CodeContextGenerator/CodeContextGenerator/Models/FileItem.cs

using CommunityToolkit.Mvvm.ComponentModel;
using System.Collections.ObjectModel;

namespace CodeContextGenerator.Models;

public partial class FileItem : ObservableObject
{
    [ObservableProperty]
    private string name;

    [ObservableProperty]
    private string fullName;

    [ObservableProperty]
    private bool isDirectory;

    [ObservableProperty]
    private bool? isSelected;

    [ObservableProperty]
    private FileItem parent;

    public ObservableCollection<FileItem> Children { get; } = new ObservableCollection<FileItem>();

    partial void OnIsSelectedChanged(bool? oldValue, bool? newValue)
    {
        if (newValue.HasValue)
        {
            UpdateChildrenSelection(newValue.Value);
        }
        UpdateParentSelection();
    }

    private void UpdateChildrenSelection(bool value)
    {
        if (!IsDirectory) return;

        foreach (var child in Children)
        {
            child.IsSelected = value;
        }
    }

    private void UpdateParentSelection()
    {
        if (Parent == null) return;

        var children = Parent.Children;
        var allSelected = children.All(c => c.IsSelected == true);
        var noneSelected = children.All(c => c.IsSelected == false);
        var hasIndeterminate = children.Any(c => c.IsSelected == null);

        Parent.IsSelected = hasIndeterminate ? null : (allSelected ? true : (noneSelected ? false : null));
        Parent.UpdateParentSelection();
    }
}