package cn.edu.bjut.chapter4;

public class CreditCard extends Card {
	private double overdraftLimit; // 透支额度

	public CreditCard(String accountNumber, double balance, 
			double overdraftLimit) {
		super(accountNumber, balance);
		this.overdraftLimit = overdraftLimit;
	}

	public CreditCard(String accountNumber, double overage) {
		this(accountNumber, overage, 0);
	}
	
	public double getOverdraftLimit() {
		return this.overdraftLimit;
	}

	public void setOverdraftLimit(double overdraftLimit) {
		this.overdraftLimit = (overdraftLimit >= 0 ? overdraftLimit : 0);
	}

	@Override
	public boolean draw(double money) {
		if (balance + overdraftLimit < money) {
			return false;
		}

		balance -= money;
		return true;
	}
}