<?php
declare(strict_types=1);
namespace UploadLogger\Core\Services;

use UploadLogger\Core\Config;

final class FloodService
{
    private Config $config;

    public function __construct(?Config $config = null)
    {
        $this->config = $config ?? new Config(['modules' => []]);
    }

    public function check(string $ip): int
    {
        $window = (int)$this->config->get('limits.flood_window_sec', 60);
        $stateDir = (string)$this->config->get('paths.state_dir', __DIR__ . '/../../state');

        $key = rtrim($stateDir, '/\\') . '/upl_' . md5('v3|' . $ip);

        $now = time();
        $count = 0;
        $start = $now;

        $fh = @fopen($key, 'c+');
        if ($fh === false) {
            return 1;
        }

        if (flock($fh, LOCK_EX)) {
            $raw = stream_get_contents($fh);
            if ($raw !== false) {
                if (preg_match('/^(\d+):(\d+)$/', trim($raw), $m)) {
                    $start = (int)$m[1];
                    $count = (int)$m[2];
                }
            }

            if ((($now - $start) > $window)) {
                $start = $now;
                $count = 0;
            }

            $count++;
            rewind($fh);
            ftruncate($fh, 0);
            fwrite($fh, $start . ':' . $count);
            fflush($fh);
            flock($fh, LOCK_UN);
        }

        fclose($fh);

        return $count;
    }
}