<?php
// sophies.rocks 
// Copyright (C) 2026 Zofia Szweda
// This file is part of sophies.rocks.
// sophies.rocks is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of
// the License, or (at your option) any later version.
// sophies.rocks is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
// You should have received a copy of the GNU Affero General Public License
// along with sophies.rocks. If not, see <https://www.gnu.org/licenses/>.
$dbPath      = '/var/lib/sophii-counter/counter.db';
$robotsPath  = '/var/www/html/robots.txt';

function isKnownBot(string $userAgent, string $robotsPath): bool {
    if ($userAgent === '') {
        return true;
    }

    if (!is_readable($robotsPath)) {
       return false;
    }

    static $botNames = null;
    if ($botNames === null) {
        $botNames = [];
        foreach (file($robotsPath, FILE_IGNORE_NEW_LINES) as $line) {
            if (preg_match('/^User-agent:\s*(.+)$/i', trim($line), $m)) {
                $name = trim($m[1]);
                if (preg_match('/^[A-Za-z0-9 _\-\.]+$/', $name) && strlen($name) > 2) {
                    $botNames[] = $name;
                }
            }
        }
    }

    foreach ($botNames as $bot) {
        if (stripos($userAgent, $bot) !== false) {
            return true;
        }
    }

    $genericPatterns = '/curl|wget|python-requests|go-http-client|scrapy|headless/i';
    if (preg_match($genericPatterns, $userAgent)) {
        return true;
    }
    return false;
}

$userAgent = $_SERVER['HTTP_USER_AGENT'] ?? '';
$isBot = isKnownBot($userAgent, $robotsPath);

$db = new SQLite3($dbPath);
$db->busyTimeout(2000);
$db->exec('CREATE TABLE IF NOT EXISTS hits (id INTEGER PRIMARY KEY, count INTEGER)');
$db->exec('INSERT OR IGNORE INTO hits (id, count) VALUES (1, 0)');

if (!$isBot) {
    $stmt = $db->prepare('UPDATE hits SET count = count + 1 WHERE id = 1');
    $stmt->execute();
}

$result = $db->querySingle('SELECT count FROM hits WHERE id = 1');

header('Content-Type: text/plain');
echo $result;