Chess world cup 2017 pairing system / candidates tournament

Hello everyone,

I only recently started to follow chess competitions, and I am interested in how players can qualify for the next candidates tournament. 2 places are awarded to the finalists of the chess world cup, with apparently all the best players participating, including the world champion.

I couldn't find the pairing system for the world cup, Is there (I imagine) a seeding system, maybe based on ratings? Does anyone know how the pairings where done during the last world cup ?

Also, if Carlsen is finalist, who gets the candidate tournament slot? Do the 2 semi finalists play a 3rd place game?
Same question goes for the Grand prix, whose top 2 finishers qualify for the candidates, if Carlsen or Karjakin or a player qualified through the world cup?

I imagine the global system is that if someone is qualified one way, the next place he would be awarded goes the the player right after him in that specific competition.
This would also mean the 2 places awarded based on ratings could go to 4th and 5th rated for example, because 1 to 3 are qualified in some other way.

Thanks for the answers if someone knows about this.

http://www.fide.com/fide/handbook.html?id=22&view=category

Thanks