from fast_P_nim import P

def safe_int_parse(s):
    try:
        return int(s)
    except ValueError:
        return -1

n = int(input("Path size to play on> "))

nimb = P(n)

human_turn = -1 # placeholder
if nimb > 0:
    human_turn = False
    print("I'll play first!")
else:
    human_turn = True
    print("You can play first!")

game_state = [True for _ in range(n)]

def display_game():
    for i in range(n):
        if game_state[i]:
            print(f'{i+1:02d}', end="")
        else:
            print(f'  ', end="")
        if i + 1 != n:
            print('-', end="")
    print()

def valid_move(i):
    if i >= n or i < 0:
        return False
    if game_state[i]:
        if i > 0:
            if i < n-1:
                return game_state[i-1] or game_state[i+1]
            else:
                return game_state[i-1]
        else:
            if i < n-1:
                return game_state[i+1]
            else:
                return True

def make_move(i):
    gs = game_state.copy()
    gs[i] = False
    if i > 0:
        gs[i-1] = not gs[i-1]
    if i < n-1:
        gs[i+1] = not gs[i+1]
    return gs

def get_nimber(gs):
    nimber_so_far = 0
    path_size = 0
    for i in range(n):
        if gs[i]:
            path_size += 1
        else:
            if path_size == 1 and n != 1:
                path_size = 0
            nimber_so_far = nimber_so_far ^ P(path_size)
            path_size = 0
    if path_size == 1 and n != 1:
        path_size = 0
    nimber_so_far = nimber_so_far ^ P(path_size)
    return nimber_so_far

def i_have_won():
    for i in range(n):
        if valid_move(i):
            return False
    return True

def find_move():
    game_state_orig = game_state.copy()
    for i in range(n):
        if valid_move(i):
            gs = make_move(i)
            if get_nimber(gs) == 0:
                return i
    raise Exception("I have been beat!")

# game_state = make_move(2-1)
# game_state = make_move(6-1)
# game_state = make_move(6-1)
# display_game()
# print(get_nimber(game_state))
# raise Exception()

while True:
    display_game()
    if human_turn:
        if i_have_won():
            print("You're out of moves. I win!")
            break
        human_turn = False
        i = -1 # placeholder
        while True:
            i = safe_int_parse(input("Make your move> ")) - 1
            if valid_move(i):
                break
            print("Hey! That's not allowed!")
            display_game()
        game_state = make_move(i)
    else:
        human_turn = True
        i = find_move()
        print(f"Hmm... I'll toggle {i + 1}")
        game_state = make_move(i)