Coupon code - WooCommerce + Ioninc

Coupon work. Mobile APPs both Android and IPhone built on the Ionic framework, integrated with WordPress via REST API endpoints. Task: To extend the WordPress WooCommerce integration in the Apps to work with WooCommerce Coupon functionality. Summary: Ionic tasks: - Add a new filed to the pricing page to enter a coupon code. - On button submission request the end point passing the coupon code and pricing information. o At the point of setting up the membership subscription the app needs to send the coupon code as part of the REST request it makes. - Handle the response from the WordPress end point validating: o If valid update pricing o If invalid display message informing the user. - Update the Apps to the latest version of Ionic / publish and test. WordPress / WooCommerce tasks (makes use of Stripe and WooCommerce Subscriptions extensions): - On the existing end point o We setup the membership o Create an order o Create a subscription o Process the payment via stripe. o Update the subscription based on the response from the payment provider. - During the process all data is manipulated to work with the existing plugins. - Note all requests via the REST API are stateless so do not reply on session data. o The process is completely stateless so does not reply on sessions. Coupons: - Coupon codes are passed over - WooCommerce checks the code against rules and looks for restrictions based sometimes on the cart contents e.g. max amount. - The cart total is calculated including coupon discounts. - At point of placing the order during normal checkout, it recalculates all the totals including coupon discounts. - Then creates the order using the existing total including any discounts. The challenge is the mechanism for calculating the coupon discounts relies heavily on the contents of the cart whereas because the REST API is stateless they do not use the cart at all, this needs to be solved in some way. I will base my decision on the solution put forward prior to awarding the job, so please read the above carefully and submit details on how you would solve this. All code will need to be submitted via our GITlab repository for review.