Add caching for travel forecasts so we don't hit APIs as hard

server/scripts/modules/travelforecast.mjs

@@ -8,16 +8,15 @@ import { registerDisplay } from './navigation.mjs';
 import calculateScrollTiming from './utils/scroll-timing.mjs';
 import { debugFlag } from './utils/debug.mjs';
 import { temperature } from './utils/units.mjs';
-import { getAggregatedOpenMeteoForecast } from './utils/weather.mjs';
+import { getCachedAggregatedOpenMeteoForecast } from './utils/weather.mjs';
+
+const MIN_TRAVEL_CITIES = 5;
 
 class TravelForecast extends WeatherDisplay {
 	constructor(navId, elemId, defaultActive) {
 		// special height and width for scrolling
 		super(navId, elemId, 'Travel Forecast', defaultActive);
 
-		// add previous data cache
-		this.previousData = [];
-
 		// cache for scroll calculations
 		// This cache is essential because baseCountChange() is called 25 times per second (every 40ms)
 		// during scrolling. Travel forecast scroll duration varies based on the number of cities configured.
@@ -45,30 +44,13 @@ class TravelForecast extends WeatherDisplay {
 		// super checks for enabled
 		if (!super.getData(weatherParameters, refresh)) return;
 
-		// clear stored data if not refresh
-		if (!refresh) {
-			this.previousData = [];
-		}
-
 		const temperatureConverter = temperature();
 		const selectedTravelCities = getTravelCitiesForLocation(this.weatherParameters);
 
-		const forecastPromises = selectedTravelCities.map(async (city, index) => {
+		const forecastPromises = selectedTravelCities.map(async (city) => {
 			try {
-				let forecast;
-				forecast = await getAggregatedOpenMeteoForecast(city.Latitude, city.Longitude);
-
-				if (forecast) {
-					// store for the next run
-					this.previousData[index] = forecast;
-				} else if (this.previousData?.[index]) {
-					// if there's previous data use it
-					if (debugFlag('travelforecast')) {
-						console.warn(`Using previous forecast data for ${city.Name} travel forecast`);
-					}
-					forecast = this.previousData?.[index];
-				} else {
-					// no current data and no previous data available
+				const forecast = await getCachedAggregatedOpenMeteoForecast(city.Latitude, city.Longitude);
+				if (!forecast) {
 					if (debugFlag('verbose-failures')) {
 						console.warn(`No travel forecast for ${city.Name} available`);
 					}
@@ -100,7 +82,11 @@ class TravelForecast extends WeatherDisplay {
 
 		// wait for all forecasts using centralized safe Promise handling
 		const forecasts = await safePromiseAll(forecastPromises);
-		this.data = forecasts;
+		const validForecasts = forecasts.filter((forecast) => forecast && !forecast.error && forecast.high !== undefined);
+		const invalidForecasts = forecasts.filter((forecast) => forecast && forecast.error);
+		this.data = validForecasts.length >= MIN_TRAVEL_CITIES
+			? validForecasts
+			: [...validForecasts, ...invalidForecasts].slice(0, Math.max(validForecasts.length, MIN_TRAVEL_CITIES));
 
 		// test for some data available in at least one forecast
 		const hasData = this.data.some((forecast) => forecast.high);

server/scripts/modules/utils/weather.mjs

@@ -16,7 +16,9 @@ const OPEN_METEO_RADAR_OBSERVATION_PARAMETERS = [
 ].join('&');
 
 const OPEN_METEO_OBSERVATION_CACHE_TTL_MS = 10 * 60 * 1000;
+const OPEN_METEO_TRAVEL_FORECAST_CACHE_TTL_MS = 30 * 60 * 1000;
 const openMeteoObservationCache = new Map();
+const openMeteoTravelForecastCache = new Map();
 
 const getPoint = async (lat, lon) => {
 	const point = await safeJson(`https://api.weather.gov/points/${lat.toFixed(4)},${lon.toFixed(4)}`);
@@ -58,6 +60,30 @@ const getAggregatedOpenMeteoForecast = async (lat, lon) => {
 	};
 };
 
+const getCachedAggregatedOpenMeteoForecast = async (lat, lon) => {
+	const cacheKey = `${lat.toFixed(4)},${lon.toFixed(4)}`;
+	const cachedEntry = openMeteoTravelForecastCache.get(cacheKey);
+	const now = Date.now();
+	if (cachedEntry && (now - cachedEntry.fetchedAt) < OPEN_METEO_TRAVEL_FORECAST_CACHE_TTL_MS) {
+		return cachedEntry.data;
+	}
+
+	const forecast = await getAggregatedOpenMeteoForecast(lat, lon);
+	if (forecast) {
+		openMeteoTravelForecastCache.set(cacheKey, {
+			data: forecast,
+			fetchedAt: now,
+		});
+		return forecast;
+	}
+
+	if (cachedEntry) {
+		return cachedEntry.data;
+	}
+
+	return false;
+};
+
 const getOpenMeteoObservationSnapshot = async (lat, lon) => {
 	const cacheKey = `${lat.toFixed(4)},${lon.toFixed(4)}`;
 	const cachedEntry = openMeteoObservationCache.get(cacheKey);
@@ -199,6 +225,7 @@ export {
 	getPoint,
 	getOpenMeteoForecast,
 	getAggregatedOpenMeteoForecast,
+	getCachedAggregatedOpenMeteoForecast,
 	getOpenMeteoObservationSnapshot,
 	aggregateWeatherForecastData,
 	getConditionText,