Thaumcraft 4 Mana bean harvester

local columnHeight = 100
local currentSlot = 1
local currentDirection = "up"
local cycleCount = 1
local stockHandle = nil
local turnDirection = "right"
local dropMode = nil

function loopSlot()
   local nextSlot = nil
   if currentSlot<16 then
      nextSlot = currentSlot+1
   else
      nextSlot = 1
   end
   selectSlot(nextSlot)
end

function place()
   local limit=16
   while turtle.getItemCount(currentSlot) == 0 and limit>0 do
      loopSlot()
      limit = limit - 1
   end
   if limit == 0 then
      print("Place limit reached - inventory empty")
   end
   print ("Items in current slot: ", turtle.getItemCount(currentSlot))
   print ("Current slot: ", currentSlot)
   return turtle.place()
end

function dig()
   if turnDirection == "none" and currentDirection == "down" then
      --do nothing
   else
      turtle.dig()
   end
end

function turtleUp()
   local limit = 5
   for i = 1,5 do
      if turtle.up() then
         return true
      else
         sleep(0.3)
      end
   end
   return false
end

function turtleDown()
   local limit = 5
   for i = 1,5 do
      if turtle.down() then
         return true
      else
         sleep(0.3)
      end
   end
   return false
end

function move()
   if currentDirection == "up" then
      return turtleUp()
   elseif currentDirection == "down" then
      return turtleDown()
   else
      print("Unknown direction: ", currentDirection)
      exit()
   end
end

function revertDirection()
   if currentDirection == "up" then
      currentDirection = "down"
   elseif currentDirection == "down" then
      currentDirection = "up"
   else
      print("Unknown current direction: ", currentDirection)
      exit()
   end
end

function selectSlot(slotNumber)
   turtle.select(slotNumber)
   currentSlot = slotNumber
end

function oneDirection()
   selectSlot(1)

   local movesInOneDir = 0
   while movesInOneDir < columnHeight do
      dig()
      if not place() and currentDirection == "up" then
         print("Cannot place, breaking")
         break
      end
      if not move() then
         print("Can't go current direction, reverting")
         break
      end
      movesInOneDir = movesInOneDir + 1
      if dropMode == "continousDrop" then
         selectSlot(2)
         turtle.dropDown()
         selectSlot(1)
         turtle.dropDown()
      end
   end
end

function turn()
    if turnDirection == "right" then
        turtle.turnRight()
    elseif turnDirection == "left" then
        turtle.turnLeft()
    elseif turnDirection == "around" then
        turtle.turnLeft()
        turtle.turnLeft()
    elseif turnDirection == "none" then
        print("Turn direction = 'none', not turning")
    else
        print("Incorrect turn direction, turning right")
        turtle.turnRight()
    end
end

function goUpAndDown()

    if turtle.getFuelLevel() < 300 then
       print("Error - low on fuel ", turtle.getFuelLevel())
       exit()
    end

    resupplyBeans()
    oneDirection()
    revertDirection()
    turn()

    oneDirection()
    revertDirection()
    turn()
end

function resupplyBeans()
    -- refilling from filing cabinet below us
    for i=1,16 do
       selectSlot(i)
       if stockHandle == "resupply" then
          turtle.suckDown()
       elseif stockHandle == "dump" then
        -- we expect vacuum hopper to grab mana beans we drop
          turtle.drop()
          --turtle.dropDown()
       elseif not stockHandle then
          -- doing nothing
       else
          print("Wrong resupply command")
          exit()
       end
    end
end

local args = {...}
if args[1] and tonumber(args[1]) then
   cycleCount = tonumber(args[1])
end

if args[2] == "resupply" then
   stockHandle = "resupply"
elseif args[2] == "dump" then
   stockHandle = "dump"
else
   print("No resupply command")
end

if args[3] == "left" or args[3] == "right" or args[3] == "around" or args[3] == "none" then
   turnDirection = args[3]
else
   print("Using default turn direction")
end

if args[4] == "continousDrop" then
   dropMode = args[4]
else
   print("No special drop mode")
end

for cycle = 1,cycleCount do
   goUpAndDown()
end