class PaySignatureService {

  static calcPaySig(appkey: string, message: string): string {

    const hmac = crypto.createHmac('sha256', appkey);

    hmac.update(message);

    return hmac.digest('hex');

  }

  static calcSignature(signData: string, sessionKey: string): string {

    const hmac = crypto.createHmac('sha256', sessionKey);

    hmac.update(signData);

    return hmac.digest('hex');

  }

}

export const virtualPayment = async (

  req: Request,

  res: Response

) => {

  const { productId, goodsPrice } = req.body;

  try {

  const uri = '/xpay/requestVirtualPayment'; //  /xpay/query_user_balance

  const appkey = 'HvkwbwYj4Y0o29MkAObPn1u2vkNr4jTP';

  const outTradeNo = uuidv4().replace(/-/g, '');

  const sessionKey = userAtuth.session_key;

  const signData = JSON.stringify({

    offerId: '123000',

    buyQuantity: 1,

    env: 0,

    currencyType: 'CNY',

    productId: String(productId),

    goodsPrice: Number(goodsPrice),

    outTradeNo: String(outTradeNo),

    attach: 'testdata',

  });

  const paySig = PaySignatureService.calcPaySig(appkey,uri + '&' + signData);

  const signature = PaySignatureService.calcSignature(signData, sessionKey);