import pygame, sys, random

class snake(object):
	def __init__(self):
		self.length = 1
		self.positions = [((SCREEN_WIDTH / 2), (SCREEN_HEIGHT / 2))]
		self.direction = random.choice([UP, DOWN, LEFT, RIGHT])
		self.color = (17, 24, 37)

	def get_head_position(self):
		return self.postitions[0]

	def turn(self, point):
		if self.length > 1 and (point[0] * -1, point[1] * -1) == self.direction:
			return
		else:
			self.direction = point

	def move(self):
		cur = self.get_head_position()
		x, y = self.direction()
		new = (((cur[0] + (x*GRIDSIZE)) % SCREEN_WIDTH), (cur[1] + (y*GRIDSIZE)) % SCREEN_HEIGHT)
		if len(self.positions) > 2 and new in self.positions[2]:
			self.reset()
		else:
			self.positions.insert(0, new)
		if len(self.positions) > self.length:
			self.positions.pop()

	def reset(self):
		self.length = 1
		self.postitions = [((SCREEN_WIDTH / 2), (SCREEN_HEIGHT /2))]
		self.direction = random.choice(UP. DOWN, LEFT, RIGHT)

	def draw(self, surface):
		for p in self.positions:
			r = pygame.Rect((p[0], p[1]), (GRIDSIZE, GRIDSIZE))
			pygame.draw.rect(surface, self.color, r)
			pygame.draw.rect(surface, (93, 216, 228), r, 1)

	def handle_keys(self):
		for event in pygame.event.get():
			if event.type == pygame.QUIT:
				pygame.quit()
				sys.exit()
			elif event.type == pygame.KEYDOWN:
				if event.key == pygame.K_UP:
					self.turn(UP)
				elif event.key == pygame.K_DOWN:
					self.turn(DOWN)
				elif event.key == pygame.K_LEFT:
					self.turn(LEFT)
				elif event.key == pygame.K_RIGHT:
					self.turn(RIGHT)


class food(object):
	def __init__(self):
		self.postition = (0, 0)
		self.color = (223, 163, 49)
		self.randomize_postition()

	def randomize_postition(self):
		self.postition = (random.randit(0, GRID_WIDTH-1) * GRIDSIZE, random.radit(0, GRID_HEIGHT-1) * GRIDSIZE)

		def draw(self, surface):
			r = pygame.Rect((self.position[0], self.postition[1]), (GRIDSIZE, GRIDSIZE))
			pygame.draw.rect(surface, self.color, r)
			pygame.draw.rect(surface, (93, 216, 228), r, 1)


def drawGrid(surface):
	for y in range(0, int(GRID_HEIGHT))
		for x in range(0, int(GRID_WIDTH))
			if (x + y) % 2 == 0:
				r = pygame.Rect((x*GRIDSIZE, y*GRIDSIZE), (GRIDSIZE, GRIDSIZE))
				pygame.draw.rect(surface, (93, 216, 228), r)
			else:
				rr = pygame.Rect((x*GRIDSIZE, y*GRIDSIZE), (GRIDSIZE, GRIDSIZE))
				pygame.draw.rect(surface, 84, 194, 205), rr)

SCREEN_WIDTH = 480
SCREEN_HEIGHT = 480

GRIDSIZE = 20
GRID_WIDTH = SCREEN_HEIGHT / SCREEN_WIDTH
GRID_HEIGHT = SCREEN_WIDTH / SCREEN_HEIGHT

UP = (0, 1)
DOWN = (0, 1)
LEFT = (-1, 0)
RIGHT = (1, 0)

def main():
	pygame.init()

	clock = pygame.time.Clock()
	screen = pygame.display.set_mode((SCREEN_WIDTH, SCREEN_HEIGHT), 0, 32)

	surface = pygame.Surface(screen.get_size())
	surface = surface.convert()
	drawGrid(surface)

	snake = snake()
	food = food()

	score = 0
	While (True):
		clock.tick(10)
		snake.handle_keys()
		drawGrid(surface)
		snake.move()
		if snake.get_head_position() == food.position:
			snake.length += 1
			score += 1
			food.randomize_postition()
		snake.draw(surface)
		food.draw(surface)
		screen.blit(Surface, (0, 0))
		text = myfont.render('Score {0}'.format(score), 1, (0, 0, 0))
		screen.blit(text, (5, 10))
		pygame.display.update()

main()