server.js

var crypto = require('crypto');
var jsonfile = require('jsonfile');
var async = require('async');
var express = require("express");
var app = express();
var Botkit = require('botkit');
var ebay = require('ebay-api');

var tokens = jsonfile.readFileSync("tokens.json");

var walmart = require('walmart')(decrypt(tokens.walmart));

/*var watson = require('watson-developer-cloud');
var alchemy_language = watson.alchemy_language({
	api_key: decrypt(tokens.watson)
})*/

var controller = Botkit.slackbot();

var bot = controller.spawn({
	token: decrypt(tokens.slack)
})

const MAX_QUERY_ITEMS = 25;
const MAX_DISPLAY_ITEMS = 5;

const PORT = process.env.PORT || 8080;

function decrypt(text){
	var decipher = crypto.createDecipher('aes-256-ctr', 'A5sHCML2SFzf')
	var dec = decipher.update(text, 'hex', 'utf8')
	dec += decipher.final('utf8');
	return dec;
}

var ebaySearchItem = function(item, callback) {
	ebay.xmlRequest({
		serviceName: 'Finding',
		opType: 'findItemsByKeywords',
		appId: decrypt(tokens.ebay),
		params: {
			keywords: item.split(" "),
			
			paginationInput: {
				entriesPerPage: MAX_QUERY_ITEMS
			}
		},
		sandbox: true,
		parser: ebay.parseResponseJson
	},
	(error, itemsResponse) => {
		if (error) {
			console.log(error);
		} else {
			var resultingList = [];
			var items = itemsResponse.searchResult.item;

			for (var i = 0; i < items.length; i++) {
				var prod = items[i];
				resultingList.push({
					"name": prod.title,
					"price": "$" + prod.sellingStatus.currentPrice.amount,
					"provider": "ebay",
					"url": "http://www.ebay.com/itm/" + prod.title.split(" ").join("+"),
					"image": prod.galleryURL
				});
			}

			callback(resultingList);
		}
	});
}

var walmartSearchItem = function(item, callback) {
	var resultingList = [];
	walmart.search(item, {numItems: MAX_QUERY_ITEMS}).then((result) => {
		for (var i = 0; i < result.items.length; i++) {
			var prod = result.items[i];
			resultingList.push({
				"name": prod.name,
				"price": "$" + prod.salePrice,
				"provider": "Walmart",
				"url": prod.productUrl,
				"image": prod.thumbnailImage
			});
		}

		callback(resultingList);
	});
}

/*var getProductEntity = function(inputText, callback) {
	alchemy_language.entities({
		text: inputText
	}, function (err, response) {
		if (err)
			console.log('Error while trying to extract entities: ', err);
		else {
			var entities = response.entities;
			var responseText = "";
			for (var i = 0; i < entities.length; i++) {
				responseText += "Entity: \n" + JSON.stringify(entities[i], null, 2) + "\n";
			}
			if (entities.length === 0) {
				responseText = "unknown";
			}
			callback(responseText);
		}
	});
}*/

var getProductEntity_ForDummies = function(inputText) {
	var words = inputText.split(" ");
	var resultText = "";
	
	for (var i = 0; i < words.length; i++) {
		var word = words[i];

		if (word[0] === word[0].toUpperCase()) {
			resultText += word + " ";
		}
	}

	if (resultText === "") {
		resultText = "unknown";
	} else {
		resultText = resultText.substring(0, resultText.length - 1);
	}

	return resultText;
}

var formatUptime = function(uptime) {
	var unit = 'second';
	if (uptime > 60) {
		uptime = uptime / 60;
		unit = 'minute';
	}
	if (uptime > 60) {
		uptime = uptime / 60;
		unit = 'hour';
	}
	if (uptime != 1) {
		unit = unit + 's';
	}

	uptime = uptime + ' ' + unit;
	return uptime;
}

bot.startRTM(function(err,bot,payload) {
	if (err) {
		throw new Error('Could not connect to Slack: ' + err);
	}
});

var triggerWords = [
	'best prices', 'cheapest prices', 'lowest prices',
	'price', 'prices', 'lowest', 'cheapest','inexpensive'];

controller.hears(triggerWords, 'direct_message', function(bot, message) {
	var targetEntity = getProductEntity_ForDummies(message.text);
	bot.reply(message, 'Searching for the best prices of ' + targetEntity + '...');

	async.parallel([
		function(callback) {
			walmartSearchItem(targetEntity, (list) => {
				callback(null, list);
			})
		},
		function(callback) {
			ebaySearchItem(targetEntity, (list) => {
				callback(null, list);
			})
		}
	], function(err, results) {
		console.log("FINISHED!!");

		var megaList = [];
		
		for (var i = 0; i < results[0].length; i++) {
			megaList.push(results[0][i]);
		}

		for (var i = 0; i < results[1].length; i++) {
			megaList.push(results[1][i]);
		}

		megaList.sort(function(a, b) {
			return parseFloat(a.price) - parseFloat(b.price);
		});
		
		const ACTUAL_DISPLAY_ITEMS = (MAX_DISPLAY_ITEMS > megaList.length ? megaList.length : MAX_DISPLAY_ITEMS);

		var bestList = megaList.slice(0, ACTUAL_DISPLAY_ITEMS);

		bot.reply(message, "Here are the top " + ACTUAL_DISPLAY_ITEMS + " lowest-priced products of " + targetEntity + ":");
		for (var i = 0; i < bestList.length; i++) {
			var item = bestList[i];

			var bodyText =	(i + 1) + ". " + item.name + " - " + item.provider + "\n" + 
							" - Price: " + item.price + "\n" + 
							" - Link: " + item.url;

			console.log(bodyText);
			bot.reply(message, bodyText);
		}
	});
});

controller.hears(['uptime', 'identify yourself', 'who are you', 'what is your name'],
	'direct_message', function(bot, message) {
	var hostname = os.hostname();
	var uptime = formatUptime(process.uptime());

	bot.reply(message,
		':robot_face: I am a bot named <@' + bot.identity.name +
		'>. I have been running for ' + uptime + ' on ' + hostname + '.');
});

console.log("LeGaCy of TeJaCy");

app.listen(PORT, function () {
	console.log('Server listening on port ' + PORT + '!');
});