BLL.User.ValidateUser C# (CSharp) Method

        public static Models.ValidationResult ValidateUser(Models.CloneDeployUser user, bool isNewUser)
        {
            var validationResult = new Models.ValidationResult();

            if (string.IsNullOrEmpty(user.Name) || !user.Name.All(c => char.IsLetterOrDigit(c) || c == '_'))
            {
                validationResult.IsValid = false;
                validationResult.Message = "User Name Is Not Valid";
                return validationResult;
            }

            if (isNewUser)
            {
                if (string.IsNullOrEmpty(user.Password))
                {
                    validationResult.IsValid = false;
                    validationResult.Message = "Password Is Not Valid";
                    return validationResult;
                }

                using (var uow = new DAL.UnitOfWork())
                {
                    if (uow.UserRepository.Exists(h => h.Name == user.Name))
                    {
                        validationResult.IsValid = false;
                        validationResult.Message = "This User Already Exists";
                        return validationResult;
                    }
                }
            }
            else
            {
                using (var uow = new DAL.UnitOfWork())
                {
                    var originalUser = uow.UserRepository.GetById(user.Id);
                    if (originalUser.Name != user.Name)
                    {
                        if (uow.UserRepository.Exists(h => h.Name == user.Name))
                        {
                            validationResult.IsValid = false;
                            validationResult.Message = "This User Already Exists";
                            return validationResult;
                        }
                    }
                }
            }

            return validationResult;
        }