main.py

import pygame
from pygame.locals import *
import time
import random

SIZE = 40
BACKGROUND_COLOR = (91, 180, 181)


class Apple:
    def __init__(self, parent_screen):
        self.image = pygame.image.load("resources/apple.jpg").convert()
        self.parent_screen = parent_screen
        self.x = SIZE*3
        self.y = SIZE*3

    # drawing apple on screen
    def draw(self):
        self.parent_screen.blit(self.image, (self.x, self.y))
        pygame.display.flip()

    # regenerating apple else where once snake eats an apple
    def move(self):
        self.x = random.randint(0, 24) * SIZE
        self.y = random.randint(0, 19) * SIZE


class Snake:
    def __init__(self, parent_screen, length):
        self.parent_screen = parent_screen
        self.length = length
        self.x = [SIZE]*length
        self.y = [SIZE]*length
        self.direction = 'down'
        self.block = pygame.image.load("resources/block.jpg").convert()

    # drawing snake with blocks
    def draw(self):

        for i in range(self.length):
            self.parent_screen.blit(self.block, (self.x[i], self.y[i]))
        pygame.display.flip()

    # increases the length as snake eats an apple
    def increase_length(self):
        self.length += 1
        self.x.append(-1)
        self.y.append(-1)

    # snake movement towards left
    def move_left(self):
        self.direction = 'left'

    # snake movement towards right
    def move_right(self):
        self.direction = 'right'

    # snake movement towards up
    def move_up(self):
        self.direction = 'up'

    # snake movement towards down
    def move_down(self):
        self.direction = 'down'

    # snake to continue walking unless movement direction is changed by arrows
    def walk(self):

        # update body
        for i in range(self.length-1, 0, -1):
            self.x[i] = self.x[i-1]
            self.y[i] = self.y[i-1]

        # update head
        if self.direction == 'left':
            self.x[0] -= SIZE
        if self.direction == 'right':
            self.x[0] += SIZE
        if self.direction == 'up':
            self.y[0] -= SIZE
        if self.direction == 'down':
            self.y[0] += SIZE

        self.draw()


class Game:
    def __init__(self):
        pygame.init()
        # pygame.display.set_caption("sh7codes - Snake asnd Apple Game")

        pygame.mixer.init()
        self.play_bg_music()
        self.surface = pygame.display.set_mode((1000, 800))
        self.surface.fill((91, 180, 181))
        self.snake = Snake(self.surface, 1)
        self.snake.draw()
        self.apple = Apple(self.surface)
        self.apple.draw()

    # basic collision fun between two objects
    def is_collision(self, x1, y1, x2, y2):
        if x1 >= x2 and x1 < x2 + SIZE:
            if y1 >= y2 and y1 < y2 + SIZE:
                return True

        return False

    # provide backgroud music for game
    def play_bg_music(self):
        pygame.mixer.music.load("resources/bg_music_1.wav")
        pygame.mixer.music.play()

    # output sound on event occurance
    def play_sound(self, sound):
        sound = pygame.mixer.Sound(f"resources/{sound}.wav")
        pygame.mixer.Sound.play(sound)

    # background picture/ surface for the game
    def render_bg(self):
        bg = pygame.image.load("resources/background.jpg")
        self.surface.blit(bg, (0, 0))

    # @main game Handler/ Controller
    def play(self):
        self.render_bg()
        self.snake.walk()
        self.apple.draw()
        self.display_score()
        pygame.display.flip()

        # Snake eating Apple scenario
        if self.is_collision(self.snake.x[0], self.snake.y[0], self.apple.x, self.apple.y):
            self.play_sound("ding")
            self.snake.increase_length()
            self.apple.move()

        # Snake colliding its own body
        for i in range(3, self.snake.length):
            if self.is_collision(self.snake.x[0], self.snake.y[0], self.snake.x[i], self.snake.y[i]):
                self.play_sound("crash")
                raise "Collision Occured"

        # snake colliding with the boundries of the window
        if not (0 <= self.snake.x[0] <= 1000 and 0 <= self.snake.y[0] <= 800):
            self.play_sound('crash')
            raise "Hit the boundry error"

    # display score on screen
    def display_score(self):
        font = pygame.font.SysFont('arial', 30)
        score = font.render(
            f"Score: {self.snake.length}", True, (255, 255, 255))
        self.surface.blit(score, (800, 10))

    # show a scorecard and replay option once game is over
    def show_game_over(self):
        self.render_bg()
        font = pygame.font.SysFont('arial', 30)
        line1 = font.render(
            f"Game is over! Your Score is: {self.snake.length}", True, (255, 255, 255))
        self.surface.blit(line1, (200, 300))
        line2 = font.render(
            "To play again press Enter. To exit press Escape!", True, (255, 255, 255))
        self.surface.blit(line2, (200, 350))
        pygame.display.flip()

        pygame.mixer.music.pause()

    # reset the game state to initial state as user opt to replay the game
    def reset(self):
        self.snake = Snake(self.surface, 1)
        self.apple = Apple(self.surface)

    # @main Game Logic
    def run(self):
        running = True
        pause = False

        while running:
            for event in pygame.event.get():
                if event.type == KEYDOWN:

                    if event.key == K_ESCAPE:
                        running = False

                    if event.key == K_RETURN:
                        pygame.mixer.music.unpause()
                        pause = False

                    if not pause:
                        if event.key == K_UP:
                            self.snake.move_up()

                        if event.key == K_DOWN:
                            self.snake.move_down()

                        if event.key == K_LEFT:
                            self.snake.move_left()

                        if event.key == K_RIGHT:
                            self.snake.move_right()

                elif event.type == QUIT:
                    running = False

            try:
                if not pause:
                    self.play()

            except Exception as e:
                self.show_game_over()
                pause = True
                self.reset()

            time.sleep(0.3)


# main functioin
if __name__ == "__main__":
    game = Game()
    game.run()