import math
import time
import pygame
from pygame.locals import *
from random import choice,randint
 
class ScrolledBackground(pygame.sprite.Sprite):
 def __init__(self,image,screen):
  pygame.sprite.Sprite.__init__(self)
  self.screen = screen
  self.width = screen.get_width()
  self.height = screen.get_height()
  self.image0 = pygame.image.load(image).convert_alpha()
  self.image1 = pygame.image.load(image).convert_alpha()
 
  self.rect0 = self.image0.get_rect()  
  self.rect1 = self.image1.get_rect()
  self.rect1.left = self.rect0.right
  self.dx = -10
  self.dy = 0
  
 def update(self):
  pass
 
 def draw(self):
  pass
 
 
class Plane(pygame.sprite.Sprite):
 def __init__(self,image,keys,screen):
  pygame.sprite.Sprite.__init__(self)
  self.keys = keys     # 上下左右按键
  self.image = pygame.image.load(image).convert_alpha()
  self.screen = screen
  self.rect = self.image.get_rect()
  self.rect.centery = self.screen.get_height()//2
  self.xspeed = 0
  self.yspeed = 0
  self.dead = False     # 新增加的属性
  
 def keys_check(self,all_keys): 
  pass
 
 def update(self):
  self.rect.move_ip(self.xspeed,self.yspeed)
  
 def draw(self):
  self.screen.blit(self.image,self.rect)
  
class Bullet(pygame.sprite.Sprite):
 def __init__(self,image,plane,group,screen):
  pygame.sprite.Sprite.__init__(self)
  self.plane = plane
  self.image = pygame.image.load(image).convert_alpha()
  self.rect = self.image.get_rect()
  self.rect.center = plane.rect.center
  self.group = group
  self.group.add(self)
  self.screen = screen
  self.screen_width = screen.get_width()
  self.screen_height = screen.get_height()  
  
 def update(self):
  self.rect.move_ip(10,0)
  if self.rect.left > self.screen_width :
   self.group.remove(self)
   
def split_images(image,rows,cols):
 """image是一张图片,把它切分为若干图,返回列表"""
 global explosion_images_list
 image = pygame.image.load(image)
 step_width = image.get_width()//cols
 step_height = image.get_height()//rows
 
 pass   
   
class Explosion(pygame.sprite.Sprite):
 """爆炸效果类，显示一系列帧图"""
 def __init__(self,surimages,position,group):
  pygame.sprite.Sprite.__init__(self)
  self.surimages = surimages      # 爆炸效果用到的surface列表
  self.index = 0
  self.amounts = len(surimages)
  self.image = self.surimages[self.index]   # 初始造型
  self.rect = self.image.get_rect()    # 矩形对象
  self.rect.center = position      # 爆炸位置
  self.group = group
  self.group.add(self)
  self.interval_time = 0.01      # 造型切换时间
  self.begin_time = time.time()     # 爆炸起始时间
  
 def update(self):         # 换造型
  
  if time.time() - self.begin_time >= self.interval_time: # 超时，则换造型
   if self.index < self.amounts:
    self.image = self.surimages[self.index]
    self.index = self.index + 1
    self.begin_time = time.time()
   else:
    self.group.remove(self)     # 造型切换完了则从组中移除自己
    
class Enemy(pygame.sprite.Sprite):
 def __init__(self,images,group,screen):
  """images是surface列表"""
  pygame.sprite.Sprite.__init__(self)
  self.screen = screen
  self.screen_width = self.screen.get_width()  # 获取屏幕宽度
  self.screen_height = self.screen.get_height() # 获取屏幕高度
  self.image = choice(images)      # 随机选择一个surface
  self.rect = self.image.get_rect()
  self.rect.left = self.screen_width + randint(10,self.screen_width)
  self.rect.centery = randint(0,self.screen_height)
  self.group = group
  self.group.add(self)       # 加入到自己的组
 def update(self):
  self.rect.move_ip(-5,0)
  if self.rect.right <= 0 :
   self.group.remove(self)
  
class Eullet(pygame.sprite.Sprite):
 """敌方子弹类"""
 def __init__(self,image,selfgroup,enemy_group,plane,screen):
  """参数列表：image，已转换成surface的对象
      selfgroup，所在的组
      enemy_group，敌人组.
      plane，我方飞机
      screen，屏幕对象
  """ 
  pass
  
 def update(self):
  self.rect.move_ip(-self.dx//30,-self.dy//30)
  if self.beyond_edge() :
   self.group.remove(self)
 
 def beyond_edge(self): 
  pass
 
def collision_check():
 """对游戏中的对象进行碰撞检测,碰撞检测有以下几种：
  1、我方飞机碰到敌方飞机，都爆炸。给我方飞机增加dead属性。
  2、我方飞机碰到敌方子弹，我方飞机爆炸，游戏结束。
  3、敌方飞机碰到我方子弹，敌方飞机爆炸。
  以下引用的是全局变量
 """
 global enemy_counter
 "我方飞机和敌方飞机任何一架的碰撞"
 if not plane1.dead:
  eny = pygame.sprite.spritecollideany(plane1, group_enemy)
  if eny!=None :               # 碰到了，我方飞机死，游戏结束    
   Explosion(explosion_images_list,eny.rect.center,group_explosion) # 在敌方飞机处发生爆炸
   Explosion(explosion_images_list,plane1.rect.center,group_explosion) # 在我方飞机处发生爆炸
   plane1.dead = True
   group_enemy.remove(eny)            # 从敌方组中移除碰撞的敌机
   
