server.js

require("dotenv").config();
const express = require("express");
const ejs = require("ejs");
const expressEjsLayouts = require("express-ejs-layouts");
const mongoose = require("mongoose");
const session = require("express-session");
const flash = require("express-flash");
const MongoDbStore = require("connect-mongo");
const passport = require("passport");
const Emitter = require("events");

const path = require("path"); // inbuilt module h .

const app = express();

const port = process.env.PORT || 3000;

// database connections.
const url = "mongodb://127.0.0.1/pizzas"; //pizzas is database name.

mongoose.connect(url, {});
const connection = mongoose.connection;
connection
  .once("open", () => {
    console.log("Database connected…");
  })
  .on("error", (err) => {
    console.log("Connection failed...");
  });

// sesion store
let mongoStore = MongoDbStore.create({
  mongoUrl: url,
  collectionName: "sessions",
});

// Event emitter
const eventEmitter = new Emitter();
app.set("eventEmitter", eventEmitter);

//session config.
app.use(
  session({
    secret: process.env.COOKIE_SECRET,
    resave: false,
    store: mongoStore,
    saveUninitialized: false,
    cookie: {
      maxAge: 1000 * 60 * 60 * 24, // cookie valid for 24 hours.
    },
    // cookie: { maxAge: 1000 * 15 }, //  expires in 15 seconds
  })
);

// passport config
const passportInit = require("./src/config/passport");
passportInit(passport); // passport hmee passport.js file ke andr chahiye rhega isliye hmmne asee pass kiya h .
app.use(
  require("express-session")({
    secret: "keyboard cat",
    resave: true,
    saveUninitialized: true,
  })
);
app.use(passport.initialize());
app.use(passport.session());

app.get("/logout", function (req, res) {
  req.logout();
  res.redirect("/login");
});

// flash middleware
app.use(flash());

// assets
app.use(express.static("public"));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));

//Global middlewares.
app.use((req, res, next) => {
  res.locals.session = req.session;
  res.locals.user = req.user;
  next();
});

// express ko pata chlega ki konsa layout yaha pr use krna h.
app.use(expressEjsLayouts);

// express ko hme batana h ki jo hmari views folder (contains html file) vo kaha pr h .
app.set("views", path.join(__dirname, "/resources/views"));

// set Template engine (express ko batana h ki hmm konsa template engine use krne wale h ).
app.set("view engine", "ejs");

// always put app.get() statement after setting the ejs layout .

//  web.js file mai jiss function ko export kiya h usko yaha pr import krenge.
// symbol(./) = current folder.
require("./src/routes/web")(app);

const server = app.listen(port, () => {
  console.log(`server is running at Port: ${port}`);
});

//socket
const io = require("socket.io")(server);
io.on("connection", (socket) => {
  // Join
  // console.log(socket.id);
  socket.on("join", (orderId) => {
    // console.log(orderId);
    socket.join(orderId);
  });
});

eventEmitter.on("orderUpdated", (data) => {
  io.to(`order_${data.id}`).emit("orderUpdated", data);
});

eventEmitter.on("orderPlaced", (data) => {
  io.to("adminRoom").emit("orderPlaced", data);
});