ViewModels/BookViewModel.cs - main - bomjkee/AvaloniaEntityApp

ViewModels/BookViewModel.cs
167 строк4 KB
bomjkee
first commit
23 фев 2025, 00:18
23 фев 2025, 00:18e1949b1
using System.Collections.ObjectModel;
using System.Linq;
using System.Threading.Tasks;
using CommunityToolkit.Mvvm.ComponentModel;
using CommunityToolkit.Mvvm.Input;
using AvaloniaApp.Services;
using AvaloniaApp.Models;

namespace AvaloniaApp.ViewModels;

public partial class BookViewModel : ViewModelBase
{
    private readonly LibraryDataService _libraryData;

    [ObservableProperty]
    private ObservableCollection<Book> _books = new ObservableCollection<Book>();
    
    [ObservableProperty]
    private ObservableCollection<Author> _authors = new ObservableCollection<Author>();

    [ObservableProperty]
    private ObservableCollection<Genre> _genres = new ObservableCollection<Genre>();

    [ObservableProperty]
    private Book? _selectedBook;

    [ObservableProperty]
    private Author? _selectedAuthor;

    [ObservableProperty]
    private Genre? _selectedGenre;

    [ObservableProperty]
    private string _title = string.Empty;

    [ObservableProperty]
    private int _publishYear;

    [ObservableProperty]
    private string? _isbn = string.Empty;

    [ObservableProperty]
    private int _quantityInStock;

    public BookViewModel(LibraryDataService libraryData)
    {
        _libraryData = libraryData;
        
        _books = _libraryData.Books;
        _authors = _libraryData.Authors;
        _genres = _libraryData.Genres;

        _libraryData.Books.CollectionChanged += (s, e) => UpdateBooks();
        _libraryData.Authors.CollectionChanged += (s, e) => UpdateAuthors();
        _libraryData.Genres.CollectionChanged += (s, e) => UpdateGenres();

        UpdateBooks();
        UpdateAuthors();
        UpdateGenres();
    }
    

    [RelayCommand]
    private async Task AddBookAsync()
    {
        if (SelectedAuthor == null || SelectedGenre == null)
        {
            return;
        }

        var book = new Book
        {
            Title = Title,
            Author = SelectedAuthor.FullName,
            PublishYear = PublishYear,
            ISBN = Isbn,
            Genre = SelectedGenre.Name,
            QuantityInStock = QuantityInStock,
            AuthorId = SelectedAuthor.Id,
            GenreId = SelectedGenre.Id
        };

        await _libraryData.AddBookAsync(book);
        ClearInput();
    }

    [RelayCommand]
    private async Task UpdateBookAsync()
    {
        if (SelectedBook == null || SelectedAuthor == null || SelectedGenre == null) return;

        SelectedBook.Title = Title;
        SelectedBook.Author = SelectedAuthor.FullName;
        SelectedBook.PublishYear = PublishYear;
        SelectedBook.ISBN = Isbn;
        SelectedBook.Genre = SelectedGenre.Name;
        SelectedBook.QuantityInStock = QuantityInStock;
        SelectedBook.AuthorId = SelectedAuthor.Id;
        SelectedBook.GenreId = SelectedGenre.Id;

        await _libraryData.UpdateBookAsync(SelectedBook);
        ClearInput();
    }

    [RelayCommand]
    private async Task DeleteBookAsync()
    {
        if (SelectedBook == null) return;

        await _libraryData.DeleteBookAsync(SelectedBook);
        ClearInput();
    }

    [RelayCommand]
    private void ClearInput()
    {
        Title = string.Empty;
        SelectedAuthor = null;
        SelectedGenre = null;
        PublishYear = 0;
        Isbn = string.Empty;
        QuantityInStock = 0;
        SelectedBook = null;
    }

    [RelayCommand]
    private void SelectBook()
    {
        if (SelectedBook == null) return;

        Title = SelectedBook.Title;
        SelectedAuthor = Authors.FirstOrDefault(a => a.Id == SelectedBook.AuthorId);
        SelectedGenre = Genres.FirstOrDefault(g => g.Id == SelectedBook.GenreId);
        PublishYear = SelectedBook.PublishYear;
        Isbn = SelectedBook.ISBN;
        QuantityInStock = SelectedBook.QuantityInStock;
    }
    
     private void UpdateBooks()
    {
        Books = new ObservableCollection<Book>(_libraryData.Books);
    }

    private void UpdateAuthors()
    {
        Authors = new ObservableCollection<Author>(_libraryData.Authors);
    }

    private void UpdateGenres()
    {
        Genres = new ObservableCollection<Genre>(_libraryData.Genres);
    }
    

    partial void OnSelectedBookChanged(Book? value)
    {
        if (value != null)
        {
            Title = value.Title;
            SelectedAuthor = Authors.FirstOrDefault(a => a.Id == value.AuthorId);
            SelectedGenre = Genres.FirstOrDefault(g => g.Id == value.GenreId);
            PublishYear = value.PublishYear;
            Isbn = value.ISBN;
            QuantityInStock = value.QuantityInStock;
        }
    }
}