snake.rb

class Square
end

class EmptySquare < Square
  def to_s
    'º'
  end
end

class FoodSquare < Square
  def to_s
    'O'
  end
end

class SnakeSquare < Square
  attr_accessor :x, :y

  def initialize(x:, y:)
    @x = x
    @y = y
    @direction = [0, 1]
  end

  def to_s
    '█'
  end
end

class Board
  def initialize(width: 15, height: 15, food_quantity: 5, snake_size: 1)
    @width   = width
    @height  = height
    @squares = height.times.map do
      width.times.map do
        EmptySquare.new
      end
    end

    food_quantity.times.map do
      @squares[rand(height)][rand(width)] = FoodSquare.new
    end

    @snake = SnakeSquare.new(x: height/2, y: width/2)
  end

  def clear
    print("\e[2J\e[f")
  end

  def render
    clear
    @squares.each.with_index do |line, y|
      line.each.with_index do |square, x|
        if @snake.x == x && @snake.y == y
          print snake
        else
          print square
        end
      end
      puts
    end
  end
end

interval = 0.8
board = Board.new

loop {
  board.render
  sleep(interval)
}