AngularJS Windows Authentication Service using .NET Web API and Hot Towel template

AngularJS-Windows-Authentication.authentication.js

angular.module('app')
.factory("authentication", ["$http", "$q", "$window", authentication]);

function authentication($http, $q, $window) {

    var user;

    function login() {
        
        // check if the user already exists for this session
        if (user) {
           return $q.when(user); // resolve with given value, necessary because calling function expects a promise.
        }
        
        var url = 'api/users/current/';
        return $http.get(url).then(function (result) {
            var result = result.data;
          
            user = {
                id: result.UserId,
                displayName: result.DisplayName,
                guid: result.ADGuid,
                isAdmin: result.IsAdmin
            };

            addUserToStorage();

            console.log("user created.");
            return $q.when(user);
        });
    }

    function addUserToStorage() {
        $window.sessionStorage["user"] = JSON.stringify(user);
    }

    function getUser() {
        return user;
    }

    function init() {
        if ($window.sessionStorage["user"]) {
            user = JSON.parse($window.sessionStorage["user"]);
        }
    }

    init();

    return {
        user: user,
        init: init,
        addUserToStorage: addUserToStorage,
        login: login,
        getUser: getUser
    };
};

base.js

(function () {
    'use strict';
    var controllerId = 'base';

    angular.module('app')
        .controller(controllerId, ['common', 'authentication', base]);

    function base(common, authentication) {

        var vm = this;

        // local vm.user object for use with topnav.html to display logged in user name
        vm.user = { displayName: "..." };

        activate();

        function activate() {
            common.activateController([login()], controllerId);
        }

        function login() {
          
            return authentication.login().then(function (data) {
                vm.user = data;
            });
        }
    }
})();

example-controller.js

// in the controllers, we can get the current user by deferring to authentication service

(function () {
    'use strict';
    var controllerId = 'sales';
    
    angular.module('app')
        .controller(controllerId, ['$q', 'common', 'authentication', sales]);
    
    function sales($q, common, authentication)
    {
      // ...
       
    // each controller has a call to getUser(), which defers to the authentication service for auth status
    var vm = this;
    vm.user = {};
    
    activate();

        function activate() {
            
            // call the getUser promise
             common.activateController([getUser()], controllerId)
                .then(function () {  });
        }
        function getUser() {
            return authentication.login().then(function(data) {
                vm.user = data;
                return $q.when(data);
            });
        }
        
        // ...
        
    }
})();

topnav.html

<nav class="navbar navbar-fixed-top navbar-inverse">
    <div class="navbar-header">
        <a href="/" class="navbar-brand">
            <span class="brand-title">
                ...
            </span>
        </a>
        <a class="btn navbar-btn navbar-toggle" data-toggle="collapse" data-target=".navbar-collapse">
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
        </a>
    </div>
    <div class="navbar-collapse collapse" >
        <div class="pull-right navbar-logo" data-ng-controller="base as vm">
            <ul class="nav navbar-nav pull-right">
                <li>
                    <a href="\">
                        Welcome, {{ vm.user.displayName }} 
                    </a>
                </li>
                <li>
                    <a href="\">
                    </a>
                </li>
                <li class="dropdown dropdown-big">
                   <a href="http://localhost:20293/Help" target="_blank">Help</a>
                </li>
            </ul>
        </div>
    </div>
</nav>

User.cs

public class User
    {  
        public int UserId { get; set; }
        public string DisplayName { get; set; }
        public string ADGuid { get; set; }
        public bool IsAdmin { get; set; }

    }

UserFactory.cs

public class UserFactory
    {
        private readonly IQwDbContext db = new QwDbContext();

        public User Create(WindowsIdentity currentWindowsUser)
        {
            var user = new User();
            
            string name = currentWindowsUser.Name.Replace("DOMAIN\\", ""); 
               
            // a much simplified case for example (better to retrieve by GUID)
            User userInDatabase = (from u in db.Users
                                         where u.FirstName.ToLower() + u.LastName.ToLower() == name.ToLower()
                                         select u).FirstOrDefault();

            if (userInDatabase != null)
            {
                user.UserId = userInDatabase.UserId;
                user.DisplayName = userInDatabase.DisplayName;
                user.IsAdmin = userInDatabase.IsAdmin;
                user.ADGuid = userInDatabase.ADGuid;
            }
            
            return user;
        }
    }

UsersController.cs

[RoutePrefix("api/users")]
public class UsersController : ApiController
    {
        /// <summary>
        ///     Gets the currently logged in user account in AD as a User object
        /// </summary>
        /// <returns></returns>
        [Route("current/")]
        public User GetCurrentUser()
        {
            User user = new UserFactory().Create(WindowsIdentity.GetCurrent());
           
            return user;
        }
    }