# Tic Tac Toe for RC
print("Welcome to a game of Tic Tac Toe!")
print("-Coded in Python 3 by Ian Ross for The Recurse Center-\n")

# Displays board in its current state
def display_board(board):
    print(board[0], "|", board[1], "|", board[2])
    print("---------")
    print(board[3], "|", board[4], "|", board[5])
    print("---------")
    print(board[6], "|", board[7], "|", board[8])

# Checks to see if there is a winning combo of squares
def is_winner(letter):
    # Horizontal combos
    if board[0] == letter and board[1] == letter and board[2] == letter:
        return True
    if board[3] == letter and board[4] == letter and board[5] == letter:
        return True
    if board[6] == letter and board[7] == letter and board[8] == letter:
        return True

    # Vertical combos
    if board[0] == letter and board[3] == letter and board[6] == letter:
        return True
    if board[1] == letter and board[4] == letter and board[7] == letter:
        return True
    if board[2] == letter and board[5] == letter and board[8] == letter:
        return True

    # Diagonal combos
    if board[0] == letter and board[4] == letter and board[8] == letter:
        return True
    if board[6] == letter and board[4] == letter and board[2] == letter:
        return True

# Checks to make sure any given square is taken
def is_space_free(square):
    return board[square] == " "

# Returns true if there is no longer a square without an X or O
def is_board_full():
    for square in board:
        if square == " ":
            return False
    return True

def get_move(letter):
    print("\nType which square you'd like to fill on the board")
    print("1 is the top left, 5 is the middle, and 9 is the bottom right \n")

    # Represented as 1 - 9 as it is easier for the user than 0 - 8
    square = int(input("\nWhich square do you choose for " + letter +"? (1 - 9) : "))
    return (square - 1)

def failed_move():
    print("Sorry, that square is taken! You have lost your turn!\n")

def make_move(square, letter):
    if is_space_free(square):
        board[square] = letter
    else:
        failed_move()

# Main loop (besides the game loop) to potentially allow for resetting with an AI
while True:
    begin = input("Would you like to play a game? (Yes/No) : ")
    if begin.lower() == "yes":
        playing_game = True
    elif begin.lower() == "no":
        print("That's too bad! Not sure why you ran this program, to be honest...")
        playing_game = False

    # Setting the board
                            # Representation
    board = [" ", " ", " ", # [0, 1, 2,
         " ", " ", " ",     # 3, 4, 5,
         " ", " ", " "]     # 6, 7, 8]
    letter = "X"

    # Game loop
    while playing_game:
        # First Turn
        if letter == "X":
            # Display the board
            display_board(board)
            move = get_move(letter)
            make_move(move, letter)

            # Before the letter switches it goe sthrough a win/draw check
            if is_winner(letter):
                display_board(board)
                print("\nCongratulations! " + letter + " won the game!")
                break
            else:
                if is_board_full():
                    display_board(board)
                    print("\nThe game is a draw!")
                    break
                else:
                    letter = "O"

        elif letter == "O":
            # Display the board
            display_board(board)
            move = get_move(letter)
            make_move(move, letter)

            if is_winner(letter):
                display_board(board)
                print("\nCongratulations! " + letter + " won the game!")
                break
            else:
                letter = "X"
    break

print("\nThanks for checking out my little project!\n")