import express from 'express';
import { randomUUID } from 'node:crypto';
import { readFileSync, writeFileSync, renameSync, mkdirSync, existsSync, unlinkSync } from 'node:fs';
import { dirname, join } from 'node:path';
import { fileURLToPath } from 'node:url';
import { authRoutes, requireAuth } from './auth.js';

const ROOT = dirname(fileURLToPath(import.meta.url));
const DATA_DIR = join(ROOT, 'data');
const DB_FILE = join(DATA_DIR, 'db.json');
const PATCH_DIR = join(DATA_DIR, 'patches');
const PORT = process.env.PORT || 3000;
const HOST = process.env.HOST; // optional, z. B. 127.0.0.1, damit nur ein Proxy auf demselben Rechner zugreifen kann

// ---------- Datenspeicher (JSON-Datei) ----------
function loadDb() {
  if (!existsSync(DB_FILE)) return { members: [], events: [], meetingPoints: [], statsArchive: [], patches: [] };
  const db = JSON.parse(readFileSync(DB_FILE, 'utf8'));
  const members = db.members || [];
  // Früher war die manuelle Korrektur eine einzelne Zahl – sie gilt für das laufende Jahr
  for (const m of members) {
    if (typeof m.playsManual === 'number') m.playsManual = { [new Date().getFullYear()]: m.playsManual };
  }
  // Ältere Termine haben kein Spiel-Feld – das waren alles Spieltage
  const events = (db.events || []).map((e) => ({ isGame: true, ...e }));
  return {
    members,
    events,
    meetingPoints: db.meetingPoints || [],
    statsArchive: db.statsArchive || [],
    // Ältere Patches haben keinen Status – die gab es schon
    patches: (db.patches || []).map((p) => ({ status: 'vorhanden', ...p })),
  };
}

function saveDb() {
  mkdirSync(DATA_DIR, { recursive: true });
  const tmp = DB_FILE + '.tmp';
  writeFileSync(tmp, JSON.stringify(db, null, 2));
  renameSync(tmp, DB_FILE);
}

const db = loadDb();

// ---------- Validierung ----------
class BadRequest extends Error {}

// memberIds: erlaubte IDs für "fährt am liebsten mit bei", pointIds: erlaubte Standard-Treffpunkte
function cleanMember(body, { memberIds, pointIds = new Set(db.meetingPoints.map((p) => p.id)), selfId }) {
  const name = String(body?.name ?? '').trim();
  if (!name) throw new BadRequest('Vorname fehlt.');
  const hasCar = !!body.hasCar;
  const seats = hasCar ? Math.min(8, Math.max(1, parseInt(body.seats, 10) || 1)) : 0;
  const alwaysDrives = hasCar && !!body.alwaysDrives;
  const ridesWith = memberIds.has(body.ridesWith) && body.ridesWith !== selfId ? body.ridesWith : null;
  const meetingPoint = hasCar && pointIds.has(body.meetingPoint) ? body.meetingPoint : null;
  const external = !!body.external;
  return { name: name.slice(0, 50), external, hasCar, seats, alwaysDrives, meetingPoint, ridesWith };
}

function cleanEvent(body) {
  const date = String(body?.date ?? '');
  if (!/^\d{4}-\d{2}-\d{2}$/.test(date)) throw new BadRequest('Ungültiges Datum.');
  const title = String(body.title ?? '').trim();
  if (!title) throw new BadRequest('Titel fehlt.');
  const note = String(body.note ?? '').trim();
  const time = cleanTime(body.time);
  const endTime = time ? cleanTime(body.endTime) : null;
  return { date, title: title.slice(0, 80), note: note.slice(0, 500), isGame: body.isGame !== false, time, endTime };
}

function cleanTime(value) {
  const t = String(value ?? '');
  return /^([01]\d|2[0-3]):[0-5]\d$/.test(t) ? t : null;
}

// Bild als data:-URL; erlaubt sind PNG, JPEG und WebP (geprüft am Dateianfang, nicht nur am Typ)
const IMAGE_TYPES = [
  { ext: 'png', magic: (b) => b.subarray(0, 8).equals(Buffer.from([0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a])) },
  { ext: 'jpg', magic: (b) => b[0] === 0xff && b[1] === 0xd8 && b[2] === 0xff },
  { ext: 'webp', magic: (b) => b.subarray(0, 4).toString('latin1') === 'RIFF' && b.subarray(8, 12).toString('latin1') === 'WEBP' },
];
const MAX_IMAGE_BYTES = 8 * 1024 * 1024;
const MAX_SVG_BYTES = 2 * 1024 * 1024;

