local empty={}
local x,y,z,d= 0,0,0,0
local FUEL,FRAME,FILLER,WINDOW,FLOOR,TRASH = 1,2,3,4,5,6

print "Welcome to TeddyJ's turtle builder"
print "Please ensure your chests and turtles are" 
print "arranged as follows:"
print "            [T]"
print "[5][4][3][2][1]"
print "T=turtle, 1..5 chests containing Floor/Window/Filler/Frame/Fuel materials"
print ""
print "How big is the gap between chests (0 for no gap)?"
local chest_gap=io.read()
print "How many panels long would you like the building?"
local length=io.read()
print "How many panels wide would you like the building?"
local width=io.read()
print "How many storeys high would you like the building?"
local storeys=io.read()

function goUp(n)
	checkFuel()
	if n==nil then n=1 end
	y=y+n
	for _=1,n do
		turtle.digUp()
		turtle.up()
	end
end

function placeDown(n)
	if turtle.detectDown() then
		turtle.select(TRASH)
		turtle.digDown()
		turtle.drop()
	end
	turtle.select(n)
	if turtle.getItemCount(n)==0 then
		refill(n)
	end
	turtle.placeDown()
end

function refill(n)
	if not(empty[n]) then
		goToChestAndRestock(n)
		goToLastPlace()
	end
end 

function goToChestAndRestock(n)
	for _=1,6 do
		turtle.digUp()
		turtle.up()
	end
	for _=1,d+3 do
		turtle.turnLeft()
	end
	for _=1,x do
		turtle.dig()
		turtle.forward()
	end
	turtle.turnRight()
	for _=0,z do
		turtle.dig()
		turtle.forward()
	end
	for _=1,(y+5) do
		turtle.down()
	end
	turtle.turnRight()
	if n>1 then
		for _=2,n do
			for i=0,chest_gap do
				turtle.forward()
			end
		end
		content=turtle.suckDown()
		for _=2,n do
			for i=0,chest_gap do
				turtle.back()
			end
		end
	else
		content=turtle.suckDown()
	end
	if not(content) then empty[n]=true end
	turtle.turnRight()
end

function goToLastPlace()
	for _=1,(y+5) do
		turtle.up()
	end
	for _=0,z do
		turtle.forward()
	end
	turtle.turnLeft()
	for _=1,x do
		turtle.forward()
	end
	for _=1,6 do
		turtle.down()
	end
	for _=1,d+5 do
		turtle.turnRight()
	end
end

function goDown(n)
	checkFuel()
	if n==nil then n=1 end
	y=y-n
	for _=1,n do
		turtle.digDown()
		turtle.down()
	end
end

function turnLeft()
	d=d-1
	if d==-1 then d=3 end
	turtle.turnLeft()
end

function turnRight()
	d=d+1
	if d==4 then d=0 end
	turtle.turnRight()
end

function checkFuel()
	if tonumber(turtle.getFuelLevel())~= nil and turtle.getFuelLevel()<80 then
		print "Fuel low"
		if turtle.getItemCount(FUEL)==0 then
			print "No fuel available, restocking"
			refill(FUEL)
		end
		print "Refueling"
		turtle.select(FUEL)
		if not(turtle.refuel()) then
			print "No fuel in slot 1! Press enter when filled"
			io.read()
		end 
	end
end

function goForward(n)
	checkFuel()
	if n==nil then n=1 end
	if d==0 then z=z+n end
	if d==1 then x=x-n end
	if d==2 then z=z-n end
	if d==3 then x=x+n end
	for _=1,n do
		turtle.dig()
		turtle.forward()
	end
end

function goBack(n)
	if n==nil then n=1 end
	if d==0 then z=z-n end
	if d==1 then x=x+n end
	if d==2 then z=z+n end
	if d==3 then x=x-n end
	for _=1,n do
		turtle.back()
	end
end


function getBlockType(i,j)
	if i==5 or j==5 then
		return FRAME
	end
	if j==2 or j==3 then
		if (i==2 or i==3) then
			return WINDOW
		else
			return FILLER
		end
	end
	return FILLER
end

function doSide(panels, isFinalSide)
	for _=1,panels do
		doPanel()
	end
	if not(isFinalSide) then
		turnLeft()
		goForward()
		turnLeft()
		goForward()
		turnRight()
	end
end

function doPanel()
	checkFuel()
	for i=1,5 do
		goUp()
		for j=1,5 do
			b=getBlockType(i,j)
			placeDown(b)
			goForward()
		end
		if i<5 then
			goBack(5)
		end
	end
	goDown(5)
end

function doFloor()
	turnLeft()
	goForward()
	turnRight()
	floor_width=(width*5)-1
	floor_length=(length*5)-1
	for i=1,floor_width do
		for i=1,floor_length do
			placeDown(FLOOR)
			goForward()
		end
		goBack(floor_length)
		turnLeft()
		goForward()
		turnRight()
	end
	turnRight()
	goForward(floor_width+1)
	turnLeft()
end

function doStorey()
	goForward()
	doFloor()
	doSide(length)
	doSide(width)
	doSide(length)
	doSide(width,true)
	goUp(6)
	goBack()
	turnLeft()
	goDown()
end

goForward()
for _=1,storeys do
	doStorey()
end
goForward()
doFloor()