import sys
import pygame
from pygame.sprite import Sprite
from pygame.sprite import Group
from time import sleep
import pygame.font

screen=pygame.display.set_mode((1200,700))
bg_color=(20,40,50)
target_speed=5
charactor_speed=7
bullet_speed=8
game_active=True
fail_times=0
pygame.init()                                                       
class Target(Sprite):
	"""建立被射擊的矩形目標"""
	def __init__(self, screen):
		super(Target, self).__init__()
		self.screen = screen
		self.width, self.height=50,150
		self.screen_rect=self.screen.get_rect()
		self.rect = pygame.Rect(0, 0, self.width, self.height)
		self.rect.right=self.screen_rect.right
		self.rect.centery = self.screen_rect.centery
		self.target_color=(255, 255, 255)
		self.y=float(self.rect.y)
		self.moving_direction=1     
	def blitme(self):
		self.screen.fill(self.target_color,self.rect)
	def update(self):		
		self.y+=target_speed*self.moving_direction
		self.rect.y=self.y
def check_boundaries(target):                                  #檢查矩形撞擊邊界和改變移動方向
	if target.rect.top<=target.screen_rect.top:
		target.moving_direction=1
	if target.rect.bottom>=target.screen_rect.bottom:
		target.moving_direction=-1
class Charactor(Sprite):
	"""建立可操縱的角色"""
	def __init__(self, screen):
		super(Charactor, self).__init__()
		self.screen = screen
		self.image=pygame.image.load('timg.bmp')
		self.rect=self.image.get_rect()
		self.screen_rect=self.screen.get_rect()
		self.rect.left=self.screen_rect.left+5
		self.rect.centery=self.screen_rect.centery
		self.moving_up=False
		self.moving_dowm=False
	def blitme(self):
		self.screen.blit(self.image,self.rect)
	def update(self):
		if self.moving_up and self.rect.top>=self.screen_rect.top:
			self.rect.y-=charactor_speed
		if self.moving_dowm and self.rect.bottom<=self.screen_rect.bottom:
			self.rect.y+=charactor_speed
	def centerer_charactor(self):
		self.rect.centery=self.screen_rect.centery

def keyup_events(event,charactor):                   #按鍵擡起
	if event.key==pygame.K_UP:
		charactor.moving_up=False
	if event.key==pygame.K_DOWN:
		charactor.moving_dowm=False

def keydowm_events(event,charactor,bullets):         #按鍵落下
	if event.key==pygame.K_UP:
		charactor.moving_up=True
	if event.key==pygame.K_DOWN:
		charactor.moving_dowm=True
	if event.key==pygame.K_SPACE:
		bullet=Bullet(screen,charactor)
		bullets.add(bullet)
		
def check_events(charactor,bullets,stats,play_button,targets):      #檢查事件發生
	for event in pygame.event.get():
		if event.type==pygame.KEYDOWN:
			keydowm_events(event,charactor,bullets)
		elif event.type==pygame.KEYUP:
			keyup_events(event,charactor)
		elif event.type==pygame.QUIT:
			sys.exit()
		elif event.type==pygame.MOUSEBUTTONDOWN:
			mouse_x,mouse_y=pygame.mouse.get_pos()
		check_play_button(stats,play_button,mouse_x,mouse_y,charactor,bullets,targets)
def check_play_button(stats,play_button,mouse_x,mouse_y,charactor,bullets,targets): #檢查開始按鈕，並清零遊戲
	button_clicked=play_button.rect.collidepoint(mouse_x,mouse_y)
	if button_clicked and not stats.game_active:
		pygame.mouse.set_visible(False)
		stats.game_active=True
		bullets.empty()
		targets.empty()
		target=Target(screen)
		targets.add(target)
		global fail_times
		fail_times=0
		charactor.centerer_charactor()
	
class Bullet(Sprite):
	"""建立子彈"""
	def __init__(self, screen,charactor):
		super(Bullet, self).__init__()
		self.screen = screen
		self.width,self.height=15,5
		self.bullet_color=(70,200,200)
		self.rect=pygame.Rect(0,0,self.width,self.height)
		self.creat_bullet=False
		self.screen_rect=self.screen.get_rect()
		self.rect.left=charactor.rect.right
		self.rect.centery=charactor.rect.centery
	def blitme(self):
		pygame.draw.rect(self.screen,self.bullet_color,self.rect)
	def update(self):
		self.rect.x+=bullet_speed

def bullet_target(targets,bullets,game_stat):           #檢查子彈撞擊矩形
	for bullet in bullets:
		collisions=pygame.sprite.groupcollide(targets,bullets,True, True)
		if collisions:
			game_stat.game_active=False
			pygame.mouse.set_visible(True)

def check_fail(bullets,game_stat):                    #檢查失敗次數，大於3則失敗
	for bullet in bullets:
		if bullet.rect.left>=bullet.screen_rect.right:
			bullets.remove(bullet)
			global fail_times
			fail_times+=1
		if fail_times>=3:
			game_stat.game_active=False
			pygame.mouse.set_visible(True)
			
class Game_stat():                              #遊戲開始時是不活躍狀態
	def __init__(self):		
		self.game_active=False


class Button():
	"""建立開始按鈕"""
	def __init__(self, screen,msg):
		self.screen = screen
		self.screen_rect=screen.get_rect()
		self.width,self.height=200,50
		self.button_color=(0,255,0)
		self.text_color=(255,255,255)
		self.font=pygame.font.SysFont(None, 48)
		self.rect=pygame.Rect(0,0,self.width,self.height)
		self.rect.center=self.screen_rect.center
		self.prep_msg(msg)
	def prep_msg(self,msg):
		self.msg_image=self.font.render(msg,True,self.text_color,self.button_color)
		self.msg_image_rect=self.msg_image.get_rect()
		self.msg_image_rect.center=self.rect.center
	def draw_button(self):
		self.screen.fill(self.button_color,self.rect)              
		self.screen.blit(self.msg_image,self.msg_image_rect)       

def run_game():
	target=Target(screen)
	targets=Group()
	charactor=Charactor(screen)
	bullets=Group()
	targets.add(target)
	stats=Game_stat()
	play_button=Button(screen,"play")
	while True:	
		check_events(charactor,bullets,stats,play_button,targets)
		screen.fill(bg_color)
		charactor.blitme()
		if stats.game_active:
			for bullet in bullets:
				bullet.blitme()	
			for target in targets:
				target.blitme()	
			check_boundaries(target)
			targets.update()				
			charactor.update()
			bullets.update()
			bullet_target(targets,bullets,stats)
			check_fail(bullets,stats)
			for bullet in bullets.copy():
				if bullet.rect.x>=bullet.screen_rect.right:
					bullets.remove(bullet)
			pygame.display.flip()
		if not stats.game_active:
			play_button.draw_button()
		pygame.display.flip()
		
run_game()