using UnityEngine;

namespace AlicizaX.UI.RecyclerView
{
    public class AlignableLinearLayoutManager : LinearLayoutManager
    {
        [SerializeField] private float alignmentRatio = 0f; // 对齐比例 (0=顶部, 1=底部, 0.5=居中)


        private float CalculateAlignmentOffset()
        {
            if (direction == Direction.Vertical)
            {
                // 垂直布局：计算视口高度相关的偏移
                float viewportHeight = viewportSize.y;
                float itemHeight = lineHeight;
                return alignmentRatio * (viewportHeight - itemHeight);
            }
            else
            {
                // 水平布局：计算视口宽度相关的偏移
                float viewportWidth = viewportSize.x;
                float itemWidth = lineHeight; // 注意：水平布局中lineHeight表示宽度
                return alignmentRatio * (viewportWidth - itemWidth);
            }
        }

        public override Vector2 CalculatePosition(int index)
        {
            float position;
            float alignmentOffset = CalculateAlignmentOffset();

            if (direction == Direction.Vertical)
            {
                position = index * (lineHeight + spacing.y) - ScrollPosition + alignmentOffset;
                return new Vector2(0, position + padding.y);
            }

            position = index * (lineHeight + spacing.x) - ScrollPosition + alignmentOffset;
            var a = new Vector2(position + padding.x, 0);
            Debug.Log("Calcu" + a);
            return a;
        }

        public override float IndexToPosition(int index)
        {
            if (index < 0 || index >= adapter.GetItemCount()) return 0;

            float len, viewLength, position;
            float alignmentOffset = CalculateAlignmentOffset();

            if (direction == Direction.Vertical)
            {
                len = index * (lineHeight + spacing.y) + alignmentOffset - ((lineHeight + spacing.y) * 2);
                viewLength = viewportSize.y;
                position = len + viewLength > contentSize.y ? contentSize.y - viewportSize.y : len;
            }
            else
            {
                len = index * (lineHeight + spacing.x) + alignmentOffset;
                viewLength = viewportSize.x;
                position = len + viewLength > contentSize.x ? contentSize.x - viewportSize.x : len;
            }



            Debug.Log($"index:{index} len:{len} view:{viewLength} position:{position}");
            return position;
        }
    }
}