// SVG ist Text und kann Skripte enthalten. Alles, was Code ausführen oder fremde Dateien nachladen könnte,
// wird abgelehnt; zusätzlich liefert /patch-img SVGs mit einer CSP aus, die Skripte sperrt.
const SVG_FORBIDDEN = [
  [/<script/i, 'Skripte'],
  [/<foreignObject/i, 'eingebettetes HTML'],
  [/<!ENTITY|<!DOCTYPE[^>]*\[/i, 'eigene Entities'],
  [/\son[a-z]+\s*=/i, 'Ereignis-Attribute (onload, onclick, …)'],
  [/javascript:|vbscript:|data:text\/html/i, 'Skript-Links'],
  [/<(iframe|embed|object|audio|video)\b/i, 'eingebettete Inhalte'],
  [/(href|src)\s*=\s*["']\s*(https?:)?\/\//i, 'Verweise auf fremde Dateien'],
  [/@import|url\(\s*["']?\s*(https?:)?\/\//i, 'nachgeladene Stile oder Bilder'],
];

function isSvg(buf) {
  const head = buf.subarray(0, 1024).toString('utf8').replace(/^\uFEFF/, '');
  // XML-Kopf, Kommentare und ein einfacher DOCTYPE (Illustrator) dürfen vor <svg> stehen
  return /^\s*(<\?xml[^>]*>\s*)?((<!--[\s\S]*?-->|<!DOCTYPE svg[^>\[]*>)\s*)*<svg[\s>]/i.test(head);
}

function checkSvg(buf) {
  if (buf.length > MAX_SVG_BYTES) throw new BadRequest('SVG ist zu groß (max. 2 MB).');
  const text = buf.toString('utf8');
  for (const [re, what] of SVG_FORBIDDEN) {
    if (re.test(text)) throw new BadRequest(`SVG enthält ${what} – bitte als einfache Grafik exportieren.`);
  }
}

function cleanImage(dataUrl) {
  const m = /^data:image\/[a-z+.-]+;base64,([A-Za-z0-9+/=]+)$/.exec(String(dataUrl ?? ''));
  if (!m) throw new BadRequest('Bild fehlt oder ist ungültig.');
  const buf = Buffer.from(m[1], 'base64');
  if (buf.length > MAX_IMAGE_BYTES) throw new BadRequest('Bild ist zu groß (max. 8 MB).');
  if (isSvg(buf)) {
    checkSvg(buf);
    return { buf, ext: 'svg' };
  }
  const type = IMAGE_TYPES.find((t) => t.magic(buf));
  if (!type) throw new BadRequest('Nur PNG-, JPEG-, WebP- oder SVG-Bilder.');
  return { buf, ext: type.ext };
}

const PATCH_STATUS = ['vorhanden', 'geplant'];

function cleanPatch(body) {
  const name = String(body?.name ?? '').trim();
  if (!name) throw new BadRequest('Name des Patches fehlt.');
  const description = String(body.description ?? '').trim();
  const status = PATCH_STATUS.includes(body.status) ? body.status : 'vorhanden';
  return { name: name.slice(0, 80), description: description.slice(0, 500), status };
}

function savePatchImage({ buf, ext }) {
  mkdirSync(PATCH_DIR, { recursive: true });
  const file = `${randomUUID()}.${ext}`;
  writeFileSync(join(PATCH_DIR, file), buf);
  return file;
}

function removePatchImage(file) {
  try { unlinkSync(join(PATCH_DIR, file)); } catch { /* schon weg */ }
}

function cleanMeetingPoint(body) {
  const name = String(body?.name ?? '').trim();
  if (!name) throw new BadRequest('Name des Treffpunkts fehlt.');
  const address = String(body.address ?? '').trim();
  if (!address) throw new BadRequest('Adresse fehlt.');
  return { name: name.slice(0, 60), address: address.slice(0, 200) };
}

function cleanPlaysCount(value) {
  return Math.min(999, Math.max(-999, parseInt(value, 10) || 0));
}

