biz2credit-code-challenge-gaurav-pandey-3/index.js

Code Challenge for Gaurav Pandey

/*
 * This API will provide distance based information
 */
const Biz2CreditAPI = (range, sLat, sLong) => {
	// As per design guidelines, all hardcoded values should be fetched from config files
	const RADIUS_OF_EARTH = 6371; // since there is only one hardcoded so written here
	/* 
        @desc: This api will convert degree value to radian 
        @param: degree (geographic degree)
        @return: radian 
    */
	const convertDeg2Rad = degree => {
		if (!degree) return 0;
		return degree * (Math.PI / 180);
	};

	/* 
        @desc: This api will verify cordinates exists within range
        @param: range number
        @param: sourceCordinates object { lat, long }
        @param: d object { lat, long }
        @return: will return true/false based on lat & long exists in given range
    */
	const isCordinatesWithInRange = (dLat, dLong) => {
		// validation input
		if (!range || !sLat || !sLong || !dLat || !dLong) return false;

		// converting degree into radian
		let rLat = convertDeg2Rad(dLat - sLat); // radian lattitude
		let rLong = convertDeg2Rad(dLong - sLong); // radian longitude

		/* As per Haversine formula */
		let area =
			Math.sin(rLat / 2) * Math.sin(rLat / 2) +
			Math.cos(convertDeg2Rad(sLat)) * Math.cos(convertDeg2Rad(dLat)) * Math.sin(rLong / 2) * Math.sin(rLong / 2);

		// distance from source to dest
		const distance = RADIUS_OF_EARTH * (2 * Math.atan2(Math.sqrt(area), Math.sqrt(1 - area)));

		// truthy if distance in within range
		return distance <= range;
	};

	/* Exposing APIs */
	return {
		isCordinatesWithInRange
	};
};

/* Exporting module */
module.exports = Biz2CreditAPI;