LoginValidations

 public class LoginValidation
    {
        private static UserRoles _currentUserRole;
        private string _username;
        private string _password;
        private string _errorMessage;
        private ActionOnError _onError;
        public LoginValidation(string userName, string password, ActionOnError onError)
        {
            this._username = userName;
            this._password = password;
            _onError = onError;
        }
        public LoginValidation()
        {

        }

        public delegate void ActionOnError(string errorMsg);
        public static UserRoles CurrentUserRole
        {
            get { return _currentUserRole; }
            private set { _currentUserRole = value; }
        }

        public bool ValidateUserInput(User user)
        {
            _currentUserRole = UserRoles.ANONYMOUS;//преди проверките

            bool emptyUsername = string.IsNullOrEmpty(_username);
            bool emptyPassword = string.IsNullOrEmpty(_password);
            bool isUsernameCorrect = _username.Length >= 5 ? true : false;
            bool isPasswordCorrect = _password.Length >= 5 ? true : false;

            if(emptyUsername || emptyPassword || !isUsernameCorrect || !isPasswordCorrect)
            {
                _errorMessage = "Имате грешка при въвеждането на потребителското име или паролата";
                _onError(_errorMessage);//not sure how it works tbh
                return false;
            }

            if (UserData.IsUserPassCorrect(_username, _password) != null)
            {
                user = UserData.IsUserPassCorrect(_username, _password);//not sure
            }
            else return false;

            //user.Username = UserData.TestUser.Username;
            //user.Password = UserData.TestUser.Password;
            //user.FacNumber = UserData.TestUser.FacNumber;
            //user.Role = UserData.TestUser.Role;

            _currentUserRole = (UserRoles)user.Role;
            Logger.LogActivity("Успешен Login");
            return true;
        }
    }