package net.sourceforge.fenixedu.domain.accounting.postingRules;

import java.math.BigDecimal;
import java.util.Collections;
import java.util.List;
import java.util.Set;

import net.sourceforge.fenixedu.dataTransferObject.accounting.AccountingTransactionDetailDTO;
import net.sourceforge.fenixedu.dataTransferObject.accounting.EntryDTO;
import net.sourceforge.fenixedu.domain.User;
import net.sourceforge.fenixedu.domain.accounting.Account;
import net.sourceforge.fenixedu.domain.accounting.AccountingTransaction;
import net.sourceforge.fenixedu.domain.accounting.EntryType;
import net.sourceforge.fenixedu.domain.accounting.Event;
import net.sourceforge.fenixedu.domain.accounting.EventType;
import net.sourceforge.fenixedu.domain.accounting.ServiceAgreementTemplate;
import net.sourceforge.fenixedu.domain.exceptions.DomainException;
import net.sourceforge.fenixedu.domain.exceptions.DomainExceptionWithLabelFormatter;
import net.sourceforge.fenixedu.util.Money;

import org.joda.time.DateTime;

public abstract class BaseAmountPlusAmountPerUnitPR extends BaseAmountPlusAmountPerUnitPR_Base {

    protected BaseAmountPlusAmountPerUnitPR() {
	super();
    }

    protected void init(EntryType entryType, EventType eventType, DateTime startDate, DateTime endDate,
	    ServiceAgreementTemplate serviceAgreementTemplate, Money baseAmount, Money amountPerUnit) {
	super.init(entryType, eventType, startDate, endDate, serviceAgreementTemplate);
	checkParameters(baseAmount, amountPerUnit);
	super.setBaseAmount(baseAmount);
	super.setAmountPerUnit(amountPerUnit);
    }

    private void checkParameters(Money baseAmount, Money amountPerUnit) {
	if (baseAmount == null) {
	    throw new DomainException(
		    "error.accounting.postingRules.BaseAmountPlusAmountPerUnitGreaterThanOnePR.baseAmount.cannot.be.null");
	}
	if (amountPerUnit == null) {
	    throw new DomainException(
		    "error.accounting.postingRules.BaseAmountPlusAmountPerUnitGreaterThanOnePR.amountPerUnit.cannot.be.null");
	}

    }

    @Override
    public void setBaseAmount(Money baseAmount) {
	throw new DomainException(
		"error.accounting.postingRules.BaseAmountPlusAmountPerUnitGreaterThanOnePR.cannot.modify.baseAmount");
    }

    @Override
    public void setAmountPerUnit(Money amountPerUnit) {
	throw new DomainException(
		"error.accounting.postingRules.BaseAmountPlusAmountPerUnitGreaterThanOnePR.cannot.modify.amountPerUnit");
    }

    public Money getAmountForUnits(Event event) {
	return getAmountPerUnit().multiply(new BigDecimal(getNumberOfUnits(event)));
    }

    @Override
    public Money calculateTotalAmountToPay(Event event, DateTime when, boolean applyDiscount) {
	return getBaseAmount().add(getAmountForUnits(event));

    }

    @Override
    public List<EntryDTO> calculateEntries(Event event, DateTime when) {
	return Collections.singletonList(new EntryDTO(getEntryType(), event, calculateTotalAmountToPay(event, when), event
		.getPayedAmount(), event.calculateAmountToPay(when), event.getDescriptionForEntryType(getEntryType()), event
		.calculateAmountToPay(when)));
    }

    @Override
    protected Set<AccountingTransaction> internalProcess(User user, List<EntryDTO> entryDTOs, Event event, Account fromAccount,
	    Account toAccount, AccountingTransactionDetailDTO transactionDetail) {
	if (entryDTOs.size() != 1) {
	    throw new DomainException(
		    "error.accounting.postingRules.BaseAmountPlusAmountPerUnitGreaterThanOnePR.invalid.number.of.entryDTOs");
	}

	final EntryDTO entryDTO = entryDTOs.get(0);
	checkIfCanAddAmount(entryDTO.getAmountToPay(), event, transactionDetail.getWhenRegistered());

	return Collections.singleton(makeAccountingTransaction(user, event, fromAccount, toAccount, entryDTO.getEntryType(),
		entryDTO.getAmountToPay(), transactionDetail));
    }

    private void checkIfCanAddAmount(Money amountToPay, Event event, DateTime when) {
	if (amountToPay.compareTo(event.calculateAmountToPay(when)) < 0) {
	    throw new DomainExceptionWithLabelFormatter(
		    "error.accounting.postingRules.BaseAmountPlusAmountPerUnitGreaterThanOnePR.amount.being.payed.must.match.amount.to.pay",
		    event.getDescriptionForEntryType(getEntryType()));
	}

    }

    protected abstract Integer getNumberOfUnits(Event event);

}