using System;
using Cysharp.Threading.Tasks;
using UnityEngine.UIElements;

namespace DanieleMarotta.RiversongCodeShowcase
{
    public class RuntimeTooltipUIController : UIControllerSystem<RuntimeTooltipUIView>, IDisposable
    {
        private VisualElement _currentSource;

        public RuntimeTooltipUIController(IServiceLocator serviceLocator) : base(serviceLocator)
        {
        }

        protected override RuntimeTooltipUIView View => UIRoot.GetView<RuntimeTooltipUIView>();

        public override async UniTask InitializeAsync()
        {
            await base.InitializeAsync();

            View.Show(false);

            UIRoot.RootVisualElement.RegisterCallback<PointerEnterEvent>(OnPointerEnter, TrickleDown.TrickleDown);
            UIRoot.RootVisualElement.RegisterCallback<PointerLeaveEvent>(OnPointerLeave, TrickleDown.TrickleDown);
        }

        public void Dispose()
        {
            UIRoot.RootVisualElement.UnregisterCallback<PointerEnterEvent>(OnPointerEnter, TrickleDown.TrickleDown);
            UIRoot.RootVisualElement.UnregisterCallback<PointerLeaveEvent>(OnPointerLeave, TrickleDown.TrickleDown);
        }

        private void OnPointerEnter(PointerEnterEvent evt)
        {
            if (evt.target is not VisualElement element) return;

            var source = element.GetFirstAncestorOrSelf(static candidate => !string.IsNullOrEmpty(candidate.tooltip));
            if (source == null || ReferenceEquals(source, _currentSource)) return;

            _currentSource = source;

            View.Show(true);
            View.AnchorTooltip(source, source.tooltip);
        }

        private void OnPointerLeave(PointerLeaveEvent evt)
        {
            if (!ReferenceEquals(evt.target, _currentSource)) return;

            _currentSource = null;
            View.Show(false);
        }
    }
}