/**
 * CheckingAccount: a version of a bank account assesses a service
 * charge when needed.
 */
public class CheckingAccount extends BankAccount {

    // instance variables
    private double lowBalance;      // low balance since account created or
                            // last service charge was deducted

    /**
     * Construct a new CheckingAccount with the given name, account number,
     * and initial balance
     */
    public CheckingAccount(String name, int number, double initialBalance){
        super(name, number, initialBalance);
        this.lowBalance = this.getBalance();
    }

    /**
     * Withdraw money from this account (may leave account balance
     * negative if insufficient funds).  pre: amount >= 0
     * @param amount dollars to be withdrawn from the account
     */
    public void withdraw(double amount) {
        super.withdraw(amount);
        if (this.getBalance() < this.lowBalance) {
            this.lowBalance = this.getBalance();
        }
    }

    /**
     * Deduct a service charge if the account balance has gotten too low
     * since the last time a service charge was deducted (or the account
     * created, whichever comes first).
     *
     * @param  minBalance minimum account balance before service
     *         charge applies
     * @param  serviceCharge amount to deduct if charge applies
     */
    public void deductServiceCharge(double minBalance, double serviceCharge){
        if (this.lowBalance < minBalance) {
            this.withdraw(serviceCharge);
        }
        this.lowBalance = this.getBalance();
    }

    /** Return a string representation of this CheckingAccount */
    public String toString() {
        return "CheckingAccount[" + this.getName() + ", " + this.getNumber() + ", " +
                this.getBalance() + "]";
    }
}