ns_sherlok

function checkFuel()
  if turtle.getFuelLevel() < 10 then
    turtle.select(1);
    turtle.refuel(1);
  end
end

function doDig()
  turtle.dig();
  turtle.forward();
  turtle.digUp();
  turtle.digDown();
end

local cellFuel = 1;
local cellTorch = 2;

function placeTorch()
  if turtle.getItemCount(cellTorch) > 0 then
    turtle.select(cellTorch);
    turtle.placeDown();
    return 1;
  else
    return 0;
  end
end

local tonnelLength = 10; -- Tonnel length

function doWork()
  for i = 1, tonnelLength do
    checkFuel();
    doDig();
    placeTorch();
  end
end

doWork();