refactor: separate regional briefing and weather sources

server/providers/regional/briefing.js

@@ -0,0 +1,125 @@
+import { makeRateLimiter, clientKey } from '../common/rate-limit.js';
+import { fetchRegionalPlace } from './place.js';
+import { fetchRegionalWeather } from './weather.js';
+import { fetchRegionalNews } from './news.js';
+import { validRegionalPoint } from './query.js';
+import { coalesceProxyRequest } from '../common/http.js';
+
+// ---------------------------------------------------------------------------
+// Regional cockpit briefing proxy
+// ---------------------------------------------------------------------------
+const REGIONAL_BRIEF_CACHE_MS = 5 * 60_000;
+
+const REGIONAL_BRIEF_STALE_MS = 60 * 60_000;
+
+const REGIONAL_BRIEF_MAX_CACHE = 120;
+
+const _regionalBriefCache = new Map();
+
+const _regionalBriefInFlight = new Map();
+
+const _regionalBriefRateLimiter = makeRateLimiter({ windowMs: 60_000, max: 30, globalMax: 90 });
+
+function trimRegionalBriefCache() {
+  while (_regionalBriefCache.size > REGIONAL_BRIEF_MAX_CACHE) {
+    const oldest = _regionalBriefCache.keys().next().value;
+    if (oldest === undefined) break;
+    _regionalBriefCache.delete(oldest);
+  }
+}
+
+/** True when at least one regional source produced usable data. */
+function regionalBriefHasAnySource({ place, weather, news } = {}) {
+  return Boolean(place || weather || (news && news.status !== 'unavailable'));
+}
+
+function regionalBriefProxy() {
+  async function refresh(point, key) {
+    const [placeResult, weatherResult] = await Promise.allSettled([
+      fetchRegionalPlace(point),
+      fetchRegionalWeather(point),
+    ]);
+    const place = placeResult.status === 'fulfilled' ? placeResult.value : null;
+    const weather = weatherResult.status === 'fulfilled' ? weatherResult.value : null;
+    const news = await fetchRegionalNews(place);
+    if (!regionalBriefHasAnySource({ place, weather, news })) {
+      throw new Error('All regional briefing sources unavailable');
+    }
+    const payload = {
+      status: place && weather && news.status !== 'unavailable' ? 'ready' : 'partial',
+      retrievedAt: new Date().toISOString(),
+      coordinates: point,
+      place,
+      placeStatus: place ? 'ready' : 'unavailable',
+      weather,
+      weatherStatus: weather ? 'ready' : 'unavailable',
+      newsStatus: news.status,
+      newsQuery: news.query,
+      newsSource: news.source,
+      articles: news.articles,
+    };
+    _regionalBriefCache.set(key, { payload, cachedAt: Date.now() });
+    trimRegionalBriefCache();
+    return payload;
+  }
+
+  function install(middlewares) {
+    middlewares.use('/api/regional-brief', async (req, res) => {
+      if (req.method !== 'GET') {
+        res.writeHead(405, { 'Content-Type': 'application/json' });
+        res.end(JSON.stringify({ error: 'Method Not Allowed' }));
+        return;
+      }
+      if (!_regionalBriefRateLimiter(clientKey(req))) {
+        res.writeHead(429, { 'Content-Type': 'application/json', 'Retry-After': '10' });
+        res.end(JSON.stringify({ error: 'Rate limit exceeded' }));
+        return;
+      }
+      const url = new URL(req.url || '', 'http://localhost');
+      const point = validRegionalPoint(url.searchParams);
+      if (!point) {
+        res.writeHead(400, { 'Content-Type': 'application/json' });
+        res.end(JSON.stringify({ error: 'Valid latitude and longitude are required' }));
+        return;
+      }
+      const key = `${(Math.round(point.latitude * 10) / 10).toFixed(1)},${(Math.round(point.longitude * 10) / 10).toFixed(1)}`;
+      const now = Date.now();
+      const cached = _regionalBriefCache.get(key);
+      if (cached && now - cached.cachedAt <= REGIONAL_BRIEF_CACHE_MS) {
+        res.writeHead(200, { 'Content-Type': 'application/json', 'Cache-Control': 'public, max-age=60', 'X-Regional-Brief': 'HIT' });
+        res.end(JSON.stringify({ ...cached.payload, status: 'cached' }));
+        return;
+      }
+      const request = coalesceProxyRequest(_regionalBriefInFlight, key, () => refresh(point, key));
+      try {
+        const payload = await request.promise;
+        res.writeHead(200, {
+          'Content-Type': 'application/json',
+          'Cache-Control': 'public, max-age=60',
+          'X-Regional-Brief': request.shared ? 'INFLIGHT' : 'MISS',
+        });
+        res.end(JSON.stringify(payload));
+      } catch {
+        if (cached && now - cached.cachedAt <= REGIONAL_BRIEF_STALE_MS) {
+          res.writeHead(200, { 'Content-Type': 'application/json', 'Cache-Control': 'no-store', 'X-Regional-Brief': 'STALE' });
+          res.end(JSON.stringify({ ...cached.payload, status: 'stale' }));
+          return;
+        }
+        res.writeHead(503, { 'Content-Type': 'application/json', 'Cache-Control': 'no-store' });
+        res.end(JSON.stringify({ error: 'Regional briefing is temporarily unavailable' }));
+      }
+    });
+  }
+
+  return {
+    name: 'regional-brief-proxy',
+    configureServer(server) {
+      install(server.middlewares);
+    },
+    configurePreviewServer(server) {
+      install(server.middlewares);
+    },
+  };
+}
+
+export { regionalBriefHasAnySource, regionalBriefProxy };