using System.Collections;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

namespace Superlazy.UI
{
    public class SLUIScrollRectRefresh : SLUIComponent
    {
        public float delay = 0.5f;
        public bool toTop = false; // 켰으면 반대방향

        private ScrollRect scrollRect;
        private RectTransform container;

        private float lastSize;
        private Coroutine autoScrollCoroutine;

        protected override void Validate()
        {
            scrollRect = gameObject.GetComponent<ScrollRect>();
        }

        protected override void Init()
        {
            container = scrollRect.content;
        }

        protected override void Enable()
        {
            if (scrollRect.horizontal)
            {
                lastSize = container.rect.width;
            }
            else
            {
                lastSize = container.rect.height;
            }
        }

        protected override void Disable()
        {
            if (autoScrollCoroutine != null)
            {
                StopCoroutine(autoScrollCoroutine);
                autoScrollCoroutine = null;
            }
        }

        private void LateUpdate()
        {
            var currentSize = scrollRect.horizontal ? container.rect.width : container.rect.height;

            if (Mathf.Abs(currentSize - lastSize) > 0.1f)
            {
                lastSize = currentSize;

                if (autoScrollCoroutine != null)
                {
                    StopCoroutine(autoScrollCoroutine);
                }
                autoScrollCoroutine = StartCoroutine(AutoScroll());
            }
        }

        private IEnumerator AutoScroll()
        {
            var elapsed = 0f;
            // 현재 스크롤 위치 (verticalNormalizedPosition: 1은 상단, 0은 하단)
            var startPosition = scrollRect.horizontal ? scrollRect.horizontalNormalizedPosition : scrollRect.verticalNormalizedPosition;
            // 목표 위치: 최신 항목이 보이도록 스크롤의 하단 (0)
            var targetPosition = toTop ? 1f : 0f;

            while (elapsed < delay)
            {
                elapsed += Time.deltaTime;
                float t = elapsed / delay;
                // EaseOutCubic easing 함수 적용 (부드럽고 자연스러운 감속)
                t = EaseOutCubic(t);
                // 현재 위치에서 목표 위치로 보간

                var newPosition = Mathf.Lerp(startPosition, targetPosition, t);
                if (scrollRect.horizontal)
                {
                    scrollRect.horizontalNormalizedPosition = newPosition;
                }
                else
                {
                    scrollRect.verticalNormalizedPosition = newPosition;
                }

                yield return null;
            }

            if (scrollRect.horizontal)
            {
                scrollRect.horizontalNormalizedPosition = targetPosition;
            }
            else
            {
                scrollRect.verticalNormalizedPosition = targetPosition;
            }
            autoScrollCoroutine = null;
        }

        private float EaseOutCubic(float t)
        {
            return 1f - Mathf.Pow(1f - t, 3f);
        }
    }
}