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

public class SkillEntry : MonoBehaviour, IBeginDragHandler, IDragHandler, IEndDragHandler
{
    [SerializeField] private Image _iconImage;
    [SerializeField] private TextMeshProUGUI _nameText;

    public SkillData Data { get; private set; }

    private Transform _dragTransform;
    private Transform _originalParent;
    private CanvasGroup _canvasGroup;
    private Vector3 _originalLocalPos;

    private void Awake()
    {
        _canvasGroup = GetComponent<CanvasGroup>();
        if (_canvasGroup == null)
            _canvasGroup = gameObject.AddComponent<CanvasGroup>();
    }

    public void SetData(SkillData data)
    {
        Data = data;
        if (_iconImage != null)
        {
            _iconImage.sprite = data != null ? data.Icon : null;
            _iconImage.enabled = data != null && data.Icon != null;
        }
        if (_nameText != null)
            _nameText.text = data != null ? data.EntryName : "";
    }

    public void OnBeginDrag(PointerEventData eventData)
    {
        if (Data == null)
        {
            eventData.pointerDrag = null;
            return;
        }

        _dragTransform = GameManager.Instance.InGameUI.DragCanvas;
        _originalParent = transform.parent;
        _originalLocalPos = transform.localPosition;

        transform.SetParent(_dragTransform);
        _canvasGroup.blocksRaycasts = false;
    }

    public void OnDrag(PointerEventData eventData)
    {
        transform.position = eventData.position;
    }

    public void OnEndDrag(PointerEventData eventData)
    {
        _canvasGroup.blocksRaycasts = true;

        // 드롭된 오브젝트 판정 — 퀵슬롯이면 등록
        GameObject hovered = eventData.pointerEnter;
        if (hovered != null)
        {
            QuickSlot slot = hovered.GetComponentInParent<QuickSlot>();
            if (slot != null && Data != null)
            {
                slot.SetEntry(Data);
            }
        }

        // 엔트리는 항상 제자리로 복귀 (원본은 목록에 남아있어야 함)
        transform.SetParent(_originalParent);
        transform.localPosition = _originalLocalPos;
    }
}