package policy.price;

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

public class PriceSelector {
	
	private int priorityNo;
	private List<PriceLine> priceList;
	
	
	public PriceSelector() {
		priceList = new ArrayList<PriceLine>();
		priorityNo = -1;
	}
	
	public void loadOne(PriceLine priceLine) {
		if (priceLine == null) {
			return;
		}
		
		int linePriorityNo = priceLine.getPriorityNo();
		
		//1. 如果行优先级低于当前优先级, 直接退出
		if (linePriorityNo < priorityNo) {
			return;
		}
		
		//2. 如果行优先级高于当前优先级，需要清空当前列表，添加行
		if (linePriorityNo > priorityNo) {
			priorityNo = linePriorityNo;
			priceList.clear();
		}
		
		priceList.add(priceLine);
	}

	public List<PriceLine> getPriceList() {
		return priceList;
	}

	public BigDecimal getLowerPrice() {
		int size = priceList.size();
		
		if (size == 0) {
			return null;
		}
		
		if (size == 1) {
			BigDecimal result = priceList.get(0).getPrice();
			return new BigDecimal(result.toString());
		}
		else {
			BigDecimal result = priceList.get(0).getPrice();
			BigDecimal current = null;
			
			for (PriceLine line: priceList) {
				current = line.getPrice();
				
				if (result.compareTo(current) > 0) {
					result = current;
				}
			}
			
			return new BigDecimal(result.toString());
		}
	}
	
}