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

namespace Livia.ViewModels.Utility;


public interface ISelectableItem
{
    public bool IsChecked { get; set; }
}


public class SelectableObservableCollection<T> : ObservableObject where T : ObservableObject, ISelectableItem
{

    public bool? CheckBoxChecked
    {
        get
        {
            if (Items.Count == 0)
                return false;

            List<bool> selected = Items.Select(item => item.IsChecked).Distinct().ToList();
            return selected.Count == 1 ? selected.Single() : null;
        }

        set
        {
            if (!value.HasValue)
                return;

            foreach (T item in Items)
            {
                item.IsChecked = value.Value;
            }
            OnPropertyChanged();
        }
    }

    public void AddRange(IEnumerable<T> list)
    {
        foreach (T item in list)
        {
            Items.Add(item);
            item.PropertyChanged += (_, args) =>
            {
                if (args.PropertyName != nameof(item.IsChecked)) return;

                OnPropertyChanged(nameof(CheckBoxChecked));
            };
        }

        //refresh after adding new stuff
        OnPropertyChanged(nameof(CheckBoxChecked));
    }

    public ObservableCollection<T> Items { get; }= [];

}