public class BankDatabase
{
    private Account[] accounts;
    
    public BankDatabase()
    {
        accounts = new Account[ 2 ];
        accounts[ 0 ] = new Account( 12345, 1000.0 );
        accounts[ 1 ] = new Account( 98765, 120000.0); 
    }
    
    private Account getAccount( int accountNumber )
    {
        for ( Account currentAccount : accounts )
        {
            if ( currentAccount.getAccountNumber() == accountNumber) 
            {
                return currentAccount;
            }
        }
        return null;
    }
    
    public boolean authenticateUser( int userPIN )
    {
        Account userAccount = getAccount( userPIN );
        if ( userAccount != null )
        {
            return userAccount.validatePIN( userPIN );
        }
        else
        {
            return false;
        }
    }
    
    public double getTotalBalance( int userAccountNumber )
    {
        return getAccount( userAccountNumber ).getTotalBalance();
    }
    
    public void debit(int userAccountNumber, double amount)
    {
        getAccount(userAccountNumber).debit(amount);
    }
}