помогите пожалуйста со змейкой на python. не получается сделать рост змейки

В коде ниже реализовано всё, кроме роста змейки. можете написать код, который будет отвечать за рост змейки, пожалуйста. А то я задолбался третий день подряд экспериментировать. Буду очень признателен за помощь

import time
import random
from tkinter import *
import os

eaten = 0

x = random.randint(65, 335)
y = random.randint(65, 435)
r = 10

move = False

foodPos1 = x - r
foodPos2 = x + r
foodPos3 = y - r
foodPos4 = y + r

x1 = 40
x2 = 60
y1 = 40
y2 = 60
moveX1 = 10
moveX2 = 10
moveY1 = 10
moveY2 = 10
root = Tk()

navigation = ''

root.title('Змейка 2024')
root.geometry('345x450')

canvas = Canvas(root, width = 350, height = 450, bg="black")      
canvas.pack() 
canvas.create_text(70,30,text='съедено: ',font="Verdana 12",fill="white")
canvas.focus_set()
eat = canvas.create_text(115,30,text=eaten,font="Verdana 12",fill="white")     
snake = canvas.create_rectangle(x1,y1,x2,y2, fill="green") 
snake1 = canvas.create_rectangle(600,y1,600,y2, fill="green")
snake2 = canvas.create_rectangle(600,y1,600,y2, fill="green")
food = canvas.create_oval(foodPos1, foodPos3, foodPos2, foodPos4, fill="red")

BX = random.randint(65, 335)
BY = random.randint(65, 435)
barpos1 = BX - r
barpos2 = BX + r
barpos3 = BY - r
barpos4 = BY + r
barrier = canvas.create_rectangle(barpos1, barpos3, barpos2, barpos4, fill="gray")

bx1 = 0
bx2 = 15
by1 = 0
by2 = 15
minus = 15
canvas.create_rectangle(bx1, by1, bx2, by2, fill="gray")
for i in range(29):
    by1 += minus
    by2 += minus
    canvas.create_rectangle(bx1, by1, bx2, by2, fill="gray")
    minus*2
minus = 15
for i in range(22):
    bx1 += minus
    bx2 += minus
    canvas.create_rectangle(bx1, by1, bx2, by2, fill="gray")
    minus*2
minus = 15
for i in range(29):
    by1 -= minus
    by2 -= minus
    canvas.create_rectangle(bx1, by1, bx2, by2, fill="gray")
    minus*2
minus = 15
for i in range(29):
    bx1 -= minus
    bx2 -= minus
    canvas.create_rectangle(bx1, by1, bx2, by2, fill="gray")
    minus*2

death = False

def loop():
    global death
    death = True
    
def move_up(event):
    global navigation
    if navigation != "down":
        navigation = "up"
def move_down(event):
    global navigation
    if navigation != "up":
        navigation = "down"
def move_right(event):
    global navigation
    if navigation != "left":
        navigation = "right"
def move_left(event):
    global navigation
    if navigation != "right":
        navigation = "left"
def tail():
    global x1
    global x2
    global y1
    global y2
    global navigation
    global eaten
    global snake1
    for i in range(eaten):
        if navigation == "up":
            snake1 = canvas.create_rectangle(x1,y1+21,x2,y2+21, fill="green")
        elif navigation == "down":
            snake1 = canvas.create_rectangle(x1,y1-21,x2,y2-21, fill="green")
        elif navigation == "left":
            snake1 = canvas.create_rectangle(x1+21,y1,x2+21,y2, fill="green")
        elif navigation == "right":
            snake1 = canvas.create_rectangle(x1-21,y1,x2-21,y2, fill="green")

def draw():
    global death
    global navigation
    global moveX1
    global moveX2
    global moveY1
    global moveY2
    global x1
    global x2
    global y1
    global y2
    global snake
    global x
    global y
    global food
    global eaten
    global eat
    global barrier
    global move
    global snake1
    global snake2
    a = 10
    collision = canvas.find_overlapping(x1, y1, x2, y2) 
    if food in collision: 
        canvas.delete(food) 
        eaten += 1 
        canvas.itemconfig(eat, text=eaten) 
        x = random.randint(50, 300) 
        y = random.randint(50, 400) 
        food = canvas.create_oval(x - r, y - r, x + r, y + r, fill="red")
        # tail()
        if eaten != 0:
            move = True
    collision1 = canvas.find_overlapping(x1, y1, x2, y2) 
    if barrier in collision1 or snake1 in collision1 or x1 == 10 or x2 == 340 or y2 == 440 or y1 == 10:
        f = open("ваши рекорды.txt", "a")
        f.write(str(eaten) + '\n')
        f.close()
        canvas.delete('all')
        canvas.create_text(160,180,text='GAME OVER',font="Verdana 12",fill="red")
        root.unbind('<Up>')
        root.unbind('<Down>')
        root.unbind('<Left>')
        root.unbind('<Right>')
        canvas.delete(snake)
        return()
    root.bind('<Up>', move_up)
    root.bind('<Down>', move_down)
    root.bind('<Left>', move_left)
    root.bind('<Right>', move_right)
    if navigation == "up":
        y1 -= moveY1
        y2 -= moveY2
    elif navigation == "down":
        y1 += moveY1
        y2 += moveY2
    elif navigation == "left":
        x1 -= moveX1
        x2 -= moveX2
    elif navigation == "right":
        x1 += moveX1
        x2 += moveX2
    canvas.delete(snake)
    time.sleep(0.1)
    snake = canvas.create_rectangle(x1,y1,x2,y2, fill="green")
    root.after(a, draw)
if death == False:
    draw()

root.mainloop()