//An instance of this class represents a basic Savings Account
// that earns interest in every monthly billing cycle based
// on the current balance when the interest is compounded
//
//Example program to illustrate very basic Java inheritance
// Norman Pestaina   Fall 2017
//
public class SavingsAccount extends BankAccount 
{ 
   //Class Constant: The default rate is also a minimum rate
   public static final double DEFAULT_INTEREST_RATE = 1.0;
   
   //Instance Variable (accountNumber, currentBalance inherited)
   private double interestRate;
   
   //Constructor
   public SavingsAccount(double initialBalance, double interestRate)
   {
      super(initialBalance);  //FIRST: Initialize inherited state
      this.interestRate = interestRate < DEFAULT_INTEREST_RATE ? 
                          DEFAULT_INTEREST_RATE : interestRate;
   }
   
   //Constructor
   public SavingsAccount(double initialBalance)
   {
      this(initialBalance, DEFAULT_INTEREST_RATE);
   }
   
   //Constructor
   public SavingsAccount()
   {
      //Parameterless super() IMPLICITLY invoked
      this.interestRate = DEFAULT_INTEREST_RATE;
   }
   
   //Accessor
   public double getInterestRate()
   {
      return this.interestRate;
   }
   
   //Mutator: specific to SavingsAccount instances
   public void addInterest()
   {
      //MUST use accessor methods to access private inherited state 
      double interest = this.getCurrentBalance() * this.interestRate / 100 / 12;
      this.deposit(interest);
   }
   
   //Override
   public String toString()
   {
      //EXTEND image to include native state
      return super.toString() + " Interest Rate " + this.interestRate + "%/Yr.";
   }
   
   //Override
   public boolean equals(Object other)
   {
      //FIRST, compare inherited state
      if (!super.equals(other))
         return false;
      
      //Compare native state  
      return this.interestRate == ((SavingsAccount)other).interestRate;
   }
}