SNAKE GAME

from tkinter import *
import random



GAME_WIDTH = 700
GAME_HEIGHT = 700
SPEED = 80
SPACE_SIZE = 50
BODY_PARTS = 3
SNAKE_COLOR = "#519940"
FOOD_COLOR = "#a8182d"
BACKGROUND_COLOR = "#000000"

def centerWindow(root, width, height):
    screen_width = root.winfo_screenwidth()
    screen_height = root.winfo_screenheight()

    x = (screen_width - width) // 2
    y = (screen_height - height) // 2

    root.geometry(f"{width}x{height}+{x}+{y}")


class Snake:
    def __init__(self):
        self.bodyParts = BODY_PARTS
        self.coordinates = []
        self.squares = []

        for i in range (0, BODY_PARTS):
            self.coordinates.append([0,0])

        for x, y in self.coordinates:
            square = canvas.create_rectangle(x, y, x + SPACE_SIZE, y + SPACE_SIZE, fill=SNAKE_COLOR)
            self.squares.append(square)

class Food:
    def __init__(self):

        x = random.randint(0,(GAME_WIDTH/SPACE_SIZE-1)) * SPACE_SIZE
        y = random.randint(0, (GAME_HEIGHT / SPACE_SIZE - 1)) * SPACE_SIZE

        self.coordinates = [x,y]

        canvas.create_oval(x, y, x + SPACE_SIZE, y + SPACE_SIZE, fill=FOOD_COLOR, tag="food")

def nextTurn(snake, food):

    x, y = snake.coordinates[0]


    if direction == "up":
        y-= SPACE_SIZE
    elif direction == "down":
        y+= SPACE_SIZE
    elif direction == "left":
        x -= SPACE_SIZE
    elif direction == "right":
        x += SPACE_SIZE

    snake.coordinates.insert(0, (x, y))
    square = canvas.create_rectangle(x, y, x + SPACE_SIZE, y + SPACE_SIZE, fill=SNAKE_COLOR)
    snake.squares.insert(0, square)

    if x == food.coordinates[0] and y == food.coordinates[1]:
        global score

        score += 1

        label.config(text = "Score: {}".format(score))

        canvas.delete("food")

        food = Food()

    else:
        del snake.coordinates[-1]
        canvas.delete(snake.squares[-1])
        del snake.squares[-1]

    if checkCollisions(snake):
        gameOver()
    else:
        root.after(SPEED, nextTurn, snake, food)



def changeDirection(new_direction):
    global direction

    if new_direction == 'left':
        if direction != 'right':
            direction = new_direction
    elif new_direction == 'right':
        if direction != 'left':
            direction = new_direction
    elif new_direction == 'up':
        if direction != 'down':
            direction = new_direction
    elif new_direction == 'down':
        if direction != 'up':
            direction = new_direction

def checkCollisions(snake):

    x, y = snake.coordinates[0]

    if x < 0 or x >= GAME_WIDTH:
        print("GAME OVER")
        return True
    elif y < 0 or y >= GAME_WIDTH:
        print("GAME OVER")
        return True

    for bodyPart in snake.coordinates[1:]:
        if x == bodyPart[0] and y == bodyPart[1]:
            print("GAME OVER")
            return True

    return False

def gameOver():
    canvas.delete(ALL)
    canvas.create_text(canvas.winfo_width()/2, canvas.winfo_height()/2, font=('consolas', 40), text="GAME OVER", fill="red", tag="gameover")

root = Tk()
root.title("Snake Game")
root.resizable(False, False)

centerWindow(root,800,800)

score = 0
direction = "down"

label = Label(root,text = "Score: {}".format(score), font=('consolas', 40))
label.pack()

canvas = Canvas(root, bg=BACKGROUND_COLOR, height=GAME_HEIGHT, width=GAME_WIDTH)
canvas.pack()

root.update()

root.bind('<Left>', lambda event: changeDirection('left'))
root.bind('<Right>', lambda event: changeDirection('right'))
root.bind('<Up>', lambda event: changeDirection('up'))
root.bind('<Down>', lambda event: changeDirection('down'))

snake = Snake()
food = Food()

nextTurn(snake, food)

root.mainloop()