ProjectLib/ProjectLibrary/Repositores/Implementations/BookLibraryRepository.cs

using ProjectLibrary.Entites;
using ProjectLibrary.Entities;
using ProjectLibrary.Repositories;
using System.Collections.Generic;
using System.Linq;

namespace ProjectLibrary.Repositories.Implementations
{
    public class BookLibraryRepository : IBookLibraryRepository
    {
        // Эмулируем базу данных в виде списка
        private readonly List<Book_Library> _bookLibraries = new List<Book_Library>();

        public void CreateBookLibrary(Book_Library bookLibrary)
        {
            // Логика для добавления связи книги и библиотеки
            _bookLibraries.Add(bookLibrary);
        }

        public void DeleteBookLibrary(int bookId, int libraryId)
        {
            // Логика для удаления связи книги и библиотеки по идентификаторам
            var bookLibrary = _bookLibraries.FirstOrDefault(bl => bl.BookID == bookId && bl.LibraryID == libraryId);
            if (bookLibrary != null)
            {
                _bookLibraries.Remove(bookLibrary);
            }
        }

        public IEnumerable<Book_Library> ReadBookLibraries(int? bookId = null, int? libraryId = null)
        {
            // Логика для получения всех связей книг и библиотек с возможностью фильтрации по bookId и libraryId
            return _bookLibraries.Where(bl =>
                (!bookId.HasValue || bl.BookID == bookId) &&
                (!libraryId.HasValue || bl.LibraryID == libraryId));
        }

        public void UpdateBookLibrary(Book_Library bookLibrary)
        {
            // Логика для обновления информации о связи книги и библиотеки
            var existingBookLibrary = _bookLibraries.FirstOrDefault(bl => bl.BookID == bookLibrary.BookID && bl.LibraryID == bookLibrary.LibraryID);
            if (existingBookLibrary != null)
            {
                _bookLibraries.Remove(existingBookLibrary);
                _bookLibraries.Add(bookLibrary);
            }
        }
    }
}