using Unity.VisualScripting;
using UnityEngine;
using UnityEngine.Events;
using UnityEngine.EventSystems;
using UnityEngine.UI;

/// <summary>
/// 移动摇杆类型
/// </summary>
public enum E_RockerType
{
    /// <summary>
    /// 固定
    /// </summary>
    Fixed,
    /// <summary>
    /// 跟随固定
    /// </summary>
    FollowFixed,
    /// <summary>
    /// 跟随
    /// </summary>
    Follow,
}

/// <summary>
/// 移动摇杆
/// </summary>
public class Rocker : MonoBehaviour, IPointerDownHandler, IPointerUpHandler, IDragHandler, IEndDragHandler
{
    /// <summary>
    /// 边界
    /// </summary>
    public float maxBoundary;

    /// <summary>
    /// 是否开始拖拽
    /// </summary>
    private bool isDrag;

    /// <summary>
    /// 摇杆底图
    /// </summary>
    public Image rockerBM;

    /// <summary>
    /// 事件触发区域
    /// </summary>
    public Image touchRect;

    /// <summary>
    /// 摇杆控制
    /// </summary>
    public Image control;

    /// <summary>
    /// 摇杆类型
    /// </summary>
    public E_RockerType e_RockerType;

    /// <summary>
    /// 方向监听
    /// </summary>
    public UnityAction<Vector2> dirListener;
    
    /// <summary>
    /// 抬起按下监听
    /// </summary>
    public UnityAction<bool> liftPressListener;

    /// <summary>
    /// 角度监听
    /// </summary>
    public UnityAction<float> angleListener;

    public void Start()
    {
        rockerBM.gameObject.SetActive(e_RockerType == E_RockerType.Fixed);
    }

    /// <summary>
    /// 是否拖拽
    /// </summary>
    /// <returns></returns>
    public bool GetIsDrag()
    {
        return isDrag;
    }

    /// <summary>
    /// 返回摇杆控制到中心点的模长
    /// </summary>
    /// <returns></returns>
    public Vector3 GetMagnitude()
    {
        return control.transform.position - rockerBM.transform.position;
    }

    public virtual void OnDrag(PointerEventData eventData)
    {
        isDrag = true;
        Vector2 localPos;
        Vector3 vector= this.transform.position + Vector3.one * maxBoundary - control.transform.position;
        RectTransformUtility.ScreenPointToLocalPointInRectangle(rockerBM.rectTransform, (eventData as PointerEventData).position, (eventData as PointerEventData).pressEventCamera, out localPos);

        if (localPos.magnitude > maxBoundary)
        {
            if (e_RockerType == E_RockerType.Follow)
            {
                rockerBM.transform.localPosition += (Vector3)localPos.normalized * (localPos.magnitude - maxBoundary);
            }
            control.transform.localPosition = localPos.normalized * maxBoundary;
        }
        else
        {
            control.transform.localPosition = localPos;
        }
        dirListener?.Invoke(localPos.normalized);

        float angel = Mathf.Atan2(localPos.x, localPos.y);
        angleListener?.Invoke(angel * Mathf.Rad2Deg);
    }

    public void OnEndDrag(PointerEventData eventData)
    {
        isDrag = false;
        control.rectTransform.anchoredPosition = Vector2.zero;
        dirListener?.Invoke(Vector2.zero);
    }

    public void OnPointerDown(PointerEventData eventData)
    {
        Vector2 localPos;
        liftPressListener?.Invoke(true);
        rockerBM.gameObject.SetActive(true);
        if (e_RockerType != E_RockerType.Fixed)
        {
            RectTransformUtility.ScreenPointToLocalPointInRectangle(touchRect.rectTransform, (eventData as PointerEventData).position, (eventData as PointerEventData).pressEventCamera, out localPos);
            rockerBM.transform.localPosition = localPos;
        }
    }

    public void OnPointerUp(PointerEventData eventData)
    {
        liftPressListener?.Invoke(false);
        if (e_RockerType != E_RockerType.Fixed)
        {
            rockerBM.gameObject.SetActive(false);
        }
    }
}