Add WUnderground WeatherProvider with Zimmerman PWS support

routes/weatherProviders/WUnderground.ts

@@ -0,0 +1,44 @@
+import { GeoCoordinates, PWS, WeatherData, ZimmermanWateringData } from "../../types";
+import { WeatherProvider } from "./WeatherProvider";
+import { httpJSONRequest } from "../weather";
+
+export default class WUnderground extends WeatherProvider {
+
+	async getWateringData( coordinates: GeoCoordinates, pws?: PWS ): Promise< ZimmermanWateringData > {
+		if ( !pws ) {
+			throw "WUnderground WeatherProvider requires a PWS to be specified.";
+		}
+
+		const url = `https://api.weather.com/v2/pws/observations/hourly/7day?stationId=${ pws.id }&format=json&units=e&apiKey=${ pws.apiKey }`;
+		let data;
+		try {
+			data = await httpJSONRequest( url );
+		} catch ( err ) {
+			console.error( "Error retrieving weather information from WUnderground:", err );
+			throw "An error occurred while retrieving weather information from WUnderground."
+		}
+
+		// Take the 24 most recent observations.
+		const samples = data.observations.slice( -24 );
+
+		// Fail if not enough data is available.
+		if ( samples.length !== 24 ) {
+			throw "Insufficient data was returned by WUnderground.";
+		}
+
+		const totals = { temp: 0, humidity: 0, precip: 0 };
+		for ( const sample of samples ) {
+			totals.temp += sample.imperial.tempAvg;
+			totals.humidity += sample.humidityAvg;
+			totals.precip += sample.imperial.precipRate;
+		}
+
+		return {
+			weatherProvider: "WUnderground",
+			temp: totals.temp / samples.length,
+			humidity: totals.humidity / samples.length,
+			precip: totals.precip,
+			raining: samples[ samples.length - 1 ].imperial.precipRate > 0
+		}
+	}
+}