Initial commit — Mek-Tech Live Labs Showcase v1.0

server/lib/camera-proxy.js

@@ -0,0 +1,47 @@
+const cache = require('./cache');
+const { getCameraById } = require('./sources/smart-city-infra');
+
+const UA = 'Mozilla/5.0 (compatible; MekTechShowcase/1.0)';
+
+async function fetchImage(url) {
+  const res = await fetch(url, {
+    headers: { 'User-Agent': UA, Accept: 'image/*' },
+    signal: AbortSignal.timeout(8000)
+  });
+  if (!res.ok) return null;
+  const type = res.headers.get('content-type') || '';
+  if (!type.includes('image')) return null;
+  const buffer = Buffer.from(await res.arrayBuffer());
+  if (buffer.length < 800) return null;
+  return { buffer, contentType: type.split(';')[0] || 'image/jpeg' };
+}
+
+async function fetchCameraFrame(cameraId) {
+  const cam = getCameraById(cameraId);
+  if (!cam) return null;
+
+  const cacheKey = `cam-frame-${cameraId}`;
+  const cached = cache.get(cacheKey, 1100);
+  if (cached) return cached;
+
+  if (cam.youtubeId) {
+    const urls = [
+      `https://i.ytimg.com/vi/${cam.youtubeId}/maxresdefault_live.jpg`,
+      `https://i.ytimg.com/vi/${cam.youtubeId}/hqdefault_live.jpg`,
+      `https://i.ytimg.com/vi/${cam.youtubeId}/hqdefault.jpg`
+    ];
+    for (const url of urls) {
+      try {
+        const frame = await fetchImage(`${url}?t=${Date.now()}`);
+        if (frame) {
+          cache.set(cacheKey, frame);
+          return frame;
+        }
+      } catch (_) { /* try next */ }
+    }
+  }
+
+  return null;
+}
+
+module.exports = { fetchCameraFrame };