Refactor common weather methods into utils class (#2958)

Co-authored-by: veeck <michael@veeck.de>

modules/default/weather/weatherutils.js

@@ -0,0 +1,98 @@
+/* MagicMirror²
+ * Weather Util Methods
+ *
+ * By Rejas
+ * MIT Licensed.
+ */
+const WeatherUtils = {
+	/**
+	 * Convert wind (from m/s) to beaufort scale
+	 *
+	 * @param {number} speedInMS the windspeed you want to convert
+	 * @returns {number} the speed in beaufort
+	 */
+	beaufortWindSpeed(speedInMS) {
+		const windInKmh = (speedInMS * 3600) / 1000;
+		const speeds = [1, 5, 11, 19, 28, 38, 49, 61, 74, 88, 102, 117, 1000];
+		for (const [index, speed] of speeds.entries()) {
+			if (speed > windInKmh) {
+				return index;
+			}
+		}
+		return 12;
+	},
+
+	/**
+	 * Convert temp (from degrees C) into imperial or metric unit depending on
+	 * your config
+	 *
+	 * @param {number} tempInC the temperature in celsius you want to convert
+	 * @param {string} unit can be 'imperial' or 'metric'
+	 * @returns {number} the converted temperature
+	 */
+	convertTemp(tempInC, unit) {
+		return unit === "imperial" ? tempInC * 1.8 + 32 : tempInC;
+	},
+
+	/**
+	 * Convert wind speed into another unit.
+	 *
+	 * @param {number} windInMS the windspeed in meter/sec you want to convert
+	 * @param {string} unit can be 'beaufort', 'kmh', 'knots, 'imperial' (mph)
+	 * or 'metric' (mps)
+	 * @returns {number} the converted windspeed
+	 */
+	convertWind(windInMS, unit) {
+		switch (unit) {
+			case "beaufort":
+				return this.beaufortWindSpeed(windInMS);
+			case "kmh":
+				return (windInMS * 3600) / 1000;
+			case "knots":
+				return windInMS * 1.943844;
+			case "imperial":
+				return windInMS * 2.2369362920544;
+			case "metric":
+			default:
+				return windInMS;
+		}
+	},
+
+	/*
+	 * Convert the wind direction cardinal to value
+	 */
+	convertWindDirection(windDirection) {
+		const windCardinals = {
+			N: 0,
+			NNE: 22,
+			NE: 45,
+			ENE: 67,
+			E: 90,
+			ESE: 112,
+			SE: 135,
+			SSE: 157,
+			S: 180,
+			SSW: 202,
+			SW: 225,
+			WSW: 247,
+			W: 270,
+			WNW: 292,
+			NW: 315,
+			NNW: 337
+		};
+
+		return windCardinals.hasOwnProperty(windDirection) ? windCardinals[windDirection] : null;
+	},
+
+	convertWindToMetric(mph) {
+		return mph / 2.2369362920544;
+	},
+
+	convertWindToMs(kmh) {
+		return kmh * 0.27777777777778;
+	}
+};
+
+if (typeof module !== "undefined") {
+	module.exports = WeatherUtils;
+}