[CC] spiral ceiling builder (replace)

if not turtle then
    printError( "Requires a Turtle" )
    return
end

local tArgs = { ... }
if #tArgs ~= 3 then
    print( "Usage: sfb <length> <width> <material>" )
    return
end

-- Mine in a quarry pattern until we hit something we can't dig
local length = tonumber( tArgs[1] )
local width = tonumber( tArgs[2] )
local material = tArgs[3]

if length < 1 then
    print( "Floor length must be natural number" )
    return
end

if width < 1 then
    print( "Floor width must be natural number" )
    return
end

local depth = 0
local item = 1

local function count()
    length = length + 1
    if math.fmod(length, 10) == 0 then
        print( "Faced "..length.." section." )
    end
end

local function tryDig()
    while turtle.detect() do
        if turtle.dig() then
            sleep(0.1)
        else
            return false
        end
    end
    return true
end

local function tryDigUp()
    while turtle.detectUp() do
        if turtle.digUp() then
            sleep(0.1)
        else
            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
            os.pullEvent( "turtle_inventory" )
        end
        print( "Resuming floor building..." )
    end
end

local function charge()
    local function tryCharge()
        for n=1,16 do
            if turtle.getItemCount(n) > 0 then
                if turtle.getItemDetail(n).name == material then
                    turtle.select(n)
                    return true
                end
            end
        end
        turtle.select(2)
        return false
    end
    if not tryCharge() then
        print( "Add more material to continue." )
        while not tryCharge() do
            os.pullEvent( "turtle_inventory" )
        end
        print( "Resuming floor building..." )
    end
end

local function tryForward()
    refuel()
    while not turtle.forward() do
        if turtle.detect() then
            if not tryDig() then
                return false
            end
        elseif turtle.attack() then
        else
            sleep( 0.1 )
        end
    end
    return true
end

local function tryPlaceUp()
    refuel()
    charge()
    while not turtle.detectUp() do
        if turtle.placeUp() then
            sleep(0.1)
        else
            return false
        end
    end
    return true
end

print( "Building the floor..." )

local function buildForward(dir)
	for n=1,dir do
		tryForward()
		tryDigUp()
		tryPlaceUp()
	end
end

local frwDir = true;

while (length > 0 or width > 0) do
	if frwDir == true then
		buildForward(length)
		width = width - 1
		frwDir = false
	else
		buildForward(width)
		length = length- 1
		frwDir = true
	end
	turtle.turnRight()
end

print( "Floor building complete" )