<?php

namespace App\Livewire\Ui\Security\Modal;

use LivewireUI\Modal\ModalComponent;

class Fail2BanJailModal extends ModalComponent
{
    public string $jail = '';
    /** @var array<int,array{
     *   ip:string,
     *   bantime:int,            // Sek.; -1 = permanent
     *   banned_at:?int,         // Unix-Timestamp
     *   remaining:?int,         // -1=permanent, 0..Sekunden, null=unbekannt
     *   until:?int,             // Unix-Timestamp oder null
     *   time_text:string,       // "HHh MMm SSs", "permanent", "—"
     *   meta_text:string,       // "seit … • bis …" oder "seit …" oder "—"
     *   box_class:string        // Tailwind-Klassen für BG/Border
     * }]
     */
    public array $rows = [];

    public static function modalMaxWidth(): string
    {
        return '4xl';
    }

    public function mount(string $jail): void
    {
        $this->jail = $jail;
        $this->load();
    }

    public function refresh(): void
    {
        $this->load(true);
    }

    public function render()
    {
        return view('livewire.ui.security.modal.fail2-ban-jail-modal');
    }

    /* ---------------- intern ---------------- */

    protected function load(bool $force = false): void
    {
        $jail = $this->jail;

        // Aktuell gebannte IPs
        [, $s] = $this->f2b('status '.escapeshellarg($jail));
        $ipList = $this->firstMatch('/Banned IP list:\s*(.+)$/mi', $s) ?: '';
        $ips = $ipList !== '' ? array_values(array_filter(array_map('trim', preg_split('/\s+/', $ipList)))) : [];

        // bantime für Jail
        $bantime = $this->getBantime($jail);

        $rows = [];
        foreach ($ips as $ip) {
            $banAt = $this->lastBanTimestamp($jail, $ip); // Unix-Timestamp oder null

            $remaining = null;
            $until = null;
            if ($banAt !== null) {
                if ($bantime === -1) {
                    $remaining = -1;
                } else {
                    $remaining = max(0, $bantime - (time() - $banAt));
                    $until = $remaining > 0 ? $banAt + $bantime : null;
                }
            }

            // Darstellung
            [$timeText, $metaText, $boxClass] = $this->present($remaining, $banAt, $until);

            $rows[] = [
                'ip'        => $ip,
                'bantime'   => $bantime,
                'banned_at' => $banAt,
                'remaining' => $remaining,
                'until'     => $until,
                'time_text' => $timeText,
                'meta_text' => $metaText,
                'box_class' => $boxClass,
            ];
        }

        $this->rows = $rows;
    }

    /** Darstellung ableiten (Farbcode + Texte) */
    private function present(?int $remaining, ?int $banAt, ?int $until): array
    {
        // Farben an dein Schema angelehnt
        $green = 'border-emerald-400/30 bg-emerald-500/10';
        $amber = 'border-amber-400/30 bg-amber-500/10';
        $rose  = 'border-rose-400/30 bg-rose-500/10';
        $muted = 'border-white/10 bg-white/5';

        if ($remaining === -1) {
            $time = 'permanent';
            $meta = $banAt ? ('seit '.$this->fmtTs($banAt)) : '—';
            return [$time, $meta, $rose];
        }

        if (is_int($remaining)) {
            if ($remaining > 0) {
                $time = $this->fmtSecs($remaining);
                $parts = [];
                if ($banAt) $parts[] = 'seit '.$this->fmtTs($banAt);
                if ($until) $parts[] = 'bis '.$this->fmtTs($until);
                $meta = $parts ? implode(' • ', $parts) : '—';
                return [$time, $meta, $amber];
            }

            // 0 Sekunden -> theoretisch abgelaufen
            $time = 'abgelaufen';
            $meta = $banAt ? ('seit '.$this->fmtTs($banAt)) : '—';
            return [$time, $meta, $muted];
        }

        // keine Info
        return ['—', '—', $muted];
    }

    /** sudo + fail2ban-client */
    private function f2b(string $args): array
    {
        $sudo = '/usr/bin/sudo';
        $f2b  = '/usr/bin/fail2ban-client';
        $out  = (string) @shell_exec("timeout 3 $sudo -n $f2b $args 2>&1");
        $ok   = stripos($out, 'Status') !== false
            || stripos($out, 'Jail list') !== false
            || stripos($out, 'pong') !== false;
        return [$ok, $out];
    }

    private function getBantime(string $jail): int
    {
        [, $out] = $this->f2b('get '.escapeshellarg($jail).' bantime');
        $val = trim($out);
        if (preg_match('/-?\d+/', $val, $m)) return (int)$m[0];
        return 600;
    }

    /** letzte "Ban <IP>"-Zeile parsen -> Unix-Timestamp */
    /** letzte "Ban <IP>"-Zeile -> Unix-Timestamp aus /var/log/fail2ban.log */
    private function lastBanTimestamp(string $jail, string $ip): ?int
    {
        $file = '/var/log/fail2ban.log';
        if (!is_readable($file)) return null;

        // nur das Dateiende lesen (performant, auch bei großen Logs)
        $tailBytes = 400000; // 400 KB
        $size = @filesize($file) ?: 0;
        $seek = max(0, $size - $tailBytes);

        $fh = @fopen($file, 'rb');
        if (!$fh) return null;
        if ($seek > 0) fseek($fh, $seek);
        $data = stream_get_contents($fh) ?: '';
        fclose($fh);

        // Beispiel: 2025-10-30 22:34:20,797 ... [sshd] Ban 193.46.255.244
        $j = preg_quote($jail, '/');
        $p = preg_quote($ip, '/');
        $pattern = '/^(\d{4}-\d{2}-\d{2})\s+(\d{2}:\d{2}:\d{2}),\d+.*\['.$j.'\]\s+Ban\s+'.$p.'\s*$/m';

        if (preg_match_all($pattern, $data, $m) && !empty($m[1])) {
            $date = end($m[1]);
            $time = end($m[2]);
            $dt = \DateTime::createFromFormat('Y-m-d H:i:s', "$date $time",
                new \DateTimeZone(date_default_timezone_get()));
            return $dt ? $dt->getTimestamp() : null;
        }
        return null;
    }

    private function firstMatch(string $pattern, string $haystack): ?string
    {
        return preg_match($pattern, $haystack, $m) ? trim($m[1]) : null;
    }

    private function buildIpDetails(string $jail, array $ips, int $bantime): array
    {
        $out = [];
        $now = time();

        foreach ($ips as $ip) {
            $banAt = $this->lastBanTimestamp($jail, $ip);
            $remaining = null; $until = null;

            if ($bantime === -1) {
                $remaining = -1; // permanent
            } elseif ($banAt !== null) {
                $remaining = max(0, $bantime - ($now - $banAt));
                $until = $remaining > 0 ? ($banAt + $bantime) : null;
            }

            $out[] = [
                'ip'        => $ip,
                'remaining' => $remaining, // -1=permanent, null=unbekannt, 0..N Sekunden
                'until'     => $until,
            ];
        }
        return $out;
    }

    private function fmtSecs(int $s): string
    {
        // kompakt: 1h 23m 45s / 05m 10s / 12s
        $h = intdiv($s, 3600);
        $m = intdiv($s % 3600, 60);
        $r = $s % 60;
        if ($h > 0) return sprintf('%dh %02dm %02ds', $h, $m, $r);
        if ($m > 0) return sprintf('%02dm %02ds', $m, $r);
        return sprintf('%ds', $r);
    }

    private function fmtTs(int $ts): string
    {
        // 29.10. 18:07
        return date('d.m. H:i', $ts);
    }
}