From bb87c836b682a9943f90d2ab588875f811b16de6 Mon Sep 17 00:00:00 2001
From: mrkmntal <marky611@gmail.com>
Date: Tue, 7 Apr 2026 18:32:07 -0400
Subject: [PATCH] Added the in-memory TTL caching for RainViewer and OpenMeteo

---
 server/scripts/modules/radar.mjs         | 37 ++++++++++++++++++++----
 server/scripts/modules/utils/weather.mjs | 23 +++++++++++++--
 2 files changed, 52 insertions(+), 8 deletions(-)

diff --git a/server/scripts/modules/radar.mjs b/server/scripts/modules/radar.mjs
index f22eaf7..51ced9d 100644
--- a/server/scripts/modules/radar.mjs
+++ b/server/scripts/modules/radar.mjs
@@ -11,9 +11,37 @@ import {
 	clearMarkers,
 } from './utils/leaflet-weather-map.mjs';
 
-class Radar extends WeatherDisplay {
-	static metadataUrl = 'https://api.rainviewer.com/public/weather-maps.json';
+const RADAR_METADATA_URL = 'https://api.rainviewer.com/public/weather-maps.json';
+const RADAR_METADATA_CACHE_TTL_MS = 2 * 60 * 1000;
+let radarMetadataCache = null;
 
+const getRadarMetadataCached = async (stillWaiting) => {
+	const now = Date.now();
+	if (radarMetadataCache && (now - radarMetadataCache.fetchedAt) < RADAR_METADATA_CACHE_TTL_MS) {
+		return radarMetadataCache.data;
+	}
+
+	const radarMetadata = await safeJson(RADAR_METADATA_URL, {
+		retryCount: 2,
+		stillWaiting,
+	});
+
+	if (radarMetadata?.host && radarMetadata?.radar?.past?.length) {
+		radarMetadataCache = {
+			data: radarMetadata,
+			fetchedAt: now,
+		};
+		return radarMetadata;
+	}
+
+	if (radarMetadataCache) {
+		return radarMetadataCache.data;
+	}
+
+	return null;
+};
+
+class Radar extends WeatherDisplay {
 	constructor(navId, elemId) {
 		super(navId, elemId, 'Local Radar');
 
@@ -48,10 +76,7 @@ class Radar extends WeatherDisplay {
 			this.updateLocationMarker();
 			await this.updateNearbyMarkers();
 
-			const radarMetadata = await safeJson(Radar.metadataUrl, {
-				retryCount: 2,
-				stillWaiting: () => this.stillWaiting(),
-			});
+			const radarMetadata = await getRadarMetadataCached(() => this.stillWaiting());
 
 			const frames = radarMetadata?.radar?.past?.slice(-this.maxFrames) ?? [];
 			if (!frames.length || !radarMetadata?.host) {
diff --git a/server/scripts/modules/utils/weather.mjs b/server/scripts/modules/utils/weather.mjs
index 5a67a4f..395cbad 100644
--- a/server/scripts/modules/utils/weather.mjs
+++ b/server/scripts/modules/utils/weather.mjs
@@ -15,6 +15,9 @@ const OPEN_METEO_RADAR_OBSERVATION_PARAMETERS = [
 	'models=best_match',
 ].join('&');
 
+const OPEN_METEO_OBSERVATION_CACHE_TTL_MS = 10 * 60 * 1000;
+const openMeteoObservationCache = new Map();
+
 const getPoint = async (lat, lon) => {
 	const point = await safeJson(`https://api.weather.gov/points/${lat.toFixed(4)},${lon.toFixed(4)}`);
 	if (!point) {
@@ -56,15 +59,24 @@ const getAggregatedOpenMeteoForecast = async (lat, lon) => {
 };
 
 const getOpenMeteoObservationSnapshot = async (lat, lon) => {
+	const cacheKey = `${lat.toFixed(4)},${lon.toFixed(4)}`;
+	const cachedEntry = openMeteoObservationCache.get(cacheKey);
+	const now = Date.now();
+	if (cachedEntry && (now - cachedEntry.fetchedAt) < OPEN_METEO_OBSERVATION_CACHE_TTL_MS) {
+		return cachedEntry.data;
+	}
+
 	const forecast = await safeJson(`https://api.open-meteo.com/v1/forecast?latitude=${lat}&longitude=${lon}&${OPEN_METEO_RADAR_OBSERVATION_PARAMETERS}`);
 	if (!forecast?.hourly?.time?.length) {
 		if (debugFlag('verbose-failures')) {
 			console.warn(`Unable to get Open-Meteo radar observation snapshot for ${lat},${lon}`);
 		}
+		if (cachedEntry) {
+			return cachedEntry.data;
+		}
 		return false;
 	}
 
-	const now = Date.now();
 	let nearestIndex = 0;
 	let nearestDelta = Number.POSITIVE_INFINITY;
 
@@ -76,13 +88,20 @@ const getOpenMeteoObservationSnapshot = async (lat, lon) => {
 		}
 	});
 
-	return {
+	const snapshot = {
 		time: forecast.hourly.time[nearestIndex],
 		temperature: forecast.hourly.temperature_2m?.[nearestIndex] ?? null,
 		weatherCode: forecast.hourly.weather_code?.[nearestIndex] ?? 0,
 		isDay: Boolean(forecast.hourly.is_day?.[nearestIndex] ?? 1),
 		timezone: forecast.timezone,
 	};
+
+	openMeteoObservationCache.set(cacheKey, {
+		data: snapshot,
+		fetchedAt: now,
+	});
+
+	return snapshot;
 };
 
 const weatherConditions = [