from microbit import *

left = (-1, 0)
right = (+1, 0)
up = (0, -1)
down = (0, +1)

turnLeft = {
    up: left,
    down: right,
    left: down,
    right: up
}

turnRight = {
    up: right,
    down: left,
    left: up,
    right: down
}

snake_direction = down
snake = [(1,0), (1,1), (1,2)]
print(snake)

frames = 0
last_a = False
last_b = False

def move(direction):
    global snake
    snake = snake[1:]
    head = snake[-1]
    new_head = ((head[0]+direction[0])%5, (head[1]+direction[1])%5)
    snake.append(new_head)
    print(snake)

while True:
    frames += 1

    now_a = button_a.is_pressed()
    now_b = button_b.is_pressed()

    if now_a and not last_a:
        snake_direction = turnLeft[snake_direction]
    if now_b and not last_b:
        snake_direction = turnRight[snake_direction]

    last_a = now_a
    last_b = now_b

    if frames % 10 == 0:
        move(snake_direction)

    display.clear()
    for chunk in snake:
        display.set_pixel(chunk[0], chunk[1], 5)

    sleep(50)