refactor: compose configurable geocoding and route services

server/providers/regional/briefing.js

@@ -14,33 +14,33 @@ 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() {
+function regionalBriefProxy({ placeProvider = fetchRegionalPlace } = {}) {
+  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);
+    }
+  }
+
   async function refresh(point, key) {
     const [placeResult, weatherResult] = await Promise.allSettled([
-      fetchRegionalPlace(point),
+      placeProvider(point),
       fetchRegionalWeather(point),
     ]);
     const place = placeResult.status === 'fulfilled' ? placeResult.value : null;

server/providers/regional/place.js

@@ -1,37 +1,42 @@
 import { fetchRegionalJson } from './http.js';
 import { normalizeRegionalPlace } from '../../../src/data/regionalBrief.js';
 
-let _nominatimQueue = Promise.resolve();
+/** Construct the serialized Nominatim adapter with a trusted endpoint. */
+export function createRegionalPlaceProvider({
+  endpoint = 'https://nominatim.openstreetmap.org/reverse',
+  requestJson = fetchRegionalJson,
+} = {}) {
+  let _nominatimQueue = Promise.resolve();
 
-let _nominatimLastRequestAt = 0;
+  let _nominatimLastRequestAt = 0;
 
-function fetchRegionalPlace(point) {
-  const task = _nominatimQueue.then(async () => {
-    const waitMs = Math.max(0, 1100 - (Date.now() - _nominatimLastRequestAt));
-    if (waitMs) await new Promise((resolve) => setTimeout(resolve, waitMs));
-    _nominatimLastRequestAt = Date.now();
-    const params = new URLSearchParams({
-      format: 'jsonv2',
-      lat: point.latitude.toFixed(5),
-      lon: point.longitude.toFixed(5),
-      zoom: '10',
-      addressdetails: '1',
-      'accept-language': 'en',
-    });
-    const payload = await fetchRegionalJson(
-      `https://nominatim.openstreetmap.org/reverse?${params}`,
-      {
+  function fetchRegionalPlace(point) {
+    const task = _nominatimQueue.then(async () => {
+      const waitMs = Math.max(0, 1100 - (Date.now() - _nominatimLastRequestAt));
+      if (waitMs) await new Promise((resolve) => setTimeout(resolve, waitMs));
+      _nominatimLastRequestAt = Date.now();
+      const params = new URLSearchParams({
+        format: 'jsonv2',
+        lat: point.latitude.toFixed(5),
+        lon: point.longitude.toFixed(5),
+        zoom: '10',
+        addressdetails: '1',
+        'accept-language': 'en',
+      });
+      const payload = await requestJson(`${endpoint}?${params}`, {
         headers: {
           'User-Agent':
             'GodsEyeView/0.1 (+https://github.com/bilawalsidhu/gods-eye-view)',
           Referer: 'https://github.com/bilawalsidhu/gods-eye-view',
         },
-      },
-    );
-    return normalizeRegionalPlace(payload);
-  });
-  _nominatimQueue = task.catch(() => null);
-  return task;
+      });
+      return normalizeRegionalPlace(payload);
+    });
+    _nominatimQueue = task.catch(() => null);
+    return task;
+  }
+
+  return fetchRegionalPlace;
 }
 
-export { fetchRegionalPlace };
+export const fetchRegionalPlace = createRegionalPlaceProvider();