Shoes.app title: 'Snake Game v0.1' do
  def game_start
    @score = para 'Score:', stroke: white
    @pos = {up: [0, -10], down: [0, 10], left: [-10, 0], right: [10, 0]}
    @rx, @ry = proc{20 + 10*rand(56)}, proc{40 + 10*rand(44)}

    create_food

    create_bricks

    create_initial_snake

    dir = :left
    @run  = animate 5 do
      check_food
      go dir
      @score.text = "Score: #{@snake.length * 10}"
      brick? @snake[0]
    end
    keypress{|k| dir = k if @pos.keys.include? k}
  end

  def go k
    x, y = @pos[k]
    @snake.unshift @snake.pop
    n = @snake.length > 1 ? 1 : 0
    @snake[0].move @snake[n].left + x, @snake[n].top + y
    @snake[0].style stroke: red
    @snake[1].style stroke: white if n > 0
  end

  def check_food
    (@snake << rect(0, 0, 10, 10)) if eat? @snake[0]
  end

  def eat? s
    @foods.each_with_index do |f, i|
      (f.move @rx[], @ry[]; return true) if f.left == s.left and f.top == s.top
    end
    return false
  end

  def brick? s
    @bricks.each do |b|
      (@run.remove; alert 'Game Over. ') if b.left == s.left and b.top == s.top
    end
  end

  def create_food
    @foods = []
    stroke lime
    50.times{@foods << rect(@rx[], @ry[], 10, 10)}
  end

  def create_bricks
    @bricks = []
    stroke deepskyblue; fill blue

    50.times{@bricks << rect(@rx[], @ry[], 10, 10)}

    20.step(570, 10){|n| @bricks << rect(n, 40, 10, 10) << rect(n, 470, 10, 10)}

    40.step(470, 10){|n| @bricks << rect(10, n, 10, 10) << rect(570, n, 10, 10)}
  end

  def create_initial_snake
    @snake = []
    stroke white; nofill

    @snake << rect(300, 100, 10, 10)

    @snake[0].style stroke: red
  end

  background black

  game_start
end