SolidScribe/server/index.js

//Set up environmental variables, pulled from .env file used as process.env.DB_HOST
const os = require('os') //Used to get path of home directory
const result = require('dotenv').config({ path:(os.homedir()+'/.env') })

//Allow user of @ in in require calls. Config in package.json
require('module-alias/register')

//Auth helper, used for decoding users web token
let Auth = require('@helpers/Auth')

//Helmet adds additional security to express server
const helmet = require('helmet')

//Setup express server
const express = require('express')
const app = express()
app.use( helmet() )
const port = 3000


//
// Request Rate Limiter 
//
const rateLimit = require('express-rate-limit');
const limiter = rateLimit({
	windowMs: 10 * 60 * 1000, // minutes
	max: 1000 // limit each IP to 100 requests per windowMs
});
 
// apply to all requests
app.use(limiter);



var http = require('http').createServer(app);
var io = require('socket.io')(http, {
	path:'/socket'
});

//Set socket IO as a global in the app
global.SocketIo = io

let noteDiffs = {}

io.on('connection', function(socket){

	//When a user connects, add them to their own room
	// This allows the server to emit events to that specific user
	// access socket.io in the controller with SocketIo global
	socket.on('user_connect', token => {
		Auth.decodeToken(token)
		.then(userData => {
			socket.join(userData.id)
		}).catch(error => {
			//Don't add user to room if they are not logged in
			// console.log(error)
		})
	})

	socket.on('join_room', rawTextId => {
		// Join user to rawtextid room when they enter
		socket.join(rawTextId)

		//If there are past diffs for this note, send them to the user
		if(noteDiffs[rawTextId] != undefined){
			
			//Sort all note diffs by when they were created.
			noteDiffs[rawTextId].sort((a,b) => { return a.time - b.time })

			//Emit all sorted diffs to user
			socket.emit('past_diffs', noteDiffs[rawTextId])
		} else {
			socket.emit('past_diffs', null)
		}

		const usersInRoom = io.sockets.adapter.rooms[rawTextId]
		if(usersInRoom){
			//Update users in room count
			io.to(rawTextId).emit('update_user_count', usersInRoom.length)

			//Debugging text
			console.log('Note diff object')
			console.log(noteDiffs)

			
			let noteDiffKeys = Object.keys(noteDiffs)
			let totalDiffs = 0
			noteDiffKeys.forEach(diffSetKey => {
				if(noteDiffs[diffSetKey]){
					totalDiffs += noteDiffs[diffSetKey].length
				}
			})

			console.log('Total notes in limbo -> ', noteDiffKeys.length)
			console.log('Total Diffs for all notes -> ', totalDiffs)

		}
	})

	socket.on('leave_room', roomId => {
		socket.leave(roomId)
		// console.log('User Left room')

		const usersInRoom = io.sockets.adapter.rooms[roomId]
		if(usersInRoom){
			// console.log('Users in room', usersInRoom.length)
			io.to(roomId).emit('update_user_count', usersInRoom.length)
		}
		
	})

	socket.on('note_diff', data => {

		//Log each diff for note
		const noteId = data.id
		delete data.id
		if(noteDiffs[noteId] == undefined){ noteDiffs[noteId] = [] }
		data.time = +new Date
		
		noteDiffs[noteId].push(data)

		//Remove duplicate diffs if they exist
		for (var i = noteDiffs[noteId].length - 1; i >= 0; i--) {

			let pastDiff = noteDiffs[noteId][i]

			for (var j = noteDiffs[noteId].length - 1; j >= 0; j--) {
				let currentDiff = noteDiffs[noteId][j]

				if(i == j){
					continue
				}

				if(currentDiff.diff == pastDiff.diff || currentDiff.time == pastDiff.time){
					console.log('Removing Duplicate')
					noteDiffs[noteId].splice(i,1)
				}
			}
		}

		//Each user joins a room when they open the app.
		io.in(noteId).clients((error, clients) => {
			if (error) throw error;

			//Go through each client in note room and send them the diff
			clients.forEach(socketId => {
				if(socketId != socket.id){
					io.to(socketId).emit('incoming_diff', data)
				}
			})

		});

	})

	socket.on('truncate_diffs_at_save', checkpoint => {

		let diffSet = noteDiffs[checkpoint.rawTextId]
		if(diffSet && diffSet.length > 0){

			//Make sure all diffs are sorted before cleaning
			noteDiffs[checkpoint.rawTextId].sort((a,b) => { return a.time - b.time })

			// Remove all diffs until it reaches the current hash
			let sliceTo = 0
			for (var i = 0; i < diffSet.length; i++) {
				if(diffSet[i].hash == checkpoint){
					sliceTo = i
					break
				}
			}


			noteDiffs[checkpoint.rawTextId] = diffSet.slice(0, sliceTo)

			if(noteDiffs[checkpoint.rawTextId].length == 0){
				delete noteDiffs[checkpoint.rawTextId]
			} 
			//Debugging
			else {
				console.log('Diffset after save')
				console.log(noteDiffs[checkpoint.rawTextId])
			}

		}
	})

	socket.on('disconnect', function(){
		// console.log('user disconnected');
	});
});


http.listen(3001, function(){
	// console.log('socket.io liseting on port 3001');
});

//Enable json body parsing in requests. Allows me to post data in ajax calls
app.use(express.json({limit: '5mb'}))


//Prefix defied by route in nginx config
const prefix = '/api'

//App Auth, all requests will come in with a token, decode the token and set global var
app.use(function(req, res, next){
	//auth token set by axios in headers
	let token = req.headers.authorizationtoken
	if(token && token != null && typeof token === 'string'){
		Auth.decodeToken(token)
		.then(userData => {
			req.headers.userId = userData.id //Update headers for the rest of the application
			req.headers.masterKey = userData.masterKey
			next()
		}).catch(error => {

			res.statusMessage = error //Throw 400 error if token is bad
		    res.status(400).end()
		})
	} else {
		next() //No token. Move along.
	}
})


// Test Area
const printResults = false
let UserTest = require('@models/User')
let NoteTest = require('@models/Note')
UserTest.keyPairTest('genMan12', '1', printResults)
.then( ({testUserId, masterKey}) => NoteTest.test(testUserId, masterKey, printResults))
.then( message => { 
	if(printResults) console.log(message) 
})
// Test Area


//Test 
app.get(prefix, (req, res) => res.send('The api is running'))

//Serve up uploaded files
app.use(prefix+'/static', express.static( __dirname+'/../staticFiles' ))

//Public routes
var public = require('@routes/publicController')
app.use(prefix+'/public', public)

//user endpoint
var user = require('@routes/userController')
app.use(prefix+'/user', user)

//notes endpoint
var notes = require('@routes/noteController')
app.use(prefix+'/note', notes)

//tags endpoint
var tags = require('@routes/tagController')
app.use(prefix+'/tag', tags)

//notes endpoint
var attachment = require('@routes/attachmentController')
app.use(prefix+'/attachment', attachment)

//quick notes endpoint
var quickNote = require('@routes/quicknoteController')
app.use(prefix+'/quick-note', quickNote)

//Output running status
app.listen(port, () => { 
	// console.log(`Listening on port ${port}!`)
})