/* Account.java -- define a bank account.  When you open an account, there
 * is an initial balance and interest rate.  Then, you can perform
 * transactions -- deposit, withdraw, earn interest and write checks.
 * We'll assume that if the user opens an account with no money, they'll
 * earn 2%, otherwise 3%.
 * This is not a realistic example -- real banks don't operate this way,
 * but this program is mainly about reviewing good program structure.
 */
public class Account
{
  // attributes of a bank account
  private double balance;
  private double interestRate;
  private int checkNumber;

  // Constructors
  public Account()
  {
    balance = 0.00;
    interestRate = 2.0;
    checkNumber = 101;
  }

  public Account(double initial)
  {
    balance = initial;
    interestRate = 3.0;
    checkNumber = 501;
  }

  public Account(Account a)
  {
    balance = a.balance;
    interestRate = a.interestRate;
    checkNumber = 1001;
  }

  // Other methods that implement routine operations.
  // Notice that all these functions use attribute variables balance
  // and/or interestRate.  For clarity, we could have typed "this.balance"
  // and "this.interestRate" because attributes belong to "this".

  public double getBalance()
  {
    return balance;
  }

  public void deposit(double amount)
  {
    balance += amount;
  }

  public void withdraw(double amount)
  {
    balance -= amount;
  }

  public void accrueInterest()
  {
    balance *= (1 + interestRate/100.0);
  }

  /* When we write a check, tell the user what the check number is,
   * deduct the amount from the balance, and increment the check number.
   * Actually, we should also check for overdraft...
   */
  public void writeCheck(double amount)
  {
    System.out.printf("Check # %d has cleared.\n", checkNumber);
    balance -= amount;
    ++checkNumber;
  }

  /* Let's transfer money to another account.  This method will take
   * an Account parameter "a", and this is the account we are sending
   * money to.  The second parameter tells how much money to transfer.
   */
  public void transfer(Account a, double amount)
  {
    this.withdraw(amount);
    a.deposit(amount);
  }

  // The toString function allows us to print somebody's balance.
  public String toString()
  {
    return String.format("$ %.2f", balance);
  }
}