tic.py

import random, pygame, time

#   Initialise pygame, window and window variables
pygame.init()
winx = 600
winy = 600
pygame.display.set_caption("Tic-Tac-Toe")
screen = pygame.display.set_mode((winx, winy))
gameSurface = pygame.Surface((winx, winy))
gameSurface.set_colorkey((0, 0, 0))
gameSurface.set_alpha(128)

#   Computer controlled player 
class Agent:
    def __init__(self, symbol):
        self.symbol = symbol

    #   Plays the best possible move for computer
    def move(self, grid):
        
        cellvals = []

        #   Append each free cell a value based on MinMax algorithm
        for row in grid:
            for cell in row:
                if cell.symbol == None:
                    cell.value = minMax(cell, grid.copy(), self.symbol, True)
                    cellvals.append(cell.value)

        maxval = max(cellvals)
        # print(maxval)

        # for row in grid:
        #     for cell in row:
        #         print(str(cell.value) + '/' + str(cell.symbol) + '   ', end='')
        #     print('\n')
        # print('\n')

        moves = []

        #   Make a List of all possible best moves
        for row in grid:
            for cell in row:
                if cell.value == maxval and cell.symbol == None:
                    moves.append(cell.id)

        #   Take a random move from that list
        move = random.randint(0, len(moves) - 1)

        #   Play the move and update the display
        for row in grid:
            for cell in row:
                if cell.id == moves[move]:
                    cell.symbol = self.symbol
                    updateGrid(grid)
                    pygame.display.update()

                    #   Strip all cells from their values
                    for a in grid:
                        for b in a:
                            b.value = None

                    return

#   Honestly, completely useless class. But looks better than just variable 
class Player:
    def __init__(self, symbol):
        self.symbol = symbol

#   TODO: Standardize cell symbol assignment
#   Class to represent each cell in TicTacToe grid
class Cell:
    def __init__(self, id):
        self.id = id
        self.symbol = None
        self.value = None
    def assign(self, symbol):
        self.symbol = symbol

#   Algorithm to find the best possible move
#   Returns -1, 0 or 1 depending on the quality of the move
def minMax(node, mgrid, symbol, isMaxing):

    #   Find the given cell on the grid
    for row in mgrid:
        for cell in row:
            if cell.id == node.id:

                #   Determine whose turn it is on that move
                if isMaxing:
                    cell.symbol = symbol
                else: 
                    if symbol == 'X':
                        cell.symbol = 'O'
                    else:
                        cell.symbol = 'X'

                win, stat = checkWinner(mgrid)
                # print(str(win) + ' ' + str(stat))

                #   Return values based on the winner
                if stat == 'end':
                    if win == 'Tie':
                        cell.symbol = None
                        return 0
                    elif win == symbol:
                        cell.symbol = None
                        return 1
                    else:
                        cell.symbol = None
                        return -1

                if isMaxing:
                    value = 999

                    for arow in mgrid:
                        for acell in arow:
                            if acell.symbol == None:
                                value = min(value, minMax(acell, mgrid, symbol, False))
                    cell.symbol = None
                    return value
                    
                else:
                    value = -999

                    for arow in mgrid:
                        for acell in arow:
                            if acell.symbol == None:
                                value = max(value, minMax(acell, mgrid, symbol, True))
                    cell.symbol = None
                    return value
    
def drawGrid():
    screen.fill((0, 0, 0))
    pygame.draw.rect(screen, (255, 255, 255), (195, 15, 15, 570), 0)
    pygame.draw.rect(screen, (255, 255, 255), (390, 15, 15, 570), 0)

    pygame.draw.rect(screen, (255, 255, 255), (15, 195, 570, 15), 0)
    pygame.draw.rect(screen, (255, 255, 255), (15, 390, 570, 15), 0)

