public MovieDto AddPromoCode(PromoCodeDto promoCodeDto)
        {
            var movie = moviesRepository.FindById(promoCodeDto.MovieId);

            if (movie == null)
            {
                throw new HttpException("Movie not found.", HttpStatusCode.NotFound);
            }

            var promoCode = PromoCode.Create(movie, promoCodeDto.PromoEnd, promoCodeDto.Percentage);

            moviesRepository.AddPromoCode(promoCode);

            return(mapper.Map <MovieDto>(movie));
        }