Computercraft Extractor Controller

--EyeDeck's extractor controller program
os.loadAPI("buttonAPI")

ex = peripheral.wrap("front")
cvt = peripheral.wrap("AdvancedGears_2")
coil = peripheral.wrap("AdvancedGears_3")
mon = peripheral.wrap("left")

mon.setTextScale(0.5)
mon.setBackgroundColor(colors.black)
mon.setTextColor(colors.white)
mon.clear()

coil.setSpeed(4096)
coil.setTorque(0)

buttonAPI.drawButton(mon,2,2,16,7,colors.black,colors.lime,"Start","startstop")
buttonAPI.drawButton(mon,20,2,16,7,colors.black,colors.blue,"Manual","manualauto")

isOn = false
autoOn = false

--Returns right-most item in extractor, else if empty returns false
function notEmpty()
  for i = 4,1,-1 do
    local item = ex.getStackInSlot(i)
    if item ~= nil then
      return item
    end
  end

  return false
end

-- Prints a message to the console and halts execution until given handle exists
-- too lazy to implement yet
function sanityCheck(handle)
end

function updateDisplay(name)
  local old_disp = term.redirect(mon)
  local power_in_hours = math.floor(coil.getEnergy() / 37507786621 * 100)*.01

  term.setCursorPos(2,10)
  term.setTextColor(colors.white)
  -- extra spaces are a hack to clear the last item if necessary ("Ammonium Chloride Solution" is long)
  write("Extracting: ".. name .."                     \n                       ")
  term.setCursorPos(2,12)
  write("Power remaining: ".. power_in_hours .."h         ")
  term.redirect(old_disp)
end

function exLoop()
  while true do
    if isOn then
      print("beginning extraction")
      jammed = false

      while isOn do
        local currentItem = notEmpty()

        if currentItem ~= false and jammed == false then
          updateDisplay(currentItem.display_name)

          cvt.setRatio(1)
          coil.setTorque(4096)
          sleep(4.2)

          cvt.setRatio(32)
          coil.setTorque(256)
          sleep(2.85)
        else
          if jammed == true then
            updateDisplay("Jammed (check output)")
          else
            updateDisplay("Idle")
          end

          if autoOn then
             coil.setTorque(0)
            sleep(8)
          else
            isOn = false
            buttonAPI.drawButton(mon,2,2,16,7,colors.black,colors.lime,"Start")
          end
        end
      end

    coil.setTorque(0)
    print("ceasing extraction")

    else -- isOn == false
      sleep(2)
    end
  end
end

function uiLoop()
  while true do
    event, _, x, y = os.pullEvent("monitor_touch")
    local button_name = buttonAPI.getButton(x,y)
    --print(button_name .. " pressed at " .. x .. "," .. y)

    if button_name == "startstop" then
      if isOn == false then
        buttonAPI.drawButton(mon,2,2,16,7,colors.black,colors.red,"Stop")
        isOn = true
      else
        buttonAPI.drawButton(mon,2,2,16,7,colors.black,colors.lime,"Start")
        isOn = false
      end
    elseif button_name == "manualauto" then
      if autoOn == false then
        buttonAPI.drawButton(mon,20,2,16,7,colors.black,colors.yellow,"Automatic")
        autoOn = true
      else
        buttonAPI.drawButton(mon,20,2,16,7,colors.black,colors.blue,"Manual")
        autoOn = false
      end
    end
  end
end

--[[
  While main function is active, if the item in the output slot remains
  unchanged for ~12 seconds or longer, assume the machine has jammed
  and set a variable to stop the main loop.
--]]
function jamLoop()
  local jamCount = 0
  local lastItem = nil
  local item = nil

  while true do
    if isOn then
      item = ex.getStackInSlot(8)

      if item ~= nil then
        if lastItem == item then
          jamCount = jamCount + 1
        else
          jamCount = 0
        end

        lastItem = item

        if jamCount >= 3 then
          jammed = true
        end
      end
    end

    sleep(4)
  end
end

if (notEmpty() ~= false) then
  updateDisplay(notEmpty().display_name)
else
  updateDisplay("Idle")
end

parallel.waitForAll(uiLoop, exLoop, jamLoop)