whmcsTools/get_user_products.php

<?php

// returns an array of product ids already bought be the client

if (!defined("WHMCS"))
    die("This file cannot be accessed directly");

add_hook('ClientAreaPageCart', 1, function($vars) {
    // check client login status
    if(!isset($vars['clientsdetails']['id'])) {
        return;
    }
    $active_pids = array();
    $free_pids = array();
    $card_pids = array();
    $free_card_pids = array();
    $clientId = $vars['clientsdetails']['id'];
    foreach($_SESSION['cart']['products'] as $item) {
        array_push($card_pids, $item['pid']);
        if($item['billingcycle'] == null) {
            array_push($free_card_pids, $item['pid']);
        }
    }
    $free_card_double_pids = array_unique(array_diff_assoc($free_card_pids, array_unique($free_card_pids)));
    // get client products
    $clientProducts = localAPI('GetClientsProducts', array('clientid' => $clientId, 'stats' => false));
    if(!$clientProducts['result'] == 'success'){
        return array('clientPids' => [],
		'clientActiveFree' => [],
		'clientCard' => $card_pids,
		'clientCardFree' => $free_card_pids,
		'clientCradDoubleFree' => $free_card_double_pids
		);
    }
    if(empty($clientProducts['products'])){
        return array('clientPids' => [],
		'clientActiveFree' => [],
		'clientCard' => $card_pids,
		'clientCardFree' => $free_card_pids,
		'clientCradDoubleFree' => $free_card_double_pids
		);
    }
    foreach($clientProducts['products']['product'] as $product) {
        array_push($active_pids, $product['pid']);
        if($product['billingcycle'] == 'Free Account' && $product['status'] == 'Active') {
            array_push($free_pids, $product['pid']);
        }
    }
    return array('clientPids' => $active_pids,
		'clientActiveFree' => $free_pids,
		'clientCard' => $card_pids,
		'clientCardFree' => $free_card_pids,
		'clientCradDoubleFree' => $free_card_double_pids
	);
});