SimplePhotosApp/Photos/ViewModels/MainWindowViewModel.cs

using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Diagnostics;
using System.Net;
using Avalonia.Controls;
using Avalonia.Input;
using Photos.Models;
using Avalonia.Platform.Storage;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Avalonia.Threading;
using CommunityToolkit.Mvvm.ComponentModel;

namespace Photos.ViewModels;

public partial class MainWindowViewModel : ViewModelBase
{
    public ObservableCollection<Photo> Photos { get; private set; } = [];

    [ObservableProperty] private Photo? _selectedPhoto;

    public string LibraryPath { get; private set; } = string.Empty;
    
    public MainWindowViewModel()
    {
        
    }

    void OpenDirectory()
    {

    }

    private void SanitizeFiles(List<string> files, IEnumerable<string> extensions)
    => files.RemoveAll(x => !extensions.Any(ex => x.EndsWith(ex, StringComparison.OrdinalIgnoreCase)));

    private async Task AddPhotosAsync(string path)
    {
        try
        {
            var files = await Task.Run(() =>
            {
                var files = Directory.GetFiles(path, "*", SearchOption.AllDirectories).ToList();
                SanitizeFiles(files, [".png", ".jpg", ".jpeg"]);
                return files;
            });

            var photosToAdd = await Task.Run(() =>
            {
                var photos = new List<Photo>();
                foreach (var file in files)
                {
                    photos.Add(new Photo(file, LibraryPath));
                }
                return photos;
            });

            await Dispatcher.UIThread.InvokeAsync(() =>
            {
                foreach (var photo in photosToAdd) Photos.Add(photo);
            });
        }
        catch (Exception ex)
        {
            Debug.WriteLine(ex);
        }
    }

    public async void WindowDropHandler(DragEventArgs e)
    {
        var files = e.DataTransfer.TryGetFiles();
        if (files is null || files.Length == 0) return;

        var localPath = Path.GetDirectoryName(files[0].TryGetLocalPath());
        if (String.IsNullOrWhiteSpace(localPath)) return;

        LibraryPath = localPath;
        Photos.Clear();

        await AddPhotosAsync(localPath);
    }

    public void PhotoClicked(PointerReleasedEventArgs e)
    {
        if(e.Source is not Image img) return;
        SelectedPhoto = Photos.FirstOrDefault(x => x.Source == img.Source);
    }

    public void SelectedPhotoClicked()
    {
        SelectedPhoto = null;
    }
}