public WalletEntity Buy(string userId, string stock, decimal price, int quantity)
{
var isPurchase = true;
decimal totalPrice = price * quantity;
var wallet = _walletQueryService.GetWallet(userId);
if (wallet.Cash < totalPrice)
{
throw new InsufficientAvailableFundsException("There are insufficient funds to complete this transaction.");
}
_walletQueryService.Update(wallet.WalletId, totalPrice, isPurchase);
_transactionQueryService.AddTransaction(userId, stock, price, quantity);
return(wallet);
}