def drawSymbol(x, y, symbol):
    if symbol == 'X':
        pygame.draw.line(screen, (255, 255, 255), (30 + 195 * x, 30 + 195 * y), (180 + 195 * x, 180 + 195 * y), 15)
        pygame.draw.line(screen, (255, 255, 255), (180 + (195 * x), 30 + (195 * y)), (30 + (195 * x), 180 + (195 * y)), 15)
    elif symbol == 'O':
        pygame.draw.circle(screen, (255, 255, 255), (105 + 195 * x, 105 + 195 * y), 75, 15)

def updateGrid(grid):
    drawGrid()
    for i in range(3):
        for j in range (3):
            if grid[i][j].symbol != None:
                drawSymbol(j, i, grid[i][j].symbol) 

def printWinner(winner):
    if winner == None:
        writeOnScreen('TIC-TAC-TOE', 50, 0, -40)
    elif winner == 'Tie':
        writeOnScreen('TIE!', 50, 0, -40)
    else:
        writeOnScreen(winner + ' is the winner!', 50, 0, -40)

    writeOnScreen('Play as "X"', 35, -100, 20)
    writeOnScreen('Play as "O"', 35, 100, 20)

def writeOnScreen(txt, size, offsetX, offsetY):
    font = pygame.font.SysFont("Arial", size)
    txt = font.render(txt, 1, (255, 255, 255))
    x = (winx - txt.get_rect().width) / 2
    y = (winy - txt.get_rect().height) / 2
    screen.blit(txt, (int(x) + offsetX, (int(y) + offsetY)))    

def checkWinner(grid):
    for i in range(3):
        if grid[i][0].symbol == grid[i][1].symbol == grid[i][2].symbol != None:
            return grid[i][0].symbol, 'end'
        elif grid[0][i].symbol == grid[1][i].symbol == grid[2][i].symbol != None:
            return grid[0][i].symbol, 'end'
    if grid[0][0].symbol == grid[1][1].symbol == grid[2][2].symbol != None:
        return grid[0][0].symbol, 'end'
    elif grid[2][0].symbol == grid[1][1].symbol == grid[0][2].symbol != None:
        return grid[2][0].symbol, 'end'
    
    for row in grid:
        for symbol in row:
            if symbol.symbol == None:
                return None, 'game'
    
    return 'Tie', 'end'

def main():
    winner = None

    while True:
        # grid = [[None for i in range(3)] for j in range(3)]
        grid = [[Cell(i + (j * 3)) for i in range(3)] for j in range(3)]
        isXTurn = True
        gamePhase = 'start'

        screen.fill((0, 0, 0))

        printWinner(winner)

        pygame.display.update()

        while True:
            for event in pygame.event.get():
                    if event.type == pygame.QUIT:
                        pygame.quit()
                        quit()
                    elif event.type == pygame.MOUSEBUTTONDOWN:
                        if gamePhase == 'game':
                            if (isXTurn and player.symbol == 'X') or (not isXTurn and player.symbol == 'O'):
                                x = event.pos[0] // 200
                                y = event.pos[1] // 200

                                if isXTurn:
                                    grid[y][x].assign('X')
                                else:
                                    grid[y][x].assign('O')

                                # print(grid)
                                updateGrid(grid)
                                # print(checkWinner(grid))
                                winner, gamePhase = checkWinner(grid)
                                isXTurn = not isXTurn
                        elif gamePhase == 'start':
                            x = event.pos[0]
                            y = event.pos[1]

                            if y > 295 and y < 345:
                                if x < 300:
                                    agent = Agent('O')
                                    player = Player('X')
                                    gamePhase = 'game'
                                    drawGrid()
                                elif x > 300:
                                    agent = Agent('X')
                                    player = Player('O')
                                    gamePhase = 'game'
                                    drawGrid()

                        pygame.display.update()
                
            if gamePhase == 'end':
                time.sleep(0.5)
                grid.clear()
                break

            if gamePhase == 'game' and ((isXTurn and agent.symbol == 'X') or (not isXTurn and agent.symbol == 'O')):
                time.sleep(0.5)
                agent.move(grid)
                isXTurn = not isXTurn
                # print(grid)
                # print(checkWinner(grid))
                winner, gamePhase = checkWinner(grid)

main()