadiusAuthenticator.verifyChapResponse(chapPassword, challenge, 'wrongpassword');
  expect(isInvalid).toBeFalsy();
});

tap.test('should calculate Message-Authenticator (HMAC-MD5)', async () => {
  const packet = Buffer.alloc(50);
  packet[0] = ERadiusCode.AccessRequest;
  packet[1] = 1;
  packet.writeUInt16BE(50, 2);
  crypto.randomBytes(16).copy(packet, 4);

  const secret = 'testing123';

  const msgAuth = RadiusAuthenticator.calculateMessageAuthenticator(packet, secret);

  expect(msgAuth.length).toEqual(16);

  // Verify it's HMAC-MD5
  const hmac = crypto.createHmac('md5', Buffer.from(secret, 'utf8'));
  hmac.update(packet);
  const expected = hmac.digest();

  expect(msgAuth.equals(expected)).toBeTruthy();
});

export default tap.start();