Turtle attack program

-- Jaffa's attack turtle program
-- Version: 1.0.1.0
local hits = 0
local tries = 0
local movemode = false
local moveallowed = false
local tstop
local ignoredkeys = {["2"]=true, ["5"]=true, ["8"]=true}
local waittext = " - Wait"

local args = { ... }
if args[1] == "movemodeon" then movemode = true end
if movemode == true then
local tx, ty = term.getCursorPos()
term.setCursorPos(1 ,ty - 1)
term.clearLine()
print("Jaffa's attack program")
end

function cleanInv ()
  for i = 1, 16 do
    if turtle.getItemCount(i) then
      turtle.select(i)
      turtle.drop()
    end
  end
  turtle.select(1)
end

function checkInv ()
  cleanInv()
  while not tstop do
    sleep(1)
    if turtle.getItemCount(4) > 0 then
      cleanInv()
    end
  end
  cleanInv()
end

function keywait ()
  while not tstop do
    local event,key = os.pullEvent()
      if (event == "key") and (key == 203) then
        if not turtle.turnLeft() then print("Error turning left") end
      elseif (event == "key") and (key == 205) then
        if not turtle.turnRight() then print("Error turning right") end
      elseif (event == "key") and (key == 200) and (moveallowed == true) then
        if not turtle.forward() then print("Error moving forward") end
      elseif (event == "key") and (key == 208) and (moveallowed == true) then
        if not turtle.back() then print("Error moving back") end
      elseif (event == "key") and (key == 76) and (movemode == true) then
        if moveallowed == true then
          moveallowed = false
          print("Move lock enabled")
        else
          moveallowed = true
          print("Move lock disbled")
        end
      elseif (event == "key") and (key == 72) and (moveallowed == true) then
        if not turtle.up() then print("Error moving up") end
      elseif (event == "key") and (key == 80) and (moveallowed == true) then
        if not turtle.down() then print("Error moving down") end
--      elseif (event == "char") and (not ignoredkeys[key]) then
--        tstop = true
      elseif (event == "char") and (key == "s") then
        tstop = true
       write(waittext)
      elseif (event == "char") and (key == "d") then
        cleanInv()
      end
  end
end

function attack ()
  while not tstop do
    if turtle.attack() then
      hits = hits + 1
    else
      sleep(0.15)
    end
    tries = tries + 1
   end
end

function stats ()
  local tx,ty = term.getCursorPos()
  while not tstop do
    sleep(2)
    local percentage = (hits/tries) * 100
    term.setCursorPos(1,ty)
    term.clearLine()
    term.setCursorPos(1,ty)
    write("Hits: ")
    write(hits)
    write("/")
    write(tries)
    write(" (")
    write(percentage)
    write("%)")
  end
  write(waittext)
end

turtle.select(1)
print("Press S to stop, D to drop")
parallel.waitForAll(keywait,attack,stats,checkInv)
local mx,my = term.getCursorPos()
term.setCursorPos((mx - string.len(waittext)),my)
print(" \\e/   ")