fineract-provider/src/main/java/org/apache/fineract/portfolio/savings/domain/interest/CompoundInterestHelper.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied. See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.fineract.portfolio.savings.domain.interest;

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

import org.apache.fineract.organisation.monetary.domain.MonetaryCurrency;
import org.apache.fineract.organisation.monetary.domain.Money;
import org.joda.time.LocalDate;

public class CompoundInterestHelper {

    /**
     * @param currency
     * @param allPeriods
     * @param lockUntil
     *            - account locked date used with the combination of
     *            immediateWithdrawalOfInterest to avoid exclusion of
     *            interestEarned
     * @param interestTransferEnabled
     *            - boolean flag used to avoid addition of interest to next
     *            posting period as income while calculating interest
     * @return
     */
    public Money calculateInterestForAllPostingPeriods(final MonetaryCurrency currency, final List<PostingPeriod> allPeriods,
            LocalDate lockUntil, Boolean interestTransferEnabled) {

        // sum up the 'rounded' values that are posted each posting period
        Money interestEarned = Money.zero(currency);

        // total interest earned in previous periods but not yet recognised
        BigDecimal interestEarnedButNotPosted = BigDecimal.ZERO;
        for (final PostingPeriod postingPeriod : allPeriods) {

            final BigDecimal interestEarnedThisPeriod = postingPeriod.calculateInterest(interestEarnedButNotPosted);

            final Money moneyToBePostedForPeriod = Money.of(currency, interestEarnedThisPeriod);

            interestEarned = interestEarned.plus(moneyToBePostedForPeriod);
            // these checks are for fixed deposit account for not include
            // interest for accounts which has post interest to linked savings
            // account and if already transfered then it includes in interest
            // calculation.
            if (postingPeriod.isInterestTransfered() || !interestTransferEnabled
                    || (lockUntil != null && !postingPeriod.dateOfPostingTransaction().isAfter(lockUntil))) {
                interestEarnedButNotPosted = interestEarnedButNotPosted.add(moneyToBePostedForPeriod.getAmount());
            }
        }

        return interestEarned;
    }
}