import pygame,sys, random
from pygame.math import Vector2

class SNAKE:
    def __init__(self):
        self.body = [Vector2(5,10), Vector2(4,10), Vector2(3,10)]
        self.direction = Vector2(1,0)
        self.new_block= False

    def draw_snake(self):
        for block in self.body:
            block_rect = pygame.Rect(int(block.x * cell_size), int(block.y * cell_size), cell_size, cell_size)
            pygame.draw.rect(screen, (pygame.Color("purple")), block_rect)

    def move_snake(self):
        if self.new_block == True:
            body_copy = self.body[:]
            body_copy.insert(0,body_copy[0] + self.direction)
            self.body = body_copy[:]
            self.new_block = False
        else:
            body_copy = self.body[:-1]
            body_copy.insert(0,body_copy[0] + self.direction)
            self.body = body_copy[:]

    def add_block(self):
        self.new_block = True
        
class FRUIT:
    def __init__(self):
        self.randomize()

    def draw_fruit(self):
        fruit_rect = pygame.Rect(int(self.pos.x * cell_size),int(self.pos.y * cell_size),cell_size,cell_size)
        screen.blit(apple,fruit_rect)
        
        
        #pygame.draw.rect(screen,(pygame.Color("dark red")),fruit_rect)
 


    def randomize(self):
        self.x = random.randint(0,cell_number -1)
        self.y = random.randint(0,cell_number -1)
        self.pos = Vector2(self.x,self.y)

class MAIN:
    def __init__(self):
        self.snake = SNAKE()
        self.fruit = FRUIT()

    def update(self):
        self.snake.move_snake()
        self.check_collision()
        self.check_fail()

    def draw_elements(self):
        self.fruit.draw_fruit()
        self.snake.draw_snake()

    def check_collision(self):
        if self.fruit.pos == self.snake.body[0]:
            self.fruit.randomize()
            self.snake.add_block()
    
    def check_fail(self):
        if not 0 <= self.snake.body[0].x < cell_number or not 0 <= self.snake.body[0].y < cell_number:
            self.game_over()
 
        for block in self.snake.body[1:]:
            if block == self.snake.body[0]:
                self.game_over()

    def game_over(self):
        pygame.quit()
        sys.exit()

pygame.init()
cell_size = 40
cell_number = 20
screen = pygame.display.set_mode((cell_number * cell_size,cell_number * cell_size))
clock = pygame.time.Clock()
apple = pygame.image.load("images/apple_00.png").convert_alpha()
apple = pygame.transform.scale(apple, (40, 40))

main_game = MAIN()

SCREEN_UPDATE = pygame.USEREVENT
pygame.time.set_timer(SCREEN_UPDATE,150)

while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()
        if event.type == SCREEN_UPDATE:
            main_game.update()
        if event.type == pygame.KEYDOWN:
            if event.key == pygame.K_UP:
                if main_game.snake.direction.y != 1:
                    main_game.snake.direction = Vector2(0,-1)
            if event.key == pygame.K_DOWN:
                if main_game.snake.direction.y != -1:
                    main_game.snake.direction = Vector2(0,1)
            if event.key == pygame.K_LEFT:
                if main_game.snake.direction.x != 1:
                    main_game.snake.direction = Vector2(-1,0)
            if event.key == pygame.K_RIGHT:
                if main_game.snake.direction.x != -1:
                    main_game.snake.direction = Vector2(1,0)

    screen.fill(pygame.Color("#028A0F"))
    main_game.draw_elements()
    pygame.display.update()
    clock.tick(60)