QuantityDiscount.java

/*
 * Copyright 2011-2014 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 pl.com.bottega.ecommerce.sales.domain.offer.discounts;

import pl.com.bottega.ecommerce.sales.domain.offer.Discount;
import pl.com.bottega.ecommerce.sales.domain.offer.DiscountPolicy;
import pl.com.bottega.ecommerce.sales.domain.productscatalog.Product;
import pl.com.bottega.ecommerce.sharedkernel.Money;

public class QuantityDiscount implements DiscountPolicy{
	private double rebateRatio;
	
	private int mininalQuantity;
	
	/**
	 * 
	 * @param rebate value of the rebate in % 
	 * @param mininalQuantity minimal quantity of the purchase that allows rebate
	 */
	public QuantityDiscount(double rebate, int mininalQuantity) {
		rebateRatio = rebate / 100;
		this.mininalQuantity = mininalQuantity;
	}

	@Override
	public Discount applyDiscount(Product product, int quantity, Money regularCost) {
		if (quantity >= mininalQuantity)
			return new Discount("over: " + quantity, regularCost.multiplyBy(rebateRatio));
		return null;
	}
}