import os

# Definition of variables and dictionary
board = {
    1: " ", 2: " ", 3: " ", 4: " ", 5: " ", 6: " ", 7: " ", 8: " ", 9: " "
    }
game_on = True
turn = "p1"


# Function to clear the print the board
def print_board():
    os.system('clear')
    print("")
    print(f"  {board[7]} |  {board[8]}  | {board[9]}")
    print("---------------")
    print(f"  {board[4]} |  {board[5]}  | {board[6]}")
    print("---------------")
    print(f"  {board[1]} |  {board[2]}  | {board[3]}")
    print("")
    print("")


# Function that will set "X" or "O" to players
def set_player():
    p1 = ""
    while p1 != "X" and p1 != "O":
        p1 = input("Player 1: Choose 'X' or 'O' and type it down on the "
                   "keyboard: ")
        if p1 == "X":
            p2 = "O"
        elif p1 == "O":
            p2 = "X"
    os.system('clear')
    print("Ready! \n \nPlayer 1 =", p1, ", Player 2 =", p2)
    return p1, p2


# Function to place an "X" or an "O" on the board
def players_turn(p1, p2, turn):
    valid_position = False
    while valid_position is False:
        if turn == "p1":
            pos = int(input("Player 1: It's your turn. "
                            "Choose the position to play (1-9): "))
            valid_position = validate_open_position_on_board(board, pos)
            # Validates an open and valid position to place user's choice
            if valid_position:
                board[pos] = p1
                turn = "p2"
        else:
            pos = int(input("Player 2: It's your turn. "
                            "Choose the position to play (1-9): "))
            valid_position = validate_open_position_on_board(board, pos)
            # Validates an open and valid position to place user's choice
            if valid_position:
                board[pos] = p2
                turn = "p1"
    return board, turn


# Function that validates if someone has already won
def validate_win(board):
    # Horizontal validation
    if (((board[7] == board[8] and board[8] == board[9]) and
        (board[7] == "X" or board[7] == "O")) or
        ((board[4] == board[5] and board[5] == board[6]) and
        (board[4] == "X" or board[4] == "O")) or
        ((board[1] == board[2] and board[2] == board[3]) and
       (board[2] == "X" or board[2] == "O"))):
        horizontal_validation = True
    else:
        horizontal_validation = False

    # Vertical validation
    if (((board[7] == board[4] and board[4] == board[1]) and
        (board[7] == "X" or board[7] == "O")) or
        ((board[8] == board[5] and board[5] == board[2]) and
        (board[8] == "X" or board[8] == "O")) or
        ((board[9] == board[6] and board[6] == board[3]) and
       (board[9] == "X" or board[9] == "O"))):
        vertical_validation = True
    else:
        vertical_validation = False

    # Diagonal validation
    if (((board[7] == board[5] and board[5] == board[3]) and
        (board[7] == "X" or board[7] == "O")) or
        ((board[1] == board[5] and board[5] == board[9]) and
       (board[1] == "X" or board[1] == "O"))):
        diagonal_validation = True
    else:
        diagonal_validation = False

    return horizontal_validation or vertical_validation or diagonal_validation


# Function that validates tie
def validate_tie(board):
    board_piece_count = 0
    if " " in board.values():
        return False
    else:
        return True

# Function that validates if position as already being taken
def validate_open_position_on_board(board, pos):
    return True if board[pos] == " " else False


# Main code that will loop through and ask if players want to continue
while game_on is True:
    os.system('clear')
    print("Welcome to Tic Tac Toe!")
    p1, p2 = set_player()
    while validate_win(board) is False and validate_tie(board) is False:
        print_board()
        board, turn = players_turn(p1, p2, turn)
    print_board()
    # Validate if the board is full and there has being a tie
    if validate_tie(board) is True:
        print("It's a tie!")
    # Otherwise, check who's turn is it, to determine the winner
    else:
        if turn == "p1":
            print("Congratulations, Player 2! You are the winner! \n")
        else:
            print("Congratulations, Player 1! You are the winner! \n")
    # End of game. Clears the board
    board = {
        1: " ", 2: " ", 3: " ", 4: " ", 5: " ", 6: " ", 7: " ", 8: " ", 9: " "
        }
    # Validates if users want to play again
    end_response = input("Do you want to play again? (y/n): ")
    if end_response == "y":
        game_on = True
    else:
        game_on = False
print("\nBye!")