Authentication

const crypto = require('crypto');

const API_KEY = process.env.MODULUS_API_KEY;
const API_SECRET = process.env.MODULUS_API_SECRET;
const BASE_URL = 'https://{your-api-endpoint}';

/**
 * Generate authentication headers for HTTP API requests
 * @param {string} method - HTTP method (GET, POST)
 * @param {string} path - Request path (e.g., /v1/terminals)
 * @param {object|null} body - Request body (null for GET requests)
 * @returns {object} Headers object with authentication
 */
function generateAuthHeaders(method, path, body = null) {
  const timestamp = new Date().toISOString();

  // SHA256 hash of body (empty string for GET)
  const bodyString = body ? JSON.stringify(body) : '';
  const bodyHash = crypto
    .createHash('sha256')
    .update(bodyString)
    .digest('hex');

  // Construct string to sign
  const stringToSign = `${method}\n${path}\n${timestamp}\n${bodyHash}`;

  // Compute HMAC-SHA256 signature
  const signature = crypto
    .createHmac('sha256', API_SECRET)
    .update(stringToSign)
    .digest('base64');

  return {
    'Content-Type': 'application/json',
    'x-api-key': API_KEY,
    'x-timestamp': timestamp,
    'x-signature': signature
  };
}

// Example: GET request
async function getTerminals() {
  const path = '/v1/terminals';
  const headers = generateAuthHeaders('GET', path);

  const response = await fetch(`${BASE_URL}${path}`, {
    method: 'GET',
    headers
  });

  return response.json();
}

// Example: POST request
async function createPayment(terminalId, paymentData) {
  const path = `/v1/terminals/${terminalId}/payments`;
  const headers = generateAuthHeaders('POST', path, paymentData);

  const response = await fetch(`${BASE_URL}${path}`, {
    method: 'POST',
    headers,
    body: JSON.stringify(paymentData)
  });

  return response.json();
}

const WebSocket = require('ws');

const API_KEY = process.env.MODULUS_API_KEY;
const WS_ENDPOINT = 'wss://{your-api-endpoint}/v1';

// Option 1: Header-based authentication (recommended)
function connectWithHeaders() {
  const ws = new WebSocket(WS_ENDPOINT, {
    headers: {
      'x-api-key': API_KEY
    }
  });

  ws.on('open', () => {
    console.log('Connected with header authentication');
  });

  ws.on('error', (error) => {
    console.error('Connection error:', error.message);
  });

  return ws;
}

// Option 2: Query parameter authentication
function connectWithQueryParam() {
  const ws = new WebSocket(`${WS_ENDPOINT}?x-api-key=${API_KEY}`);

  ws.on('open', () => {
    console.log('Connected with query parameter authentication');
  });

  return ws;
}