public ActionResult DoExchange(Guid id, [FromBody] DoExchangeRequest request)
{
var exchange = _repository.GetByApiKey(id);
var upCurrencies = request.Currencies.ToUpper();
var from = upCurrencies.Substring(0, 3);
var to = upCurrencies.Substring(3);
if (!exchange.CanExchange(request.Currencies, request.Amount))
{
return(BadRequest("Couldn't perform the exchange.\n" +
$"Required amount: {request.Amount}\n" +
$"Actual balance: {exchange.Balances[from]}"));
}
var amountUsd = request.Amount * exchange.GetPrice(from + "USD");
var percent = amountUsd / exchange.GetFullBalanceInUsd() * 100;
_repository.Percentages[from] -= percent;
_repository.Percentages[to] += percent;
_repository.ApplyPercentageChanges();
return(new JsonResult(_repository.GetAll()));
}