function selectStoneBrick()
    currentSelectedBlock = turtle.getItemDetail()
    if currentSelectedBlock ~= nil then
        for i = 1,16 do
            iBlockDetail = turtle.getItemDetail(i)
            if iBlockDetail ~= nil then
                if iBlockDetail.name == "minecraft:stonebrick" then
                    break
                end
            end
            if i == 16 then
                error("oh noes stone brick ran out")
            end
        end
    end
end

function forwardDig()
    blockInFront, blockInspect = turtle.inspect()
    if blockInFront then
        turtle.dig()
    end
    turtle.forward()
end

function downDig()
    blockDown, blockInspect = turtle.inspectDown()
    if blockDown then
        turtle.digDown()
    end
    turtle.down()
end

function upDig()
    blockUp, blockInspect = turtle.inspectUp()
    if blockUp then
        turtle.digUp()
    end
    turtle.up()
end

function clearSpace()
    turtle.turnRight()
    for i = 1, 3 do
        upDig()
    end
    for i = 1, 5 do
        for j = 1, 6 do
            forwardDig()
        end
        turtle.turnRight(2)
        downDig()
    end
end

function buildNextBitOfBridge()
    clearSpace()
end

function checkFuel()
    fuelLevel = turtle.getFuelLevel()
    if fuelLevel < 50 then
        for i = 1, 16 do
            turtle.select(i)
            turtle.refuel(64)
        end
    end
end

function mainLoop()
   while true do
       checkFuel()
       buildNextBitOfBridge()
   end
end

mainLoop()