// Manuelle Korrekturen pro Jahr: { "2026": 2, ... }
function cleanPlaysManual(value) {
  const out = {};
  if (value && typeof value === 'object') {
    for (const [year, n] of Object.entries(value)) {
      if (/^\d{4}$/.test(year) && cleanPlaysCount(n)) out[year] = cleanPlaysCount(n);
    }
  }
  return out;
}

function memberIds() {
  return new Set(db.members.map((m) => m.id));
}

function findOr404(list, id, res, what) {
  const item = list.find((x) => x.id === id);
  if (!item) res.status(404).json({ error: `${what} nicht gefunden.` });
  return item;
}

// ---------- App ----------
const app = express();
app.disable('x-powered-by');
// Hinter nginx: echte Client-IP und HTTPS erkennen. Standard: Proxy auf demselben Rechner.
// Im Docker-Container kommt nginx über das Docker-Netz → TRUST_PROXY="loopback, uniquelocal"
app.set('trust proxy', process.env.TRUST_PROXY || 'loopback');
// Patch-Uploads enthalten ein Bild, alles andere bleibt klein
app.use('/api/patches', express.json({ limit: '12mb' }));
app.use(express.json({ limit: '1mb' }));

// Öffentlich: Startseite, Login, CSS/Bilder
app.use(express.static(join(ROOT, 'public'), { extensions: ['html'] }));
authRoutes(app);

// Patch-Bilder sind öffentlich (Dateinamen sind zufällige IDs)
app.use('/patch-img', express.static(PATCH_DIR, {
  maxAge: '30d',
  immutable: true,
  setHeaders: (res, path) => {
    res.setHeader('X-Content-Type-Options', 'nosniff');
    // SVG direkt aufgerufen: keine Skripte, keine fremden Inhalte
    if (path.endsWith('.svg')) res.setHeader('Content-Security-Policy', "default-src 'none'; style-src 'unsafe-inline'; img-src data:; sandbox");
  },
}));

// Nächste Spieltage für die Startseite – nur Datum, Titel und Anzahl der Zusagen
function todayIso() {
  const d = new Date();
  return `${d.getFullYear()}-${String(d.getMonth() + 1).padStart(2, '0')}-${String(d.getDate()).padStart(2, '0')}`;
}

app.get('/api/upcoming', (req, res) => {
  const today = todayIso();
  res.json(db.events
    .filter((e) => e.date >= today)
    .sort((a, b) => a.date.localeCompare(b.date))
    .slice(0, 3)
    .map((e) => ({ date: e.date, title: e.title, time: e.time, isGame: e.isGame, attendeeCount: e.attendees.length })));
});

// ---------- Jahresstatistik ----------
// Spiele pro Mitglied (ohne Externe) in einem Jahr: Spiel-Events mit Zusage bis heute + manuelle Korrektur.
// Termine ohne Spiel (Treffen, Grillen, …) zählen nicht.
function yearStats(year) {
  const today = todayIso();
  const fromCalendar = new Map();
  for (const ev of db.events) {
    if (!ev.isGame || !ev.date.startsWith(`${year}-`) || ev.date > today) continue;
    for (const id of ev.attendees) fromCalendar.set(id, (fromCalendar.get(id) || 0) + 1);
  }
  return db.members.filter((m) => !m.external).map((m) => {
    const calendar = fromCalendar.get(m.id) || 0;
    const manual = m.playsManual?.[year] || 0;
    return { id: m.id, name: m.name, calendar, manual, total: Math.max(0, calendar + manual) };
  }).sort((a, b) => b.total - a.total || a.name.localeCompare(b.name, 'de'));
}

// Abgeschlossene Jahre werden einmalig eingefroren; das neue Jahr startet automatisch bei 0
function archiveFinishedYears() {
  const current = new Date().getFullYear();
  const years = new Set(db.events.map((e) => +e.date.slice(0, 4)));
  for (const m of db.members) for (const y of Object.keys(m.playsManual || {})) years.add(+y);
  let changed = false;
  for (const year of [...years].sort()) {
    if (year >= current || db.statsArchive.some((a) => a.year === year)) continue;
    db.statsArchive.push({ year, savedAt: new Date().toISOString(), entries: yearStats(year) });
    changed = true;
    console.log(`Jahresstatistik ${year} archiviert.`);
  }
  if (changed) {
    db.statsArchive.sort((a, b) => b.year - a.year);
    saveDb();
  }
}

archiveFinishedYears();
setInterval(archiveFinishedYears, 60 * 60 * 1000);

