build

turtle.refuel()

local running = true
print("Tower Time!")

local slot = 2

function forward()
  checkSlot()
  turtle.forward()
  turtle.placeDown()
end

function left()
  checkSlot()
  turtle.turnLeft()
  turtle.forward()
  turtle.placeDown()
end

function right()
  checkSlot()
  turtle.turnRight()
  turtle.forward()
  turtle.placeDown()
end

function checkSlot()
    if (not turtle.getItemDetail()) and slot == 16 then
      print("Out of Items")
      running = false
    elseif (not turtle.getItemDetail()) then
      slot = slot + 1

      if (not turtle.getItemDetail()) then
        running = false
        print('Next slot empty, quitting')
      end
    end
end

while running and not (turtle.detect() and turtle.detectUp()) do
  print("Curr Slot: ", slot)
  turtle.select(slot)
  checkSlot()
  turtle.up()
  turtle.placeDown()

  for i = 1, 4 do
    forward()
    forward()
    forward()
    right()
    left()
    forward()
    right()
    left()
    right()
    left()
    right()
    left()
    right()
    left()
    right()
    forward()
    left()
    right()
    forward()
    forward()
  end
end