<?php

namespace App\Services;

use App\Models\GameAccount;
use Carbon\CarbonImmutable;
use Illuminate\Support\Facades\DB;

class LauncherGameTicketService
{
    private const string ALPHABET = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789';

    public function __construct(private readonly VMangosSrpService $srp) {}

    /** @return array{account: string, ticket: string, expires_at: string} */
    public function issue(GameAccount $account, string $launcherSessionToken, int $clientBuild): array
    {
        $username = $this->srp->normalizeUsername((string) $account->username);
        if (preg_match('/^[A-Z0-9]{3,16}$/D', $username) !== 1) {
            throw new \RuntimeException('Account name is incompatible with the 1.12.1 client.');
        }

        $ticket = '';
        for ($i = 0; $i < 16; $i++) {
            $ticket .= self::ALPHABET[random_int(0, strlen(self::ALPHABET) - 1)];
        }

        [$saltHex, $verifierHex] = $this->srp->makeRegistrationData($username, $ticket);
        $now = CarbonImmutable::now('UTC');
        $expires = $now->addSeconds(max(5, min(60, (int) config('moonwell.launcher.game_ticket_ttl'))));

        DB::connection(config('moonwell.auth_connection'))->table('launcher_ticket')->upsert([[
            'account_id' => (int) $account->id,
            'generation_id' => random_bytes(16),
            'srp_salt' => hex2bin($saltHex),
            'srp_verifier' => hex2bin(str_pad($verifierHex, 64, '0', STR_PAD_LEFT)),
            'client_build' => $clientBuild,
            'launcher_session_hash' => hash('sha256', $launcherSessionToken, true),
            'issued_at' => $now->format('Y-m-d H:i:s.u'),
            'expires_at' => $expires->format('Y-m-d H:i:s.u'),
            'claim_nonce' => null,
        ]], ['account_id'], ['generation_id', 'srp_salt', 'srp_verifier', 'client_build', 'launcher_session_hash', 'issued_at', 'expires_at', 'claim_nonce']);

        return [
            'account' => $username,
            'ticket' => $ticket,
            'expires_at' => $expires->format('Y-m-d\TH:i:s\Z'),
        ];
    }
}