develop an custom module for opencart 2.3.0.2

we will have a number of affiliate members , and we will create a 5% coupon code for each member, so when the coupon code is used for that affiliate member, he will earn commission. and some product can earn them 10% commission or 15% commission we set on the module. any items not custom assigned to a special commission % will default to 5% commission. we are currently using this module to connect Coupon code to affiliate members. [login to view URL] we planned on using the module “Product-specific commission module” to be able to set certain products or category to allow 10% commission fee earning for affiliates. [login to view URL] so if a £30 backpack allows 10% commission . affiliate will earn 10% commission ex VAT £100 office chair allows 5% commission. affiliate will earn 5% commission ex VAT the customer orders a backpack and office chair using the coupon code. total £130 minus 5% coupon code = £123.50 and the affiliate will earn £2.85 + £4.75 commission . = £7.60 if customer only used the tracking code and no coupon code. the affiliate member can still earn the £8 commission . £5 + £3 = £8 (10% from backpack and 5% from office chair) affiliate members will also advertise there affiliate tracking for the homepage . which will earn them commission when people use their links to buy items. even without a coupon code. commission will still be the same 5% for all the items unless we set them to 10% etc [login to view URL] We're hoping to get a new module designed to achieve this, what we want to achieve is. 1) create coupon codes and have the option to assign them to an affiliate . 2) be able to have the option to set certain products or category to allow more commission for affiliate. this way we can set low commission for expensive products. and high commission rate for low price products. 3) affiliate will get the commission every time for all that customer's future orders (even without coupon), just like with regular tracking. And it's still possible to pay commissions only for orders with coupon, if that's what you need. Optionally, it's possible to use coupon code for affiliate tracking even when coupon itself can not be applied (expired, disabled, etc). 4) the home affiliate tracking will still let affiliate earn commission without the use of the coupon code, and they can earn the set commission rate set for the products. we are using Journal Theme for our store. the finish module will need to work for our store. please email me for questions.