import java.util.ArrayList;

public class Account {
	
	// The current balance in the account.
	private int balance = 200;  // Protected by lock on "this"
	
	private ArrayList<AccountListener> listeners = new ArrayList<AccountListener>();
	
	/**
	 * Withdraw money from an account.  If this would bring the balance below 0, wait
	 * for a deposit to occur
	 * @param amount the amount to withdraw
	 * @throws InterruptedException thrown if the thread is interrupted while it is waiting
	 * for a deposit.
	 */
	public synchronized void withdraw (int amount) throws InterruptedException {
		// What would the new balance be?
		int newBalance = balance - amount;
		
		// Wait until the new balance would be positive
		while (newBalance < 0) {
			System.out.println("waiting");
			
			// Wait for a deposit
			wait();
			System.out.println("awakened");
			
			// Check what the new balance would now be
			newBalance = balance - amount;
		}
		
		// Update the balance
		balance = newBalance;
		System.out.println(balance);
		
		// Update the display
		notifyListeners();
	}
	
	/**
	 * Deposit money into the account
	 * @param amount the amount to deposit
	 */
	public synchronized void deposit (int amount) {
		// Do the deposit
		balance = balance + amount;
		System.out.println(balance);

		
		// Notify any threads that are waiting for a deposit to occur.
		notifyAll();
		
		// Update the display.
		notifyListeners();
	}

	/**
	 * @return
	 */
	public synchronized int getBalance() {
		// TODO Auto-generated method stub
		return balance;
	}

	/**
	 * @param bank
	 */
	public void addListener(AccountListener bank) {
		listeners.add(bank);
	}
	
	public void notifyListeners() {
		for (int i = 0; i < listeners.size(); i++) {
			listeners.get(i).balanceChanged(balance);
		}
	}
	
}