using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;

namespace BF
{
    public class CellObj
    {
        public GameObject gameObject;
        public int index; //从0开始 实际index
        public int objectIndex; //从0开始 cell递增 cell唯一索引
    }

    public class ScrollRectCenter : ScrollRect
    {
        protected override void Awake()
        {
            content.localPosition = Vector3.zero;
            content.pivot = horizontal ? new Vector2(0, 0.5f) : new Vector2(0.5f, 1);
        }

        private ScrollRectCenterController cachescrollRectCenterController;
        public ScrollRectCenterController scrollRectCenterController
        {
            get
            {
                if (null == cachescrollRectCenterController)
                {
                    cachescrollRectCenterController = GetComponent<ScrollRectCenterController>();
                }
                return cachescrollRectCenterController;
            }
        }
        private Vector3 currentVelocity = Vector3.zero;

        protected override void LateUpdate()
        {
            if (!content)
                return;

            if (scrollRectCenterController.moveToImmediately)
            {
                if (vertical)
                {
                    Vector3 vector3Tager = new Vector3(content.localPosition.x, scrollRectCenterController.targetPosition, content.localPosition.z);
                    content.localPosition = vector3Tager;
                }
                else if (horizontal)
                {
                    Vector3 vector3Tager = new Vector3(scrollRectCenterController.targetPosition, content.localPosition.y, content.localPosition.z);
                    content.localPosition = vector3Tager;
                }
                scrollRectCenterController.moveToImmediately = false;
                if (vertical)
                {
                    OnUpdatePositionVer();
                }
                else if (horizontal)
                {
                    OnUpdatePositionHor();
                }
            }

            //更新cell size
            if (vertical)
            {
                if (Mathf.Abs(content.localPosition.y - scrollRectCenterController.targetPosition) > 1)
                {
                    OnUpdatePositionVer();
                }
                else
                {
                    return;
                }
            }
            else if (horizontal)
            {
                if (Mathf.Abs(content.localPosition.x - scrollRectCenterController.targetPosition) > 1)
                {
                    OnUpdatePositionHor();
                }
                else
                {
                    return;
                }
            }

            // 非drag时 平滑移动至中心点
            if (!scrollRectCenterController.isDrag)
            {
                if (vertical)
                {
                    Vector3 vector3Tager = new Vector3(content.localPosition.x, scrollRectCenterController.targetPosition, content.localPosition.z);
                    content.localPosition = Vector3.SmoothDamp(content.localPosition, vector3Tager,
                        ref currentVelocity, 0.05f, Mathf.Infinity, Time.unscaledDeltaTime);
                }
                else if (horizontal)
                {
                    Vector3 vector3Tager = new Vector3(scrollRectCenterController.targetPosition, content.localPosition.y, content.localPosition.z);
                    content.localPosition = Vector3.SmoothDamp(content.localPosition, vector3Tager,
                        ref currentVelocity, 0.05f, Mathf.Infinity, Time.unscaledDeltaTime);
                }
            }
        }

        private void OnUpdatePositionHor()
        {
            scrollRectCenterController.OnUpdatePositionHor();
        }

        private void OnUpdatePositionVer()
        {
            scrollRectCenterController.OnUpdatePositionVer();
        }
    }
}