#game board to hold data

game_board = ["-", "-", "-",
              "-", "-", "-",
              "-", "-", "-"]

# know if game over
game_still_on = True

winner = None

# current player
current_player = "X"

# Play game
def play_game():

  # display game board
  display_game_board()

  while game_still_on:

    # Handle a turn
    handle_turn(current_player)

    # Check if game over
    check_if_game_over()

    # Flip to the other player
    flip_player()

  # print the winner or tie
  if winner == "X" or winner == "O":
    print(" Congratulations" + winner + "you won!" )
  elif winner == None:
    print("Game draw.")

def display_game_board():
  print("\n")
  print(game_board[0] + " | " + game_board[1] + " | " + game_board[2] + "     1 | 2 | 3")
  print("---------")
  print(game_board[3] + " | " + game_board[4] + " | " + game_board[5] + "     4 | 5 | 6")
  print("---------")
  print(game_board[6] + " | " + game_board[7] + " | " + game_board[8] + "     7 | 8 | 9")
  print("\n")


def handle_turn(player):

  # input spot from player
  print(player + "'s turn.")
  spot = input("Choose a spot from 1-9: ")

  valid = False
  while not valid:

    while spot not in ["1", "2", "3", "4",      "5", "6", "7", "8", "9"]:
        spot = input("Hey! Choose a spot from 1-9: ")

    spot = int(spot) - 1

    if game_board[spot] =="-":
      valid = True
    else:
     print("Opps! You have entered an incorrect spot. Try again.")

  game_board[spot] = player

  # display game board
  display_game_board()

# Check if game over
def check_if_game_over():
  check_for_winner()
  check_for_tie()


# Check winner
def check_for_winner():

  global winner

  row_winner = check_rows()
  column_winner = check_columns()
  diagonal_winner = check_diagonals()
  # Determine the winner
  if row_winner:
    winner = row_winner
  elif column_winner:
    winner = column_winner
  elif diagonal_winner:
    winner = diagonal_winner
  else:
    winner = None

def check_rows():

  global game_still_on

  row_1 = game_board[0] == game_board[1] == game_board[2] != "-"
  row_2 = game_board[3] == game_board[4] == game_board[5] != "-"
  row_3 = game_board[6] == game_board[7] == game_board[8] != "-"

  if row_1 or row_2 or row_3:
    game_still_on = False
  # Return  winner
  if row_1:
    return game_board[0]
  elif row_2:
    return game_board[3]
  elif row_3:
    return game_board[6]
  else:
    return None

def check_columns():

  global game_still_on

  column_1 = game_board[0] == game_board[3] == game_board[6] != "-"
  column_2 = game_board[1] == game_board[4] == game_board[7] != "-"
  column_3 = game_board[2] == game_board[5] == game_board[8] != "-"

  if column_1 or column_2 or column_3:
    game_still_on = False
  # Return the winner
  if column_1:
    return game_board[0]
  elif column_2:
    return game_board[1]
  elif column_3:
    return game_board[2]
  else:
    return None

def check_diagonals():

  global game_still_on

  diagonal_1 = game_board[0] == game_board[4] == game_board[8] != "-"
  diagonal_2 = game_board[2] == game_board[4] == game_board[6] != "-"

  if diagonal_1 or diagonal_2:
    game_still_on = False
  # Return the winner
  if diagonal_1:
    return game_board[0]
  elif diagonal_2:
    return game_board[2]
  else:
    return None
#check tie
def check_for_tie():

  global game_still_on

  if "-" not in game_board:
    game_still_on = False
    return True
  else:
    return False

# Flip the current player
def flip_player():

  global current_player

  if current_player == "X":
    current_player = "O"
  elif current_player == "O":
    current_player = "X"
#play game
play_game()