using GCGame;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.EventSystems;
// 注：JoyStickLogic运动范围由JoyStickRoot决定
// 默认JoyStickRoot左下角 = 屏幕（0,0）位置，如有修改，给ScenePointToRootOffset函数加上对应偏移
public class JoyStickLogic : MonoBehaviour, IDragHandler, IPointerDownHandler, IPointerUpHandler
{
    private const float _idleAlpha = 0.7f;
    private const float _activeAlpha = 1f;

    public int? CurrentPointerId { get; private set; }

    // 摇杆输入
    public Vector2? input { get; private set; }
    private RectTransform _rectTransform;
    // 自适应位置范围
    private RectTransform _flexibleArea;
    // 可移动部分根节点
    private Image _background;
    // 方向箭头
    private Image _arrow;
    // 方向球
    private Image _joyStick;
    // 摇杆左下角位置偏移
    private Vector2 _anchorPos;
    // 摇杆可运动区域最小xy，最大xy
    private Vector4 _joyStickArea;
    // 摇杆原始位置
    private Vector2 _originPos;
    private float _joyStickRadius;
    
    private void Awake()
    {
        _rectTransform = (RectTransform)transform;
        _flexibleArea = (RectTransform)_rectTransform.Find("FlexibleArea");
        _background = _rectTransform.Find("BackGround").GetComponent<Image>();
        _joyStick = _background.transform.Find("JoyStickSprite").GetComponent<Image>();
        _arrow =  _background.transform.Find("Arrow").GetComponent<Image>();
        _originPos = _background.rectTransform.anchoredPosition;
        _anchorPos = _rectTransform.anchoredPosition;
    }
    
    // Use this for initialization
    private void Start()
    {
        SetPressed(false);
        SetMoving(false);
        var flexibleRect = _flexibleArea.rect;
        var joyStickRect = _background.rectTransform.rect;
        _joyStickArea = new Vector4(joyStickRect.size.x * 0.5f,
            joyStickRect.size.y * 0.5f,
            flexibleRect.size.x - joyStickRect.size.x * 0.5f,
            flexibleRect.size.y - joyStickRect.size.y * 0.5f);
        if (_joyStickArea.x > _joyStickArea.z)
            _joyStickArea.z = _joyStickArea.x;
        if (_joyStickArea.y > _joyStickArea.w)
            _joyStickArea.w = _joyStickArea.y;
        _joyStickRadius = _background.rectTransform.rect.width * 0.5f - _joyStick.rectTransform.rect.width * 0.5f;
    }

    public void OnPointerDown(PointerEventData eventData)
    {
        if (PlayerPreferenceData.SystemUseJoyStick && CurrentPointerId == null && ProcessInput.Instance != null && !ProcessInput.Instance.isBlocked)
        {
            CurrentPointerId = eventData.pointerId;
            SetPressed(true);
            var uiPos = UIManager.Instance().ScreenPointToUiPoint(eventData.position, false) - _anchorPos;
            uiPos.x = Mathf.Clamp(uiPos.x, _joyStickArea.x, _joyStickArea.z);
            uiPos.y = Mathf.Clamp(uiPos.y, _joyStickArea.y, _joyStickArea.w);
            _background.rectTransform.anchoredPosition = uiPos;
        }
    }
//
//    public void OnBeginDrag(PointerEventData eventData)
//    {
//        if (CurrentPointerId == eventData.pointerId)
//            SetMoving(true);
//    }

    public void OnDrag(PointerEventData eventData)
    {
        if (PlayerPreferenceData.SystemUseJoyStick && CurrentPointerId == eventData.pointerId)
        {
            var uiPos = UIManager.Instance().ScreenPointToUiPoint(eventData.position, false) - _anchorPos;
            var delta = uiPos - _background.rectTransform.anchoredPosition;
            if (delta == Vector2.zero)
            {
                input = Vector2.zero;
                SetMoving(false);
            }
            else
            {
                input = delta.normalized;
                var magnitude = delta.magnitude;
                delta = input.Value * Mathf.Min(magnitude, _joyStickRadius);
                SetMoving(true);
                // 注：箭头图标原始方向是向右的
                _arrow.rectTransform.localRotation = Quaternion.FromToRotation(Vector3.right, (Vector3)input.Value);
            }
            _joyStick.rectTransform.anchoredPosition = delta;
        }
    }
    
    public void OnPointerUp(PointerEventData eventData)
    {
        if (CurrentPointerId == eventData.pointerId)
            ReleaseJoyStick();
    }
    
