Construction Script

function estimatefuel(width, length, height)
	return (((width * height * 2) + ((length - 2) * height * 2) + ((length - 1) * (width - 1))) - turtle.getFuelLevel()) / 80
end

function digforward(n)
	for i = 1, n do
		repeat
			if turtle.detect() then turtle.dig() end
		until turtle.forward()
	end
end

function refuel(n)
	print("Refueling turtle.")
	for i = n, 16 do
		turtle.select(i)
		turtle.refuel()
	end

	turtle.select(1)
	print("Turtle has " .. turtle.getFuelLevel() .. " fuel left.")
end


function inventory()
	if turtle.getItemCount(1) < 2 then
		for i = 1, 16 do
			turtle.select(i)
			turtle.transferTo(1, 64)
		end
		turtle.select(1)
		if turtle.getItemCount(1) < 2 then
			print("Turtle has run out of blocks to place. Please refill turtle and press Enter to continue construction.")
			io.read()
		end
	end
end

function placeforward(n)
	inventory()
	turtle.placeDown()
	if n > 1 then digforward(1) placeforward((n - 1)) end
end


--I got this to work. I don't even know how it works, just don't touch it.
function buildceiling(width, length)
	placeforward(length - 2)
	turtle.turnRight()
	digforward(1)
	if ((length - 2) * (width - 2)) > 0 then buildceiling(length , (width - 1)) end
end

function buildwalls(width, length, height)
	for i = 1, 2 do
		placeforward(length)
		turtle.turnRight()
		digforward(1)
		placeforward(width - 2)
		digforward(1)
		turtle.turnRight()
	end
	if height > 1 then digup(1) buildwalls(width, length, (height - 1)) end
end

function digup(n)
	for i = 1, n do
		repeat
			if turtle.detectUp() then turtle.digUp() end
		until turtle.up()
	end
end

function build(width, length, height)
	digup(1)
	buildwalls(width, length, height)
	digforward(1)
	turtle.turnRight()
	digforward(1)
	turtle.turnLeft()
	buildceiling(width, length)
end

print("Enter the Length (forward):")
length = tonumber(io.read())
print("Enter the Width (across):")
width = tonumber(io.read())
print("Enter the Height:")
height = tonumber(io.read())
estimate = estimatefuel(width, length, height)
if estimate > 0 then print("Estimating the turtle will require "..estimate.." peices of coal.\nPlace them into the turtle and press Enter to continue.") io.read() refuel(1) end
print("Please fill the turtle's inventory with required building materials.")
io.read()
print("Turtle will now begin construction.")
build(width, length, height)