/// <summary>
/// Find appropriate books through books collection.
/// </summary>
/// <param name="parameter">Criteria.</param>
/// <param name="books">Collection.</param>
/// <returns>Appropriate books collection.</returns>
public IEnumerable <Book> FindBooks(IFinder <Book> predicate, AbstractBookStorage books)
{
IList <Book> allBooksInStorage = Refresh(books);
List <Book> findedBooks = new List <Book>();
foreach (var book in allBooksInStorage)
{
if (predicate.BookIsRight(book))
{
findedBooks.Add(book);
}
}
if (findedBooks.Count == 0)
{
throw new BookNotExistsException("Error: we could't find book(s) with such criteria.");
}
return(findedBooks);
}
/// <summary>
/// Refresh books local collection.
/// </summary>
/// <param name="books">Books to be saved.</param>
/// <returns>Books collection.</returns>
public IList <Book> Refresh(AbstractBookStorage books)
{
return(booksRepository.Refresh(books));
}
/// <summary>
/// Constrictor.
/// </summary>
/// <param name="storage">Storage wich contain all books data.</param>
public BookListService(AbstractBookStorage storage)
{
booksRepository = storage;
}