package tictactoe;
import java.util.Scanner;

/** Tic Tac Toe
 *  The user ('X') plays against the computer ('O')
 *  The first player is chosen randomly.
 * @author gorr
 */
public class TicTacToe {

    /**
     *  the game character symbol for the player
     */
    public static final char PLAYER = 'X';
    /**
     *  the game character symbol for the computer
     */
    public static final char COMPUTER = 'O';
    /**
     *  the game character symbol for an empty place on the board
     */
    public static final char EMPTY = '-';
    
    /**
     * the current board 
     */
    // !!!!!! DECLARE BOARD HERE
    
    /**
     * the current player 
     */
    char currentPlayer;                        
    
    /**
     * Use for reading input from the user
     */
    Scanner in = new Scanner(System.in);
        
    /**
     * Plays the game of TicTacToe. Stops when either 1) a player wins or 2) no
     * spaces are left on the board.
     */
    public void play() {
        
        openingGreeting(); // greeting
        
        currentPlayer = initPlayer();  // pick starting player     
        initBoard();   // initialize the board
        int moves = 0;
        boolean hasWon = false;
        while (moves < 9 && !hasWon) {      // game loop over moves and hasWon
            if (currentPlayer == PLAYER) {
                userTurn();
            } else {
                computerTurn();
            }
            System.out.println("The board is now: \n" + this);
            hasWon = checkWin();   // has a player won?
            currentPlayer = swapPlayer();          // swap the currentPlayer
            moves++;
        }
        if (!hasWon) {
            System.out.println("No one won.");
        }
        
    }
    
    /** Welcome the player
     */
    public void openingGreeting() {
        System.out.println("\nWELCOME TO TICTACTOE\n");
        System.out.println("You will be X, the computer will be O.");
        System.out.println("The starting player will be picked randomly.");
        System.out.println("Enjoy the game and good luck!\n");
        
    }

    /** Initialize the values in the board to all blanks. 
     * Note, each board position is either:
     *   PLAYER - this is the user 
     *   COMPUTER - this is the computer 
     *   EMPTY -  indicates the position is empty 
     */
    public void initBoard() {
        // !!!!!! INITIALIZE BOARD HERE
    }

    /**
     * Swap the current player. That is, if the current player is 'X', it is
     * swapped to be 'O', and vice versa.
     * @return the new current player
     */
    public char swapPlayer() {
        if (currentPlayer == PLAYER) {
            currentPlayer = COMPUTER;
        } else {
            currentPlayer = PLAYER;
        }
        return currentPlayer;
    }

    /**
     * Randomly pick which player (user or computer) goes first. Set the
     * currentPlayer to the first player. It is assumed that the user is always
     * "X" and the computer is always "O".
     * @return the first player
     */
    public char initPlayer() {
        if (Math.random() < .5) {
            currentPlayer = PLAYER;
            System.out.println("You are the first player.");
        } else {
            currentPlayer = COMPUTER;
            System.out.println("The computer is the first player.");
        }
        return currentPlayer;
    }

    /**
     * Chooses which position the computer will play. Sets that position of the
     * board to "O"
     */
    public void computerTurn() {
        System.out.println("\nIt is the computer's turn. ");
        
        // !!!!!! DECIDE WHERE THE COMPUTER WILL PLAY
    }

    /**
     * Have the user choose which position to play. Sets that position of the
     * board to "X"
     */
    public void userTurn() {
        System.out.println("\nIt is your turn.");
        int row = -1;
        int col = -1;
        do {
            System.out.println("Enter the row (0-2) and column (0-2) of your move:");
            row = readValue();
            col = readValue();
            if (board[row][col] == EMPTY) {
                break;
            } else {
                System.out.println("This space is not empty. Try again.");
            }
        } while (board[row][col] != EMPTY);
        board[row][col] = PLAYER;    
    }

    /**
     * Utility method to prompt user for a value in the range of 0 to 2
     * It makes sure that the user enters a number between 0 and 2. If not, it loops
     * and asks for another input. 
     *
     * @return the value of the row or column
     */
    public int readValue() {
        int val = -1;
        while (true) {
            val = in.nextInt();
            if (val < 0 || val > 2) {
                System.out.println("You have not entered a value in the range 0 to 2. Please try again.");
            } else {
                break;
            }
        }
        return val;
    }

    /**
     * Checks to see if the currentPlayer has won.
     *
     * @return true if the currentPlayer has won.
     */
    public boolean checkWin() {
        // check rows
        String seqWin = "" + currentPlayer + currentPlayer + currentPlayer;
        boolean hasWon = false;
        String seq = "";

        // check rows
        for (int i = 0; i < board.length; i++) {
            seq = "";
            for (int j = 0; j < board.length; j++) {
                seq += board[i][j];
            }
            if (seq.equals(seqWin)) {
                hasWon = true;
            }
        }
         
        // !!!!!! YOU NEED TO CHECK THE COLUMNS AND DIAGONALS!

        if (hasWon) {
            if (currentPlayer == PLAYER) {
                System.out.println("Congratulations - you have won!");
            } else {
                System.out.println("Sorry, the computer won and you lost. "
                        + "\nBetter luck next time");
            }
        }
        return hasWon;
    }

	 /**
     * @return  string representation of the board.
     */
    public String toString() {
        String b = "\t";
        // !!!!!! CREATE STRING REPRESENTATION OF THE BOARD
        return b;
    }
}