adding functionality to a current site

We have a website but want to add some relative small things. It is a badge reward system. So persons collect points for certain activities and the points are collected in the system. Now we want to show the badged based on rules. We have 2 types of badges. Direct reward badges (when a user did something the user gets a badge.) Calculation badges (only the best one gets the badde or one should have a number of points to get a badge, etc) So we register the points arlready Now we need someone to the badges on the site of each user. The template are using the twig template engine. We collect data of users in a database. The database is mysql and the site in php