import pygame
from pygame.sprite import Sprite


class Alien(Sprite):
    """表示单个外星人的类"""

    def __init__(self, ai__settings, screen):
        """初始化外星人并设置其起始位置"""
        super(Alien, self).__init__()
        self.screen = screen
        self.ai_settings = ai__settings

        # 加载外星人图像，并设置其rect属性
        self.image = pygame.image.load('images/alien.png')
        self.rect = self.image.get_rect()
        # 每个外星人最初都在屏幕左上角附件
        self.rect.x = self.rect.width
        self.rect.y = self.rect.height
        # 储存外星人的准确位置
        self.x = float(self.rect.x)

    def blitme(self):
        """在指定位置绘制外星人"""
        self.screen.blit(self.image, self.rect)

    def check_edges(self):
        """如果外星人位于屏幕边缘，就返回True"""
        screen_rect = self.screen.get_rect()
        if self.rect.right >= screen_rect.right:
            return True
        elif self.rect.left <= 0:
            return True

    def update(self):
        """向左或向右移动外星人"""
        self.x += (self.ai_settings.alien_speed_factor * self.ai_settings.fleet_direction)
        self.rect.x = self.x


class BossAlien(Sprite):
    """BOSS外星人"""

    def __init__(self, ai_settings, screen, health=500):
        """初始化外星人并设置其初始位置"""
        self.screen = screen
        self.ai_settings = ai_settings
        self.health = health

        # 加载外星人图像，并设置其rect属性
        self.image = pygame.image.load('images/bossalien.png')
        self.rect = self.image.get_rect()
        self.screen_rect = screen.get_rect()

        self.rect.x = 550
        self.rect.y = 100

        # 储存外星人的精准位置
        self.x = float(self.rect.x)

    # 设置生命值
    # health=100

    def blitme(self):
        """在指定位置绘制外星人"""
        self.screen.blit(self.image, (self.rect.x, self.rect.y))

    def draw_health_bar(self, screen):
        """显示血条"""
        # 参数依次表示：在screen上面绘制，颜色，（改图案左上角的坐标，长度和高度）

        # 灰色的空白血条
        pygame.draw.rect(screen, (0, 230, 0), ((380, 100), (500, 10)))
        # 红色的现有血条
        pygame.draw.rect(screen, (255, 0, 0), ((380, 100), (self.health, 10)))

    def check_edges(self):
        """如果外星人位于屏幕边缘就返回True"""
        screen_rect = self.screen.get_rect()
        if self.rect.right >= screen_rect.right:
            return True
        elif self.rect.left <= 0:
            return True

    def update(self):
        """向左向右移动外星人"""
        self.x += (self.ai_settings.alien_speed_factor * self.ai_settings.bossalien_direction)
        self.rect.x = self.x