<?php
declare(strict_types=1);
namespace Esun\Customer\Observer;

use Magento\Framework\Event\Observer;
use Magento\Framework\Event\ObserverInterface;
use Magento\Sales\Model\Order;

class MarkCompleteOrderShipped implements ObserverInterface
{
    public function execute(Observer $observer): void
    {
        $order = $observer->getEvent()->getOrder();
        if (!$order instanceof Order || $order->getState() !== Order::STATE_COMPLETE
            || in_array((string)$order->getStatus(), ['shipped', 'received'], true)) {
            return;
        }
        $ordered = 0.0;
        $shipped = 0.0;
        foreach ($order->getAllVisibleItems() as $item) {
            $ordered += max(0.0, (float)$item->getQtyOrdered() - (float)$item->getQtyCanceled());
            $shipped += (float)$item->getQtyShipped();
        }
        if ($ordered > 0 && $shipped >= $ordered) {
            $order->setStatus('shipped');
        }
    }
}