Add Loyalty Points Feature to Open Source Point of Sale

Open Source Point of sale, is an Online point of sales system written in PHP, now we need to add a Loyalty points system to it, meaning, that a in the settings we can choose, how many points will be given with every X amount spent, then a field in the customer profile/accounts to view how many points they have, and edit them, also an option to show CURRENT points on sales receipt + when X amount of points is reached system informs the user. - This is a very small and short project wont take allot if done by a good PHP/mysql programmer !