using UnityEngine;
using UnityEngine.EventSystems;

public class CursorManager : MonoBehaviour
{
    public static CursorManager Instance;

    public Texture2D defaultCursor; // 默认光标
    public Texture2D hoverCursor;   // 悬停光标

    private GameObject lastHoveredObject;

    private void Awake()
    {
        if (Instance == null)
        {
            Instance = this;
            DontDestroyOnLoad(gameObject);
        }
        else
        {
            Destroy(gameObject);
        }
    }

    private void Update()
    {
        // 检测鼠标指向的物体
        if (EventSystem.current.IsPointerOverGameObject())
        {
            PointerEventData pointerData = new PointerEventData(EventSystem.current)
            {
                position = Input.mousePosition
            };

            // 获取指针下的对象
            var results = new System.Collections.Generic.List<RaycastResult>();
            EventSystem.current.RaycastAll(pointerData, results);

            if (results.Count > 0)
            {
                GameObject hoveredObject = results[0].gameObject;

                // 判断是否为新的悬停物体，且是否实现了IPointer接口
                if (hoveredObject != lastHoveredObject && 
                    (hoveredObject.GetComponent<IPointerEnterHandler>() != null ||
                     hoveredObject.GetComponent<IPointerClickHandler>() != null ||
                     hoveredObject.GetComponent<IPointerDownHandler>() != null))
                {
                    Cursor.SetCursor(hoverCursor, Vector2.zero, CursorMode.Auto);
                    lastHoveredObject = hoveredObject;
                }
            }
            else
            {
                ResetCursor();
            }
        }
        else
        {
            ResetCursor();
        }
    }

    private void ResetCursor()
    {
        if (lastHoveredObject != null)
        {
            Cursor.SetCursor(defaultCursor, Vector2.zero, CursorMode.Auto);
            lastHoveredObject = null;
        }
    }

    public void SetHover()
    {
        Cursor.SetCursor(hoverCursor, Vector2.zero, CursorMode.Auto);
    }

    public void SetNormal()
    {
        Cursor.SetCursor(defaultCursor, Vector2.zero, CursorMode.Auto);
    }
}