enchanting turtle v0.2

local bookSlot = 1
local enchantSlot = 16

local emptySlotsStart = 2
local emptySlotsEnd = 15

local xpSide = "right"
local grinderSide = "left"
local manualSide  = "back"

local xp = peripheral.wrap(xpSide)

local enchantLevel = 30
local levelLow = 60
local levelHigh = 120




function getBook()
  if turtle.getItemCount(bookSlot) < 1 then
    turtle.select(bookSlot)
    turtle.suckUp()
    clearInv()
    if turtle.getItemCount(bookSlot) < 2 then
      return false
    end
  end

  return true
end

function setGrind(isGrind)
  redstone.setOutput(grinderSide, isGrind)
end

local lastLevel
function checkXP()
  local level = xp.getLevels()
  if level ~= lastLevel then
    print("level " .. level)
  end

  lastLevel = level
  if level <= levelLow then
    setGrind(true)
  elseif level >= levelHigh then
    setGrind(false)
  end

  return level >= enchantLevel
end

function clearInv()
  for i = emptySlotsStart, emptySlotsEnd do
    turtle.select(i)
    turtle.dropDown()
  end
  if turtle.getItemCount(enchantSlot) > 0 then
    turtle.select(enchantSlot)
    if turtle.compareTo(bookSlot) then
      turtle.dropUp()
    else
      turtle.dropDown()
    end
  end
  turtle.select(bookSlot)
end

function enchant()
  turtle.select(bookSlot)
  turtle.transferTo(enchantSlot, 1)
  turtle.select(enchantSlot)
  local good = xp.enchant(enchantLevel)
  if good then
    print("Enchant successful")
  else
    print("Enchant failed")
  end
  clearInv()
end

function setManual(isManual)
  if isManual then
    setGrind(false)
    xp.setAutoCollect(false)
  else
    xp.setAutoCollect(true)
  end
end

function isManualSignal()
  return redstone.getInput(manualSide)
end

function main()
  clearInv()
  while true do
    if isManualSignal() then
      setManual(true)
      sleep(1)
    else
      setManual(false)
      if checkXP() and getBook() then
        enchant()
      else
        sleep(5)
      end
    end
  end
end

main()