# Add your Python code here. E.g.
from microbit import *
from random import randint as rnd

FREE=0
UP=1
RIGHT=2
DOWN=3
LEFT=4
FOOD=5

class Coord:
    def __init__(self, y, x):
        self.x = x
        self.y = y

    def move(self, dir):
        if dir == UP:
            if self.y > 0:
                self.y -= 1
        if dir == DOWN:
            if self.y < 4:
                self.y += 1
        if dir == LEFT:
            if self.x > 0:
                self.x -= 1
        if dir == RIGHT:
            if self.x < 4:
                self.x += 1

board = [
    [FREE,FREE,FREE,FREE,FREE],
    [FREE,FREE,FREE,FREE,FREE],
    [FREE,FREE,FREE,FREE,FREE],
    [FREE,FREE,FREE,FREE,FREE],
    [FREE,FREE,FREE,FREE,FREE]
];

def bget(coord):
    return board[coord.y][coord.x]

def bset(coord, val):
    board[coord.y][coord.x] = val

def put_food():
    while True:
        x = rnd(0,4)
        y = rnd(0,4)
        if board[y][x] == FREE:
            board[y][x] = FOOD
            break

board[2][0] = RIGHT
board[2][1] = RIGHT

head = Coord(2,1)
tail = Coord(2,0)

put_food()

while True:
    for y in range(0,5):
        for x in range(0,5):
            n = board[y][x]
            brt = 0

            if n == FOOD:
                brt = 3
            elif x==head.x and y == head.y:
                brt = 9
            elif n >= 1 and brt <= 4:
                brt = 6

            display.set_pixel(x,y, brt)

    sleep(500)

    # handle input, move head
    dire = bget(head)

    if button_a.was_pressed():
        dire -= 1
        if dire == 0:
            dire = 4

    if button_b.was_pressed():
        dire += 1
        if dire == 5:
            dire = 1

    bset(head, dire)
    head.move(dire)

    if head.x < 0 or head.x > 4 or head.y < 0 or head.y > 4:
        break

    oldh = bget(head)
    if oldh != FREE and oldh != FOOD:
        break

    bset(head, dire)

    if oldh == FOOD:
        put_food()
    else:
        tt = bget(tail)
        bset(tail, FREE)
        tail.move(tt)

while True:
    if button_a.was_pressed() or button_b.was_pressed():
        reset()