{
        "Roles": [
            "5b7fd72537651320a03494f8",
            "5b7fdc06e3fcb037d016e26a"
        ],
        "_id": "5b8e530be2d4630fd4f4b34a",
        "Username": "ctucker",
        "FirstName": "Chris",
        "LastName": "Tucker",
        "Email": "ctucker@innovate.com",
        "createdAt": "2018-09-04T09:40:27.091Z",
        "updatedAt": "2018-09-04T09:40:27.091Z",
        "__v": 0
    }

const userSchema = new mongoose.Schema({

    Username: {
        type: String,
        required: true,
        minlength: 5,
        maxlength: 255,
        unique: true
    },
    FirstName: {
        type: String
    },
    LastName: {
        type: String
    },
    Email: {
        type: String,
        required: true,
        minlength: 5,
        maxlength: 255
    },
    Password: {
        type: String,
        required: true,
        minlength: 5,
        maxlength: 1024
    },
    Roles: [{type: mongoose.Schema.Types.ObjectId, ref: Roles}],
    Active: {type: Boolean, default: true},
    SuperUser: {type: Boolean, default: false}
},{
    timestamps: true
});

const rolesSchema = new mongoose.Schema({
    RoleName: {
        type: String,
        required: true,
        minlength: 5,
        maxlength: 255,
        unique: true
    },
    Description: {
        type: String
    },
    Active: {type: Boolean, default: true}
}, {
    timestamps: true
});

router.post('/', [auth, admin], async (req, res) => {

  const { error } = validate(req.body);
  if (error) return res.status(400).send(error.details[0].message);

  let user = await User.findOne({ Username: req.body.Username });
  if (user) return res.status(400).send('User with username: ', req.body.Username, 'already exists. Please try with any other username');

  let roleInput = [];

  if(req.body.Roles !== null) {
    req.body.Roles.forEach( async (element) => {
      objectId = mongoose.Types.ObjectId(element);
      roleInput.push(objectId);
    });
  }

  console.log('Role info ', roleInput);

  user = new User(_.pick(req.body, ['Username', 'FirstName', 'LastName' ,'Email', 'Password', 'Active','SuperUser']));

  console.log('User Input => ', user);

  const salt = await bcrypt.genSalt(10);
  user.Password = await bcrypt.hash(user.Password, salt);

  roleInput.forEach( async (objectId) => {
    user.Roles.push(objectId);
  });

  console.log('User Input after role addition => ', user);

  await user.save();

  const token = user.generateAuthToken();
  res.header('x-auth-token', token).send(_.pick(user, ['_id', 'FirstName', 'LastName' ,'Email', 'Roles']));

});

const user = await User.findOne().populate('Roles');
// output => user.Roles // will be array of mongo documents

'use strict';

let user = await User.findOne({
  Username: req.body.Username
}).populate('Roles');

if (user && user.Roles.length > 0) {
  for (let role of user.Roles) {
    console.log(role.RoleName);// logs `RoleName`
  }
}