EBook EBook(StoreContext context, Book book)
{
var eBook = EBooks.FirstOrDefault(b => b.Id == book.Id);
if (eBook != null)
return eBook;
eBook = new EBook { RegisteredAt = Clock.GetTime() };
context.Books.Add(eBook);
return eBook;
}
Book Book(EBook eBook)
{
return new Book(
eBook.Id,
eBook.Isbn,
eBook.Title,
eBook.PublishedAt,
eBook.Price,
eBook.Authors.Select(a => a.Name)
);
}