app.js

const path = require("path");

const express = require("express");
const bodyParser = require("body-parser");
const mongoose = require("mongoose");
const session = require("express-session");
const MongoDBStore = require("connect-mongodb-session")(session);
const csrf = require("csurf");
const flash = require("connect-flash");
const multer = require("multer");
const helmet = require("helmet");
const compression = require("compression");
const errorController = require("./controllers/error");
const User = require("./models/user");
const isAuth = require("./middlewares/is-auth");

const MONGODB_URI = process.env.MONGODB_URI;

const app = express();

const fileStorage = multer.diskStorage({
  destination: (req, file, cb) => {
    cb(null, "images");
  },
  filename: (req, file, cb) => {
    cb(null, new Date().getTime() + "-" + file.originalname);
  },
});
const fileFilter = (req, file, cb) => {
  if (
    file.mimetype === "image/png" ||
    file.mimetype === "image/jpg" ||
    file.mimetype === "image/jpeg"
  ) {
    cb(null, true);
  } else {
    cb(null, false);
  }
};
const store = new MongoDBStore({
  uri: MONGODB_URI,
  collection: "sessions",
});
const csrfProtection = csrf();
app.set("view engine", "ejs");
app.set("views", path.join(__dirname, "views"));

const adminRoutes = require("./routes/admin");
const shopRoutes = require("./routes/shop");
const authRoutes = require("./routes/auth");

app.use(bodyParser.urlencoded({ extended: false }));
app.use(
  multer({
    dest: "images",
    storage: fileStorage,
    fileFilter: fileFilter,
  }).single("image")
); //one file expected, "image" is the field name,dest is the folder in while image will be stored
app.use(express.static(path.join(__dirname, "public")));
app.use("/images", express.static(path.join(__dirname, "images")));
app.use(
  session({
    secret: "my secret",
    resave: false,
    saveUninitialized: false,
    store: store,
  })
);

app.use(compression());
//use csrfProtection middleware after creating session;
app.use(csrfProtection);
app.use(flash());
//passing common data to all the views
app.use((req, res, next) => {
  res.locals.emailID = req.session.user?.email;
  res.locals.isLoggedIn = req.session.isLoggedIn;
  res.locals.isAuthenticated = req.session.isLoggedIn;
  res.locals.csrfToken = req.csrfToken();
  next();
});

app.use((req, res, next) => {
  if (req.session.user) {
    User.findById(req.session.user._id)
      .then((user) => {
        req.user = user; //storing mongodb user object
        next();
      })
      .catch((err) => {
        console.error(err);
      });
  } else {
    next();
  }
});

app.use("/admin", isAuth, adminRoutes);
app.use(shopRoutes);
app.use(authRoutes);
app.use("/500", errorController.get500);
app.use(errorController.get404);
//error handling middleware
app.use((error, req, res, next) => {
  console.log(error);
  res.redirect("/500");
});
mongoose
  .connect(MONGODB_URI)
  .then((result) => {
    User.findOne().then((user) => {
      if (!user) {
        const user = new User({
          name: "test",
          email: "test@test.com",
          cart: {
            items: [],
          },
        });
        user.save();
      }
    });
    app.listen(process.env.PORT || 3000);
  })
  .catch((err) => {
    console.log(err);
  });