-- original script by matdombrock/pyramid.lua

b = 0 --bricks laid
w = 0 --wall number
h = 5 --height of the structure in layers
i = 0 --current number layers
x = 9--how wide the base should be
n = 1 --selection number for inv

function start()
    turtle.up()
end
function sel()
    if turtle.getItemCount(n) <1 then--check to see if we are out of material
        n = n+1
    end
    if n > 16 then --if we are done the last item slot
        n = 1 --switch back to slot one
        while turtle.getItemCount(1) <1 do --if there is nothing in slot one ask user to refill
            print ('please reload, by filling slot one last')
            sleep(1)
        end
    end
    turtle.select(n)--change slot
end




function buildlayer()
    if w == 0 then
        x = x -1
    end
    while w < 4 do --while we have not built 4 walls yet
        while b < x do

            sel()
            turtle.digDown()
            turtle.placeDown()
            turtle.forward()--build the wall
            b = b + 1
        end
        while b == x do
            turtle.turnLeft()--turn so we can build the next wall
            w = w+1
            b = 0
        end
        if w == 3 then
            x = x-1
        end
    end

    while w == 4 do
        turtle.placeDown()
        turtle.up()--move up so we can start another layer

        turtle.forward()
        w = 0
    end
end
start()
while i < h do--while we have not reached our intended height
    buildlayer()
    i = i+1
end