app.js

require("dotenv").config();

const express = require("express");
const ejs = require("ejs");
const mongoose = require("mongoose");
const session = require("express-session");
const passport = require("passport");
const passportLocalMongoose = require("passport-local-mongoose");
const GoogleStrategy = require("passport-google-oauth20").Strategy;
const findOrCreate = require("mongoose-findorcreate");

const app = express();
mongoose.connect(process.env.DB_HOST, {
  useNewUrlParser: true,
  useUnifiedTopology: true,
});
mongoose.set("useCreateIndex", true);

app.use(express.urlencoded({ extended: true }));
app.use(express.json());
app.use(express.static("public"));
app.set("view engine", "ejs");
app.use(
  session({
    secret: "This is a secret key",
    resave: false,
    saveUninitialized: false,
  })
);

app.use(passport.initialize());
app.use(passport.session());

const userSchema = new mongoose.Schema({
  email: String,
  password: String,
  googleId: String,
});

userSchema.plugin(passportLocalMongoose);
userSchema.plugin(findOrCreate);

const User = mongoose.model("user", userSchema);

// use static authenticate method of model in LocalStrategy
passport.use(User.createStrategy());

// use static serialize and deserialize of model for passport session support
passport.serializeUser(function (user, done) {
  done(null, user);
});

passport.deserializeUser(function (user, done) {
  done(null, user);
});

passport.use(
  new GoogleStrategy(
    {
      clientID: process.env.CLIENT_ID,
      clientSecret: process.env.CLIENT_SECRET,
      callbackURL: "http://localhost:3000/auth/google/secrets",
      userProfileURL: "https://www.googleapis.com/oauth2/v3/userinfo",
    },
    function (accessToken, refreshToken, profile, cb) {
      User.findOrCreate({ googleId: profile.id }, function (err, user) {
        return cb(err, user);
      });
    }
  )
);

app.listen("3000", () => {
  console.log("Server started at 3000");
});

app.get("/", (req, res) => {
  res.render("home");
});

app.get(
  "/auth/google",
  passport.authenticate("google", { scope: ["profile"] })
);

app.get(
  "/auth/google/secrets",
  passport.authenticate("google", { failureRedirect: "/login" }),
  function (req, res) {
    // Successful authentication, redirect home.
    res.redirect("/secrets");
  }
);

app
  .route("/login")
  .get((req, res) => {
    res.render("login");
  })
  .post((req, res) => {
    const user = new User({
      username: req.body.username,
      password: req.body.password,
    });

    req.logIn(user, (err) => {
      if (err) {
        res.redirect("/login");
      } else {
        passport.authenticate("local")(req, res, () => {
          res.redirect("/secrets");
        });
      }
    });
  });

app
  .route("/register")
  .get((req, res) => {
    res.render("register");
  })
  .post((req, res) => {
    User.register(
      { username: req.body.username },
      req.body.password,
      (err, newUser) => {
        if (err) {
          console.log(err);
          res.redirect("/register");
        } else {
          passport.authenticate("local")(req, res, () => {
            console.log("here");
            res.redirect("/secrets");
          });
        }
      }
    );
  });
//

app.route("/secrets").get((req, res) => {
  if (req.isAuthenticated()) {
    res.render("secrets");
  } else {
    res.redirect("/login");
  }
});

app.get("/logout", (req, res) => {
  req.logOut();
  res.redirect("/");
});