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

# 创建子弹类，把子弹的图片转化为图像对象，设定固定的移动速度
class Bullet():
 def __init__(self,bulletfilename,bulletpos):
  self.bulletimg = pygame.image.load(bulletfilename)
  self.bullet_rect = self.bulletimg.get_rect()
  self.bullet_image = self.bulletimg.subsurface(self.bullet_rect)
  self.bullet_rect.midbottom = bulletpos
  self.speed = 2
 def move(self):
  self.bullet_rect.top -= self.speed

# 创建玩家飞机类，用面向对象的思想来对待
class play_plane_fly():
 def __init__(self,play_image_filename,play_pos):
  self.image = pygame.image.load(play_image_filename)
  self.plane_rect = self.image.get_rect()
  self.play_image = self.image.subsurface(self.plane_rect)
  self.plane_rect.midtop = play_pos
  self.speed = 2
  # 子弹是由玩家飞机发射的，所以创建列表，存储子弹对象，使该列表变为该类的属性
  self.bullets = []
  self.is_hitted = False

 # 生成函数，完成发射子弹动作，同时将每个子弹对象存在列表中
 def shoot(self,bullet_filename):
  bulletobj = Bullet(bullet_filename,self.plane_rect.midtop)
  self.bullets.append(bulletobj)

 # 向上移动，当飞机移动到边框位置时，无法移动
 def moveup(self):
  if self.plane_rect.top <= 0:
   self.plane_rect.top = 0
  else:
   self.plane_rect.top -= self.speed

 # 向下移动，当飞机移动到边框位置时，无法移动
 def movedown(self):
  if self.plane_rect.top >= 950 - self.plane_rect.height:
   self.plane_rect.top = 950 - self.plane_rect.height
  else:
   self.plane_rect.top += self.speed

 # 向右移动，当飞机移动到边框位置时，无法移动
 def moveleft(self):
  if self.plane_rect.left <= -40:
   self.plane_rect.left = -40
  else:
   self.plane_rect.left -= self.speed

 # 向左移动，当飞机移动到边框位置时，无法移动
 def moveright(self):
  if self.plane_rect.left >= 700 - self.plane_rect.width:
   self.plane_rect.left = 700 - self.plane_rect.width
  else:
   self.plane_rect.left += self.speed

# 生成敌机类，设定固定的移动速度
class Enemy():
 def __init__(self,enemyfilename,enemypos):

  self.img = pygame.image.load(enemyfilename)
  self.enemy_rect = self.img.get_rect()
  self.enemy_image = self.img.subsurface(self.enemy_rect)
  self.enemy_rect.midbottom = enemypos
  self.speed = 1

 def move(self):
  self.enemy_rect.bottom += self.speed

clock = pygame.time.Clock()
def main():
 # 初始化文字屏幕
 pygame.font.init()
 # 初始化图像屏幕
 pygame.init()
 # 设定游戏帧
 clock.tick(50)
 # 设定游戏屏幕大小
 screen = pygame.display.set_mode((660,950))
 # 设定游戏名称
 pygame.display.set_caption('飞机大战')
 # 加载背景图片，生成图像对象
 background = pygame.image.load('image/background.png').convert()
 backgroundsurface = pygame.transform.scale(background, (660, 950))
 # 加载游戏结束图片，生成图像对象
 gameover = pygame.image.load('image/gameover.png').convert()
 gameoversurface = pygame.transform.scale(gameover,(660, 950))
 playplanefilename = 'image/myself.png'
 planepos = [330,600]
 player = play_plane_fly(playplanefilename,planepos)
 bulletfilename = 'image/bullet.png'
 # 按频率生成子弹，初始化数字为0
 bullet_frequency = 0
 enemyfilename = 'image/airplane.png'
 # 按频率生成敌机，初始化数字为0
 enemy_frequency = 0
 enemys = []
 myfont = pygame.font.SysFont("arial", 40)
 textImage = myfont.render("Score ", True, (0,0,0))
 # 初始化得分为0
 Score = 0
 # 敌机被子弹击中时的动画，将每张图片的图像对象存在列表中
 enenys_down = []
 enemy0_down = pygame.image.load('image/airplane_ember0.png')
 enemy0_down_rect = enemy0_down.get_rect()
 enemydown0 = enemy0_down.subsurface(enemy0_down_rect)
 enenys_down.append(enemydown0)
 enemy1_down = pygame.image.load('image/airplane_ember1.png')
 enemy1_down_rect = enemy1_down.get_rect()
 enemydown1 = enemy1_down.subsurface(enemy1_down_rect)
 enenys_down.append(enemydown1)
 enemy2_down = pygame.image.load('image/airplane_ember2.png')
 enemy2_down_rect = enemy2_down.get_rect()
 enemydown2 = enemy2_down.subsurface(enemy2_down_rect)
 enenys_down.append(enemydown2)
 enemy3_down = pygame.image.load('image/airplane_ember3.png')
 enemy3_down_rect = enemy3_down.get_rect()
 enemydown3 = enemy3_down.subsurface(enemy3_down_rect)
 enenys_down.append(enemydown3)


