using UnityEngine;
using UnityEngine.UI;

[ExecuteAlways]
public class CustomWrapGrid : LayoutGroup
{
    public float spacingX = 0f;
    public float spacingY = 0f;

    private float _containerWidth;
    private Vector2 _currentPos;
    // 新增变量记录总高度
    private float _totalHeight;
    protected override void OnEnable()
    {
        base.OnEnable();
        CalculateLayout();
    }

    public override void SetLayoutHorizontal()
    {
        CalculateLayout();
    }

    public override void SetLayoutVertical()
    {
        // 这里需要空实现，因为布局逻辑在SetLayoutHorizontal中完成
    }

    public override void CalculateLayoutInputVertical()
    {
        CalculateLayout(); 
        float minHeight = _totalHeight;
        SetLayoutInputForAxis(minHeight, minHeight, 0, 1); // 修正参数设置
    }

    void CalculateLayout()
    {
        _totalHeight = 0f; // 重置总高度
        if (rectChildren.Count == 0) return;

        _containerWidth = rectTransform.rect.width - padding.horizontal;
        _currentPos = new Vector2(padding.left, -padding.top);
        float rowHeight = 0f;
        foreach (RectTransform child in rectChildren)
        {
            // 跳过隐藏的对象
            if (!child.gameObject.activeSelf) continue;

            // 获取子物体尺寸
            float childWidth = LayoutUtility.GetPreferredWidth(child);
            float childHeight = LayoutUtility.GetPreferredHeight(child);

            // 换行判断
            if (_currentPos.x + childWidth > _containerWidth - padding.right)
            {
                StartNewRow(ref _currentPos, ref rowHeight);
            }

            // 设置子物体位置
            SetChildAlongAxis(child, 0, _currentPos.x, childWidth);
            SetChildAlongAxis(child, 1, _currentPos.y, childHeight);

            // 更新当前行状态
            _currentPos.x += childWidth + spacingX;
            rowHeight = Mathf.Max(rowHeight, childHeight);
        }
        // 最终加上最后一行高度
        _totalHeight = Mathf.Abs(_currentPos.y) + rowHeight - padding.top;
    }

    void StartNewRow(ref Vector2 pos, ref float rowHeight)
    {
        pos.x = padding.left;
        pos.y += rowHeight + spacingY;
        rowHeight = 0f;
    }

    // 当子物体变化时自动刷新
    protected override void OnRectTransformDimensionsChange()
    {
        base.OnRectTransformDimensionsChange();
        CalculateLayout();
    }

#if UNITY_EDITOR
    protected override void OnValidate()
    {
        base.OnValidate();
        CalculateLayout();
    }
#endif
}