Tunnel... (Default program.)

-- A revised version of the built in tunnelling script that mines a 3x3 tunnel (as opposed to 3x2)
-- Fills in any missing floor blocks with blocks from slot 1 (in theory)
-- returns to start point (buggy won't refuel)
-- Mk III v0.1
-- changes by LN

local tArgs = { ... }
if #tArgs ~= 1 then  -- No length supplied error out with message
  print( "Usage: tunnel <length>" )
  return
end

-- If value supplied check to make sure it's positive
local length = tonumber( tArgs[1] )
if length < 1 then
  print( "Tunnel length must be positive" )
  return
end

-- some more variables (wtf is depth?)
local depth = 0
local collected = 0
local dbg = 0 -- change to 1 if you want test messages to be displayed (LN)

local function collect() -- function works out how much shit you've collected (fails with lapis &amp; redstone iirc)
  collected = collected + 1
  if math.fmod(collected, 25) == 0 then
	print( "Mined "..collected.." items." )
  end
end

local function test(txt) -- function to print test/debug messages, bit spammy but shows what turtle thinks it's doing... even when it isn't... :D/>/> (LN)
  if dbg == 1 then
	print("Turtle says: " , txt )
	sleep(5) -- change to shorter/longer to speed up/slow down debug
  end
end

local function reverseTurtle() -- 180 degree turn (LN)
  turtle.turnRight()
  turtle.turnRight()
  test("Reversing Turtle")
end

local function tryDig()
  while turtle.detect() do
	if turtle.dig() then
	  collect()
	  sleep(0.5)
	  test("Dig Fwd")
	else
	  test("Dig Fwd Fail")
	  return false
	end
  end
  return true

end

local function tryDigUp()
  while turtle.detectUp() do
	if turtle.digUp() then
	  collect()
	  sleep(0.5)
	  test("Dig Up")
	else
	  test("Dig Up Fail")
	  return false
	end
  end
  return true

end

local function tryDigDown()
  while turtle.detectDown() do
	if turtle.digDown() then
	  collect()
	  sleep(0.5)
	  test("Dig Down")
	else
	  test("Dig Down Fail")
	  return false
	end
  end
  return true

end

local function refuel()
  local fuelLevel = turtle.getFuelLevel()
  if fuelLevel == "unlimited" or fuelLevel > 0 then
	return
  end

  local function tryRefuel()
	for n=1,16 do
	  if turtle.getItemCount(n) > 0 then
		turtle.select(n)
		if turtle.refuel(1) then
		  turtle.select(1)
		  return true
		end
	  end
	end
	turtle.select(1)
	return false
  end

  if not tryRefuel() then
	print( "Add more fuel to continue." )
	while not tryRefuel() do
	  sleep(1)
	end
	print( "Resuming Tunnel." )
  end
end

local function tryUp()
  refuel()
  while not turtle.up() do
	if turtle.detectUp() then
	  if not tryDigUp() then
		test("Move Up &amp; Dig")
		return false
	  end
	elseif turtle.attackUp() then
	  collect()
	  test("Attacking Up")
	else
	  sleep( 0.5 )
	end
  end
  return true

end

local function tryDown()
  refuel()
  while not turtle.down() do
	if turtle.detectDown() then
	  if not tryDigDown() then
		test("Move Down &amp; Dig")
		return false
	  end
	elseif turtle.attackDown() then
	  collect()
	  test("Attacking Down")
	else
	  sleep( 0.5 )
	end
  end
  return true

end

local function tryForward()
  refuel()
  while not turtle.forward() do
	if turtle.detect() then
	  if not tryDig() then
		test("Move Fwd &amp; Dig")
		return false
	  end
	elseif turtle.attack() then
	  collect()
	  test("Attacking Fwd")
	else
	  sleep( 0.5 )
	end
  end
  return true

end

print( "Tunnelling..." )

--[[ Tunnel cross section
| 1 | 2 | 3 |
| 4 | 5 | 6 |
| 7 | 8 | 9 |
Turtle starts at 7, digs 4, moves 4, digs 1, moves 1, digs 2, moves 2, digs 5 &amp; 3, moves 3, digs 6, moves 6, 9 -> 9, 8 -> 8... and back to 7. Places blocks below at 7, 9 , 8. (in that order)
]]

for n=1,length do
  turtle.placeDown()
  test("Place A")
  tryDigUp()
  tryUp()
  tryDigUp()
  tryUp()
  turtle.turnRight()
  test("Turning Right")
  tryDig()
  tryForward()
  tryDigDown()
  tryDig()
  tryForward()
  tryDigDown()
  tryDown()
  tryDigDown()
  tryDown()
  reverseTurtle()
  test("Reversing direction faced")
  tryDig()
  turtle.placeDown()
  test("Place Down C")
  tryForward()
  turtle.placeDown()
  test("Place Down B")
  tryForward()
  turtle.turnRight()
  test("Turning Right")

  if n<length then
	tryDig()
	if not tryForward() then
	  print( "Aborting Tunnel." )
	  break
	end
  else
	print( "Tunnel complete." )
	print( "Returning to start..." )

-- Return to where we started
-- This section is not 100% correct. It should fuel when low on fuel and doesn't, though the tryForward works everywhere else.
-- Does work if the fuel doesn't run out, could just add a manual refuel but that would mean a)in long distances it'd still run out, b)in short dsiatnces I waste fuel... :P/>/>

	reverseTurtle()
	  while length > 0 do
		if tryForward() then
		  length = length - 1
		else
		tryDig()
		end
	  end
	reverseTurtle()
  end
end

print( "Tunnel complete." )
print( "Mined "..collected.." items total." )