server.js

const express = require("express");
const app = express();
const bodyparser = require("body-parser");
const {sessionMiddleware, wrap} = require("./sessionMiddleware");
// const session = require("express-session");
const cookieParser = require('cookie-parser');
app.use('/bootstrap', express.static('./node_modules/bootstrap/dist'))

// Create node server
const http = require("http");
const server = http.createServer(app);

// Create socket server and bind to node server
const {Server} = require("socket.io");
const io = new Server(server);

// Use session
app.use(sessionMiddleware);
app.set('view engine', 'ejs');
app.set('socketio', io);
app.use(express.static("public"))
app.use(bodyparser());
app.use(cookieParser());
// app.use(session({secret: "93uwu92349ij2i3409"}));

const indexRouter = require("./routes/index"); 
const registerRouter = require("./routes/register");
const loginRouter = require("./routes/login");
const updateRouter = require("./routes/update");
const dashboardRouter = require("./routes/dashboard");
const coursesRouter = require("./routes/courses");
 
app.use("/", indexRouter);
app.use("/register", registerRouter);
app.use("/login",  loginRouter);
app.use("/update", updateRouter);
app.use("/dashboard", dashboardRouter);
app.use("/dashboard/tutors", dashboardRouter);
app.use("/courses", coursesRouter);
app.use("/courses/math", coursesRouter);

app.locals.users = {};

// Use socket session middleware
io.use(wrap(sessionMiddleware));

// Listen for socket events
io.on("connection", (socket) => {

    // Check if user is logged in
    if(app.locals.currentUserId > 0){

        // Save current socket id
        app.locals.currentSocketId = socket.id;

        // Bind and save current user id and socket id
        app.locals.users[app.locals.currentSocketId] = socket.request.session.currentUserId;

        socket.emit("updateUsers", app.locals.users);
    }

    // Disconnect socket
    socket.on("disconnect", () => {
        delete app.locals.users[socket.id];
        socket.emit("updateUsers", app.locals.users);
    });

});

server.listen(3000);