import random 

# a python program for tic-tac-toe game
# module intro for introduction
# module show_board for values
# module playgame 

def introduction():
    print("Hello this a sample tic tac toe game")
    print("It will rotate turns between players one and two")
    print("While 3,3 would be the bottom right.")
    print("Player 1 is X and Player 2 is O")

def draw_board(board):
    print("    |    |")
    print("  " + board[7] + " | " + board[8] + "  | " + board[9])
    print("    |    |")
    print("-------------")
    print("    |    |")
    print("  " + board[4] + " | " + board[5] + "  | " + board[6])
    print("    |    |")
    print("-------------")
    print("    |    |")
    print("  " + board[1] + " | " + board[2] + "  | " + board[3])
    print("    |    |")

def input_player_letter():
    # Lets the player type witch letter they want to be.
    # Returns a list with the player's letter as the first item, and the computer's letter as the second.
    letter = ''
    while not (letter =='X' or letter == 'O'):
        print("Do you want to be X or O? ")
        letter = input("> ").upper()

    # the first element in the list is the player’s letter, the second is the computer's letter.
    if letter == 'X':
        return ['X', 'O']
    else:
        return ['O', 'X']

def frist_player():
    guess = random.randint(0, 1)
    if guess == 0:
        return "Computer"
    else:
        return "Player"

def play_again():
    print("Do you want to play again? (y/n)")
    return input().lower().startswith('y')

def make_move(board, letter, move):
    board[move] = letter

def is_winner(bo, le):
    # Given a board and a player’s letter, this function returns True if that player has won.
    # We use bo instead of board and le instead of letter so we don’t have to type as much.
    return ((bo[7] == le and bo[8] == le and bo[9] == le) or 
    (bo[4] == le and bo[5] == le and bo[6] == le) or 
    (bo[1] == le and bo[2] == le and bo[3] == le) or
    (bo[7] == le and bo[4] == le and bo[1] == le) or
    (bo[8] == le and bo[5] == le and bo[2] == le) or 
    (bo[9] == le and bo[6] == le and bo[3] == le) or 
    (bo[7] == le and bo[5] == le and bo[3] == le) or 
    (bo[9] == le and bo[5] == le and bo[1] == le))

def get_board_copy(board):
    dupe_board = []
    for i in board:
        dupe_board.append(i)
    return dupe_board

def is_space_free(board, move):
    return board[move] == ' '

def get_player_move(board):
    # Let the player type in their move
    move = ' '
    while move not in '1 2 3 4 5 6 7 8 9'.split() or not is_space_free(board, int(move)):
        print("What is your next move? (1-9)")
        move = input()
    return int(move)

def choose_random_move_from_list(board, moveslist):
    possible_moves = [] 
    for i in moveslist:
        if is_space_free(board, i):
            possible_moves.append(i)
        
    if len(possible_moves) != 0:
        return random.choice(possible_moves)
    else:
        return None

def get_computer_move(board, computer_letter):
    if computer_letter == 'X':
        player_letter = 'O'
    else:
        player_letter = 'X'
    
    for i in range(1, 10):
        copy = get_board_copy(board)
        if is_space_free(copy, i):
            make_move(copy, computer_letter, i)
            if is_winner(copy, computer_letter):
                return i

    
    for i in range(1, 10):
        copy = get_board_copy(board)
        if is_space_free(copy, i):
            make_move(copy, player_letter, i)
            if is_winner(copy, player_letter):
                return i
            
    move = choose_random_move_from_list(board, [1, 3, 7, 9])
    if move != None:
        return move

    if is_space_free(board, 5):
        return 5

    return choose_random_move_from_list(board, [2, 4, 6, 8])

def is_board_full(board):
    for i in range(1, 10):
        if is_space_free(board, i):
            return False
    return True

print("Welcome To Tic Tac Toe!")

while True: 
    the_board = [' '] * 10
    player_letter, computer_letter = input_player_letter()
    turn = frist_player()
    print("The " + turn + " go frist.")
    game_is_playing = True
    
    while game_is_playing: 
        if turn == 'player':
            #players turn 
            draw_board(the_board)
            move = get_player_move(the_board)
            make_move(the_board, player_letter, move)

            if is_winner(the_board, player_letter):
                draw_board(the_board)
                print("Hoory! You have won the game!")
                game_is_playing = False
            else:
                if is_board_full(the_board):
                    draw_board(the_board)
                    print("The game is tie!")
                    break
                else:
                    turn = 'computer'
        else:
            #Computer's turn
            move = get_computer_move(the_board, computer_letter)
            make_move(the_board, computer_letter, move)

            if is_winner(the_board, computer_letter):
                draw_board(the_board)
                print("The computer has beaten you! You Lose.")
                game_is_playing = False
            else:
                if is_board_full(the_board):
                    draw_board(the_board)
                    print("The game is a tie!")
                    break
                else:
                   turn = 'player'
    if not play_again():
        break