using UnityEngine;
using UnityEngine.EventSystems;

public class DragSize : MonoBehaviour,  IDragHandler
{
    public enum Mode { Height,Width,Left,Right}
    public Mode mode;
    public float MinSize =85f;
    public float MaxSize =850f;
    private float NewSize;
    
    private RectTransform panelRectTransform;
    void Start()
    {
        panelRectTransform = transform.parent as RectTransform;        
    }

    public void OnDrag(PointerEventData data)
    {
        if (Input.GetMouseButton(0))
        {
            if (panelRectTransform == null)
                return;
            if (NewSize < MinSize) NewSize = MinSize;
            if (NewSize > MaxSize) NewSize = MaxSize;
            switch (mode)
            {
                case Mode.Width:
                    break;
                case Mode.Height:
                    NewSize = Input.mousePosition.y;
                    if (NewSize < MinSize) NewSize = MinSize;
                    if (NewSize > MaxSize) NewSize = MaxSize;
                    panelRectTransform.sizeDelta = new Vector2(panelRectTransform.sizeDelta.x, NewSize);
                    break;
                case Mode.Left:
                    NewSize = Input.mousePosition.x ;
                    if (NewSize < MinSize) NewSize = MinSize;
                    if (NewSize > MaxSize) NewSize = MaxSize;
                    panelRectTransform.offsetMin = new Vector2(NewSize, panelRectTransform.offsetMin.y);
                    break;
                case Mode.Right:
                    NewSize = Input.mousePosition.x - Screen.width;
                    if (NewSize < MinSize) NewSize = MinSize;
                    if (NewSize > MaxSize) NewSize = MaxSize;
                    panelRectTransform.offsetMax = new Vector2(NewSize, panelRectTransform.offsetMax.y);
                    break;
                
            }
            
        }
    }
}