local tArgs = { ... }
if #tArgs ~= 1 then
	print( "Usage: stairdown <length>. Place 1 cobble in slot 16, then stacks in the remainder of the inventory and ensure turtle has sufficient fuel." )
	return
end

local depth = tonumber( tArgs[1] )
if depth < 1 then
	print( "Stair depth must be positive" )
	return
end

local forward = 0
local down = 0
local slot = 1

local function PlaceBlock()
	turtle.select(slot)
	for testSlot=1,15 do
		if turtle.compareTo(testSlot,16) then
			slot = testSlot
			return true
		end
	end
	if turtle.detectDown() then
		turtle.digDown()
		turtle.placeDown()
	else
		turtle.placeDown()
	end
	return true
end

local function MoveForward()
	turtle.forward()
	forward = forward + 1
	return true
end

local function MoveDown()
	turtle.down()
	down = down + 1
	return true
end


local function DigForward()
	if turtle.detect() then
		turtle.dig()
		MoveForward()
	else
		MoveForward()
	end
	return true
end

local function DigDown()
	if turtle.detectDown() then
		turtle.digDown()
		MoveDown()
	else
		MoveDown()
	end
	return true
end

local function StairDown()
	if turtle.detectDown() then
		turtle.digDown()
		MoveDown()
		PlaceBlock()
	else
		turtle.down()
		PlaceBlock()
	end
	return true
end

--[[	while turtle.detectDown() do
		if turtle.digDown() then
			MoveDown()
			sleep(0.5)
		else
			return false
		end
	end
	return true
]]

print( "Making stairs..." )
for n=1,depth do
	StairDown()
	DigForward()

end