router.post("/register", upload.single("profile_picture"), (req, res) => {
  User.findOne({ email: req.body.email })
    .then(user => {
      if (user) {
        cloudinary.v2.uploader.destroy(req.file.public_id, (err, result) => console.log(result, err));
        return res.status(400).json({ success: false, message: "User already exists." });
      }

      const newUser = new User({
        email: req.body.email,
        password: req.body.password,
        name: req.body.name,
        profile_picture: {
          url: "",
          public_id: ""
        }
      });

      bcrypt.genSalt(10, (err, salt) => {
        if (err) {
          cloudinary.v2.uploader.destroy(req.file.public_id, (err, result) => console.log(result, err));
          return res.status(500).json({ success: false, message: "User could not be created." });
        }

        bcrypt.hash(newUser.password, salt, (err, hash) => {
          if (err) {
            cloudinary.v2.uploader.destroy(req.file.public_id, (err, result) => console.log(result, err));
            return res.status(500).json({ success: false, message: "User could not be created." });
          }

          newUser.password = hash;
          newUser.profile_picture.url = req.file.url;
          newUser.profile_picture.public_id = req.file.public_id;

          newUser.save();

          return res.status(200).json({ success: true, message: "User successfully registered." });
        });
      })
    })
    .catch(err => {
      console.log(err);
      return res.status(500).json({ success: false, message: "User could not be created." });
    });
});