USB Simplification Plugin support

I want to make/have made for me a plugin that automatically attaches hotpluged usb devices to a selected vm unless they are already assigned in the xml file of another vm in which case it assigns the usb device to the vm which has it in the xml (I don't know why unraid doesn't allow you to disconnect and reconnect usb devices that already are assigned to a vm) this plugin would basically be a fork of this https://lime-technology.com/forum/index.php?topic=47240.0 but it would automatically do it for a pre specified vm (unless it is already assigned to another vm in it's xml)

The plugin would just need to manage devices XMLs and UDEV rules for hot plugging, there is a useful blog post here:

http://rolandtapken.de/blog/2011-04/how-auto-hotplug-usb-devices-libvirt-vms-update-1

I did experiment with UDEV rules but wasn't able to make them work, even restarting UDEV the rules aren't applied when I plug usb devices.

I very little (no) experience with extensions (making them) (the installation part seems easy enough) any quick tips for a learning side project? Maybe listing the pcie properties (of lspci) of a selected device? I heave no idea where to start so any help is appreciated.