<?php
// SPDX-License-Identifier: GPL-3.0-or-later
declare(strict_types=1);

namespace Aiwend\Usage;

/**
 * The per-client daily budget bucket one chat request is charged to (Phase 89). Built by the REST layer from the connecting
 * address (or account), so the chat pipeline never sees an address. The limit is computed lazily: only the first chargeable
 * message of a client and day creates the bucket, so only then is the site limit read.
 */
final class ClientAllowance
{
    /** @param \Closure(): int $limit daily limit in units for a bucket that does not exist yet */
    public function __construct(
        public readonly string $bucket,
        public readonly string $kind,
        private \Closure $limit,
    ) {
    }

    public function limitUnits(): int
    {
        return max(0, (int) ($this->limit)());
    }
}