// ?year=2025 → archiviertes Jahr, sonst das laufende Jahr (live)
app.get('/api/stats', (req, res) => {
  archiveFinishedYears();
  const current = new Date().getFullYear();
  const years = [current, ...db.statsArchive.map((a) => a.year)];
  const year = parseInt(req.query.year, 10) || current;
  if (year === current) return res.json({ year, live: true, years, entries: yearStats(year) });
  const archived = db.statsArchive.find((a) => a.year === year);
  if (!archived) return res.status(404).json({ error: `Für ${year} gibt es keine Statistik.` });
  res.json({ year, live: false, years, savedAt: archived.savedAt, entries: archived.entries });
});

// ---------- Patches ----------
const sortedPatches = () => [...db.patches].sort((a, b) => b.createdAt.localeCompare(a.createdAt));

app.get('/api/patches', (req, res) => {
  res.json(sortedPatches());
});

// Ab hier nur mit Login
app.use(requireAuth);

app.post('/api/patches', (req, res) => {
  const fields = cleanPatch(req.body);
  const image = savePatchImage(cleanImage(req.body.image));
  const patch = { id: randomUUID(), ...fields, image, createdAt: new Date().toISOString() };
  db.patches.push(patch);
  saveDb();
  res.status(201).json(patch);
});

// Bild ist optional – ohne Bild werden nur Name und Beschreibung geändert
app.put('/api/patches/:id', (req, res) => {
  const patch = findOr404(db.patches, req.params.id, res, 'Patch');
  if (!patch) return;
  const fields = cleanPatch(req.body);
  if (req.body.image) {
    const old = patch.image;
    patch.image = savePatchImage(cleanImage(req.body.image));
    removePatchImage(old);
  }
  Object.assign(patch, fields);
  saveDb();
  res.json(patch);
});

app.delete('/api/patches/:id', (req, res) => {
  const patch = db.patches.find((p) => p.id === req.params.id);
  if (patch) removePatchImage(patch.image);
  db.patches = db.patches.filter((p) => p.id !== req.params.id);
  saveDb();
  res.status(204).end();
});
app.use(express.static(join(ROOT, 'private'), {
  extensions: ['html'],
  setHeaders: (res) => res.setHeader('Cache-Control', 'private, no-cache'),
}));

// Mitglieder
app.get('/api/members', (req, res) => {
  res.json(db.members);
});

app.post('/api/members', (req, res) => {
  const member = { id: randomUUID(), ...cleanMember(req.body, { memberIds: memberIds() }) };
  db.members.push(member);
  saveDb();
  res.status(201).json(member);
});

app.put('/api/members/:id', (req, res) => {
  const member = findOr404(db.members, req.params.id, res, 'Mitglied');
  if (!member) return;
  Object.assign(member, cleanMember(req.body, { memberIds: memberIds(), selfId: member.id }));
  saveDb();
  res.json(member);
});

app.delete('/api/members/:id', (req, res) => {
  const { id } = req.params;
  db.members = db.members.filter((m) => m.id !== id);
  for (const m of db.members) if (m.ridesWith === id) m.ridesWith = null;
  for (const ev of db.events) ev.attendees = ev.attendees.filter((a) => a !== id);
  saveDb();
  res.status(204).end();
});

// Manuelle Korrektur der gespielten Spiele (z. B. spontane Fahrten, die nicht im Kalender stehen)
app.put('/api/members/:id/plays-manual', (req, res) => {
  const member = findOr404(db.members, req.params.id, res, 'Mitglied');
  if (!member) return;
  const year = new Date().getFullYear();
  member.playsManual = { ...member.playsManual, [year]: cleanPlaysCount(req.body?.manual) };
  saveDb();
  res.json({ id: member.id, year, manual: member.playsManual[year] });
});

// Ersetzt die komplette Gruppe (Import aus JSON-Datei)
app.post('/api/members/import', (req, res) => {
  if (!Array.isArray(req.body)) throw new BadRequest('Erwarte eine Liste von Mitgliedern.');
  const rows = req.body
    .filter((m) => String(m?.name ?? '').trim())
    .map((m) => ({ ...m, id: typeof m.id === 'string' && m.id ? m.id : randomUUID() }));
  const ids = new Set(rows.map((m) => m.id));
  const imported = rows.map((m) => ({
    id: m.id,
    ...cleanMember(m, { memberIds: ids, selfId: m.id }),
    playsManual: cleanPlaysManual(m.playsManual),
  }));
  db.members = imported;
  for (const ev of db.events) ev.attendees = ev.attendees.filter((a) => ids.has(a));
  saveDb();
  res.json(db.members);
});

