<?php

namespace Modules\Core\Shipping\Contracts;

use Illuminate\Support\Collection;
use Modules\Core\Shipping\Models\Shipment;

/**
 * A carrier that can print several shipments' labels as one PDF — behind
 * the Pending Vouchers screen's "Print selected". Same side effects as
 * printLabel() per shipment (issuing pending vouchers, setting
 * label_printed_at).
 */
interface SupportsBatchLabels
{
    /**
     * @param  Collection<int, Shipment>  $shipments
     */
    public function printLabels(Collection $shipments): string;
}