<?php

declare(strict_types=1);

namespace App;

final class RegistrationIdentityAllocator
{
    private JsonStore $store;

    /**
     * @param array<string, mixed> $config
     */
    public function __construct(
        string $storagePath,
        private readonly array $config,
    ) {
        $this->store = new JsonStore($storagePath);
    }

    /**
     * @return array{uid_number: string, gid_number: string, samba_sid: string}
     */
    public function allocate(): array
    {
        $payload = $this->store->read();
        $nextUid = (int) ($payload['next_uid_number'] ?? ($this->config['ldap']['uid_number_start'] ?? 1000010));
        $nextRid = (int) ($payload['next_samba_rid'] ?? ($this->config['ldap']['samba_rid_start'] ?? 1025));
        $gidNumber = (int) ($this->config['ldap']['gid_number_default'] ?? 1000012);
        $domainSid = trim((string) ($this->config['ldap']['samba_domain_sid'] ?? ''));

        $payload['next_uid_number'] = $nextUid + 1;
        $payload['next_samba_rid'] = $nextRid + 1;
        $this->store->write($payload);

        return [
            'uid_number' => (string) $nextUid,
            'gid_number' => (string) $gidNumber,
            'samba_sid' => $domainSid !== '' ? $domainSid . '-' . $nextRid : '',
        ];
    }
}