using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

/// <summary>
/// Double-clicking a slider resets it to its default value. The default is the slider's authored
/// value, serialized when the component is added (runtime seeding from settings/persistence must not
/// overwrite it, so it is captured at edit time, not in Awake). The reset goes through slider.value,
/// so onValueChanged listeners (persistence, SliderCurve, value labels) fire as if the user dragged.
/// </summary>
[RequireComponent(typeof(Slider))]
public class SliderDoubleClickReset : MonoBehaviour, IPointerClickHandler
{
    [SerializeField, Tooltip("Raw slider value restored on double-click. Seeded from the slider's authored value when the component is added.")]
    private float _defaultValue;

    [SerializeField, Tooltip("Max seconds between the two clicks.")]
    private float _maxClickInterval = 0.25f;

    [SerializeField, Tooltip("Max pointer movement (screen pixels) between the two clicks.")]
    private float _maxPointerDistance = 8f;

    private float _lastClickTime = float.NegativeInfinity;
    private Vector2 _lastClickPosition;

    public void OnPointerClick(PointerEventData eventData)
    {
        if (eventData.button != PointerEventData.InputButton.Left) return;

        if (eventData.dragging || (eventData.position - eventData.pressPosition).sqrMagnitude > _maxPointerDistance * _maxPointerDistance)
        {
            _lastClickTime = float.NegativeInfinity;
            return;
        }

        bool isDouble = Time.unscaledTime - _lastClickTime <= _maxClickInterval
            && (eventData.position - _lastClickPosition).sqrMagnitude <= _maxPointerDistance * _maxPointerDistance;

        _lastClickTime = isDouble ? float.NegativeInfinity : Time.unscaledTime;
        _lastClickPosition = eventData.position;

        if (isDouble) GetComponent<Slider>().value = _defaultValue;
    }

    private void Reset() => _defaultValue = GetComponent<Slider>().value;
}