/// <summary> /// Add a movie to an existing watchlist /// </summary> public async Task <ActionResult <Watchlist> > AddMovie(int watchlistId, int movieId) { var watchlist = await _watchlistService.AddMovieToListAsync(GetUserId(), watchlistId, movieId); if (watchlist == null) { return(new BadRequestObjectResult(Errors.AddErrorToModelState("Watchlist doesn't exist", ModelState))); } return(new OkObjectResult(watchlist)); }