routes.js

'use strict';

const Q = require('q');
const _ = require('lodash');

const GraphAPI = require('./graphAPI');
const sessionStore = require('./sessionStore');

const userService = require('./services/user');
const config = require('./config');

const FB_VERIFY_TOKEN = config.fbWebhookVerifyToken;
const FB_PAGE_ID = config.fbPageID;



function extractMessagingObjects(body) {
	var messages = [];

	for (var i = 0; i < body.entry.length; i++) {
		var eventEntry = body.entry[i];
		if (eventEntry.id.toString() === FB_PAGE_ID){
			var recievedMessages = _.filter(eventEntry.messaging, function(msg) {
				return !!(msg.message || msg.postback);
			})
			messages = messages.concat(recievedMessages);
		}
	}

	return messages;
}


//Main routes
exports.get = function(req, res, next) {
	if (req.query['hub.mode'] === 'subscribe' && req.query['hub.verify_token'] === FB_VERIFY_TOKEN) {
		res.send(req.query['hub.challenge']);
	} else {
		res.sendStatus(400);
	}
}


exports.receive = function(req, res, next) {
	//respond as soon as possible
	res.status(200).end();
	
	const messages = extractMessagingObjects(req.body);
	if (!messages.length) {
		return;
	}

	var processPromises = _.map(messages, (messaging) => {
		return processMessage(messaging);
	});

	Q.all(processPromises)
	.then(function(){
		console.log('all messages processed');
	})
	.catch(function(err) {
		console.error('error handling messages', err);
		console.error(err.stack);
	});
}


//user data handlers
const handleAttachment = require('./handlers/attachment');
const handleQuickReply = require('./handlers/quickreply');
const handleTextMessage = require('./handlers/message');
const handlePostback = require('./handlers/postback');


function processMessage(messaging) {
	
	const sender = messaging.sender.id;

	let sessionId;
	let session;
	let newSession;
	
	return sessionStore.findOrCreate(sender)
		.then(data => {
			sessionId = data.sessionId;
			session = data.session;
			newSession = data.newSession;
		
			if (!session.context.userData) {
				return GraphAPI.getUserProfile(sender)
					.then(user => {
						user.recipientId = sender;
						session.context.userData = user;
						return data;
					});
			}
			return data;	
		})
		.then(data => {
	
			if (!session.context.userData._id) {
				return userService.getOrCreateUserByRecipientId(sender, session.context.userData)	
					.then(user => {
						session.context.userData._id = user._id.toString();
						return sessionStore.saveSession(sessionId, session); 
					});
			}
		})
		.then(() => {
			return userService.logActivity(session.context.userData._id);
		})
		.then(() => {
			//console.log(session.context);
			return GraphAPI.sendTypingOn(sender);
		})
		.then(() => {

			const atts = messaging.message && messaging.message.attachments;
			if (atts) {
				return handleAttachment(sender, sessionId, session.context, atts);
			} 

			const quickReply = messaging.message && messaging.message.quick_reply;
			if (quickReply) {
				return handleQuickReply(sender, sessionId, session.context, quickReply.payload);
			} 

			const msg = messaging.message && messaging.message.text;
			if (msg) {
				return handleTextMessage(sessionId, session.context, msg);
			} 

			const payload = messaging.postback && messaging.postback.payload;
			if (payload) {
				return handlePostback(sender, sessionId, session.context, payload);
			}
		})
		.catch(err => {
			console.log(err.stack);
		});
}