 while True:
  # 动态显示得分
  score = str(Score)
  myscore = pygame.font.SysFont("arial", 40)
  scoreImage = myscore.render(score, True, (0, 0, 0))
  # 判断事件，防止卡顿或者意外退出
  for event in pygame.event.get():
   if event.type == pygame.QUIT:
    pygame.quit()
    exit()
  key_pressed = pygame.key.get_pressed()
  if key_pressed[K_UP] or key_pressed[K_w]:
   player.moveup()
  if key_pressed[K_DOWN] or key_pressed[K_s]:
   player.movedown()
  if key_pressed[K_LEFT] or key_pressed[K_a]:
   player.moveleft()
  if key_pressed[K_RIGHT] or key_pressed[K_d]:
   player.moveright()

  screen.blit(backgroundsurface, (0, 0))

  if not player.is_hitted:
   # 按频率生成子弹
   if bullet_frequency % 30 == 0:
    player.shoot(bulletfilename)
   bullet_frequency += 1
   if bullet_frequency >= 30:
    bullet_frequency = 0
   # 让子弹动起来
   for i in player.bullets:
    i.move()
    screen.blit(i.bullet_image,i.bullet_rect)
    # 当子弹飞出屏幕，删除子弹对象
    if i.bullet_rect.bottom <= 0:
     player.bullets.remove(i)
   # 按频率生成敌机
   if enemy_frequency % 100 == 0:
    enemypos = [random.randint(30, 630), 0]
    enemyplane = Enemy(enemyfilename, enemypos)
    #将敌机对象添加到列表中
    enemys.append(enemyplane)
   enemy_frequency += 1
   if enemy_frequency >= 100:
    enemy_frequency = 0
   # 让敌机动起来
   for i in enemys:
    i.move()
    screen.blit(i.enemy_image,i.enemy_rect)
    # 当敌机飞出屏幕，删除敌机对象
    if i.enemy_rect.bottom >= 950:
     enemys.remove(i)
    # 遍历子弹对象，判断子弹是否击中敌机
    for j in player.bullets:
     # 如果击中，分数增加，同时移除该子弹和敌机对象
     if pygame.Rect.colliderect(j.bullet_rect,i.enemy_rect):
      Score += 100
      enemys.remove(i)
      player.bullets.remove(j)
      for k in enenys_down:
       screen.blit(k,i.enemy_rect)
    # 遍历敌机对象，判断玩家是否和敌机相撞
    if pygame.Rect.colliderect(player.plane_rect,i.enemy_rect):
     # 修改is_hitted的值，跳出该层循环
     player.is_hitted = True
     break


   screen.blit(player.play_image,player.plane_rect)
   screen.blit(textImage, (0,0))
   screen.blit(scoreImage, (110, 0))
   pygame.display.update()
  # 玩家退出时显示分数和游戏结束
  else:
   screen.blit(gameoversurface,(0,0))
   screen.blit(textImage, (0, 0))
   screen.blit(scoreImage, (110, 0))
   pygame.display.update()
   time.sleep(2)
   break

main()