import curses
from random import randrange, choice
from collections import defaultdict

actions = ['Up', 'Left', 'Down', 'Right', 'Restart', 'Exit']

letter_codes = [ord(ch) for ch in 'WASDRQwasdrq']

actionsdict = dict(zip(lettercodes, actions * 2))

Init: init()
Game: game()
Win: lambda: not_game('Win')
Gameover: lambda: not_game('Gameover')

def main(stdscr):
 def init():
 #重置游戲棋盤
 return 'Game'
 def not_game(state):
 #畫出 GameOver 或者 Win 的界面
 #讀取用戶輸入得到action，判斷是重啟游戲還是結束游戲
 responses = defaultdict(lambda: state) ＃默認是當前狀態(tài)，沒有行為就會一直在當前界面循環(huán)
 responses['Restart'], responses['Exit'] = 'Init', 'Exit' #對應不同的行為轉(zhuǎn)換到不同的狀態(tài)
 return responses[action]
 def game():
 #畫出當前棋盤狀態(tài)
 #讀取用戶輸入得到action
 if action == 'Restart':
  return 'Init'
 if action == 'Exit':
  return 'Exit'
 #if 成功移動了一步:
  if 游戲勝利了:
  return 'Win'
  if 游戲失敗了:
  return 'Gameover'
 return 'Game'
 state_actions = {
  'Init': init,
  'Win': lambda: not_game('Win'),
  'Gameover': lambda: not_game('Gameover'),
  'Game': game
 }
 state = 'Init'
 #狀態(tài)機開始循環(huán)
 while state != 'Exit':
 state = state_actions[state]()

def get_user_action(keyboard):
 char = "N"
 while char not in actions_dict:
 char = keyboard.getch()
 return actions_dict[char]

def transpose(field):
 return [list(row) for row in zip(*field)]

def invert(field):
 return [row[::-1] for row in field]

class GameField(object):
 def __init__(self, height=4, width=4, win=2048):
 self.height = height #高
 self.width = width  #寬
 self.win_value = 2048 #過關分數(shù)
 self.score = 0  #當前分數(shù)
 self.highscore = 0  #最高分
 self.reset()  #棋盤重置

 def spawn(self):
  new_element = 4 if randrange(100) > 89 else 2
  (i,j) = choice([(i,j) for i in range(self.width) for j in range(self.height) if self.field[i][j] == 0])
  self.field[i][j] = new_element
#### 重置棋盤
 def reset(self):
 if self.score > self.highscore:
  self.highscore = self.score
 self.score = 0
 self.field = [[0 for i in range(self.width)] for j in range(self.height)]
 self.spawn()
 self.spawn()
#### 一行向左合并
(注：這一操作是在 move 內(nèi)定義的，拆出來是為了方便閱讀)
def move_row_left(row):
 def tighten(row): # 把零散的非零單元擠到一塊
 new_row = [i for i in row if i != 0]
 new_row += [0 for i in range(len(row) - len(new_row))]
 return new_row
 def merge(row): # 對鄰近元素進行合并
 pair = False
 new_row = []
 for i in range(len(row)):
  if pair:
  new_row.append(2 * row[i])
  self.score += 2 * row[i]
  pair = False
  else:
  if i + 1 < len(row) and row[i] == row[i + 1]:
   pair = True
   new_row.append(0)
  else:
   new_row.append(row[i])
 assert len(new_row) == len(row)
 return new_row
 #先擠到一塊再合并再擠到一塊
 return tighten(merge(tighten(row)))

def move(self, direction):
 def move_row_left(row):
 #一行向左合并
 moves = {}
 moves['Left'] = lambda field: [move_row_left(row) for row in field]
 moves['Right'] = lambda field: invert(moves['Left'](invert(field)))
 moves['Up'] = lambda field: transpose(moves['Left'](transpose(field)))
 moves['Down'] = lambda field: transpose(moves['Right'](transpose(field)))
 if direction in moves:
 if self.move_is_possible(direction):
  self.field = moves[direction](self.field)
  self.spawn()
  return True
 else:
  return False

 def is_win(self):
 return any(any(i >= self.win_value for i in row) for row in self.field)
 def is_gameover(self):
 return not any(self.move_is_possible(move) for move in actions)
#### 判斷能否移動
def move_is_possible(self, direction):
 defrow_is_left_movable(row):
 def change(i):
  if row[i] == 0 and row[i + 1] != 0: # 可以移動
  return True
  if row[i] != 0 and row[i + 1] == row[i]: # 可以合并
  return True
  return False
 return any(change(i) for i in range(len(row) - 1))
 check = {}
 check['Left'] = lambda field: any(row_is_left_movable(row) for row in field)
 check['Right'] = lambda field: check['Left'](invert(field))
 check['Up'] = lambda field: check['Left'](transpose(field))
 check['Down'] = lambda field: check['Right'](transpose(field))
 if direction in check:
 return check[direction](self.field)
 else:
 return False

def draw(self, screen):
 help_string1 = '(W)Up (S)Down (A)Left (D)Right'
 help_string2 = ' (R)Restart (Q)Exit'
 gameover_string = '  GAME OVER'
 win_string = '  YOU WIN!'
 def cast(string):
 screen.addstr(string + 'n')
 #繪制水平分割線
 def draw_hor_separator():
 line = '+' + ('+------' * self.width + '+')[1:]
 separator = defaultdict(lambda: line)
 if not hasattr(draw_hor_separator, "counter"):
  draw_hor_separator.counter = 0
 cast(separator[draw_hor_separator.counter])
 draw_hor_separator.counter += 1
 def draw_row(row):
 cast(''.join('|{: ^5} '.format(num) if num > 0 else '| ' for num in row) + '|')
 screen.clear()
 cast('SCORE: ' + str(self.score))
 if 0 != self.highscore:
 cast('HGHSCORE: ' + str(self.highscore))
 for row in self.field:
 draw_hor_separator()
 draw_row(row)
 draw_hor_separator()
 if self.is_win():
 cast(win_string)
 else:
 if self.is_gameover():
  cast(gameover_string)
 else:
  cast(help_string1)
 cast(help_string2)

def main(stdscr):
 def init():
 #重置游戲棋盤
 game_field.reset()
 return 'Game'
 def not_game(state):
 #畫出 GameOver 或者 Win 的界面
 game_field.draw(stdscr)
 #讀取用戶輸入得到action，判斷是重啟游戲還是結束游戲
 action = get_user_action(stdscr)
 responses = defaultdict(lambda: state) #默認是當前狀態(tài)，沒有行為就會一直在當前界面循環(huán)
 responses['Restart'], responses['Exit'] = 'Init', 'Exit' #對應不同的行為轉(zhuǎn)換到不同的狀態(tài)
 return responses[action]
 def game():
 #畫出當前棋盤狀態(tài)
 game_field.draw(stdscr)
 #讀取用戶輸入得到action
 action = get_user_action(stdscr)
 if action == 'Restart':
  return 'Init'
 if action == 'Exit':
  return 'Exit'
 if game_field.move(action): # move successful
  if game_field.is_win():
  return 'Win'
  if game_field.is_gameover():
  return 'Gameover'
 return 'Game'
 state_actions = {
  'Init': init,
  'Win': lambda: not_game('Win'),
  'Gameover': lambda: not_game('Gameover'),
  'Game': game
 }
 curses.use_default_colors()
 game_field = GameField(win=32)
 state = 'Init'
 #狀態(tài)機開始循環(huán)
 while state != 'Exit':
 state = state_actions[state]()

curses.wrapper(main)