ExchangeRateMonetarySummaryStatistics.java

/**
 * Copyright (c) 2012, 2014, Credit Suisse (Anatole Tresch), Werner Keil and others by the @author tag.
 *
 * 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.javamoney.moneta.convert;

import java.util.Objects;

import javax.money.CurrencyUnit;
import javax.money.MonetaryAmount;
import javax.money.convert.CurrencyConversion;
import javax.money.convert.ExchangeRateProvider;

import org.javamoney.moneta.function.DefaultMonetarySummaryStatistics;
import org.javamoney.moneta.function.MonetarySummaryStatistics;

/**
 * Summary statistics.
 */
class ExchangeRateMonetarySummaryStatistics  extends DefaultMonetarySummaryStatistics {

	private final ExchangeRateProvider provider;

	private final CurrencyConversion currencyConversion;

	ExchangeRateMonetarySummaryStatistics(CurrencyUnit currencyUnit,
			ExchangeRateProvider provider) {
		super(currencyUnit);
		this.provider = provider;
		currencyConversion = provider.getCurrencyConversion(getCurrencyUnit());

	}

	@Override
	public void accept(MonetaryAmount amount) {
		super.accept(currencyConversion.apply(amount));
	}

	@Override
	public MonetarySummaryStatistics combine(
			MonetarySummaryStatistics summaryStatistics) {

		if (isDifferentCurrency(Objects.requireNonNull(summaryStatistics)
				.getCurrencyUnit())) {

			return super.combine(convert(summaryStatistics));

		} else {
			return super.combine(summaryStatistics);
		}
	}

	private MonetarySummaryStatistics convert(
			MonetarySummaryStatistics summaryStatistics) {

		if (summaryStatistics.isExchangeable()) {
			return summaryStatistics.to(getCurrencyUnit());
		}
		return create(summaryStatistics);
	}

	private MonetarySummaryStatistics create(MonetarySummaryStatistics summary) {

		ExchangeRateMonetarySummaryStatistics another = new ExchangeRateMonetarySummaryStatistics(
				getCurrencyUnit(), provider);

		another.average = currencyConversion.apply(summary
				.getAverage());
		another.count = summary.getCount();
		another.max = currencyConversion.apply(summary.getMax());
		another.min = currencyConversion.apply(summary.getMin());
		another.sum = currencyConversion.apply(summary.getSum());
		return another;
	}

	private boolean isDifferentCurrency(CurrencyUnit unit) {
		return !getCurrencyUnit().equals(unit);
	}

	@Override
	public boolean isExchangeable() {
		return true;
	}

	@Override
	public MonetarySummaryStatistics to(CurrencyUnit unit) {
		CurrencyConversion currencyConversion = provider.getCurrencyConversion(unit);
		ExchangeRateMonetarySummaryStatistics another = new ExchangeRateMonetarySummaryStatistics(
				unit, provider);
		another.average = currencyConversion.apply(average);
		another.count = count;
		another.max = currencyConversion.apply(max);
		another.min = currencyConversion.apply(min);
		another.sum = currencyConversion.apply(sum);
		return another;
	}

}