local args={ ... }
local row = 0
local col = 0
if args[1] == "help" then
	print("Usage: lay {right} {ahead} {gaps} {floors}")
	return
end

local rows = tonumber(args[1])
local columns = tonumber(args[2])
local gaps = tonumber(args[3])
gaps = gaps+1
local floors = tonumber(args[4])
local selected = 16
local start = "start"
local direction = "right"
local floor = 0
local up = 0
if columns < 1 then
        columns = 1
end
if rows < 1 then
        rows = 1
end
if floors < 1 then
        floors = 1
end
if gaps < 1 then
        gaps = 3
end
while floor < floors do
        gap = 0
        while row < rows do
                while turtle.getItemCount(selected) == 0 do
                        selected=selected-1
			if selected == 0 then
				selected = 16
			end
                        if selected == 1 then
				if turtle.getItemCount(selected) == 0 then
	                                selected = 16
	                                print("Waiting for flooring blocks")
				end
                        end
                end
                turtle.select(selected)
                if start == "start" then
                        start = "homer"
                else
	                turtle.placeDown()
		end
                col=col+1
                if col == columns then
                        col=0
                        row=row+1
			if row < rows then
	                        if direction == "right" then
	                                turtle.turnRight()
	                                turtle.forward()
	                                turtle.turnRight()
	                                direction = "left"
	                        elseif direction == "left" then
	                                turtle.turnLeft()
	                                turtle.forward()
	                                turtle.turnLeft()
	                                direction = "right"
	                        end
			end
                end
                if col == 0 then
                        col=0
                else
                        turtle.forward()
                end
        end
        while gap < gaps do
                gap=gap+1
                turtle.up()
		up = up+1
        end
	if direction == "right" then
		print("final direction is right")
	        turtle.turnLeft()
	else
		print("final direction is left")
		turtle.turnRight()
	end
        local backtrack = 1
        while backtrack < rows do
                backtrack = backtrack+1
                turtle.forward()
        end
        if direction == "right" then
		backtrack = 1
		turtle.turnLeft()
	        while backtrack < columns do
	                backtrack = backtrack+1
	                turtle.forward()
	        end
		turtle.turnRight()
		turtle.turnRight()
	else
	        turtle.turnRight()
	end
        floor = floor+1
	col = 0
	row = 0
	direction = "right"
end
local down = 0
while down < up do
	turtle.down()
	down = down+1
end