app.js

const express = require("express");
const app = express();
const bodyParser = require("body-parser");
const bcrypt = require("bcrypt");
const jwt = require("jsonwebtoken");

// require database connection
const dbConnect = require("./db/dbConnect");
const User = require("./db/userModel");
const auth = require("./auth");

// execute database connection
dbConnect();

// body parser configuration
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));

// Fix CORS
app.use((request, response, next) => {
  response.append("Access-Control-Allow-Origin", "*");
  response.append("Access-Control-Allow-Methods", "GET,PUT,POST,DELETE");
  response.append("Access-Control-Allow-Headers", "Content-Type");
  next();
});

// Landing page for back-end
app.get("/", (request, response, next) => {
  response.json({ message: "Hey! This is your server response!" });
  next();
});

// registration endpoint
app.post("/registration", (request, response) => {
  // hash the password
  bcrypt
    .hash(request.body.password, 10)
    .then((hashedPassword) => {
      // create a new user instance and collect the data
      const user = new User({
        email: request.body.email,
        password: hashedPassword,
      });

      // save the new user
      user
        .save()
        // return success if the new user is added to the database successfully
        .then((result) => {
          response.status(201).send({
            message: "User created successfully",
            result,
          });
        })
        // catch error if the new user wasn't added successfully to the database
        .catch((error) => {
          response.status(500).send({
            message: "Error creating user, maybe email already exists?",
            error,
          });
        });
    })
    // catch error if the password hash isn't successful
    .catch((e) => {
      response.status(500).send({
        message: "Password was not hashed successfully",
        e,
      });
    });
});

// login endpoint
app.post("/login", (request, response) => {
  // check if email exists
  User.findOne({ email: request.body.email })

    // if email exists
    .then((user) => {
      // compare the password entered and the hashed password found
      bcrypt
        .compare(request.body.password, user.password)

        // if the passwords match
        .then((passwordCheck) => {
          // check if password matches
          if (!passwordCheck) {
            return response.status(400).send({
              message: "Incorrect password, please try again.",
              error,
            });
          }

          // create JWT token
          const token = jwt.sign(
            {
              userId: user._id,
              userEmail: user.email,
            },
            "RANDOM-TOKEN",
            { expiresIn: "24h" }
          );

          // return success response
          response.status(200).send({
            message: "Login successful!",
            email: user.email,
            token,
          });
        })
        // catch error if password does not match
        .catch((error) => {
          response.status(400).send({
            message: "Incorrect password, please try again.",
            error,
          });
        });
    })
    // catch error if email does not exist
    .catch((e) => {
      response.status(404).send({
        message: "Email not found, please try again.",
        e,
      });
    });
});

// bcrypt.hash(request.body.password, 10).then().catch();

// free endpoint
// app.get("/free-endpoint", (request, response) => {
//   response.json({ message: "You are free to access me anytime." });
// });

// authentication endpoint
// app.get("/auth-endpoint", auth, (request, response) => {
//   response.json({ message: "You are authorized to access me." });
// });

// module.exports = app;
app.listen(8000, () => console.log("Server is up!")); // Local