using Unity.VisualScripting;
using UnityEngine;
using UnityEngine.EventSystems; 
public class ManualScroller : MonoBehaviour, IScrollHandler, IBeginDragHandler, IDragHandler, IPointerEnterHandler, IPointerExitHandler
{
    public RectTransform viewport;
    public RectTransform content;
    public float scrollSpeed = 50.0f;
    private bool isMouseOver = false;
    private Vector2 lastDragPosition;  
    public void OnScroll(PointerEventData eventData)
    {
        if (!isMouseOver) return;

        Vector2 pos = content.anchoredPosition;
        pos.y -= eventData.scrollDelta.y * scrollSpeed;
        if (pos.y < 0) pos.y = 0;
        if (viewport.rect.height + pos.y > content.rect.height) pos.y = content.rect.height - viewport.rect.height;
        content.anchoredPosition = pos;
    }
    public void OnBeginDrag(PointerEventData eventData)
    {
        if (!isMouseOver) return;

        lastDragPosition = eventData.position;
    }
    public void OnDrag(PointerEventData eventData)
    {
        if (!isMouseOver) return;

        Vector2 delta = eventData.position - lastDragPosition;
        Vector2 pos = content.anchoredPosition;
        pos.y += delta.y;
        content.anchoredPosition = pos;
        lastDragPosition = eventData.position;
    }
    public void OnEndDrag(PointerEventData eventData)
    {

    }
    public void OnPointerEnter(PointerEventData eventData)
    {
        isMouseOver = true;
    }

    public void OnPointerExit(PointerEventData eventData)
    {
        isMouseOver = false;
    }
}