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

public class VirtualPad : MonoSingleton<VirtualPad>, IDragHandler, IPointerUpHandler, IPointerDownHandler
{
    [SerializeField]
    private Image Controller, stick;

    private Canvas canvas;
    private Camera uiCamera;
    private RectTransform canvasRect;

    private bool istouch = false;
    private bool isDrag = false;

    private Vector2 saveVec;
    private Vector2 moveVec;

    private void Awake()
    {
        _instance = this;
        canvas = transform.parent.GetComponent<Canvas>();
        canvasRect = canvas.GetComponent<RectTransform>();
    }

    private void Update()
    {
        if (isDrag)
        {
            BattleMgr.Instance.MoveToDir(moveVec);
        }
    }

    public void OnDrag(PointerEventData eventData)
    {
        if(BattleMgr.Instance.CurrentBattleType == BattleMgr.BattleType.Pvp) return;

        Controller.enabled = true;
        stick.enabled = true;
        isDrag = true;

        Vector2 dragVec;
        RectTransformUtility.ScreenPointToLocalPointInRectangle(canvasRect, eventData.position, uiCamera, out dragVec);
        moveVec = (dragVec - saveVec).normalized;
        float dragDist = Mathf.Min(Vector2.Distance(saveVec, dragVec), 82f);
        stick.rectTransform.anchoredPosition = saveVec + (moveVec * dragDist);
    }

    public void OnPointerUp(PointerEventData eventData)
    {
        istouch = false;
        isDrag = false;
        moveVec = Vector2.zero;
        Controller.enabled = false;
        stick.enabled = false;
    }

    public void OnPointerDown(PointerEventData eventData)
    {
        RectTransformUtility.ScreenPointToLocalPointInRectangle(canvasRect, eventData.position, uiCamera, out saveVec);
        Controller.rectTransform.anchoredPosition = saveVec;
        stick.rectTransform.anchoredPosition = saveVec;
        istouch = true;
    }

    public static bool isTouchScreen()
    {
        return Instance.istouch;
    }

    public static void setCamera(Camera uicam)
    {
        Instance.uiCamera = uicam;
    }
}