stawros/konta-walutowe
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fix: Double to BigDecimal

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This commit is contained in:
Piotr Dec 2024-06-10 23:52:47 +02:00
parent b11607088a
commit f42dcce74b
Signed by: stawros
GPG key ID: F89F27AD8F881A91
15 changed files with 93 additions and 57 deletions
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36
src/main/java/eu/ztsh/wymiana/service/CurrencyService.java
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@ -45,8 +45,8 @@ public class CurrencyService {
}
var exchanged = performExchange(from,
Optional.ofNullable(user.currencies().get(request.to().toUpperCase())).orElse(create(request.to())),
Optional.ofNullable(request.toSell()).orElse(0D),
Optional.ofNullable(request.toBuy()).orElse(0D));
Optional.ofNullable(request.toSell()).orElse(BigDecimal.ZERO),
Optional.ofNullable(request.toBuy()).orElse(BigDecimal.ZERO));
user.currencies().putAll(exchanged);
return userService.update(user);
})
@ -55,32 +55,36 @@ public class CurrencyService {
private Currency create(String symbol) {
// TODO: check if supported - now limited to PLN <-> USD
return new Currency(symbol.toUpperCase(), 0D);
return new Currency(symbol.toUpperCase(), BigDecimal.ZERO);
}
private Map<String, Currency> performExchange(Currency from, Currency to, double toSell, double toBuy) {
double exchangeRate;
double neededFromAmount;
double requestedToAmount;
private Map<String, Currency> performExchange(Currency from, Currency to, BigDecimal toSell, BigDecimal toBuy) {
BigDecimal exchangeRate;
BigDecimal neededFromAmount;
BigDecimal requestedToAmount;
if (from.symbol().equalsIgnoreCase("PLN")) {
exchangeRate = nbpService.getSellRate(to.symbol());
neededFromAmount = round(toBuy != 0 ? toBuy * exchangeRate : toSell);
requestedToAmount = round(toBuy != 0 ? toBuy : toSell / exchangeRate);
neededFromAmount = round(toBuy.signum() != 0 ? toBuy.multiply(exchangeRate) : toSell);
requestedToAmount = round(toBuy.signum() != 0 ? toBuy : divide(toSell, exchangeRate));
} else {
exchangeRate = nbpService.getBuyRate(from.symbol());
neededFromAmount = round(toBuy != 0 ? toBuy / exchangeRate : toSell);
requestedToAmount = round(toBuy != 0 ? toBuy : toSell * exchangeRate);
neededFromAmount = round(toBuy.signum() != 0 ? divide(toBuy, exchangeRate) : toSell);
requestedToAmount = round(toBuy.signum() != 0 ? toBuy : toSell.multiply(exchangeRate));
}
if (neededFromAmount > from.amount()) {
if (neededFromAmount.compareTo(from.amount()) > 0) {
throw new InsufficientFundsException();
}
var newFrom = new Currency(from.symbol(), from.amount() - neededFromAmount);
var newTo = new Currency(to.symbol(), to.amount() + requestedToAmount);
var newFrom = new Currency(from.symbol(), from.amount().subtract(neededFromAmount));
var newTo = new Currency(to.symbol(), to.amount().add(requestedToAmount));
return Stream.of(newFrom, newTo).collect(Collectors.toMap(Currency::symbol, currency -> currency));
}
private double round(double input) {
return BigDecimal.valueOf(input).setScale(2, RoundingMode.HALF_UP).doubleValue();
private BigDecimal round(BigDecimal input) {
return input.setScale(2, RoundingMode.HALF_UP);
}
private BigDecimal divide(BigDecimal input, BigDecimal division) {
return input.setScale(2, RoundingMode.HALF_UP).divide(division, RoundingMode.HALF_UP);
}
}