def clear_output():
    print("\n"*100)

def print_banner():
    print("TicTacToe - v1.0\n")

def play_again():
    global board, marker, current_player

    while True:
        play_again = input("Do you want to play again? [Y/N]: ").upper()

        if play_again == 'Y':
            board = {1: '1', 2: '2', 3: '3', 4: '4', 5: '5', 6: '6', 7: '7', 8: '8', 9: '9'}
            marker = {'player1': 'A', 'player2': 'B'}
            current_player = '1'

            return True
        elif play_again == 'N':
            return False

def game_over():
    winner = 'N'

    # Check for X/O winner
    for player, mark in marker.items():
        # Horizontal
        if board[7] == mark and board[8] == mark and board[9] == mark:
            winner = (player, mark)
        elif board[4] == mark and board[5] == mark and board[6] == mark:
            winner = (player, mark)
        elif board[1] == mark and board[2] == mark and board[3] == mark:
            winner = (player, mark)
        # Vertical
        elif board[7] == mark and board[4] == mark and board[1] == mark:
            winner = (player, mark)
        elif board[8] == mark and board[5] == mark and board[2] == mark:
            winner = (player, mark)
        elif board[9] == mark and board[6] == mark and board[3] == mark:
            winner = (player, mark)

        # Diagonal
        elif board[7] == mark and board[5] == mark and board[3] == mark:
            winner = (player, mark)
        elif board[9] == mark and board[5] == mark and board[1] == mark:
            winner = (player, mark)

    # Check if winner has been found
    if winner != 'N':
        clear_output()
        print(f"*** THE WINNER IS {winner[0]}/{winner[1]} ***")
        return not play_again()

    # Check if it is a draw
    elif not board[1].isdigit() and not board[2].isdigit() and not board[3].isdigit()\
            and not board[4].isdigit() and not board[5].isdigit() and not board[6].isdigit()\
            and not board[7].isdigit() and not board[8].isdigit() and not board[9].isdigit():
        clear_output()
        print(f"** THE GAME ENDS IN DRAW **")
        return not play_again()
    else:
        return False

def print_board(board):
    print(f" {board[7]} | {board[8]} | {board[9]} ")
    print(f" {board[4]} | {board[5]} | {board[6]} ")
    print(f" {board[1]} | {board[2]} | {board[3]} ")
    print(f"\n P1 - {marker['player1']}")
    print(f" P2 - {marker['player2']}")


def start_game():
    while True:
        player1 = input("(Player 1) What marker would you like to be? [X/O]: ").upper()

        if player1 == 'X':
            player2 = 'O'
            break
        elif player1 == 'O':
            player2 = 'X'
            break
        else:
            clear_output()
            print("Invalid Marker! Please enter x or o")

    return (player1, player2)

def select_position(playerid):
    player = "player" + playerid
    position = input(f"(Player {playerid}, [{marker[player]}]) Select Position (1-9): ")

    if position == "q":
        print("Exiting...")
        exit()

    if position.isdigit():
        position = int(position)

        # Verify position  is in range
        if position >= 1 and position <= 9:

            # Position is available
            if board[position].isdigit():
                board[position] = marker[player]

                if playerid == '1':
                    return '2'
                else:
                    return '1'
            # Position is taken
            else:
                print("Uh oh... already selected!")

    return playerid

# Store board in key:value pairs, isnum = not taken
board = {1: '1', 2: '2', 3: '3', 4: '4', 5: '5', 6: '6', 7: '7', 8: '8', 9: '9'}

# Current Player is either 1 or 2
current_player = '1'

# Store the Player Makers (X/O)
marker = {'player1': 'A', 'player2': 'B'}

# Start Game Loop
while not game_over():
    if marker['player1'] == 'A' or marker['player2'] == 'B':
        marker['player1'], marker['player2'] = start_game()

    clear_output()

    print_banner()
    print_board(board)
    current_player = select_position(current_player)