realtorca.js

'use strict';

const request = require('request-promise');
const querystring = require('querystring');

const MAP_URL = 'https://www.realtor.ca/Residential/Map.aspx';
const API_URL = 'https://api2.realtor.ca';
const clientSettingsDefaults = {
	CultureId: 1,
	ApplicationId: 37
}

const priceTiers = [0, 25000, 50000, 75000, 100000, 125000, 150000, 175000, 200000, 225000, 250000, 275000, 300000, 325000, 350000, 375000, 400000, 425000, 450000, 475000, 500000, 550000, 600000, 650000, 700000, 750000, 800000, 850000, 900000, 950000, 1000000, 1100000, 1200000, 1300000, 1400000, 1500000, 1600000, 1700000, 1800000, 1900000, 2000000, 2500000, 3000000, 4000000, 5000000, 7500000, 10000000];

class Realtor {
	static post(options) {
		let optionDefaults = {
			...clientSettingsDefaults,
			PropertySearchTypeId: 1
		};
		let form;

		if (typeof options === 'object')
			form = Object.assign(optionDefaults, options);

		return request({
			method: 'POST',
			uri: API_URL + "/Listing.svc/PropertySearch_Post",
			form: form,
			json: true
		});
	}

	static getPropertyDetails(options={}) {
		let optionDefaults = {
			...clientSettingsDefaults,
			HashCode: 0
		};
		let params = {};
		let url = "";

		params = Object.assign(optionDefaults, options);

		url = API_URL + "/Listing.svc/PropertyDetails?"  + querystring.encode(params);

		return request({
			uri: url,
			json: true
		});
	}

	static buildUrl(options) {
		if (options.PriceMin) {
			options = findNextPriceTier(options, true);
		}

		if (options.PriceMax) {
			options = findNextPriceTier(options, false);
		}

		let qs = '#';

		for (let prop in options) {
			qs += prop + '=' + options[prop] + '&';
		}

		return MAP_URL + qs.slice(0, -1); //To remove trailing ampersand or pound
	}
	
	/**
	 * Given a URL from realtor.ca, attemtps to parse the query string parameters into a usable filter option set.
	 * @param {string} url The realtor.ca URL string that represents the filters
	 */
	static optionsFromUrl(url) {
		return querystring.parse(url);	
	}
}

function findNextPriceTier(options, minFlag) {
	let opt = (minFlag ? "PriceMin" : "PriceMax");
	let cost = options[opt];

	if (priceTiers.indexOf(cost) !== -1)
		return options;

	if (cost > priceTiers[priceTiers.length-1]) {
		delete options[opt];
		return options;
	}

	for (let i = 0; i < priceTiers.length; i++) {
		if (priceTiers[i] > options[opt]) {
			options[opt] = priceTiers[i];
			break;
		}
	}

	return options;
}

module.exports = Realtor;