//
//    //private void OnEnable()
//    //{
//    //    GameManager.AddLateUpdate(UpdateJoyStick, GameManager.joyStickUpdateOrder);
//    //}
//
//    //private void OnDisable()
//    //{
//    //    GameManager.RemoveLateUpdate(UpdateJoyStick, GameManager.joyStickUpdateOrder);
//    //}
//    
//    /// <summary>
//    /// 发送摇杆状态
//    /// </summary>
//    private void SendMoveDirection()
//    {
//        CurrentInput = mRect_JoySticSprite.anchoredPosition;
//        if (CurrentInput != Vector2.zero)
//            CurrentInput = CurrentInput.normalized;
//    }
//    private Vector2 ScenePointToRootOffset(Vector2 screenPoint)
//    {
//        // 按照100单位比，JoyStickRoot左下角 = 屏幕（0,0）位置；
//        // 如果有特殊Ui尺寸或者其他修改，需要额外处理；
//        return UIManager.Instance().ScreenPointToUiPoint(screenPoint, false);
//    }

    public void CloseWindow()
    {
        ReleaseJoyStick();
        gameObject.SetActive(false);
    }

    public void OpenWindow()
    {
        gameObject.SetActive(true);
    }

    public void ReleaseJoyStick()
    {
        input = null;
        CurrentPointerId = null;
        SetPressed(false);
        SetMoving(false);
        _background.rectTransform.anchoredPosition = _originPos;
        _joyStick.rectTransform.anchoredPosition = Vector2.zero;
    }

    private void SetPressed(bool isActive)
    {
        SetImageAlpah(_background, isActive);
        SetImageAlpah(_joyStick, isActive);
    }

    private void SetMoving(bool isMoving)
    {
        _arrow.gameObject.SetActive(isMoving);
    }
    
    private static void SetImageAlpah(Graphic image, bool isActive)
    {
        var color = image.color;
        color.a = isActive ? _activeAlpha : _idleAlpha;
        image.color = color;
    }
//
//    public bool IsInBackClick(Vector3 clickPoint)
//    {
//        var pointVec = Utils.PositionToRectLocal(mRect_backClick, clickPoint);
//        return mRect_backClick.rect.Contains(pointVec);
//    }
//
//    public void OnPointerDown(Vector2 point)
//    {
//        if (!IsCloseWindow)
//        {
//            IsActive = true;
//            // 拖动时重设精灵透明度
//            SetImageAlpah(m_JoyStickSprite, 1);
//            SetImageAlpah(m_BackGround2, 1);
//            mRect_JoySticSpriteArrow.gameObject.SetActive(true);
//            OnDrag(point);
//        }
//    }
//
//    public void ArrowDirect()
//    {
//        Vector3 localPos = mRect_JoySticSpriteParent.InverseTransformPoint(mRect_JoySticSprite.position);
//        float angle = Vector3.Angle(localPos, new Vector3(1, 0, 0));
//        int dir = localPos.y < 0 ? -1 : 1;
//        mRect_JoySticSpriteArrow.localEulerAngles = new Vector3(0, 0, angle * dir);
//    }
//
//    public void OnDrag(Vector2 point)
//    {
//        if (!IsCloseWindow)
//        {
//            var newPos = ScenePointToRootOffset(point);
//            // 小球尚未超出偏移范围时
//            if ((newPos - mRect_JoySticSpriteParent.anchoredPosition).magnitude < _parentRadius)
//                mRect_JoySticSprite.anchoredPosition = newPos - mRect_JoySticSpriteParent.anchoredPosition;
//            // 小球超出偏移范围，需要移动外圈时
//            else
//            {
//                // 算法比较麻烦 - 先用小球移动外圈的位置，然后用外圈和偏移值确定小球位置
//                var offset = newPos - mRect_JoySticSpriteParent.anchoredPosition;
//                // 圈内预期偏移数值
//                var offsetInCircle = offset.normalized * _parentRadius;
//                // 外圈预期位置，然后用边界进行校正
//                var newParentPos = newPos - offsetInCircle;
//                newParentPos = GetSpritePosInBoundary(_parentRadius, newParentPos);
//                mRect_JoySticSpriteParent.anchoredPosition = newParentPos;
//                // 重新对齐小球位置
//                mRect_JoySticSprite.anchoredPosition = offsetInCircle;
//            }
//            ArrowDirect();
//        }
//    }
//    
//    public void OnPointerUp()
//    {
//        // 恢复摇杆精灵透明度
//        ReleaseJoyStick();
//    }
//    
//    /// <summary>
//    /// 在满足边界范围的情况下，移动目标RectTransform
//    /// </summary>
//    /// <param name="radius">目标半径</param>
//    /// <param name="anchoredPosition">目标预期位置</param>
//    /// <returns></returns>
//    private Vector2 GetSpritePosInBoundary(float radius, Vector2 anchoredPosition)
//    {
//        var maxPos = _rectTransform.rect.size - Vector2.one * radius;
//        var minPos = Vector2.one * radius;
//        anchoredPosition.x = Mathf.Clamp(anchoredPosition.x, minPos.x, maxPos.x);
//        anchoredPosition.y = Mathf.Clamp(anchoredPosition.y, minPos.y, maxPos.y);
//        return anchoredPosition;
//    }
//
//    private void UpdateJoyStick()
//    {
//        if (IsActive)
//            SendMoveDirection();
//        else
//            CurrentInput = Vector2.zero;
//    }
}