--Main Program
print("running Program !")
CycleSquareRoom()


--Functions

function CycleSquareRoom() --spirals through a n*n square room
    print("please define the length of your Square rooms sides")
	local sides = read()
	print("please define a turning direction [left or right]")
	local dir=read()
	print("turning" ..dir)
	local turns=sides-2
	local mov=sides-1
	local reqFuel = 0

	reqMoves(mov)

	if turtle.getFuelLevel()>reqFuel then
        while turns>0 and mov>1 do
            for i =0, turns do
                moveNForward(mov)
                turns = turns-1
                mov = mov-1
                turn(dir)
                print("turned " ..dir)
                end
            inturn(dir)
        end
    else
        print("Not enough Fuel !")
    end
end

function turn(turndir) --turns the defined way
    if turndir == "right" then turtle.turnRight()
    else turtle.turnLeft() end
end

function invturn(turndir) --turns the other way
    if turndir == "left" then turtle.turnRight()
    else turtle.turnLeft() end
end

function moveNForward(n) --moves n blocks forward
    print("moving " ..n.. " blocks")
	if n~=nil then
		n = tonumber(n)
		for i = 0, n do
			turtle.forward()
		end
	else
		print("no input specified")
	end
end

function reqMoves(n) --calculates the amount of moves and fuel required
    while n>0 do
        reqFuel = reqFuel+(n-1)*n
        n = (n-1)
    end
    print(reqFuel.." moves are required")
end