/*
 * This is a java playing program.
 * It isn't well commented, but it is
 * an example of a working program.
 */

import tio.*;

class TicTacToe {
    static final int EMPTY = 0;
    static final int NONE = 0;
    static final int USER = 1;
    static final int COMPUTER = 2;
    static final int STALEMATE = 3;

    public static void main(String[] args) {
	// Data objects
	// 1 = user, 2 = computer
	int turn = USER;

	// We will represent the board as nine cells 
        // 0 = empty, 1 = user, 2 = computer
	int[][] board = new int[3][3];

	// move: 1-9 representing ul through lr
	int move;

	// winner: 0 = none, 1 = user, 2 = computer, 3 = stalemate
	int winner;

	// Print Instructions
        System.out.println("This is a tic-tac-toe game");
	System.out.println("You are playing against the computer!");
	System.out.println("Enter 1-9 to indicate your move");

	// Print the board
	print_board(board);

	// While (game not over)
	while(true) {
	    if(turn == USER) {
		System.out.println("Your move");
		move = -1;
		while (move<0 || move>9 || board[move/3][move%3] != EMPTY) {
		    System.out.println("Please enter your move(0-9): ");
		    move = Console.in.readInt();
		    Console.in.readChar();
		}
	    } else {
		move = computer_move(board);
		System.out.println("Computer move: " + move);
	    }

	    // Update the board
	    board[(int)(move/3)][move%3] = turn;

	    // Print the board
	    print_board(board);

	    // if game is over
	    winner = checkWinner(board);

	    if(winner != NONE)
		break;

	    // switch turn
	    if(turn == USER) {
		turn = COMPUTER;
	    } else {
		turn = USER;
	    }

	}

	// Print out the outcome
	switch(winner) {
	case USER:
	    System.out.println("You won!");
	    break;
	case COMPUTER: 
	    System.out.println("Computer won!");
	    break;
	default:
	    System.out.println("Tie!");
	    break;
	}
    }

    // Print the board
    public static void print_board(int[][] board) {
	System.out.print(printChar(board[0][0]));
	System.out.print("|");
	System.out.print(printChar(board[0][1]));
	System.out.print("|");
	System.out.println(printChar(board[0][2]));
	System.out.println("-----");
	System.out.print(printChar(board[1][0]));
	System.out.print("|");
	System.out.print(printChar(board[1][1]));
	System.out.print("|");
	System.out.println(printChar(board[1][2]));
	System.out.println("-----");
	System.out.print(printChar(board[2][0]));
	System.out.print("|");
	System.out.print(printChar(board[2][1]));
	System.out.print("|");
	System.out.println(printChar(board[2][2]));
    }

    // Return an X or O, depending upon whose move it was
    public static char printChar(int b) {
	switch(b) {
	case EMPTY:
	    return ' ';
	case USER:
	    return 'X';
	case COMPUTER:
	    return 'O';
	}
	return ' ';
    }

    // See if the game is over
    public static int checkWinner(int[][] board) {
	// Check if someone won
	// Check horizontals

	// top row
	if((board[0][0] == board[0][1]) && (board[0][1] == board[0][2]))
	    return board[0][0];

	// middle row
	if((board[1][0] == board[1][1]) && (board[1][1] == board[1][2]))
	    return board[1][0];

	// bottom row
	if((board[2][0] == board[2][1]) && (board[2][1] == board[2][2]))
	    return board[2][0];

	// Check verticals

	// left column
	if((board[0][0] == board[1][0]) && (board[1][0] == board[2][0]))
	    return board[0][0];

	// middle column
	if((board[0][1] == board[1][1]) && (board[1][1] == board[2][1]))
	    return board[0][1];

	// right column
	if((board[0][2] == board[1][2]) && (board[1][2] == board[2][2]))
	    return board[0][2];

	// Check diagonals
	// one diagonal
	if((board[0][0] == board[1][1]) && (board[1][1] == board[2][2]))
	    return board[0][0];

	// the other diagonal
	if((board[0][2] == board[1][1]) && (board[1][1] == board[2][0]))
	    return board[0][2];

	// Check if the board is full
	if(board[0][0] == EMPTY || 
           board[0][1] == EMPTY || 
           board[0][2] == EMPTY || 
	   board[1][0] == EMPTY ||
	   board[1][1] == EMPTY ||
	   board[1][2] == EMPTY ||
	   board[2][0] == EMPTY ||
	   board[2][1] == EMPTY ||
	   board[2][2] == EMPTY)
	    return NONE;

	return STALEMATE;
    }

    // Generate a random computer move
    public static int computer_move(int[][] board) {
	int move = (int)(Math.random()*9);

	while(board[move/3][move%3] != EMPTY) 
	    move = (int)(Math.random()*9);

	return move;
    }
}