import random
import turtle as t
t.bgcolor('yellow') 
caterpillar = t.Turtle() 
caterpillar.shape('square')
caterpillar.color('red')
caterpillar.speed(0) 
caterpillar.penup() 
caterpillar.hideturtle() 
leaf = t.Turtle()

leaf_shape = ((0, 0), (14, 2), (18, 6), (20, 20), (6, 18), (2, 14)) 
t.register_shape('leaf', leaf_shape) 
leaf.shape('leaf')
leaf.color('green')
leaf.penup() 
leaf.hideturtle() 
leaf.speed(0)
game_started = False 
text_turtle = t.Turtle() 
text_turtle.write('Press SPACE to start', align='center', font=('Arial', 16, 'bold'))
text_turtle.hideturtle()
score_turtle = t.Turtle() 
score_turtle.hideturtle()
score_turtle.speed(0) 

def outside_window():
    left_wall = -t.window_width() / 2
    right_wall = t.window_width() / 2
    top_wall = t.window_height() / 2
    bottom_wall = -t.window_height() / 2
    (x, y) = caterpillar.pos() 
    outside = \
        x< left_wall or \
        x> right_wall or \
        y< bottom_wall or \
        y> top_wall
    return outside

def game_over():
    caterpillar.color('yellow')
    leaf.color('yellow')
    t.penup()
    t.hideturtle()
    t.write('GAME OVER!', align='center', font=('Arial', 30, 'normal'))

def display_score(current_score):
    score_turtle.clear()
    score_turtle.penup()
    x = (t.window_width() / 2) - 50
    y = (t.window_height() / 2) - 50
    score_turtle.setpos(x, y)
    score_turtle.write(str(current_score), align='right', font=('Arial', 40, 'bold'))

def place_leaf():
    leaf.ht()
    leaf.setx(random.randint(-200, 200))
    leaf.sety(random.randint(-200, 200))
    leaf.st()
def start_game():
    global game_started
    if game_started:
        return
    game_started = True

    score = 0
    text_turtle.clear()

    caterpillar_speed = 2
    caterpillar_length = 3
    caterpillar.shapesize(1, caterpillar_length, 1)
    caterpillar.showturtle()
    display_score(score)
    place_leaf()

    while True:
        caterpillar.forward(caterpillar_speed)
        if caterpillar.distance(leaf) < 20:
            place_leaf()
            caterpillar_length = caterpillar_length + 1
            caterpillar.shapesize(1, caterpillar_length, 1) 
            caterpillar_speed = caterpillar_speed + 1
            score = score + 10
            display_score(score)
        if outside_window():
            game_over()
            break
def move_up():
    if caterpillar.heading() == 0 or caterpillar.heading() == 180:
        caterpillar.setheading(90)

def move_down():
    if caterpillar.heading() == 0 or caterpillar.heading() == 180:
        caterpillar.setheading(270)

def move_left():
    if caterpillar.heading() == 90 or caterpillar.heading() == 270:
        caterpillar.setheading(180)

def move_right():
    if caterpillar.heading() == 90 or caterpillar.heading() == 270:
        caterpillar.setheading(0)
t.onkey(start_game, 'space')
t.onkey(move_up, 'Up')
t.onkey(move_right, 'Right')
t.onkey(move_down, 'Down')
t.onkey(move_left, 'Left')
t.listen()
t.mainloop()