public BookErrorCodes AddNewBook(string title, string author, double cost, long ISBN, int shelfID) { var existingShelf = shelfManager.GetShelf(shelfID); if (existingShelf == null) { return(BookErrorCodes.NoSuchShelf); } if (ValidateISBN(ISBN) == false) { return(BookErrorCodes.IncorrectISBN); } var sameBooks = bookManager.GetListOfBooksByTitle(title); if (sameBooks.Count > 0) { bookManager.AddBook(title, author, cost, ISBN, sameBooks.First().ShelfID); return(BookErrorCodes.OkButBookIsPutInAnotherShelfWithExistingBooks); } else { bookManager.AddBook(title, author, cost, ISBN, shelfID); } return(BookErrorCodes.ok); }
public ShelfErrorCodes RemoveShelf(int shelfID) { var shelf = shelfManager.GetShelf(shelfID); if (shelf == null) { return(ShelfErrorCodes.NoSuchShelf); } else { if (shelf.Books != null) { return(ShelfErrorCodes.TheShelfContainsBooks); } else { shelfManager.RemoveShelf(shelf); } return(ShelfErrorCodes.ok); } }