import curses #控制字符界面
from random import  randrange, choice
#random.randrange([start], stop[, step])，
# 從指定范圍內(nèi)拳喻，按指定基數(shù)遞增的集合中 獲取一個隨機數(shù)即碗。
#random.choice從序列中獲取一個隨機元素耀怜。
from collections import  defaultdict#默認字典



letter_codes = [ord(ch) for ch in 'WASDRQwasdrq']#ord函數(shù)以一個字符為參數(shù)贡茅，返回對應(yīng)的ASCII數(shù)值锐秦，或者Unicode數(shù)值
actions = ['Up', 'Left', 'Down', 'Right', 'Restart', 'Exit']
actions_dict = dict(zip(letter_codes,actions*2)) #zip() 函數(shù)用于將可迭代的對象作為參數(shù)，將對象中對應(yīng)的元素打包成一個個元組辅鲸，然后返回由這些元組組成的對象，這樣做的好處是節(jié)約了不少的內(nèi)存腹殿。
#[(W,Up),(A,Left),..(q,Exit)]-->{W:Up, A:Left,...q:Exit}

#用戶輸入
def get_user_action(keyboard):
    char = 'N'
    while char not in actions_dict:
        char = keyboard.getch()
    return  actions_dict[char]
#矩陣轉(zhuǎn)置
def transpose(field):#進行一個二維列表的轉(zhuǎn)換
    return [list(row) for row in zip(*field)]

#矩陣逆轉(zhuǎn)
def invert(field):
    return [row[::-1] for row in field]

#創(chuàng)建棋盤
class GameField(object):#class:類的關(guān)鍵字独悴；GameField：自定義類的標識符；object锣尉；要繼承的類名（是一個更大的類刻炒，可以從這個父類中繼承一些功能和特性），object是默認值自沧。
    def __init__(self, height=4, width=4, win=2048):#__init__是超類object下的一個初始化對象數(shù)據(jù)的函數(shù)
        self.height = height    #高
        self.width = width      #寬
        self.win_value = win    #過關(guān)分數(shù)
        self.score = 0          #當前分數(shù)
        self.highscore = 0      #最高分數(shù)
        self.reset()            #棋盤重置
    #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)]#嵌套的列表坟奥，四行四列
        self.spawn()
        self.spawn()#在嵌套的列表里隨機的生成元素

    def move(self,direction):#合并
        #一行向左合并
        def move_row_left(row):
            def tighten(row): #把零散的非零單元擠到一起
                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])#合并
                        self.score += 2 * row[i]#記錄分數(shù)
                        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起
            return tighten(merge(tighten(row)))
        #通過對矩陣進行轉(zhuǎn)置和逆轉(zhuǎn)，可以直接從左移得到其余三個方向的移動操作
        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
    #判斷輸贏
    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)

    #繪制游戲界面
    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')#調(diào)用方法把字符串打印到屏幕

        #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))#繪制當前分數(shù)和最高分
        if 0 != self.highscore:
            cast('HIGHSCORE：' + str(self.highscore))
        for row in self.field:
            draw_hor_separator()#繪制分割線
            draw_row(row)#繪制行
        draw_hor_separator()#繪制底邊的線
        if self.is_win():
            cast(win_string)
        else:
            if self.is_gameover():
                cast(gameover_string)
            else:
                cast(help_string1)
        cast(help_string2)

    #棋盤操作
    #隨機生成一個2或者4
    def spawn(self):
        new_element = 4 if randrange(100) > 89 else 2#9:1的比例生成4和2
        (i,j) = choice([(i,j) for i in range(self.width) for j in range(self.height) if self.field[i][j] ==0])#通過choice選擇一個未被占領(lǐng)的位置
        self.field[i][j] = new_element

    #判斷能否移動
    def move_is_possible(self,diretion):
            def row_is_left_movable(row):#判斷是否可以向左移動
                def change(i):
                    if row[i] == 0 and row[i + 1] !=0:
                        return True
                    if row[i] !=0 and row[i + 1] == row[i]:
                        return  True
                    return False
                return any(change(i) for i in range(len(row) - 1))#any,只要有一個是ture結(jié)果就是ture
            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 diretion in check:
                return check[diretion](self.field)
            else:
                return False
#主邏輯
def main(stdscr):#標準屏幕，curses模塊
    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)
        #讀取用戶輸入得到的action爱谁，判斷是重啟游戲還是結(jié)束游戲
        action = get_user_action(stdscr)
        responses = defaultdict(lambda : state)#默認是當前狀態(tài)晒喷，沒有行為就會一直在當前界面循環(huán)
        #collections.defaultdict可以接受一個函數(shù)作為參數(shù)來初始化
        responses['Restart'],responses['Exit']='Init','Exit'#對應(yīng)不同的行為轉(zhuǎn)換到不同的狀態(tài)
        return responses[action]
    def game():
        #畫出當前棋盤的狀態(tài)
        game_field.draw(stdscr)
        #讀取用戶輸入得到的action
        action = get_user_action(stdscr)
        if action == 'Restart':
            return  'Init'
        if action == 'Exit':
            return  'Exit'
        if game_field.move(action):
            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=2048)


    state = 'Init'
    #狀態(tài)機開始循環(huán)
    while state != 'Exit':
        state = state_actions[state]()
curses.wrapper(main)#把stdscr對象傳入main函數(shù)里，wrapper接口