game.js

import {update as updateSnake, draw as drawSnake, SNAKE_SPEED, getSnakeHead, sankeIntersection} from './snake.js'
import {update as updateFood, draw as drawFood} from './food.js'
import {outsideGrid} from './grid.js'

let lastRenderTime = 0
let gameOver = false
const gameBoard = document.getElementById('game-board')

function main(currentTime){
    if(gameOver){
        if(confirm('You lost. Press OK to restart.')){
            window.location =''
        }
        return
    }

    window.requestAnimationFrame(main)
    const secondSinceLastRender = (currentTime - lastRenderTime) / 1000
    if(secondSinceLastRender < 1 / SNAKE_SPEED) return

    lastRenderTime = currentTime

    update()
    draw()
}

window.requestAnimationFrame(main)

function update() {
    updateSnake()
    updateFood()
    checkDeath()
}

function draw() {
    gameBoard.innerHTML=''
    drawSnake(gameBoard)
    drawFood(gameBoard)
}

function checkDeath(){
    gameOver = outsideGrid(getSnakeHead()) || sankeIntersection()
}