app.js

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

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

//execute database connection
dbConnect();

// Curb Cores Error by adding a header here
app.use((req, res, next) => {
  res.setHeader("Access-Control-Allow-Origin", "*");
  res.setHeader(
    "Access-Control-Allow-Headers",
    "Origin, X-Requested-With, Content, Accept, Content-Type, Authorization"
  );
  res.setHeader(
    "Access-Control-Allow-Methods",
    "GET, POST, PUT, DELETE, PATCH, OPTIONS"
  );
  next();
});

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

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

//register endpoint
app.post("/register", (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",
            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: "Passwords does not match",
              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 : "Passwords does not match",
            error,
          });
        });
    })
    //catch error if email does not exist
    .catch((e) => {
      response.status(404).send({
        message : "Email not found",
        e,
      });
    });
});

//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;