from tkinter import *
from random import randint
from time import sleep

root = Tk()
STEP = 125
root.geometry("500x500")
color = {"2" : "pink",
         "4" : "red",
         "8" : "blue",
         "16": "brown",
         "32": "white",
         "64": "green",
         "128":"yellow"}

field = [[None] * 4 for i in range(4)]

def game_end():
    for line in field:
        if None in line:
            return False

    for i in range(4):
        for j in range(3):
            if field[i][j]["text"] == field[i][j + 1]["text"]:
                return False
            if field[j][i]["text"] == field[j + 1][i]["text"]:
                return False
    return True

def add_title():
    i, j = randint(0, 3), randint(0, 3)
    while field[i][j] is not None:
        i, j = randint(0, 3), randint(0, 3)

    field[i][j] = Label(root, text = "2", height = 3, width = 1, font="Arial 24", bg="pink")
    for k in range(1, 5):
        field[i][j]["width"] = k
        field[i][j].place(y = i * STEP, x = j * STEP)
        root.update()
        sleep(0.25)

def left(event):
    flag = False
    for i in range(4):
        free = 0
        for j in range(4):
            if field[i][j] is None:
                free += 1
            else:
                if free > 0:
                    field[i][j - free] = field[i][j]
                    field[i][j] = None
                    for k in range(0, STEP + 1):
                        field[i][j - free].place(y = i * STEP, x = j * STEP - free * k)
                        root.update()
                        sleep(0.001)
                    flag = True
                if j - free > 0 and field[i][j - free]["text"] == field[i][j - free - 1]["text"]:
                    for k in range(0, STEP + 1):
                        field[i][j - free].place(y = i * STEP, x = (j  - free) * STEP -  k)
                        root.update()
                        sleep(0.001)
                    field[i][j - free].destroy()
                    field[i][j - free] = None
                    field[i][j - free - 1]["text"] = str(int(field[i][j - free - 1]["text"]) * 2)
                    field[i][j - free - 1]["bg"] = color[field[i][j - free - 1]["text"]]
                    free += 1
                    flag = True

    if flag:
        add_title()
        if game_end():
            lab = Label(root, text = "GAME OVER", height = 10, width = 10, font="Arial 24", bg="yellow")
            lab.place(x = 100, y = 100)

def right(event):
    flag = False
    for i in range(4):
        free = 0
        for j in range(3, -1, -1):
            if field[i][j] is None:
                free += 1
            else:
                if free > 0:
                    field[i][j + free] = field[i][j]
                    field[i][j] = None
                    field[i][j + free].place(y = i * STEP, x = (j + free) * STEP)
                    flag = True
                if j + free < 3 and field[i][j + free]["text"] == field[i][j + free + 1]["text"]:
                    field[i][j + free].destroy()
                    field[i][j + free] = None
                    field[i][j + free + 1]["text"] = str(int(field[i][j + free + 1]["text"]) * 2)
                    free += 1
                    flag = True

    if flag:
        add_title()
        if game_end():
            print('END')

def down(event):
    flag = False
    for j in range(4):
        free = 0
        for i in range(3, -1, -1):
            if field[i][j] is None:
                free += 1
            else:
                if free > 0:
                    field[i + free][j] = field[i][j]
                    field[i][j] = None
                    field[i + free][j].place(y = (i + free) * STEP, x = j * STEP)
                    flag = True
                if i + free < 3 and field[i + free][j]["text"] == field[i + free + 1][j]["text"]:
                    field[i + free][j].destroy()
                    field[i + free][j] = None
                    field[i + free + 1][j]["text"] = str(int(field[i + free + 1][j]["text"]) * 2)
                    free += 1
                    flag = True
    if flag:
        add_title()
        if game_end():
            print('END')


def up(event):
    flag = False
    for j in range(4):
        free = 0
        for i in range(4):
            if field[i][j] is None:
                free += 1
            else:
                if free > 0:
                    field[i - free][j] = field[i][j]
                    field[i][j] = None
                    field[i - free][j].place(y = (i - free) * STEP, x = j * STEP)
                    flag = True
                if i - free > 0 and field[i - free][j]["text"] == field[i - free - 1][j]["text"]:
                    field[i - free][j].destroy()
                    field[i - free][j] = None
                    field[i - free - 1][j]["text"] = str(int(field[i - free - 1][j]["text"]) * 2)
                    free += 1
                    flag = True
    if flag:
        add_title()
        if game_end():
            print('END')



root.bind('<Down>', down)
root.bind('<Left>', left)
root.bind('<Up>', up)
root.bind('<Right>', right)
add_title()
add_title()
root.mainloop()