import pygame
import random

# Initialize Pygame
pygame.init()

# Set up some constants
WIDTH, HEIGHT = 800, 600
FPS = 60
WHITE = (255, 255, 255)
BLACK = (0, 0, 0)
RED = (255, 0, 0)

# Set up the display
screen = pygame.display.set_mode((WIDTH, HEIGHT))
pygame.display.set_caption("Space Shooter")
clock = pygame.time.Clock()

# Player class
class Player(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()
        self.image = pygame.Surface((50, 50))
        self.image.fill(WHITE)
        self.rect = self.image.get_rect()
        self.rect.centerx = WIDTH // 2
        self.rect.bottom = HEIGHT - 10
        self.speed_x = 0

    def update(self):
        self.speed_x = 0
        keys = pygame.key.get_pressed()
        if keys[pygame.K_LEFT]:
            self.speed_x = -5
        if keys[pygame.K_RIGHT]:
            self.speed_x = 5
        self.rect.x += self.speed_x
        if self.rect.left < 0:
            self.rect.left = 0
        if self.rect.right > WIDTH:
            self.rect.right = WIDTH

    def shoot(self):
        bullet = Bullet(self.rect.centerx, self.rect.top)
        all_sprites.add(bullet)
        bullets.add(bullet)

# Enemy class
class Enemy(pygame.sprite.Sprite):
    def __init__(self):
        super().__init__()
        self.image = pygame.Surface((30, 30))
        self.image.fill(RED)
        self.rect = self.image.get_rect()
        self.rect.x = random.randrange(WIDTH - self.rect.width)
        self.rect.y = random.randrange(-100, -40)
        self.speed_y = random.randrange(1, 8)

    def update(self):
        self.rect.y += self.speed_y
        if self.rect.top > HEIGHT + 10:
            self.kill()

# Bullet class
class Bullet(pygame.sprite.Sprite):
    def __init__(self, x, y):
        super().__init__()
        self.image = pygame.Surface((10, 20))
        self.image.fill(WHITE)
        self.rect = self.image.get_rect()
        self.rect.bottom = y
        self.rect.centerx = x
        self.speed_y = -10

    def update(self):
        self.rect.y += self.speed_y
        if self.rect.bottom < 0:
            self.kill()

# Set up sprite groups
all_sprites = pygame.sprite.Group()
enemies = pygame.sprite.Group()
bullets = pygame.sprite.Group()

# Create the player
player = Player()
all_sprites.add(player)

# Game loop
running = True
while running:
    # Keep the loop running at the right speed
    clock.tick(FPS)

    # Process input (events)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False
        elif event.type == pygame.KEYDOWN:
            if event.key == pygame.K_SPACE:
                player.shoot()

    # Update
    all_sprites.update()

    # Spawn enemies
    if random.random() < 0.01:
        enemy = Enemy()
        all_sprites.add(enemy)
        enemies.add(enemy)

    # Check for collisions between bullets and enemies
    hits = pygame.sprite.groupcollide(enemies, bullets, True, True)

    # Draw / render
    screen.fill(BLACK)
    all_sprites.draw(screen)
    pygame.display.flip()

pygame.quit()