Back in 2014-17 i used to work actively as lead on Adversewow, we ran cataclysm untill Mists of Pandaria servers.
With the server not in existence anymore, i feel like the repositories can be made public so people can learn from the commits, so to the link you'll find the full commit history+source.
There are better cores out there, this one is to copy pasta from or learn from

Enjoy.