import pygame
import random
from time import sleep
from pygame.locals import *
BLACK = (0,0,0)
WHITE = (255,255,255)

window_height = 600
window_width = 800
screen = pygame.display.set_mode((window_width, window_height))
pygame.display.set_caption("Snake")
fps = 10
fps_clock = pygame.time.Clock()
pygame.font.init()
font = pygame.font.SysFont('Comic San MS', 25)


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

    def generate(self):
        apple = pygame.image.load('apple.png')
        apple = pygame.transform.scale(apple, (25,25))
        screen.blit(apple,(self.x, self.y))
        # pygame.draw.rect(screen, WHITE, pygame.Rect(self.x, self.y, 10, 10))

class Snake:
    def __init__(self, x, y, food_pos):
        self.cells =[(x-40,y),(x-20,y),(x,y)]
        self.dir_x = 1
        self.dir_y = 0
        self.food_pos = food_pos

    def move(self):
        del self.cells[0]
        last_cell = self.cells[-1]
        self.cells.append((last_cell[0]+self.dir_x*20, last_cell[1]+self.dir_y*20))

    def draw(self):
        head = pygame.image.load('snake.png')
        body = pygame.image.load('snake.png')

        if self.dir_x == 1 and self.dir_y == 0:
            pass
        elif self.dir_x == -1 and self.dir_y == 0:
            head = pygame.transform.rotate(head, 180)
            body = pygame.transform.flip(body, True, False)
        elif self.dir_x == 0 and self.dir_y == 1:
            head = pygame.transform.rotate(head, -90)
            body = pygame.transform.rotate(body, -90)
        else:
            head = pygame.transform.rotate(head, 90)
            body = pygame.transform.rotate(body, 90)


        head = pygame.transform.scale(head, (18, 18))
        body = pygame.transform.scale(body, (18, 18))



        for i in self.cells:
            if i != self.cells[-1]:
                screen.blit(body, (i[0], i[1]))
            else:
                screen.blit(head, (i[0], i[1]))
                # pygame.draw.rect(screen, WHITE, pygame.Rect(i[0],i[1],18,18))

    def grow(self):
        self.cells.insert(0, self.cells[0])

    def hit_ceiling(self):
        if self.cells[-1][1] <=0:
            return True
        else:
            return False

    def hit_floor(self):
        if self.cells[-1][1] + 20 >= window_height:
            return True
        else:
            return False

    def hit_wall(self):
        if self.cells[-1][0] <= 0 or self.cells[-1][0]+20 >= window_width:
            return True
        else:
            return False

class Score:
    def __init__(self):
        self.score = 0

    def draw(self):
        textsurface = font.render('Your Score: {0}'.format(self.score), False, WHITE)
        screen.blit(textsurface, (window_width-150, 40))


class Game:
    def __init__(self):
        self.q = 0
        snake_x = window_width/2
        snake_y = window_height/2
        x = 20 * random.randint(1, 19)
        y = 20 * random.randint(1, 14)
        self.food = Food(x, y)
        self.food.generate()
        self.snake = Snake(snake_x, snake_y, (self.food.x, self.food.y))
        self.score = Score()

    def collision(self, x1, y1, x2, y2):
        if x2 < x1 < x2 + 20:
            if y2 < y1 < y2 + 20:
                return True
        else:
            return False

    def draw(self):
        screen.fill(BLACK)
        img = pygame.image.load('background.jpg')
        img = pygame.transform.scale(img, (window_width-40, window_height-40))

        screen.blit(img, (20,20))
        # pygame.draw.rect(screen, BLACK, (10, 10, window_width-20, window_height-20))

    def update(self):
        self.draw()
        self.food.generate()
        self.snake.food_pos = (self.food.x, self.food.y)
        self.snake.move()
        self.snake.draw()
        if self.snake.hit_ceiling() or self.snake.hit_floor() or self.snake.hit_wall():
            self.q = 1


        for i in range(len(self.snake.cells)-1):
            if self.snake.cells[i] == self.snake.cells[-1]:
                self.q = 1

        if self.collision(self.snake.cells[-1][0]+10, self.snake.cells[-1][1]+10, self.food.x, self.food.y):
            x = 20 * random.randint(1, 38)
            y = 20 * random.randint(1, 28)
            self.food = Food(x, y)
            self.snake.grow()
            self.food.generate()
            self.score.score += 1
        self.score.draw()


def main():
    pygame.init()
    game = Game()
    flag = True
    while flag:
        for event in pygame.event.get():
            if event.type == KEYDOWN:
                if event.key == 273 and not game.snake.dir_y == 1:
                        game.snake.dir_y = -1
                        game.snake.dir_x = 0
                elif event.key == 274 and not game.snake.dir_y == -1:
                        game.snake.dir_y = 1
                        game.snake.dir_x = 0
                elif event.key == 276 and not game.snake.dir_x == 1:
                        game.snake.dir_y = 0
                        game.snake.dir_x = -1
                elif event.key == 275 and not game.snake.dir_x == -1:
                        game.snake.dir_y = 0
                        game.snake.dir_x = 1
            if event.type == QUIT:
                flag = False
                break
        game.update()
        if game.q == 1:
            screen.fill(BLACK)
            font = pygame.font.SysFont('Comic San MS', 35)
            gameover = font.render("Game Over", 1, WHITE)
            w = gameover.get_width()
            h = gameover.get_height()
            screen.blit(gameover, (window_width//2 - w//2, window_height//2 - h//2))

        pygame.display.update()
        fps_clock.tick(fps)

if __name__ == '__main__':
    main()