LivreLand/Model/Manager.cs

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Model
{
    public class Manager
    {
        private ILibraryManager LibraryManager { get; set; }

        public ReadOnlyCollection<Book> Books { get; private set; }
        private List<Book> books = new();

        public Manager(ILibraryManager libMgr)
        {
            LibraryManager = libMgr;
            Books = new ReadOnlyCollection<Book>(books);
        }

        public async Task<Book> GetBookById(string id)
            => await LibraryManager.GetBookById(id);

        public async Task<Book> GetBookByISBN(string isbn)
            => await LibraryManager.GetBookByISBN(isbn);

        public async Task<(long count, IEnumerable<Book> books)> GetBooksByTitle(string title, int index, int count, string sort = "")
        {
            var result = await LibraryManager.GetBooksByTitle(title, index, count, sort);
            return (result.Item1, result.Item2);
        }

        public async Task<(long count, IEnumerable<Book> books)> GetBooksByAuthorId(string authorId, int index, int count, string sort = "")
        {
            var result = await LibraryManager.GetBooksByAuthorId(authorId, index, count, sort);
            return (result.Item1, result.Item2);
        }

        public async Task<(long count, IEnumerable<Book> books)> GetBooksByAuthor(string author, int index, int count, string sort = "")
        {
            var result = await LibraryManager.GetBooksByAuthor(author, index, count, sort);
            return (result.Item1, result.Item2);
        }

        public async Task<Author> GetAuthorById(string id)
            => await LibraryManager.GetAuthorById(id);

        public async Task<(long count, IEnumerable<Author> authors)> GetAuthorsByName(string substring, int index, int count, string sort = "")
        {
            var result = await LibraryManager.GetAuthorsByName(substring, index, count, sort);
            return (result.Item1, result.Item2);
        }
    }
}