app.js

const mongoose = require("mongoose");
const path = require("path");
const session = require("express-session");
const MongoDBStore = require("connect-mongodb-session")(session);
const express = require("express");
const dotenv = require("dotenv");
const bodyParser = require("body-parser");
const csrf = require("csurf");
const flash = require("connect-flash");
const multer = require("multer");
const { v4: uuidv4 } = require("uuid"); //FOR WINDOWS ONLY

dotenv.config();

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

const ErrorController = require("./controllers/error");

const User = require("./models/user");

const app = express();

const store = new MongoDBStore({
  uri: process.env.MONGO_URI,
  collection: "sessions",
});
var csrfProtection = csrf();

const fileStorage = multer.diskStorage({
  destination: (req, file, cb) => {
    cb(null, "images");
  },
  filename: (req, file, cb) => {
    // cb(null, new Date().toISOString() + "-" + file.originalname);
    cb(null, uuidv4());
  },
});

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);
  }
};

//for ejs
app.set("view engine", "ejs");
app.set("views", "views");

app.use(bodyParser.urlencoded({ extended: true }));
app.use(
  multer({ storage: fileStorage, fileFilter: fileFilter }).single("image")
);
app.use(express.static(path.join(__dirname, "temp")));
app.use(express.static(path.join(__dirname, "public"))); //we can add multiple static folders
// the app will go through all the folders until it hits the first file which is needed
app.use("/images", express.static(path.join(__dirname, "images")));

app.use(
  session({
    secret: "my secret",
    resave: false,
    saveUninitialized: false,
    store: store,
  })
);
app.use(csrfProtection);
app.use(flash());

app.use((req, res, next) => {
  res.locals.isAuthenticated = req.session.isLoggedIn;
  res.locals.csrfToken = req.csrfToken();
  next();
});

app.use((req, res, next) => {
  if (!req.session.user) {
    return next();
  }
  User.findById(req.session.user._id)
    .then((user) => {
      if (!user) {
        return next();
      }
      req.user = user;
      next();
    })
    .catch((err) => {
      // throw new Error(err); //this will just throw an error and reloading sign will be on loop
      //rather than this we can use next and wrap this error inside the next to avoid such situations
      next(new Error(err));
      //btw this is just for async. for sync it will directly work and go to /500
    });
});

app.use("/admin", adminRoutes);

app.use(shopRoutes);

app.use(authRoutes);

app.get("/500", ErrorController.get505);

app.use(ErrorController.errorPage);

app.use((error, req, res, next) => {
  console.log(error);
  // res.status(error.httpStatusCode).render(...);
  // res.redirect('/500');
  // res.locals.csrfToken = req.csrfToken();
  res.status(500).render("500", {
    pageTitle: "ERROR!",
    path: "/500",
    isAuthenticated: req.session.isLoggedIn,
  });
});

mongoose
  .connect(process.env.MONGO_URI)
  .then((result) => {
    console.log("connected!");
    app.listen(process.env.PORT || 3000);
  })
  .catch((err) => console.log(err));
// .catch((err) => {
//   const error = new Error(err);
//   next(error);
// });