Add /api/mensa endpoint

rogue-thi-app/package.json

@@ -22,7 +22,8 @@
     "react-bootstrap": "^1.4.0",
     "react-dom": "^17.0.1",
     "react-leaflet": "^3.0.5",
-    "react-placeholder": "^4.0.3"
+    "react-placeholder": "^4.0.3",
+    "xml-js": "^1.6.11"
   },
   "devDependencies": {
     "eslint": "^7.15.0",

rogue-thi-app/pages/api/mensa.js

@@ -0,0 +1,31 @@
+import xmljs from 'xml-js'
+import MemoryCache from '../../lib/memory-cache'
+
+const CACHE_TTL = 60 * 60 * 1000
+const URL_DE = 'https://www.max-manager.de/daten-extern/sw-erlangen-nuernberg/xml/mensa-ingolstadt.xml'
+const URL_EN = 'https://www.max-manager.de/daten-extern/sw-erlangen-nuernberg/xml/en/mensa-ingolstadt.xml'
+
+const cache = new MemoryCache({ ttl: CACHE_TTL })
+
+async function fetchPlan (lang) {
+  const url = (lang || 'de') === 'de' ? URL_DE : URL_EN
+
+  let plan = cache.get(url)
+
+  if (!plan) {
+    const resp = await fetch(url)
+    plan = xmljs.xml2js(await resp.text(), { compact: true })
+
+    cache.set(url, plan)
+  }
+
+  return plan
+}
+
+export default async function handler (req, res) {
+  const plan = await fetchPlan(req.query.lang)
+
+  res.statusCode = 200
+  res.setHeader('Content-Type', 'application/json')
+  res.end(JSON.stringify(plan))
+}