static void exchangeNXTForCurrency(
Transaction transaction,
Account account,
final long currencyId,
final long rateNQT,
long units) {
long extraUnits = 0;
long remainingAmountNQT = Math.multiplyExact(units, rateNQT);
List<CurrencySellOffer> currencySellOffers = new ArrayList<>();
try (DbIterator<CurrencySellOffer> offers =
CurrencySellOffer.getOffers(
new ValidOffersDbClause(currencyId, rateNQT, false),
0,
-1,
" ORDER BY rate ASC, creation_height ASC, transaction_height ASC, transaction_index ASC ")) {
for (CurrencySellOffer offer : offers) {
currencySellOffers.add(offer);
}
}
for (CurrencySellOffer offer : currencySellOffers) {
if (remainingAmountNQT == 0) {
break;
}
long curUnits =
Math.min(
Math.min(remainingAmountNQT / offer.getRateNQT(), offer.getSupply()),
offer.getLimit());
if (curUnits == 0) {
continue;
}
long curAmountNQT = Math.multiplyExact(curUnits, offer.getRateNQT());
extraUnits = Math.addExact(extraUnits, curUnits);
remainingAmountNQT = Math.subtractExact(remainingAmountNQT, curAmountNQT);
offer.decreaseLimitAndSupply(curUnits);
long excess = offer.getCounterOffer().increaseSupply(curUnits);
Account counterAccount = Account.getAccount(offer.getAccountId());
counterAccount.addToBalanceNQT(curAmountNQT);
counterAccount.addToUnconfirmedBalanceNQT(
Math.addExact(
Math.multiplyExact(
curUnits - excess, offer.getRateNQT() - offer.getCounterOffer().getRateNQT()),
Math.multiplyExact(excess, offer.getRateNQT())));
counterAccount.addToCurrencyUnits(currencyId, -curUnits);
Exchange.addExchange(
transaction, currencyId, offer, offer.getAccountId(), account.getId(), curUnits);
}
account.addToCurrencyAndUnconfirmedCurrencyUnits(currencyId, extraUnits);
account.addToBalanceNQT(-(Math.multiplyExact(units, rateNQT) - remainingAmountNQT));
account.addToUnconfirmedBalanceNQT(remainingAmountNQT);
}
@Override
void applyAttachment(
Transaction transaction, Account senderAccount, Account recipientAccount) {
Attachment.MonetarySystemCurrencyIssuance attachment =
(Attachment.MonetarySystemCurrencyIssuance) transaction.getAttachment();
Currency.addCurrency(transaction, senderAccount, attachment);
senderAccount.addToCurrencyAndUnconfirmedCurrencyUnits(
transaction.getId(), attachment.getInitialSupply());
}