InvoiceTaxCompleter.java

package io.konik.calculation;

import io.konik.util.Amounts;
import io.konik.zugferd.Invoice;
import io.konik.zugferd.entity.trade.Trade;
import io.konik.zugferd.entity.trade.item.Item;
import io.konik.zugferd.entity.trade.item.ItemTax;
import io.konik.zugferd.entity.trade.item.SpecifiedSettlement;
import io.konik.zugferd.unqualified.Amount;

import javax.validation.constraints.NotNull;
import java.math.BigDecimal;
import java.math.RoundingMode;

public class InvoiceTaxCompleter implements Correction<Invoice> {

	@Override
	public Invoice correct(@NotNull Invoice invoice) {

		if (invoice != null && invoice.getTrade() != null && invoice.getTrade().getItems() != null) {
			Trade trade = invoice.getTrade();

			for (Item item : trade.getItems()) {
				SpecifiedSettlement settlement = item.getSettlement();

				if (settlement.getMonetarySummation() != null) {
					Amount lineTotal = settlement.getMonetarySummation().getLineTotal();

					if (lineTotal != null) {
						if (settlement.getTradeTax() != null) {
							for (ItemTax tax : settlement.getTradeTax()) {
								if (tax.getPercentage() != null) {
									BigDecimal value = lineTotal.getValue();
									BigDecimal calculated = value.multiply(tax.getPercentage().divide(BigDecimal.valueOf(100))).setScale(2, RoundingMode.HALF_UP);

									tax.setCalculated(new Amount(calculated, lineTotal.getCurrency()));
								} else {
									tax.setCalculated(Amounts.zero(lineTotal.getCurrency()));
								}
							}
						}
					} else {
						if (settlement.getTradeTax() != null) {
							settlement.getTradeTax().clear();
						}
					}
				}
			}
		}
		return invoice;
	}
}