write("How many levels should I dig: ")
local levels = tonumber(io.read())

write("Enter fuel slot (1-9): ")
local fuelSlot = tonumber(io.read())

write("Enter torches slot (1-9): ")
local torchSlot = tonumber(io.read())

write("Digging a 3x3 for "..levels.." levels!\n")

function checkFuel()
  if turtle.getFuelLevel() < 5 then
    turtle.select(1)
    if not turtle.refuel(1) then
      error("Out of fuel")
    end
  end
end

function placeTorch()
  turtle.select(torchSlot)
  turtle.turnLeft()
  turtle.turnLeft()
  turtle.place()
  turtle.turnRight()
  turtle.turnRight()
end

function dig()
  while turtle.detect() do
    turtle.dig()
  end
end

function digUp()
  while turtle.detectUp() do
    turtle.digUp()
  end
end

function mineLayer()
  dig()
  turtle.forward()

  turtle.turnLeft()
  dig()
  digUp()
  turtle.up()
  dig()
  digUp()
  turtle.up()
  dig()

  turtle.turnRight()
  turtle.turnRight()
  dig()
  turtle.down()
  dig()
  turtle.down()
  dig()

  turtle.turnLeft()
end

local levelsSinceTorch = 1

for i=1,levels do
  checkFuel()
  mineLayer()
  if levelsSinceTorch % 6 == 0 then
    placeTorch()
  end
  levelsSinceTorch = levelsSinceTorch + 1
end

turtle.turnLeft()
turtle.turnLeft()
for i=1,levels do
  if turtle.detect() then
    turtle.dig()
  end
  turtle.forward()
end

write("Finished mining\n")