qr code event ticketing.

Hy, I want to build a website that handle events where users can go and buy tickets online and where the ticket are automaticaly emaild to the user who can present it at the entrance of the event. The ticket can be scanned with a qrcode scanner and it give back a result that depends on the ticket. I mean if the ticket is accepted it gives you an accepted sign, if the ticket was used before it gives you an error sign. Something like tickera or event espresso ticketing system. Of course i want to know if there are some plugins that together can do this job done with maybe only some php scripting if needed. Help please.