// Treffpunkte
app.get('/api/meeting-points', (req, res) => {
  res.json([...db.meetingPoints].sort((a, b) => a.name.localeCompare(b.name, 'de')));
});

app.post('/api/meeting-points', (req, res) => {
  const point = { id: randomUUID(), ...cleanMeetingPoint(req.body) };
  db.meetingPoints.push(point);
  saveDb();
  res.status(201).json(point);
});

app.put('/api/meeting-points/:id', (req, res) => {
  const point = findOr404(db.meetingPoints, req.params.id, res, 'Treffpunkt');
  if (!point) return;
  Object.assign(point, cleanMeetingPoint(req.body));
  saveDb();
  res.json(point);
});

app.delete('/api/meeting-points/:id', (req, res) => {
  db.meetingPoints = db.meetingPoints.filter((p) => p.id !== req.params.id);
  for (const m of db.members) if (m.meetingPoint === req.params.id) m.meetingPoint = null;
  saveDb();
  res.status(204).end();
});

// Spieltage
app.get('/api/events', (req, res) => {
  res.json([...db.events].sort((a, b) => a.date.localeCompare(b.date)));
});

// Kalenderdateien (.ics) – alle kommenden Termine oder ein einzelner
app.get('/api/calendar.ics', (req, res) => {
  const today = todayIso();
  sendIcs(res, 'hcrb-termine.ics', db.events.filter((e) => e.date >= today).sort((a, b) => a.date.localeCompare(b.date)));
});

app.get('/api/events/:id/ics', (req, res) => {
  const ev = findOr404(db.events, req.params.id, res, 'Termin');
  if (ev) sendIcs(res, `hcrb-${ev.date}.ics`, [ev]);
});

app.get('/api/events/:id', (req, res) => {
  const ev = findOr404(db.events, req.params.id, res, 'Termin');
  if (ev) res.json(ev);
});

app.post('/api/events', (req, res) => {
  const createdBy = db.members.some((m) => m.id === req.body?.createdBy) ? req.body.createdBy : null;
  const ev = {
    id: randomUUID(),
    ...cleanEvent(req.body),
    createdBy,
    attendees: createdBy ? [createdBy] : [],
  };
  db.events.push(ev);
  saveDb();
  res.status(201).json(ev);
});

app.put('/api/events/:id', (req, res) => {
  const ev = findOr404(db.events, req.params.id, res, 'Termin');
  if (!ev) return;
  Object.assign(ev, cleanEvent(req.body));
  saveDb();
  res.json(ev);
});

app.delete('/api/events/:id', (req, res) => {
  db.events = db.events.filter((e) => e.id !== req.params.id);
  saveDb();
  res.status(204).end();
});

// Zusagen / Absagen
app.put('/api/events/:id/attendees/:memberId', (req, res) => {
  const ev = findOr404(db.events, req.params.id, res, 'Termin');
  if (!ev) return;
  if (!findOr404(db.members, req.params.memberId, res, 'Mitglied')) return;
  if (!ev.attendees.includes(req.params.memberId)) ev.attendees.push(req.params.memberId);
  saveDb();
  res.json(ev);
});

app.delete('/api/events/:id/attendees/:memberId', (req, res) => {
  const ev = findOr404(db.events, req.params.id, res, 'Termin');
  if (!ev) return;
  ev.attendees = ev.attendees.filter((a) => a !== req.params.memberId);
  saveDb();
  res.json(ev);
});

// ---------- iCalendar ----------
function icsText(s) {
  return String(s).replace(/\\/g, '\\\\').replace(/;/g, '\\;').replace(/,/g, '\\,').replace(/\r?\n/g, '\\n');
}

