Add loyalty program to existing POS software (php)

I have a PHP based POS software. I would like to add a new functionality to it, a customer loyalty program. Imagine I get loyalty cards for my clients, like these: [login to view URL] I would like to add a loyalty module to the software, integrated to the client profile, where every time client Joe Smith makes a purchase, he makes an X number of points that can later on be redeemed. You will edit the existing software, add the tables in MySql and add and comment the code needed for this. The new features are: 1. The system will allow you to create levels of client privilege (regular, gold, platinum, diamond, etc). 2. The system will allow rewards to be set by level (gold makes 1 point per dollar, diamond makes 2, etc) 3. The system will allow promotions per product (product sku 1001 earns double points on august) 4. The system will allow a client to redeem points for product according to guidelines set by the administrator (for example, 1 point = $0.01) 5. Every time a client makes a purchase, his account will be updated.