Drawer Monitor

--[[
Instructions:
> label set [Factory Name]
> pastebin get XQ0zrAwW [Program Name]
> [Program Name]
--]]

function findDrawer()
  local compatible = {"storagedrawers:controller"} --only support controller
  for i, item_id in ipairs(compatible) do
    local drawer = peripheral.find(item_id)
    if drawer then return drawer end
  end
  return nil
end

function createMessageFromContainer(container)
  local msg = os.getComputerLabel()
  if container then
    for slot, item in pairs(container.list()) do
      msg = msg..("\n%s %d %d"):format(item.name, item.count, container.getItemLimit(slot))
    end
  end
  return msg
end

function main()
  peripheral.find("modem", rednet.open)
  while true do
    while not rednet.isOpen() do
      os.sleep(10)
      peripheral.find("modem", rednet.open)
    end
    local drawer = findDrawer()
    local msg = createMessageFromContainer(drawer)
    rednet.broadcast(msg, "ITEM_UPDATE")
    os.sleep(10)
  end
end

main()