public async Task <bool> WatchStory(string storyId, string userId)
{
var story = await database.StoryRepository.FindById(storyId) ??
throw new EntityNotFoundException("Story not found");
if (story.UserStories.Any(us => us.UserId == userId))
{
return(true);
}
var userStory = UserStory.Create(story.Id, userId);
story.UserStories.Add(userStory);
return(await database.Complete());
}
