Accumulate coupons into single coupon

functions.php

<?php

// Hook the function to the filter
add_filter('gens_raf_coupon_amount', 'modify_raf_coupon_amount', 10, 2);
function modify_raf_coupon_amount($amount, $order_id) {
    // Get the user email from the order
    $order = wc_get_order($order_id);
    if (!$order) return $amount;
    $rafID = get_post_meta($order_id,'_wpgens_raf_id',true);
    if(!$rafID) {
        $rafID = $order->get_meta('_wpgens_raf_id');
    }
    // Determine the user email
    if (filter_var($rafID, FILTER_VALIDATE_EMAIL)) {
        $user_email = $rafID; // This is already an email
    } else {
        $gens_users = get_users(array(
            "meta_key" => "gens_referral_id",
            "meta_value" => $rafID,
            "number" => 1,
            "fields" => array("ID", "user_email")
        ));
        
        if (is_array($gens_users) && !empty($gens_users)) {
            $user_email = $gens_users[0]->user_email;
        } else {
            // If we can't determine the email, return the original amount
            return $amount;
        }
    }
    
    // Find existing RAF coupons for this user
    $args = array(
        'posts_per_page' => -1,
        'post_type'      => 'shop_coupon',
        'meta_query'     => array(
            array(
                'key'     => 'customer_email',
                'value'   => $user_email,
                'compare' => '=',
            ),
        ),
    );
    $existing_coupons = get_posts($args);
    
    $total_amount = floatval($amount);
    $coupons_to_delete = array();
    
    foreach ($existing_coupons as $coupon) {
        if (strpos($coupon->post_title, 'RAF-') === 0) {
            $coupon_amount = get_post_meta($coupon->ID, 'coupon_amount', true);
            $total_amount += floatval($coupon_amount);
            $coupons_to_delete[] = $coupon->ID;
        }
    }
    
    // Delete the existing RAF coupons
    foreach ($coupons_to_delete as $coupon_id) {
        wp_delete_post($coupon_id, true);
    }
    
    return $total_amount;
}