#! /usr/bin/python3

import random, copy

def game_logic(l):
    oldHash = hash(tuple(l))

    line_active= True
    global moved
    merged = False
    while line_active:
        for i in range(board_line-1):
            if l[i] == None and l[i+1] != None:
                l.pop(i)
                l.insert(i+1,None)
            elif l[i] != None and l[i] == l[i+1] and merged != True:
                mi=l.pop(i)
                l.insert(i,int(mi)*2)

                l.pop(i+1)
                l.insert(i+1,None)

                merged = True
                oldHash = hash(tuple(l))
                moved = True

        newHash = hash(tuple(l))

        if oldHash == newHash:
            # print('Exiting: Boxes didn't move')
            line_active = False
        else:
            # print('Repeating: Boxes moved')
            oldHash = newHash
            moved = True

    return l
            
def movement():
    m = input('\nMove the numbers: ')
    global moved
    global board
    global board_reset
    moved=False
    board_temp=copy.deepcopy(board)

    undo = ['u','r']

    up = ['k','w'] #straight
    left = ['h','a'] #straight
    down = ['j','s'] #back
    right = ['l','d'] #back

    line = left + right
    column = up + down

    def rev(rl):
        if m in left + up:
            gl = game_logic(rl) #k
        else:
            gl = game_logic(rl[::-1])[::-1] #j
        return gl

    if m in line:
        for i in range(0,board_size,board_line):
            rl = board[i:i+board_line]
            board[i:i+board_line] = rev(rl)
    elif m in column:
        for i in range(board_line):
            rl = board[i::board_line]
            board[i::board_line] = rev(rl)
    elif m in undo:
        board=board_reset
        print(board)
    else:
        raise ValueError('Can not move this way')

    if m not in undo and moved == True:
        board_reset=copy.deepcopy(board_temp)

def print_board():
    for i in range(0,board_size,board_line):
        print('{!s:<4}'.join(' '*(board_line+1)).format(*board[i:i+board_line]))

def add_number():
    global board
    indices = [i for i, x in enumerate(board) if x == None]
    p = random.choice(indices)
    board[p] = random.choices([2,4],weights=[80,20])[0]
    print('\nNew number at position',p+1)

#TODO: Make a class so i can remove globals and simplify code
# class Game():
#   def init():
global board
global board_reset
game_state = True
board = []
board_line = 3
board_size = board_line**2
for i in range(board_size):
    board.insert(i,None)

add_number()
board_reset = copy.deepcopy(board)

# def run():
global moved
while game_state:

    print('\nnew choice')
    print_board()

    try:
        movement()
    except ValueError:
        # continue
        pass

    if moved == False:
        print('DID NOT MOVE')
        continue

    try:
        add_number()
    except IndexError:
        # catch game over here
        game_state = False
        print('Game Over')