import crypto from 'crypto';

// Type definitions
interface RequestHeaders {
  'Content-Type': string;
  'x-api-key': string;
  'x-signature': string;
  'x-timestamp': string;
}

function generateSignature(
  secretKey: string,
  method: string,
  fullUrl: string,
  body: any | null,
  timestamp: number
): string {
  // Parse body - if empty/null, use empty string, then stringify it
  const parseBody = body ? (typeof body === 'object' ? body : JSON.parse(body)) : '';
  const bodyString: string = JSON.stringify(parseBody);
  const signatureContent: string = `${timestamp}|${method}|${fullUrl}|${bodyString}`;

  return crypto
    .createHmac('sha256', secretKey)
    .update(signatureContent)
    .digest('hex');
}

// Usage Example
const apiKey: string = 'YOUR_API_KEY';
const secretKey: string = 'YOUR_SECRET_KEY';
const timestamp: number = Date.now();
const signature: string = generateSignature(
  secretKey,
  'GET',
  'https://testnet.trustsig.xyz/v1/balance/query',
  null,
  timestamp
);

// Headers for API request
const headers: RequestHeaders = {
  'Content-Type': 'application/json',
  'x-api-key': apiKey,
  'x-signature': signature,
  'x-timestamp': timestamp.toString()
};