import pygame
import time
import numpy as np
# 此模块包含游戏所需的常量
from pygame.locals import *

# 设置棋盘的长宽
BOARDWIDTH = 48
BOARDHEIGHT = 28
# 分数
score = 0



class Food(object):
 def __init__(self):
 self.item = (4, 5)

 # 画出食物
 def _draw(self, screen, i, j):
 color = 255, 0, 255
 radius = 10
 width = 10
 # i:1---34 j:1---25
 position = 10 + 20 * i, 10 + 20 * j
 # 画出半径为 10 的粉色实心圆
 pygame.draw.circle(screen, color, position, radius, width)

 # 随机产生食物
 def update(self, screen, enlarge, snack):
 if enlarge:
  self.item = np.random.randint(1, BOARDWIDTH - 2), np.random.randint(1, BOARDHEIGHT - 2)
  while self.item in snack.item:
  self.item = np.random.randint(1, BOARDWIDTH - 2), np.random.randint(1, BOARDHEIGHT - 2)
 self._draw(screen, self.item[0], self.item[1])


# 贪吃蛇
class Snack(object):
 def __init__(self):
 # self.item = [(3, 25), (2, 25), (1, 25), (1,24), (1,23),
 # (1,22), (1,21), (1,20), (1,19), (1,18), (1,17), (1,16)]
 # x 水平方向 y 竖直方向
 # 初始方向竖直向上
 self.item = [(3, 25), (2, 25), (1, 25), (1, 24), ]
 self.x = 0
 self.y = -1

 def move(self, enlarge):
 # enlarge 标记贪吃蛇有没有吃到食物
 if not enlarge:
  # 吃到食物删除尾部元素
  self.item.pop()
 # 新蛇头的坐标为旧蛇头坐标加上移动方向的位移
 head = (self.item[0][0] + self.x, self.item[0][1] + self.y)
 # 将新的蛇头坐标插入在 list 最前面
 self.item.insert(0, head)

 def eat_food(self, food):
 global score
 # snack_x,snack_y 蛇头坐标
 # food_x, food_y 食物坐标
 snack_x, snack_y = self.item[0]
 food_x, food_y = food.item
 # 比较蛇头坐标与食物坐标
 if (food_x == snack_x) and (food_y == snack_y):
  score += 100
  return 1
 else:
  return 0

 def toward(self, x, y):
 # 改变蛇头朝向
 if self.x * x >= 0 and self.y * y >= 0:
  self.x = x
  self.y = y

 def get_head(self):
 # 获取蛇头坐标
 return self.item[0]

 def draw(self, screen):
 # 画出贪吃蛇
 # 蛇头为半径为 15 的红色实心圆
 radius = 15
 width = 15
 # i:1---34 j:1---25
 color = 255, 0, 0
 # position 为图形的坐标
 position = 10 + 20 * self.item[0][0], 10 + 20 * self.item[0][1]
 pygame.draw.circle(screen, color, position, radius, width)
 # 蛇身为半径为 10 的黄色实心圆
 radius = 10
 width = 10
 color = 255, 255, 0
 for i, j in self.item[1:]:
  position = 10 + 20 * i, 10 + 20 * j
  pygame.draw.circle(screen, color, position, radius, width)


# 初始界面
def init_board(screen):
 board_width = BOARDWIDTH
 board_height = BOARDHEIGHT
 color = 10, 255, 255
 width = 0
 # width:x, height:y
 # 左右边框占用了 X: 0 35*20
 for i in range(board_width):
 pos = i * 20, 0, 20, 20
 pygame.draw.rect(screen, color, pos, width)
 pos = i * 20, (board_height - 1) * 20, 20, 20
 pygame.draw.rect(screen, color, pos, width)
 # 上下边框占用了 Y: 0 26*20
 for i in range(board_height - 1):
 pos = 0, 20 + i * 20, 20, 20
 pygame.draw.rect(screen, color, pos, width)
 pos = (board_width - 1) * 20, 20 + i * 20, 20, 20
 pygame.draw.rect(screen, color, pos, width)


# 游戏失败
def game_over(snack):
 broad_x, broad_y = snack.get_head()
 flag = 0
 old = len(snack.item)
 new = len(set(snack.item))
 # 游戏失败的两种可能
 # 咬到自身
 if new < old:
 flag = 1
 # 撞到边框
 if broad_x == 0 or broad_x == BOARDWIDTH - 1:
 flag = 1
 if broad_y == 0 or broad_y == BOARDHEIGHT - 1:
 flag = 1

 if flag:
 return True
 else:
 return False


# 打印字符
def print_text(screen, font, x, y, text, color=(255, 0, 0)):
 # 在屏幕上打印字符
 # text是需要打印的文本，color为字体颜色
 # (x,y)是文本在屏幕上的位置
 imgText = font.render(text, True, color)
 screen.blit(imgText, (x, y))


# 按键
def press(keys, snack):
 global score
 # K_w 为 pygame.locals 中的常量
 # keys[K_w] 返回 True or False
 # 上移
 if keys[K_w] or keys[K_UP]:
 snack.toward(0, -1)
 # 下移
 elif keys[K_s] or keys[K_DOWN]:
 snack.toward(0, 1)
 # 左移
 elif keys[K_a] or keys[K_LEFT]:
 snack.toward(-1, 0)
 # 右移
 elif keys[K_d] or keys[K_RIGHT]:
 snack.toward(1, 0)
 # 重置游戏
 elif keys[K_r]:
 score = 0
 main()
 # 退出游戏
 elif keys[K_ESCAPE]:
 exit()


# 游戏初始化
def game_init():
 # pygame 初始化
 pygame.init()
 # 设置游戏界面大小
 screen = pygame.display.set_mode((BOARDWIDTH * 20, BOARDHEIGHT * 20))
 # 设置游戏标题
 pygame.display.set_caption('贪吃蛇游戏')
 # sound = pygame.mixer.Sound(AUDIONAME)
 # channel = pygame.mixer.find_channel(True)
 # channel.play(sound)
 return screen


# 开始游戏
def game(screen):
 snack = Snack()
 food = Food()
 # 设置中文字体和大小
 font = pygame.font.SysFont('SimHei', 20)
 is_fail = 0
 while True:
 for event in pygame.event.get():
  if event.type == QUIT:
  exit()
 # 填充屏幕
 screen.fill((0, 0, 100))
 init_board(screen=screen)
 # 获得用户按键命令
 keys = pygame.key.get_pressed()
 press(keys, snack)
 # 游戏失败打印提示
 if is_fail:
  font2 = pygame.font.Font(None, 40)
  print_text(screen, font2, 400, 200, "GAME OVER")
 # 游戏主进程
 if not is_fail:
  enlarge = snack.eat_food(food)
  food.update(screen, enlarge, snack)
  snack.move(enlarge)
  is_fail = game_over(snack=snack)
  snack.draw(screen)
 # 游戏刷新
 pygame.display.update()
 time.sleep(0.1)


# 主程序
def main():
 screen = game_init()
 game(screen)


if __name__ == '__main__':
 main()