 "我方飞机碰到敌方子弹，我方死，游戏结束。"
 if not plane1.dead:
  b = pygame.sprite.spritecollideany(plane1, group_enemy_bullet)
  if b!=None :               # 碰到了，我方飞机死，游戏结束    
   Explosion(explosion_images_list,plane1.rect.center,group_explosion) # 在我方飞机处发生爆炸
   plane1.dead = True
   
 "敌方飞机碰到我方子弹，我方子弹爆，敌方爆炸"
 result_dict = pygame.sprite.groupcollide(group_bullet1, group_enemy, True, True) # 一颗子弹可能打到几架飞机
 if result_dict !={}:
  missle = list(result_dict.keys())[0]          # 碰到我方子弹
  enemy_list = result_dict[missle]
  #Explosion(explosion_images_list,missle.rect.center,group_explosion)
  enemy_counter += len(enemy_list)       # 大于一定的数量，如果我方战机没死，则成功结束
  for e in enemy_list: Explosion(explosion_images_list,e.rect.center,group_explosion)
  
  pygame.display.set_caption("风火轮少儿编程_城市之战射击游戏，当前打爆敌机数：" + str(enemy_counter) + "，请自行编写游戏成功结束的代码！")
  
  
 
if __name__ == "__main__":
 
 width,height = 480,360
 enemy_bullet = "images/bullet2.png"
 enemy_images = ["images/enemy0.png","images/enemy1.png","images/enemy2.png","images/enemy3.png"]
 explosion_images = "images/explosion.png"
 image = "images/night city with street.png"
 plane_image1 = "images/plane.png"
 bullet_image1 = "images/bullet.png"
 
 pygame.init()
 screen = pygame.display.set_mode((width,height))
 pygame.display.set_caption("城市之战,按上下左右操作飞机。风火轮少儿编程_www.scratch8.net")
 
 enemy_bullet = pygame.image.load(enemy_bullet)
 enemy_images = [pygame.image.load(img) for img in enemy_images] # 形成敌机的surface列表
 explosion_images_list = []        # 爆炸效果surface列表
 explosion_images = split_images(explosion_images,2,13) # 按2行13列切分图形，返回surface列表
 
 
 keys1 = [K_UP,K_DOWN,K_LEFT,K_RIGHT]
 plane1 = Plane(plane_image1,keys1,screen)
 bg = ScrolledBackground(image,screen)
 running = True
 clock = pygame.time.Clock()
 
 bullet1_shoot_EVENT = USEREVENT + 1
 pygame.time.set_timer(bullet1_shoot_EVENT,500)
 
 "敌机定时生成事件"
 enemy_EVENT = USEREVENT + 2
 pygame.time.set_timer(enemy_EVENT,1000)
 
 "敌机定时发射子弹事件"
 enemy_shoot_EVENT = USEREVENT + 3
 pygame.time.set_timer(enemy_shoot_EVENT,50)
 
 group_explosion = pygame.sprite.Group()
 group_bullet1 = pygame.sprite.Group()
 group_enemy = pygame.sprite.Group()
 group_enemy_bullet = pygame.sprite.Group()
 enemy_amounts = 100       # 大于这个数量则游戏成功结束
 enemy_counter = 0
 while running:
  for event in pygame.event.get():
   if event.type == QUIT:
    running = False
    break
   if event.type == bullet1_shoot_EVENT: # 我方子弹1发射事件
    if not plane1.dead:
     Bullet(bullet_image1,plane1,group_bullet1,screen)
   if event.type == enemy_EVENT:   # 定时生成一架敌机
    Enemy(enemy_images,group_enemy,screen)
    
   if event.type == enemy_EVENT:   # 定时生成一枚敌机子弹
    Eullet(enemy_bullet,group_enemy_bullet,group_enemy,plane1,screen)
    
   
  all_keys = pygame.key.get_pressed() # 所有按键检测
  plane1.keys_check(all_keys)   # 对plane1进行按键检测
  
  bg.update()       # 更新背景坐标
  group_bullet1.update()    # 我方子弹更新
  if not plane1.dead :
   plane1.update()     # 飞机1坐标更新
  group_enemy.update()     # 敌机坐标
  group_enemy_bullet.update()   # 敌机子弹更新
  group_explosion.update()    # 爆炸效果更新
  
  "坐标都更新完后，应该进行碰撞检测"
  collision_check()
  
  screen.fill((0,0,0))
  bg.draw()
  group_bullet1.draw(screen)
  if not plane1.dead :
   plane1.draw()
  group_enemy.draw(screen)
  group_enemy_bullet.draw(screen)
  group_explosion.draw(screen)
  pygame.display.update()
  clock.tick(30)
 pygame.quit()