// Zeilen länger als 75 Byte werden umgebrochen (RFC 5545), ohne UTF-8-Zeichen zu zerteilen
function icsFold(line) {
  const out = [];
  let cur = '';
  let bytes = 0;
  for (const ch of line) {
    const n = Buffer.byteLength(ch);
    if (bytes + n > (out.length ? 74 : 75)) {
      out.push(cur);
      cur = '';
      bytes = 0;
    }
    cur += ch;
    bytes += n;
  }
  out.push(cur);
  return out.join('\r\n ');
}

const compactDate = (iso) => iso.replaceAll('-', '');
const compactTime = (t) => t.replace(':', '') + '00';

function shiftDate(iso, days) {
  const [y, m, d] = iso.split('-').map(Number);
  const dt = new Date(Date.UTC(y, m - 1, d + days));
  return dt.toISOString().slice(0, 10);
}

const VTIMEZONE_BERLIN = [
  'BEGIN:VTIMEZONE', 'TZID:Europe/Berlin',
  'BEGIN:DAYLIGHT', 'TZOFFSETFROM:+0100', 'TZOFFSETTO:+0200', 'TZNAME:CEST',
  'DTSTART:19700329T020000', 'RRULE:FREQ=YEARLY;BYMONTH=3;BYDAY=-1SU', 'END:DAYLIGHT',
  'BEGIN:STANDARD', 'TZOFFSETFROM:+0200', 'TZOFFSETTO:+0100', 'TZNAME:CET',
  'DTSTART:19701025T030000', 'RRULE:FREQ=YEARLY;BYMONTH=10;BYDAY=-1SU', 'END:STANDARD',
  'END:VTIMEZONE',
];

function icsEvent(ev, stamp) {
  const names = ev.attendees.map((id) => db.members.find((m) => m.id === id)?.name).filter(Boolean)
    .sort((a, b) => a.localeCompare(b, 'de'));
  const description = [ev.note, names.length ? `Zusagen (${names.length}): ${names.join(', ')}` : '']
    .filter(Boolean).join('\n\n');
  const lines = ['BEGIN:VEVENT', `UID:${ev.id}@hcrb`, `DTSTAMP:${stamp}`];
  if (ev.time) {
    // Ohne Ende: 6 Stunden, höchstens bis Mitternacht
    const [h, m] = ev.time.split(':').map(Number);
    const end = ev.endTime && ev.endTime > ev.time
      ? ev.endTime
      : `${String(Math.min(23, h + 6)).padStart(2, '0')}:${h + 6 > 23 ? '59' : String(m).padStart(2, '0')}`;
    lines.push(`DTSTART;TZID=Europe/Berlin:${compactDate(ev.date)}T${compactTime(ev.time)}`);
    lines.push(`DTEND;TZID=Europe/Berlin:${compactDate(ev.date)}T${compactTime(end)}`);
  } else {
    lines.push(`DTSTART;VALUE=DATE:${compactDate(ev.date)}`);
    lines.push(`DTEND;VALUE=DATE:${compactDate(shiftDate(ev.date, 1))}`);
  }
  lines.push(`SUMMARY:${icsText(ev.title)}`);
  if (description) lines.push(`DESCRIPTION:${icsText(description)}`);
  lines.push(`CATEGORIES:${ev.isGame ? 'Airsoft,Spiel' : 'HCRB'}`, 'END:VEVENT');
  return lines;
}

function sendIcs(res, filename, events) {
  const stamp = new Date().toISOString().replace(/[-:]/g, '').replace(/\.\d+/, '');
  const lines = [
    'BEGIN:VCALENDAR', 'VERSION:2.0', 'PRODID:-//HCRB//Plan-Tool//DE', 'CALSCALE:GREGORIAN', 'METHOD:PUBLISH',
    'X-WR-CALNAME:HCRB Termine', 'X-WR-TIMEZONE:Europe/Berlin',
    ...(events.some((e) => e.time) ? VTIMEZONE_BERLIN : []),
    ...events.flatMap((ev) => icsEvent(ev, stamp)),
    'END:VCALENDAR',
  ];
  res.setHeader('Content-Type', 'text/calendar; charset=utf-8');
  res.setHeader('Content-Disposition', `attachment; filename="${filename}"`);
  res.send(lines.map(icsFold).join('\r\n') + '\r\n');
}

app.use('/api', (req, res) => {
  res.status(404).json({ error: 'Unbekannte Anfrage.' });
});

app.use((err, req, res, next) => {
  if (err instanceof BadRequest) return res.status(400).json({ error: err.message });
  console.error(err);
  res.status(500).json({ error: 'Serverfehler.' });
});

app.listen(PORT, HOST, () => {
  console.log(`HCRB läuft auf http://${HOST || 'localhost'}:${PORT}`);
});