fuel

function cls()
 term.clear()
 term.setCursorPos(1,1)
end
function ceil(num)
 return math.ceil(num)
end


function canrefuel(items_needed)
 local actual_items=0
 for i=1,16 do
  turtle.select(i)
  actual_items=actual_items+turtle.getItemCount(i)
 end
 if actual_items>=items_needed then
  return true
 else
  return false
 end
end

function refuel_sub(items_needed)
 local items_remaining=items_needed
 for i=1,16 do
  turtle.select(i)
  if turtle.getItemCount(i)>=items_remaining then
   turtle.refuel(items_remaining)
   return
  else
   turtle.refuel(items_remaining)
   items_remaining=items_remaining-turtle.getItemCount(i)
  end
 end
end

function refuel(moves_needed,items_needed)
 if canrefuel(items_needed) then
  refuel_sub()
 else
  print("Not enough coals, try again")
 end
end


cls()
print("Input amount of moves")
local moves_needed = tonumber(io.read())

if moves_needed<=turtle.getFuelLevel() then
 print("You already have enough fuel")
else
 items_needed=ceil((moves_needed-turtle.getFuelLevel())/80)

 if items_needed>1 then
  print("Ok, put ",items_needed," coals in the turtle inventory")
 else
  print("Ok, put 1 coal in the turtle inventory")
 end

 print("<press enter to continue>")
 while true do
  local event,key = os.pullEvent("key")
  if key==28 then break
 end

 refuel(moves_needed,items_needed)

end