From 7b6bf964cb3ff2aa431c793213e1d5ebf62e1b94 Mon Sep 17 00:00:00 2001
From: Dicken <dicken@noreply.localhost>
Date: Tue, 26 May 2026 14:49:49 +0200
Subject: [PATCH] Dateien nach "backend/src/routes" hochladen

---
 backend/src/routes/calendar.js | 68 +++++++++++++++++++++++++---------
 1 file changed, 51 insertions(+), 17 deletions(-)

diff --git a/backend/src/routes/calendar.js b/backend/src/routes/calendar.js
index 7084600..85a7652 100644
--- a/backend/src/routes/calendar.js
+++ b/backend/src/routes/calendar.js
@@ -4,26 +4,60 @@ const http    = require('http');
 const { authenticate } = require('../middleware/auth');
 const router  = express.Router();
 
-// Fetch iCal feed server-side (avoids CORS)
-router.get('/fetch', authenticate, (req, res) => {
+// Fetch mit Redirect-Unterstützung (bis 5 Hops)
+function fetchWithRedirects(url, hops = 0) {
+  return new Promise((resolve, reject) => {
+    if (hops > 5) return reject(new Error('Zu viele Redirects'));
+    let parsed;
+    try { parsed = new URL(url); } catch { return reject(new Error('Ungültige URL')); }
+
+    const lib = parsed.protocol === 'https:' ? https : http;
+    const req = lib.get(url, {
+      headers: {
+        'User-Agent': 'Mozilla/5.0 DickenDock/1.0',
+        'Accept': 'text/calendar, text/plain, */*',
+      }
+    }, res => {
+      // Redirect folgen
+      if ([301,302,303,307,308].includes(res.statusCode) && res.headers.location) {
+        const next = res.headers.location.startsWith('http')
+          ? res.headers.location
+          : new URL(res.headers.location, url).href;
+        res.destroy();
+        return fetchWithRedirects(next, hops + 1).then(resolve).catch(reject);
+      }
+      if (res.statusCode !== 200)
+        return reject(new Error(`HTTP ${res.statusCode}`));
+
+      let data = '';
+      res.setEncoding('utf8');
+      res.on('data', d => {
+        data += d;
+        if (data.length > 3 * 1024 * 1024) { res.destroy(); reject(new Error('Feed zu groß (max 3MB)')); }
+      });
+      res.on('end', () => resolve(data));
+    });
+    req.on('error', reject);
+    req.setTimeout(10000, () => { req.destroy(); reject(new Error('Timeout nach 10s')); });
+  });
+}
+
+router.get('/fetch', authenticate, async (req, res) => {
   const { url } = req.query;
   if (!url) return res.status(400).json({ error: 'URL fehlt' });
-  let parsed;
-  try { parsed = new URL(url); }
-  catch { return res.status(400).json({ error: 'Ungültige URL' }); }
-  if (!['http:','https:'].includes(parsed.protocol))
-    return res.status(400).json({ error: 'Nur HTTP/HTTPS erlaubt' });
+  try {
+    new URL(url); // validate
+  } catch { return res.status(400).json({ error: 'Ungültige URL' }); }
 
-  const lib = parsed.protocol === 'https:' ? https : http;
-  const req2 = lib.get(url, { headers:{ 'User-Agent':'DickenDock/1.0' } }, r2 => {
-    if (r2.statusCode !== 200)
-      return res.status(502).json({ error: `Feed antwortet mit ${r2.statusCode}` });
-    let data = '';
-    r2.on('data', d => { data += d; if (data.length > 2*1024*1024) { r2.destroy(); res.status(413).json({ error: 'Feed zu groß (max 2MB)' }); } });
-    r2.on('end', () => res.type('text/calendar').send(data));
-  });
-  req2.on('error', e => res.status(502).json({ error: e.message }));
-  req2.setTimeout(8000, () => { req2.destroy(); res.status(504).json({ error: 'Timeout' }); });
+  try {
+    const data = await fetchWithRedirects(url);
+    // Prüfen ob es wirklich iCal ist
+    if (!data.includes('BEGIN:VCALENDAR'))
+      return res.status(502).json({ error: 'Kein gültiger iCal-Feed (BEGIN:VCALENDAR fehlt)' });
+    res.type('text/calendar; charset=utf-8').send(data);
+  } catch(e) {
+    res.status(502).json({ error: e.message });
+  }
 });
 
 module.exports = router;