import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Observable;
import java.util.Observer;
import javax.swing.ImageIcon;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JPanel;

/**
 * This class represents a GUI for a basic rock-paper-scissors game.
 * @author Marty Stepp
 * @version CSE 331 Spring 2011, 5/2/2011
 */
public class RockPaperScissorsGui {
	private JFrame frame;
	private JButton move1;
	private JButton move2;
	private JButton play;
	private Game game;
	
	/**
	 * Constructs the GUI and displays it on the screen.
	 */
	public RockPaperScissorsGui() {
		game = Game.getInstance();
		setupComponents();
		handleEvents();
		doLayout();
		frame.setVisible(true);
	}
	
	// sets up graphical components in the window
	private void setupComponents() {
		frame = new JFrame("Rock-Paper-Scissors");
		frame.setLocation(300, 100);
		frame.setSize(400, 300);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		
		move1 = new JButton(new ImageIcon("blank.png"));
		move2 = new JButton(new ImageIcon("blank.png"));
		play = new JButton("Play");
	}
	
	// attaches various listeners to handle events
	private void handleEvents() {
		ActionListener listener = new ButtonListener();
		play.addActionListener(listener);
		Observer observer = new GameObserver();
		game.addObserver(observer);
	}
	
	// sets up containers for layout in the window
	private void doLayout() {
		Container moves = new JPanel(new FlowLayout());
		moves.add(move1);
		moves.add(move2);
		
		frame.add(moves);
		frame.add(play, BorderLayout.SOUTH);
	}
	
	// This observer responds to changes in the state of the TTT game
	// by updating the GUI to reflect the changes.
	private class GameObserver implements Observer {
		public void update(Observable arg0, Object arg1) {
			// update the weapon buttons
			String file1 = game.getWeapon1().toString().toLowerCase() + ".png";
			String file2 = game.getWeapon2().toString().toLowerCase() + ".png";
			move1.setIcon(new ImageIcon(file1));
			move2.setIcon(new ImageIcon(file2));
			
			// highlight the winner
			int winner = game.winner();
			move1.setBackground(null);
			move2.setBackground(null);
			if (winner == 1) {
				move1.setBackground(Color.YELLOW);
			} else if (winner == 2) {
				move2.setBackground(Color.YELLOW);
			}
		}
	}
	
	// This listener responds to clicks on the "Play" button.
	private class ButtonListener implements ActionListener {
		/**
		 * Called when the Play button is clicked.
		 * Plays a new game round of tic-tac-toe.
		 */
		public void actionPerformed(ActionEvent event) {
			game.playRound();
		}
	}
}