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

public class CardCarousel : MonoBehaviour
{
    [Header("垂直布局设置")] public float startOffset = -1; // 起始Y位置（顶部）
    public float endOffset = 1; // 结束Y位置（底部）
    public float cardSpacing = 100; // 卡片垂直间距

    [Header("运动控制")] public float slideSpeed = 100f; // 垂直移动速度
    public bool slideDownward = false; // 向下滑动为true，向上滑动为false
    public bool isPlaying = true;

    private List<RectTransform> imageList;

    private void Start()
    {
        InitializeCarousel();
    }

    private void InitializeCarousel()
    {
        imageList = new List<RectTransform>();
        float currentYPosition = startOffset; // 从顶部开始

        foreach (RectTransform child in transform)
        {
            imageList.Add(child);
            // 设置垂直位置（X保持为0）
            child.anchoredPosition = new Vector2(0f, currentYPosition);
            currentYPosition -= cardSpacing; // 向下排列，所以减去间距
        }

        Debug.Log($"初始化了 {imageList.Count} 个卡片，起始Y: {startOffset}, 间距: {cardSpacing}");
    }

    private void Update()
    {
        if (!isPlaying || imageList.Count == 0) return;

        // 计算垂直移动量
        float verticalDirection = slideDownward ? -1f : 1f;
        float deltaY = verticalDirection * slideSpeed * Time.deltaTime;

        foreach (var image in imageList)
        {
            // 垂直移动
            image.anchoredPosition += new Vector2(0f, deltaY);

            // 检查是否需要回收
            if (slideDownward)
            {
                // 向下滑动：卡片移动到endOffset(底部)以下时，回收到顶部
                if (image.anchoredPosition.y < endOffset)
                {
                    // 找到当前最高的卡片
                    float highestY = GetHighestCardPosition();
                    image.anchoredPosition = new Vector2(0f, highestY + cardSpacing);
                }
            }
            else
            {
                // 向上滑动：卡片移动到startOffset(顶部)以上时，回收到底部
                if (image.anchoredPosition.y > startOffset)
                {
                    // 找到当前最低的卡片
                    float lowestY = GetLowestCardPosition();
                    image.anchoredPosition = new Vector2(0f, lowestY - cardSpacing);
                }
            }
        }
    }

    /// <summary>
    /// 获取当前最高卡片的位置（最大的Y值）
    /// </summary>
    private float GetHighestCardPosition()
    {
        if (imageList.Count == 0) return startOffset;

        float highestY = imageList[0].anchoredPosition.y;
        foreach (var card in imageList)
        {
            if (card.anchoredPosition.y > highestY)
            {
                highestY = card.anchoredPosition.y;
            }
        }

        return highestY;
    }

    /// <summary>
    /// 获取当前最低卡片的位置（最小的Y值）
    /// </summary>
    private float GetLowestCardPosition()
    {
        if (imageList.Count == 0) return endOffset;

        float lowestY = imageList[0].anchoredPosition.y;
        foreach (var card in imageList)
        {
            if (card.anchoredPosition.y < lowestY)
            {
                lowestY = card.anchoredPosition.y;
            }
        }

        return lowestY;
    }

    /// <summary>
    /// 添加新卡片到轮播
    /// </summary>
    public void AddCard(RectTransform newCard)
    {
        if (newCard == null) return;

        newCard.SetParent(transform);
        newCard.localScale = Vector3.one;

        // 获取当前最高卡片位置，新卡片放在它下面
        float highestY = GetHighestCardPosition();
        newCard.anchoredPosition = new Vector2(0f, highestY - cardSpacing);
        imageList.Add(newCard);
    }

    /// <summary>
    /// 设置播放状态
    /// </summary>
    public void SetPlaying(bool playing)
    {
        isPlaying = playing;
    }

    /// <summary>
    /// 设置滑动方向（true=向下，false=向上）
    /// </summary>
    public void SetDirection(bool downward)
    {
        slideDownward = downward;
    }

    /// <summary>
    /// 切换滑动方向
    /// </summary>
    public void ToggleDirection()
    {
        slideDownward = !slideDownward;
        Debug.Log($"滑动方向切换为: {(slideDownward ? "向下" : "向上")}");
    }

    /// <summary>
    /// 获取所有卡片位置信息（用于调试）
    /// </summary>
    public void DebugCardPositions()
    {
        for (int i = 0; i < imageList.Count; i++)
        {
            Debug.Log($"卡片 {i}: Y位置 = {imageList[i].anchoredPosition.y}");
        }
    }
}