namespace Runtime
{
    // ImageHierarchyBlender.cs
using UnityEngine;
using UnityEngine.UI;
using System.Collections.Generic;
using System.IO;

public class ImageHierarchyBlender : MonoBehaviour
{
    public RectTransform parentContainer; // 父级容器
    public Shader blendShader;           // 混合Shader
    public string fileName = "BlendedResult";

    // 混合模式枚举
    public enum BlendMode { AlphaBlend, Multiply, Screen }
    public BlendMode blendMode = BlendMode.AlphaBlend;

    [ContextMenu("Export Blended Image")]
    public void ExportBlendedImage()
    {
        // 获取所有图形组件
        List<Graphic> graphics = GetAllGraphics(parentContainer.gameObject);
        
        // 创建RenderTexture
        Vector2Int size = GetTotalSize(parentContainer);
        RenderTexture rt = new RenderTexture(size.x, size.y, 0);
        
        // 初始化画布
        Texture2D finalTexture = InitializeCanvas(size);
        Graphics.Blit(finalTexture, rt);

        // 混合所有层
        foreach (Graphic graphic in graphics)
        {
            if (!graphic.gameObject.activeInHierarchy) continue;
            
            // 获取元素信息
            Texture2D elementTex = CaptureGraphic(graphic);
            Vector2 position = GetRelativePosition(graphic.rectTransform, parentContainer);
            
            // 混合到画布
            BlendLayer(ref finalTexture, elementTex, position, rt);
            DestroyImmediate(elementTex);
        }

        // 保存结果
        SaveTexture(finalTexture);
        
        // 清理资源
        RenderTexture.active = null;
        DestroyImmediate(rt);
        DestroyImmediate(finalTexture);
    }

    // 获取所有子物体的Graphic组件（递归）
    List<Graphic> GetAllGraphics(GameObject parent)
    {
        List<Graphic> graphics = new List<Graphic>();
        Graphic parentGraphic = parent.GetComponent<Graphic>();
        if (parentGraphic != null) graphics.Add(parentGraphic);
        
        foreach (Transform child in parent.transform)
        {
            graphics.AddRange(GetAllGraphics(child.gameObject));
        }
        return graphics;
    }

    // 计算容器总尺寸
    Vector2Int GetTotalSize(RectTransform rectTransform)
    {
        return new Vector2Int(
            Mathf.RoundToInt(rectTransform.rect.width),
            Mathf.RoundToInt(rectTransform.rect.height)
        );
    }

    // 初始化画布
    Texture2D InitializeCanvas(Vector2Int size)
    {
        Texture2D tex = new Texture2D(size.x, size.y, TextureFormat.ARGB32, false);
        Color[] pixels = new Color[size.x * size.y];
        for (int i = 0; i < pixels.Length; i++) pixels[i] = Color.clear;
        tex.SetPixels(pixels);
        tex.Apply();
        return tex;
    }

    // 捕获单个图形元素
    Texture2D CaptureGraphic(Graphic graphic)
    {
        // 创建临时RenderTexture
        RenderTexture rt = new RenderTexture(
            (int)graphic.rectTransform.rect.width,
            (int)graphic.rectTransform.rect.height, 0
        );
        
        // 渲染元素
        graphic.material = null; // 重置材质
        GraphicCapture(graphic, rt);
        
        // 转换为Texture2D
        Texture2D tex = new Texture2D(rt.width, rt.height, TextureFormat.ARGB32, false);
        RenderTexture.active = rt;
        tex.ReadPixels(new Rect(0, 0, rt.width, rt.height), 0, 0);
        tex.Apply();
        RenderTexture.active = null;
        DestroyImmediate(rt);
        return tex;
    }

    // 渲染单个图形到RenderTexture
    void GraphicCapture(Graphic graphic, RenderTexture rt)
    {
        Material material = new Material(blendShader);
        material.mainTexture = graphic.mainTexture;
        material.color = graphic.color;
        
        Graphics.SetRenderTarget(rt);
        GL.PushMatrix();
        GL.LoadOrtho();
        material.SetPass(0);
        
        GL.Begin(GL.QUADS);
        GL.TexCoord2(0, 0); GL.Vertex3(0, 0, 0);
        GL.TexCoord2(1, 0); GL.Vertex3(1, 0, 0);
        GL.TexCoord2(1, 1); GL.Vertex3(1, 1, 0);
        GL.TexCoord2(0, 1); GL.Vertex3(0, 1, 0);
        GL.End();
        
        GL.PopMatrix();
    }

    // 获取相对位置
    Vector2 GetRelativePosition(RectTransform child, RectTransform parent)
    {
        Vector2 localPosition = child.anchoredPosition;
        
        // 处理锚点差异
        Vector2 parentPivot = parent.pivot;
        Vector2 childAnchorMin = child.anchorMin;
        Vector2 parentSize = parent.rect.size;
        
        return new Vector2(
            localPosition.x + (childAnchorMin.x - parentPivot.x) * parentSize.x,
            localPosition.y + (childAnchorMin.y - parentPivot.y) * parentSize.y
        );
    }

    // 混合单层
    void BlendLayer(ref Texture2D baseTex, Texture2D blendTex, Vector2 position, RenderTexture rt)
    {
        Material blendMaterial = new Material(blendShader);
        blendMaterial.SetTexture("_BlendTex", blendTex);
        blendMaterial.SetVector("_Position", position);
        blendMaterial.SetFloat("_BlendMode", (float)blendMode);

        Graphics.Blit(baseTex, rt, blendMaterial);
        RenderTexture.active = rt;
        baseTex.ReadPixels(new Rect(0, 0, rt.width, rt.height), 0, 0);
        baseTex.Apply();
    }

    // 保存为PNG
    void SaveTexture(Texture2D tex)
    {
        byte[] bytes = tex.EncodeToPNG();
        string path = Path.Combine(Application.streamingAssetsPath, "Exports", fileName + ".png");
        Directory.CreateDirectory(Path.GetDirectoryName(path));
        File.WriteAllBytes(path, bytes);
        Debug.Log($"Saved to: {path}");
    }
}
}