////////////////////////////////////////////////////////
//
//	tttboard.h
//
//	Started 1/14/98 by Jeff Ondich
//	Last modified: 1/14/98
//
//	This is the interface for the class TTTBoard.
//	TTTBoard objects store the current state of
//	a game of Tic-Tac-Toe, and provide operations for
//	manipulating the game.
//
////////////////////////////////////////////////////////

#ifndef	TTTBOARD_H
#define	TTTBOARD_H

typedef		char	PlayerID;

const PlayerID kPlayerX = 'X';
const PlayerID kPlayerO = 'O';
const PlayerID kNoPlayer = ' ';

enum
{
	kTopLeft = 0,
	kTopMiddle,
	kTopRight,
	kMiddleLeft,
	kMiddleMiddle,
	kMiddleRight,
	kBottomLeft,
	kBottomMiddle,
	kBottomRight
};


class TTTBoard
{
private:
	char		mBoard[9];
	PlayerID	mWhoseTurn;

public:
	// Constructor
				TTTBoard( void );


	// Getting information about data members
	
	bool		IsOpen( int theSquare ) const;
	PlayerID	WhoIsThere( int theSquare ) const;
	PlayerID	WhoseTurn( void ) const;
	bool		CanWin( PlayerID thePlayer, int & theSquare ) const;
	bool		CanBlock( PlayerID thePlayer, int & theSquare ) const;
	
	
	// Making moves

	bool		MakeMove( PlayerID thePlayer, int theSquare );


	// Displaying the state of the game

	void		DrawBoard( void );		
};

////////////////////////////////////////////////////////
//
//	Descriptions of the member functions
//
////////////////////////////////////////////////////////

// The constructor TTTBoard() initializes the board
// to empty--neither X nor O has moved--and sets
// mWhoseTurn to kPlayerX.

// IsOpen() returns false if theSquare is
// occupied by an X or an O, and true otherwise.

// WhoIsThere() returns kPlayerX, kPlayerO, or kNoPlayer,
// depending on what is in theSquare.

// WhoseTurn() returns kPlayerX or kPlayerO, depending on
// whose turn it is.  As indicated in the description of
// the constructor, X always goes first.

// CanWin() determines whether there is a square in which
// thePlayer can move to win the game.  If it is
// thePlayer's move and there is a winning move available,
// CanWin() sets theSquare equal to the winning move
// and returns true.  Otherwise, CanWin() returns false.

// CanBlock() determines whether there is a square in which
// thePlayer can move to prevent the other player from
// getting three in a row on the next move.  If it is
// thePlayer's move and there is a blocking move available,
// CanBlock() sets theSquare equal to the blocking move
// and returns true.  Otherwise, CanBlock() returns false.

// If it is thePlayer's move and theSquare is open, MakeMove()
// makes a move for thePlayer in theSquare and returns true.
// Otherwise, MakeMove() returns false.

// DrawBoard() prints some kind of representation of the
// Tic-Tac-Toe board to standard output (cout).  For
// example, the display might look like this:
//
//       |   |
//     X | O |
//       |   |
//    -----------
//       |   |
//     X |   |
//       |   |
//    -----------
//       |   |
//     O |   |
//       |   |
//
//    It is X's turn.
//

#endif