JavaScript: screenshot rendered web page Browser style

I assume this question might have been asked before but after hours of searching, I haven't found anything satisfying.

Here's my question: Is it possible to screenshot a fully rendered web page using JavaScript? A little like what most browsers do on windows on the press of ctrl+p.

I have looked into a lot of alternative solutions like html2Canvas.js but none suits my needs. The biggest issue being my web page almost entirely rendered on client side using Javascript. This is also why server side solution like PhantomJS are hardly applicable.

I need the screenshots to be printed as image or PDF. Any idea?

Thanks.