WooCommerce plugin with sales referrals

We need to build a WooCommerce sales referral plugin. Project brief (provisional): - stand alone plugin that on activation requires WooCommerce - upon installation a custom database will be created (it will store all user's transactions) - admin can enable or disable any user's option to be or not affiliate - a custom field will be used in WP user list to display and filter affiliate status (yes/no) - admin can choose to have as tracking code WP user_id, WP username or both - admin can select a flat fee per sale or a percentage fee per sale (at user level admin can individually edit the fees) - when the website is accessed via "?tracking=" in URL, a cookie will be stored with the affiliate id or username - admin can set up cookie life (default 30 days) - any sale will check if the tracking cookie is stored in user's browser. if it is then that order have affiliate's ID as referral - any user registration will check if the tracking cookie is stored in user's browser. if it is then that user will have affiliate's ID as referral - the default WooCommerce order listing will include referral id column and also the detailed order (admin can modify order's referral id) - the default Wordpress user listing will include affiliate id column and the total sales generated (unpaid, paid and total) - admin will have a filterable list with all affiliates and their totals (unpaid, paid and total) - admin will have a filterable list with all commissions (unpaid, paid and total) - admin will have a full reports like orders with or without referrals in a specific interval, ordered by their option (numbers and charts with evolution) - admin can select one, more or all commissions to be paid then a PayPal mass payment file will be generated - admin can upload a PayPal mass payment response file that will mark paid, rejected, etc all the affiliate's transactions - admin can manually process (edit/update) affiliate's payments - affiliates can see in front end via a short-code their commissions (date, amount, status, payment date) - admin can set a minimum commission that will qualify the affiliate to request a payment - commissions will have the following status: pending, accepted, confirmed and paid (once an order payment is received the commission is accepted. admin will have to confirm them manually) Reports will include: - total orders, total orders made via affiliates (count, sum) - total numbers of users and total number of affiliates (count) - a custom PHP file will be coded to listen for reports generation in JSON format (general numbers, a specific order with all details, a specific report via some specific filters) eg. [login to view URL] will output total orders (count and sum) and total customers (count and sum), [login to view URL] will output all details for order 333, [login to view URL] will output sales report for that specific interval (count and sum using charts) (all reports will be shown as figures and charts and will have the following AND filters: affiliate name, affiliate email, date (interval free set start/end + preset some useful shorcuts like current year, last year, current month, last 6 months, current week, last week, today, yesterday)) Plugin workflow: - existing users can opt-in for being affiliates via WP/Woo hooks - new users can opt-in to be affiliates in the registration process WP/Woo hooks - affiliates will receive a notification each time a commission is earned (they can opt-out from receiving the notification) - affiliates can see their commission stats in front end - affiliates can request payout if they reached the minimum requirement - admin will receive a notification of payment request Requirements: - the code must be clean and well documented / commented - the code must follow the current industry standards - the plugin should not cause any lags or memory leaks - plugin will use [login to view URL] library or equivalent if agreed