smelter

currentSlot =  turtle.getSelectedSlot()

function refuelOnce()
  if turtle.getFuelLevel() < 20 then
    turtle.select(16)
    turtle.refuel(1)
    turtle.select(currentSlot)
 end
end

function searchForChest()
  for search = 1,4 do
    succes, data = turtle.inspect()
     if data.name ~= "minecraft:chest" then
      turtle.turnLeft()
   end
  end
end

function fillFromChest()
  for i = 1,14 do
    turtle.select(i)
   turtle.suck()
 end
 putCoalToSlot16()
end

function dropToChest()

  if turtle.getSelectedSlot() == 16 then
    turtle.drop()
  else
    turtle.select(14)
    turtle.drop()
  end
end


function putCoalToSlot16 ()
  for i = 1,15 do
    turtle.select(i)
    data = turtle.getItemDetail()

      if turtle.getItemCount() > 0 and data.name == "minecraft:coal" then
        turtle.transferTo(16)
     end
    end
    refuelOnce()
 end

function smelt()
print("Moving up to furnace")
  for searchOven = 1,4 do
    succes, data = turtle.inspect()
      if data.name ~= "minecraft:furnace" and data.name ~= "minecraft:lit_furnace" then
        turtle.turnLeft()
     end
    turtle.select(16)
  end

turtle.drop()
turtle.up()
turtle.forward()

  for i =  1,15 do
    turtle.select(i)
      if turtle.dropDown() then
      breaking = false
        break
    end

    succes, data = turtle.inspectDown()
    if turtle.getSelectedSlot() == 15 and data.name ~= "minecraft:lit_furnace" then
      print("No smelting Furnace")
      breaking = true
    else
    breaking = false
 end
end

if breaking == true then
print("checking for smelting product that is left")
turtle.forward()
turtle.down()
turtle.turnLeft()
turtle.turnLeft()
succes, data = turtle.inspect()
  if data.name == "minecraft:furnace" then
    turtle.suck()
  else
    while true do
    succes, data = turtle.inspect()
    if data.name == "minecraft:furnace" then
      turtle.suck()
      break
    elseif data.name == "minecraft:furnace" then
    turtle.suck()
    break
    end
  end
end

end
if breaking  == false then
turtle.forward()
turtle.down()
turtle.turnLeft()
turtle.turnLeft()
smeltTime = 0


  while true do
    smeltTime = smeltTime + 1
    print(smeltTime)

      if smeltTime > 1200 then
        print("smelting time is over")
        break
      end

    succes, data = turtle.inspect()
    turtle.select(14)
      if data.name == "minecraft:furnace" and turtle.suck() then
         break
      elseif data.name == "minecraft:furnace" then
      break
       end
    end
   end
end


function smeltProductInChest()

turtle.up()
turtle.forward()
turtle.forward()
turtle.down()
turtle.down()
searchForChest()
dropToChest()

  for i = 1,16 do
    turtle.select(i)
    if turtle.suck() then
      data = turtle.getItemDetail()
      if data.name ~= "minecraft:coal" then
        turtle.drop()
      else
         turtle.transferTo(16)
       end
      end
     end

turtle.select(16)
turtle.drop()
turtle.select(1)
turtle.up()

end

function ask()
print("want to get the furnace going?")
term.write("yes = 1 | no = 0 : ")
answer = tonumber(read())
answer = tonumber(answer)
if answer == 1 then
  print("great, getting started")


elseif answer == 0 then
  print("no problem, shutting down")

elseif type(answer) ~= number then
  print("sorry, invalid input")
  ask()
end

  return answer
end

while true do
ask()
if answer == 0 then
  break
 end
searchForChest()
fillFromChest()
smelt()
smeltProductInChest()
end