Refer a Friend system for Wechat

need a referral system in wechat. how it works. wechat user will be able to refer their x number of friend to our wechat account, and once their referred friend follow our wechat account or purchase something from us (we can decide which to set) the referral will be able to get a gift. Both user and us must be able to trace and keep track on the number referral done and number of success followed or purchase. We will provide rewards in terms of gift or monetary when a x number of successful referred friend is met. this system must be able to integrate into our existing wechat shop and wechat account.