/* extended version including sample answers for exercises */

public class BankAccount {

  private int balance = 0;
  private int id = 0;

  public int getBalance() {
    return balance;
  }

  public void deposit(int amount) {
    System.out.println("Depositing " + amount + "$ into account " + id);
    balance = balance + amount;
  }

  public void withdraw(int amount) {
    if (amount > balance) {
      amount = balance;
      System.out.println("No overdraft facility, will only withdraw " + amount + "$ from account " + id);
    }
    System.out.println("Withdrawing " + amount + "$ from account " + id);
    balance = balance - amount;

  }

  public int transaction(int amount) {

    if (amount > 0)
      deposit(amount);
    else
      withdraw(-amount);
    
    return balance;
  }

  public String toString() {
    return "<Account " + id + ": " + balance + "$ in credit>";
  }


  private static int idCounter = 0;

  // called a "static factory"
  //public static BankAccount openAccount() {
  //  BankAccount newAccount = new BankAccount();
  //  newAccount.id = idCounter++;
  //  System.out.println("Created new account with Id = " + newAccount.id);
  //  return newAccount;
  //}

  public BankAccount() {
    id = idCounter++;
    System.out.println("Created new account with Id = " + id);
  }

  public BankAccount(int initialBalance) {
    id = idCounter++;
    System.out.println("Created new account with Id = " + id);
    transaction(initialBalance);
  }

}