// 
using System.Collections.Generic;
using EventCubeMelt;
using UnityEngine;
using UnityEngine.EventSystems;

namespace EventCubeMelt.UI
{
    public class UIDragManager : MonoBehaviour
    {
        public static UIDragManager Instance;
        
        [HideInInspector]
        public RectTransform dragContainer; // 用于存放正在拖拽的物体的容器
        
        private Dictionary<int, Queue<PieceRenderer>> _pools = new(); // 对象池
        
        private Canvas _rootCanvas; // 主Canvas，用于坐标计算
        private void Awake() 
        {
            if (!Instance) 
                Instance = this;

            _rootCanvas = GetComponentInParent<Canvas>();
            dragContainer = GetComponent<RectTransform>();
            InitializePools();
        }

        private void InitializePools() 
        {
            
        }
        // 
        #region LOG
        private static void ELog(string message)
        {
#if UNITY_EDITOR
            if (!EventCubeMeltLogPolicy.EnableELog) return;
            Debug.Log($"<color=orange> UIDragManager => {message} </color>");
#endif
        }
        #endregion
        // 创建可拖动Piece
        public PieceRenderer CreateDragPiece(GameObject go, PointerEventData eventData)
        {
            var newItem = Instantiate(go,transform);
            newItem.gameObject.name = "DragPiece";
            var pieceRender = newItem.GetComponent<PieceRenderer>();
            if (!pieceRender)
            {
                pieceRender = newItem.AddComponent<PieceRenderer>();
            }
            pieceRender.CopyData(go.GetComponent<PieceRenderer>());
            pieceRender.OffsetYWithDelta = pieceRender.OffsetY;
            UpdatePiecePos(eventData, pieceRender);
            pieceRender.transform.localScale = Vector3.one * pieceRender.ScaleFactor;
            pieceRender.gameObject.SetActive(true);

            return pieceRender;

        }

        public void UpdatePiecePos(PointerEventData eventData, PieceRenderer pieceRender,float diff = 0f)
        {
            var offset = pieceRender.OffsetYWithDelta + diff;
            var screenPosition = eventData.position;
            var scrPos = new Vector2(screenPosition.x, screenPosition.y + offset);
            
            ELog($"UpdatePiecePos ->{diff} {offset} ");
            // 设置初始位置（在手指下方一点，视觉效果更好）
            RectTransformUtility.ScreenPointToWorldPointInRectangle( dragContainer, scrPos, _rootCanvas.worldCamera, out var worldPos);
            pieceRender.transform.position = worldPos;
        }
    }
}