ComputerCraft Tutorial: boring_0_2

-- ################################
-- Boring by mining turtle
-- version 0.2
-- http://hevohevo.hatenablog.com/

-- ########## config
MIN_FUEL_LEVEL = 400
CLOSE_HOLE_FLAG = true -- boolean. whether close a hole
LID_BLOCK_SLOT = 1

local args={...}
-- reverse CLOSE_HOLE flag
if #args > 0 then
  CLOSE_HOLE_FLAG = not CLOSE_HOLE_FLAG
end

-- ########## functions
function myRefuel()
  local function refuelAll()
    for i=1, 16 do
      turtle.select(i)
      turtle.refuel()
    end
    print("Fuel: ",turtle.getFuelLevel(), " (required: ",MIN_FUEL_LEVEL,")")
  end

  refuelAll()
  while turtle.getFuelLevel() < MIN_FUEL_LEVEL do
    os.sleep(1)
    -- wait for putting items in inventory
    os.pullEvent("turtle_inventory")
    refuelAll()
  end

  turtle.select(1)
end

function revolve(depth)
  for i=1, 4 do -- dig four sides
    turtle.dig()
    turtle.turnRight()
  end

  turtle.digDown() -- dig down side

  if turtle.getFuelLevel() > depth then
    return turtle.down() -- return true/false
  else
    return false -- if fuel shortage
  end
end

function closeHole()
  turtle.select(LID_BLOCK_SLOT)
  turtle.down()

  for i=1,4 do
    turtle.place()
    turtle.turnRight()
  end

  turtle.up()
  turtle.placeDown()
end

function backToHome(n)
  for i=1, n do -- back to home position.
    turtle.up()
  end
end

-- ########## main
myRefuel()

local depth = 0
while revolve(depth) do
  depth = depth +1
end

backToHome(depth)
if CLOSE_HOLE_FLAG then closeHole() end