import { Suspense } from "react";
import Link from "next/link";
import { verifySessionToken } from "@/lib/admin-auth";
import { getAuditLogs } from "@/lib/audit-log";
import { cookies } from "next/headers";
import { AdminNav } from "@/components/admin/AdminNav";

async function AuditLogsContent() {
  const cookieStore = await cookies();
  const token = cookieStore.get("admin_session")?.value;

  if (!token) {
    return (
      <div className="text-center py-12">
        <p className="text-red-400 font-semibold">Nicht authentifiziert</p>
        <Link href="/admin/login" className="text-orange-400 underline mt-4 inline-block">
          Zurück zum Login
        </Link>
      </div>
    );
  }

  const session = await verifySessionToken(token);
  if (!session) {
    return (
      <div className="text-center py-12">
        <p className="text-red-400 font-semibold">Session abgelaufen</p>
        <Link href="/admin/login" className="text-orange-400 underline mt-4 inline-block">
          Erneut anmelden
        </Link>
      </div>
    );
  }

  const logs = await getAuditLogs({ limit: 100, offset: 0 });

  const successCount = logs.filter((l) => l.success).length;
  const failedCount = logs.filter((l) => !l.success).length;
  const uniqueIps = new Set(logs.map((l) => l.ip_addr)).size;

  const oneHourAgo = new Date(Date.now() - 60 * 60 * 1000).toISOString();
  const recentLogs = logs.filter((l) => l.timestamp > oneHourAgo);
  const recentFailed = recentLogs.filter((l) => !l.success).length;

  return (
    <div className="space-y-6">
      <div>
        <h1 className="text-2xl font-bold text-white tracking-tight">Audit-Logs</h1>
        <p className="text-sm text-slate-500 mt-0.5">Login-Aktivitäten und Sicherheitsereignisse</p>
      </div>

      <div className="grid grid-cols-2 md:grid-cols-4 gap-4">
        {[
          { label: "Erfolgreich (Gesamt)", wert: successCount, color: "text-green-400" },
          { label: "Fehlgeschlagen (Gesamt)", wert: failedCount, color: "text-red-400" },
          { label: "Fehlgeschlagen (1h)", wert: recentFailed, color: recentFailed >= 5 ? "text-red-400" : "text-green-400" },
          { label: "Eindeutige IPs", wert: uniqueIps, color: "text-white" },
        ].map((k) => (
          <div key={k.label} className="bg-[#18212f] border border-gray-800 p-4 rounded-lg">
            <div className="text-xs text-slate-500 mb-1">{k.label}</div>
            <div className={`text-2xl font-bold ${k.color}`}>{k.wert}</div>
          </div>
        ))}
      </div>

      {recentFailed >= 5 && (
        <div className="bg-red-500/10 border border-red-500/30 p-4 rounded-lg">
          <p className="text-sm font-semibold text-red-400">⚠️ Verdächtige Aktivität erkannt</p>
          <p className="text-sm text-red-400/70 mt-1">
            {recentFailed} fehlgeschlagene Login-Versuche in der letzten Stunde
          </p>
        </div>
      )}

      <div className="bg-[#18212f] border border-gray-800 rounded-lg overflow-hidden">
        <div className="overflow-x-auto">
          <table className="w-full text-sm">
            <thead className="border-b border-gray-800">
              <tr className="text-xs text-slate-500 uppercase tracking-wide">
                <th className="px-4 py-3 text-left font-medium">Zeitstempel</th>
                <th className="px-4 py-3 text-left font-medium">E-Mail</th>
                <th className="px-4 py-3 text-left font-medium">IP-Adresse</th>
                <th className="px-4 py-3 text-left font-medium">Status</th>
                <th className="px-4 py-3 text-left font-medium">Grund</th>
              </tr>
            </thead>
            <tbody className="divide-y divide-gray-800/50">
              {logs.length === 0 ? (
                <tr>
                  <td colSpan={5} className="px-4 py-8 text-center text-slate-500">
                    Keine Audit-Logs vorhanden
                  </td>
                </tr>
              ) : (
                logs.map((log) => (
                  <tr key={log.id} className="hover:bg-[#111925] transition-colors">
                    <td className="px-4 py-3 whitespace-nowrap text-slate-400">
                      {new Date(log.timestamp).toLocaleString("de-DE")}
                    </td>
                    <td className="px-4 py-3 font-mono text-slate-300 truncate">{log.email}</td>
                    <td className="px-4 py-3 font-mono text-slate-400 text-xs">{log.ip_addr}</td>
                    <td className="px-4 py-3">
                      <span className={`inline-flex items-center px-2.5 py-0.5 rounded-full text-xs font-medium ${
                        log.success
                          ? "bg-green-500/10 text-green-400 border border-green-500/20"
                          : "bg-red-500/10 text-red-400 border border-red-500/20"
                      }`}>
                        {log.success ? "✓ Erfolgreich" : "✗ Fehlgeschlagen"}
                      </span>
                    </td>
                    <td className="px-4 py-3 text-slate-500 text-xs">
                      {log.reason ? formatReason(log.reason) : "–"}
                    </td>
                  </tr>
                ))
              )}
            </tbody>
          </table>
        </div>
      </div>

      <div className="bg-blue-500/10 border border-blue-500/20 p-4 rounded-lg">
        <p className="text-sm text-blue-400">
          <strong>Hinweis:</strong> Detaillierte Geräte-Informationen sind in der Supabase-Tabelle{" "}
          <code className="bg-[#111925] px-2 py-0.5 rounded border border-blue-500/20 font-mono text-xs">
            admin_audit_logs
          </code>{" "}
          gespeichert.
        </p>
      </div>
    </div>
  );
}

function formatReason(reason: string): string {
  const reasons: Record<string, string> = {
    invalid_password: "Falsches Passwort",
    user_not_found_or_inactive: "User nicht gefunden / inaktiv",
    missing_credentials: "Fehlende Anmeldedaten",
    invalid_token: "Ungültiger Token",
    token_expired: "Token abgelaufen",
  };
  return reasons[reason] || reason;
}

export default function AuditLogsPage() {
  return (
    <div className="min-h-screen bg-[#111925]">
      <AdminNav />
      <div className="max-w-6xl mx-auto px-4 py-8">
        <Suspense
          fallback={
            <div className="text-center py-12">
              <p className="text-slate-500">Lädt Audit-Logs…</p>
            </div>
          }
        >
          <AuditLogsContent />
        </Suspense>
      </div>
    </div>
  );
}