import pygame
import random
import sys

# 初始化pygame
pygame.init()

# 游戏常量
SCREEN_WIDTH = 800
SCREEN_HEIGHT = 600
FPS = 60
PLAYER_SPEED = 5
OBSTACLE_SPEED = 3
GRAVITY = 0.5

# 颜色定义
WHITE = (255, 255, 255)
BLUE = (135, 206, 235)
BROWN = (139, 69, 19)
GREEN = (34, 139, 34)
RED = (255, 0, 0)
BLACK = (0, 0, 0)

class Player:
    def __init__(self, x, y):
        self.x = x
        self.y = y
        self.width = 30
        self.height = 40
        self.velocity_y = 0
        self.on_ground = False
        
    def update(self):
        # 应用重力
        if not self.on_ground:
            self.velocity_y += GRAVITY
        
        self.y += self.velocity_y
        
        # 限制在屏幕内
        if self.y > SCREEN_HEIGHT - self.height - 50:
            self.y = SCREEN_HEIGHT - self.height - 50
            self.velocity_y = 0
            self.on_ground = True
        elif self.y < 0:
            self.y = 0
            self.velocity_y = 0
            
    def jump(self):
        if self.on_ground:
            self.velocity_y = -12
            self.on_ground = False
            
    def move_left(self):
        self.x -= PLAYER_SPEED
        if self.x < 0:
            self.x = 0
            
    def move_right(self):
        self.x += PLAYER_SPEED
        if self.x > SCREEN_WIDTH - self.width:
            self.x = SCREEN_WIDTH - self.width
            
    def draw(self, screen):
        # 绘制滑雪者（简单矩形表示）
        pygame.draw.rect(screen, RED, (self.x, self.y, self.width, self.height))
        # 绘制滑雪板
        pygame.draw.rect(screen, BLACK, (self.x - 5, self.y + self.height, self.width + 10, 5))

class Obstacle:
    def __init__(self, x, y, width, height, type):
        self.x = x
        self.y = y
        self.width = width
        self.height = height
        self.type = type  # 'tree' or 'rock'
        
    def update(self):
        self.y -= OBSTACLE_SPEED  # 障碍物向上移动（相对运动）
        
    def is_off_screen(self):
        return self.y + self.height < 0
        
    def draw(self, screen):
        if self.type == 'tree':
            # 绘制树
            pygame.draw.rect(screen, GREEN, (self.x, self.y, self.width, self.height))
        elif self.type == 'rock':
            # 绘制石头
            pygame.draw.rect(screen, BROWN, (self.x, self.y, self.width, self.height))

class Game:
    def __init__(self):
        self.screen = pygame.display.set_mode((SCREEN_WIDTH, SCREEN_HEIGHT))
        pygame.display.set_caption("滑雪大冒险")
        self.clock = pygame.time.Clock()
        self.font = pygame.font.Font(None, 36)
        
        self.player = Player(SCREEN_WIDTH // 2, SCREEN_HEIGHT - 90)
        self.obstacles = []
        self.score = 0
        self.game_over = False
        self.obstacle_timer = 0
        self.obstacle_interval = 60  # 每60帧生成一个障碍物
        
    def spawn_obstacle(self):
        # 随机生成障碍物
        obstacle_type = random.choice(['tree', 'rock'])
        width = random.randint(20, 40)
        height = random.randint(30, 60)
        x = random.randint(0, SCREEN_WIDTH - width)
        y = SCREEN_HEIGHT
        
        obstacle = Obstacle(x, y, width, height, obstacle_type)
        self.obstacles.append(obstacle)
        
    def check_collisions(self):
        player_rect = pygame.Rect(self.player.x, self.player.y, 
                                self.player.width, self.player.height)
        
        for obstacle in self.obstacles:
            obstacle_rect = pygame.Rect(obstacle.x, obstacle.y, 
                                      obstacle.width, obstacle.height)
            if player_rect.colliderect(obstacle_rect):
                self.game_over = True
                
    def update(self):
        if not self.game_over:
            # 更新玩家
            self.player.update()
            
            # 生成障碍物
            self.obstacle_timer += 1
            if self.obstacle_timer >= self.obstacle_interval:
                self.spawn_obstacle()
                self.obstacle_timer = 0
                
            # 更新障碍物
            for obstacle in self.obstacles[:]:
                obstacle.update()
                if obstacle.is_off_screen():
                    self.obstacles.remove(obstacle)
                    self.score += 10  # 成功避开障碍物得分
                    
            # 检查碰撞
            self.check_collisions()
            
            # 增加游戏难度
            if self.score > 0 and self.score % 100 == 0:
                global OBSTACLE_SPEED
                OBSTACLE_SPEED += 0.5
                
    def draw(self):
        # 绘制天空背景
        self.screen.fill(BLUE)
        
        # 绘制雪地
        pygame.draw.rect(self.screen, WHITE, (0, SCREEN_HEIGHT - 50, SCREEN_WIDTH, 50))
        
        # 绘制玩家
        self.player.draw(self.screen)
        
        # 绘制障碍物
        for obstacle in self.obstacles:
            obstacle.draw(self.screen)
            
        # 绘制分数
        score_text = self.font.render(f"分数: {self.score}", True, BLACK)
        self.screen.blit(score_text, (10, 10))
        
        # 绘制游戏结束信息
        if self.game_over:
            game_over_text = self.font.render("游戏结束! 按R重新开始", True, RED)
            text_rect = game_over_text.get_rect(center=(SCREEN_WIDTH // 2, SCREEN_HEIGHT // 2))
            self.screen.blit(game_over_text, text_rect)
            
    def handle_events(self):
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                return False
            elif event.type == pygame.KEYDOWN:
                if event.key == pygame.K_r and self.game_over:
                    # 重新开始游戏
                    self.__init__()
                    
        # 处理按键
        keys = pygame.key.get_pressed()
        if keys[pygame.K_LEFT]:
            self.player.move_left()
        if keys[pygame.K_RIGHT]:
            self.player.move_right()
        if keys[pygame.K_SPACE]:
            self.player.jump()
            
        return True
        
    def run(self):
        running = True
        while running:
            running = self.handle_events()
            self.update()
            self.draw()
            pygame.display.flip()
            self.clock.tick(FPS)
            
        pygame.quit()
        sys.exit()

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