using CommunityToolkit.Mvvm.ComponentModel;
using OpenTap;
using System.ComponentModel;
using System.Windows;
using System.Windows.Controls;

namespace OpenTapEditor
{
    /// <summary>
    /// ErrorSpan.xaml 的交互逻辑
    /// </summary>
    [ObservableObject]
    public partial class ErrorSpan : UserControl
    {

        public static readonly DependencyProperty SourceProperty =
            DependencyProperty.RegisterAttached("Source", typeof(object), typeof(ErrorSpan), new PropertyMetadata(null, OnSourceChanged));

        private static void OnSourceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            if (d is ErrorSpan element && e.Property == SourceProperty)
            {
                element.Source = e.NewValue;
            }
        }

        public object Source
        {
            get => GetValue(SourceProperty);
            set
            {
                var old = GetValue(SourceProperty);
                if (old is INotifyPropertyChanged ildNpc)
                {
                    ildNpc.PropertyChanged -= Npc_PropertyChanged;
                }

                SetValue(SourceProperty, value);
                Refresh();
                if (value is INotifyPropertyChanged npc)
                {
                    npc.PropertyChanged += Npc_PropertyChanged;
                }
            }
        }

        private void Refresh()
        {
            OnPropertyChanged(nameof(HasError));
            OnPropertyChanged(nameof(ErrorMessage));
        }

        public bool HasError => SourceHasError();
        public string ErrorMessage => SourceErrorMessage();

        private void Npc_PropertyChanged(object? sender, PropertyChangedEventArgs e)
        {
            Refresh();
        }

        public bool SourceHasError()
        {
            return (Source is ValidatingObject vo) && vo?.Rules.FirstOrDefault(r => r?.IsValid() == false) != null;
        }

        public string SourceErrorMessage()
        {
            if (Source is ValidatingObject vo)
            {
                return vo?.Rules?.FirstOrDefault(r => r?.IsValid() == false)?.ErrorMessage;
            }
            return null;
        }

        public ErrorSpan()
        {
            InitializeComponent();
        }
    }
}