I think it is past, so " You were happy"?
-me- is the tense infix for present perfect tense. Past would be "Mlifurahi"
So, "you have been happy" wiuld be the accurate translation.
that's perfect continuous tense, which translates to 'mmekuwa mkifurahi' i.e. 'you have been in the state of happiness'
It's in plural. Mmefurahi
If it is singular It's should Have been Umefurahi