import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.SwingConstants;


public class SwingTicTacToe extends JFrame implements ActionListener{

	private boolean xTurn = true;
	private String[] inputs = {"","","","","","","","","",""};

	private JLabel output = new JLabel("Welcome to Tic Tac Toe!", SwingConstants.CENTER);

	private JButton zero = new JButton();
	private JButton one = new JButton();
	private JButton two = new JButton();	
	private JButton three = new JButton();
	private JButton four = new JButton();
	private JButton five = new JButton();
	private JButton six = new JButton();
	private JButton seven = new JButton();
	private JButton eight = new JButton();

	JButton[] buttonList = {zero, one, two, three, four, five, six, seven, eight};

	/**
	 * Creates the TicTacToe board with nine buttons and Pittsburgh Steeler colors!
	 */
	public SwingTicTacToe(){

		super("Tic Tac Toe!");
		setSize(600,600);

		this.getContentPane().setBackground(Color.YELLOW);
		this.setDefaultCloseOperation(EXIT_ON_CLOSE);

		add(output, BorderLayout.NORTH);

		JPanel buttons = new JPanel();
		buttons.setLayout(new GridLayout(3,3));

		for(int i = 0; i < buttonList.length; i++){
			if(i % 2 == 0){
				buttonList[i].setBackground(Color.YELLOW);
				buttonList[i].setForeground(Color.BLACK);
			}
			else{
				buttonList[i].setBackground(Color.BLACK);
				buttonList[i].setForeground(Color.YELLOW);
			}

			buttonList[i].setFont(new Font("", Font.BOLD, 80));
			buttonList[i].addActionListener(this);
			buttonList[i].setActionCommand(Integer.toString(i));
			buttons.add(buttonList[i]);
		}
		add(buttons, BorderLayout.CENTER);
	}

	/**
	 * This main frame is its own ActionListener
	 * Therefore, it implements this method that changes the button that the user picks to the user's letter (either X or O)
	 * And it also determines if this move ends the game
	 */
	@Override
	public void actionPerformed(ActionEvent e) {
		String buttonString = e.getActionCommand();
		int index = Integer.parseInt(buttonString);

		recordTurn(index);

		boolean tie = checkTie();
		boolean xWin = checkWin("X");
		boolean oWin = checkWin("O");

		int playAgain = 5;

		if(xWin){
			output.setText("X Wins!!!");
			JOptionPane.showMessageDialog(this, "X WINS!!!");
			playAgain = playAgain();
		}
		else if(oWin){
			output.setText("O Wins!!!");
			JOptionPane.showMessageDialog(this, "O WINS!!!");
			playAgain = playAgain();
		}
		else if(tie){
			output.setText("CAT!! (A cat is a TIE in Tic Tac Toe)");
			JOptionPane.showMessageDialog(this, "Looks like we have a CAT!! (A cat is a TIE in Tic Tac Toe)");
			playAgain = playAgain();
		}
		
		if(playAgain == 0)
			resetGame();
		else if(playAgain == 1)
			System.exit(0);
		
	}

	/**
	 * Checks the array of user inputs to see if there is a tie
	 * @return
	 */
	private boolean checkTie() {
		boolean tie = false;
		String piece = "";

		if(!(inputs[0].equalsIgnoreCase(piece) || inputs[1].equalsIgnoreCase(piece) || inputs[2].equalsIgnoreCase(piece) || inputs[3].equalsIgnoreCase(piece) || inputs[4].equalsIgnoreCase(piece) || inputs[5].equalsIgnoreCase(piece) || inputs[6].equalsIgnoreCase(piece) || inputs[7].equalsIgnoreCase(piece) || inputs[8].equalsIgnoreCase(piece)))
			tie = true;

		return tie;
	}

	/**
	 * Resets the game board resetting all of the buttons to be blank and the Welcome message appears
	 */
	private void resetGame() {
		for(int i = 0; i < buttonList.length; i++){
			buttonList[i].setText("");
			inputs[i] = "";
		}
		xTurn = true;
		output.setText("Welcome to Tic Tac Toe!!");
	}


	/**
	 * Asks the user if he/she would like to play again.
	 * @return 0 if the user wants to play again, 1 if user wants to quit
	 */
	private int playAgain() {
		Object[] options = {"Yes, please",
		"No, thanks"};
		int n = JOptionPane.showOptionDialog(this, "Would you like to play again?", "Play Again", JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE, null, options, options[1]);
		return n;
	}

	/**
	 * Checks the input array to see if the specified user has won yet
	 * @param piece the user's letter (either X or O)
	 * @return true if the specified user won, false if not
	 */
	private boolean checkWin(String piece) {

		if(horizontalWin(piece) || verticalWin(piece) || diagnolWin(piece))
			return true;
		else
			return false;

	}

	private boolean horizontalWin(String piece) {
		boolean win = false;

		for(int i = 0; i < 7; i+=3){
			if(inputs[i].equalsIgnoreCase(piece) && inputs[i+1].equalsIgnoreCase(piece) && inputs[i+2].equalsIgnoreCase(piece)){
				win = true;
				break;
			}
		}

		return win;
	}

	private boolean diagnolWin(String piece) {

		boolean win = false;

		if(inputs[0].equalsIgnoreCase(piece) && inputs[4].equalsIgnoreCase(piece) && inputs[8].equalsIgnoreCase(piece))
			win = true;
		else if(inputs[6].equalsIgnoreCase(piece) && inputs[4].equalsIgnoreCase(piece) && inputs[2].equalsIgnoreCase(piece))
			win = true;

		return win;
	}

	private boolean verticalWin(String piece) {
		boolean win = false;
		
		for(int i = 0; i < 3; i++){
			if(inputs[i].equalsIgnoreCase(piece) && inputs[i+3].equalsIgnoreCase(piece) && inputs[i+6].equalsIgnoreCase(piece)){
				win = true;
				break;
			}
		}
		return win;
	}

	/**
	 * If user picks empty space, it records their move and changes the button's text to the user's letter
	 * If space is not empty, an error message appears at the top of the frame to tell the user to pick an empty space.
	 * This message will show until the user picks an empty space
	 * @param index the space that the user selected (index in the input array)
	 */
	private void recordTurn(int index) {

		if(!inputs[index].equalsIgnoreCase("")){
			output.setText("Woah! That is already is selected. Pick a different one.");
		}
		else{
			if(xTurn){
				inputs[index] = "X";
				buttonList[index].setText("X");
				xTurn = false;
			}
			else{
				inputs[index] = "O";
				buttonList[index].setText("O");
				xTurn = true;
			}
			output.setText("Select where you want to place your piece!");
		}

	}
	
	public static void main(String[] args) {
		SwingTicTacToe game = new SwingTicTacToe();
		game.setVisible(true);
	}
	

}