Rules engine

I need to implement a rules engine which keeps increasing with time. So if a user belongs to a particular profile, particular challenge, has completed some percentage of the challenge, and is now on some day
then I need to show him a particular challenge.

Right now I have only 24 cases which would be 24*5 by the end of this week. How can I keep this dynamic? I have heard of GitHub - ulfurinn/wongi-engine: A rule engine written in Ruby.
Have you ever used this? Or should I make my own rules engine?