---

import tkinter as tk
from enum import Enum

CELL = 20
WIDTH, HEIGHT = 400, 400

class Direction(Enum):
    UP = (0, -1)
    DOWN = (0, 1)
    LEFT = (-1, 0)
    RIGHT = (1, 0)

class Snake:
    def __init__(self, x, y):
        self.x, self.y = x, y
        self.direction = Direction.UP

    def move(self):
        dx, dy = self.direction.value
        self.x += dx
        self.y += dy

    def draw(self, canvas):
        canvas.create_rectangle(
            self.x, self.y,
            self.x + CELL, self.y + CELL,
            fill="#933", outline=""
        )

class App:
    def __init__(self, root):
        self.root = root
        self.root.title("Snake")

        self.canvas = tk.Canvas(root, width = WIDTH, height = HEIGHT, bg="#F99")
        self.canvas.pack()

        self.snake = Snake(WIDTH // 2, HEIGHT // 2)

        self.root.bind("<Key>", self.on_key)

        self.tick()
    
    def on_key(self, event):
        mapping = {
            "Up": Direction.UP,
            "Down": Direction.DOWN,
            "Left": Direction.LEFT,
            "Right": Direction.RIGHT,
        }

        if event.keysym in mapping:
            self.snake.direction = mapping[event.keysym]
    
    def tick(self):
        self.snake.move()
        self.snake.draw(self.canvas)
        self.root.after(100, self.tick)

if __name__ == "__main__":
    root = tk.Tk()
    App(root)
    root.mainloop()