/*
* Copyright 2015 the original author or authors.
*
* Licensed 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.spockframework.smoke.mock;
/**
* A bank deposit with <a href="https://en.wikipedia.org/wiki/Compound_interest">compound interest</a>.
*/
public interface IDeposit {
class DepositException extends Exception {
public DepositException(String message) {
super(message);
}
}
double getAnnualNominalInterestRate();
double getCompoundingPeriodInMonths();
default double getCompoundingPeriodsPerYear() {
return 12 / getCompoundingPeriodInMonths();
}
default double getBalance(double principalAmount, double numberOfYears) throws DepositException {
if(principalAmount < 0) throw new IllegalArgumentException("Invalid principalAmount: " + principalAmount);
if(numberOfYears < 0) throw new DepositException("Invalid numberOfYears: " + numberOfYears);
double j = getAnnualNominalInterestRate();
double n = getCompoundingPeriodsPerYear();
return principalAmount * Math.pow(1 + j / n, n * numberOfYears);
}
default double getCompoundInterest(double principalAmount, double numberOfYears) throws DepositException {
return getBalance(principalAmount, numberOfYears) - principalAmount;
}
}