Calculate quantity by single item product into order admin page through bulk action selection (filter) - Woocommerce

calculate-quantity-by-single-item-product-into-order-admin-page-through-bulk-action-selection-filter-woocommerce.php

<?php
// Display the custom actions on admin Orders bulk action dropdown
add_filter('bulk_actions-edit-shop_order', 'orders_bulk_action_delivery_collect_calc');
function orders_bulk_action_delivery_collect_calc($bulk_actions)
{
    $bulk_actions['delivery-collect'] = __("Calcolo quantità degli ordini", 'woocommerce');

    return $bulk_actions;
}

// Process the bulk action from selected orders
add_filter('handle_bulk_actions-edit-shop_order', 'delivery_collect_calc_bulk_action_edit_shop_order', 10, 3);
function delivery_collect_calc_bulk_action_edit_shop_order($redirect_to, $action, $post_ids)
{

    if ($action === 'delivery-collect')
    {
        $order_numbers = []; // Initializing
        $cod_orders_total = 0; // Initializing
        // $salary_per_order = 1.5;
        foreach ($post_ids as $post_id)
        {
            // Get Order status
            $order = wc_get_order($post_id);

            /*if( $order->get_payment_method() === 'cod' ) {
                $cod_orders_total = (float) $order->get_total();
            }*/

            // Order status change to "completed" (To enable uncomment the line below)
            // $order->update_status("completed");
            $cod_orders_total += (float)$order->get_total();
            $order_numbers[] = $order->get_order_number(); // Adding processed order numbers to an array
            

            // initializes the array that will contain the product categories with the ordered quantities of each
            $count_by_cat = array();
            

            // for each product ordered
            foreach ($order->get_items() as $item)
            {
                $product = $item->get_product();

                $product_names = [$item->get_name() ];

                // get product categories
                $terms = get_the_terms($product->get_id() , 'product_cat');

                foreach ($product_names as $term)
                {
                    $cat_name = $term;
                    // if the product category is already present in the array, add the quantities
                    if (array_key_exists($cat_name, $count_by_cat))
                    {
                        $count_by_cat[$cat_name] += $item->get_quantity();
                        // otherwise it adds the category and quantity to the array
                        
                    }
                    else
                    {
                        $count_by_cat[$cat_name] = $item->get_quantity();
                    }
                }
            }
        }

        $orders_count = count($order_numbers);
        $amount_to_collect = $cod_orders_total;

        // Adding the right query vars to the returned URL
        $redirect_to = add_query_arg(array(
            'collect_action' => $action,
            'processed_count' => $orders_count,
            'proc_order_nums' => implode(', ', $order_numbers) ,
            'amount_to_collect' => $amount_to_collect,
            'nome_prodotto' => $cat_name,
            'quantità' => $count_by_cat,
        ) , $redirect_to);
    }
    return $redirect_to;
}

// Display the results notice from bulk action on orders
add_action('admin_notices', 'set_delivery_collect_bulk_action_admin_notice');
function set_delivery_collect_bulk_action_admin_notice()
{

    global $pagenow;

    if ('edit.php' === $pagenow && isset($_GET['post_type']) && 'shop_order' === $_GET['post_type'] && isset($_GET['collect_action']) && isset($_GET['processed_count']) && isset($_GET['proc_order_nums']) && isset($_GET['amount_to_collect']) && isset($_GET['quantità']))
    {

        $count_ids = intval($_GET['processed_count']);
        $amount = floatval($_GET['amount_to_collect']);
        $currency = get_woocommerce_currency_symbol();

        printf('<div class="notice notice-success fade is-dismissible"><p>' . _n("Su %s ordine selezionato, l'importo calcolato da riscuotere è di %sL'ID dell'ordine processato è %s.", "Su %s ordini selezionati, l'importo calcolato da riscuotere è di %sGli ID degli ordini processati sono %s.", $count_ids, "woocommerce") . '</p>', $count_ids, '<code>' . number_format_i18n($amount, 2) . '</code> (' . $currency . ').</p><p>', '<code>' . $_GET['proc_order_nums'] . '</code>',);

        echo "<br>Totale quantità d'ordine per singolo prodotto:<br><br>";
        echo "<ul style='list-style: disc; padding: 0 20px 0 20px;'>";
        foreach ($_GET['quantità'] as $key => $value)
        {

            echo "<li> " . $key . " ( <strong style='color:red;'>" . $value . "</strong> )</li>";

        }

        echo "</ul>";
        echo '<br></div>';

    }

}