What's the easiest way of making links to select a language which takes multilingual text from gettext, po, mo files (Wordpress)?

Question

I've been playing with po and mo files and they are working fine so far. But I want to make links for the user to select the languages.

What's the easiest and most efficient way of doing this?

Or is there any other way of doing this besides using gettext? (it will be OK too)

(I swear I've looked for that for days on Google and never found something useful and I think it should be a quite common functionality)