directions = {up = {x = 0, y = -1}, down = {x = 0, y = 1}, left = {x = -1, y = 0}, right = {x = 1, y = 0}}

function love.load()
  game = {}
  game.width = love.graphics.getWidth()
  game.height = love.graphics.getHeight()
  game.running = true

  player = {}
  player.x = game.width / 2
  player.y = game.height / 2
  player.dir = "left"
  player.speed = 150
  player.color = {255, 255, 255}
  player.points = {}
  player.max_length = 100

  love.graphics.setBackgroundColor(0, 0, 0)
end

function love.update(dt)
  if game.running then

    -- Figure out the next position for the snake's head
    player.x = player.x + directions[player.dir].x * player.speed * dt
    player.y = player.y + directions[player.dir].y * player.speed * dt
    table.insert(player.points, 1, {x = player.x, y = player.y})

    -- Is the player running into a wall?
    if player.x <= 0 or player.x >= game.width or player.y <= 0 or player.y >= game.height then
      game.running = false
    end

    -- Keep the snake no larger than the max_length
    if #player.points >= player.max_length then
      table.remove(player.points)
    end
  end
end

function love.draw()
  if game.running then

    -- Draw the snake's segments
    love.graphics.setColor(unpack(player.color))
    for _, pos in pairs(player.points) do
      love.graphics.point(pos.x, pos.y)
    end

  else
    -- Game Over Screen
    love.graphics.printf("Game Over", game.width / 2, game.height / 2, 0, "center")
  end
end

function love.keypressed(key)
  if directions[key] then
    player.dir = key
  end

  if key == "escape" then
    love.event.push("q")
  end
end