using UnityEngine;
using UnityEditor;
using System.IO;
using System.Linq;

public class SyncFBXMaterialToPrefab : Editor
{
    [MenuItem("Assets/材质工具/同步 FBX 材质到对应 Prefab", true)]
    static bool Validate()
    {
        return Selection.assetGUIDs.Any(guid => AssetDatabase.GUIDToAssetPath(guid).EndsWith(".fbx"));
    }

    [MenuItem("Assets/材质工具/同步 FBX 材质到对应 Prefab")]
    static void SyncMaterialsFromFBX()
    {
        foreach (string guid in Selection.assetGUIDs)
        {
            string fbxPath = AssetDatabase.GUIDToAssetPath(guid);
            if (!fbxPath.EndsWith(".fbx")) continue;

            GameObject fbxModel = AssetDatabase.LoadAssetAtPath<GameObject>(fbxPath);
            if (fbxModel == null) continue;

            string prefabPath = Path.ChangeExtension(fbxPath, ".prefab");

            prefabPath = prefabPath.Replace("Models", "Prefabs");
            
            GameObject prefab = AssetDatabase.LoadAssetAtPath<GameObject>(prefabPath);
            if (prefab == null)
            {
                Debug.LogWarning($"未找到对应的 prefab: {prefabPath}");
                continue;
            }

            // 获取 FBX 中当前 remap 的材质信息（用名字匹配 Renderer 路径）
            var fbxRenderers = fbxModel.GetComponentsInChildren<Renderer>(true);
            var fbxMatMap = fbxRenderers.ToDictionary(
                r => GetRelativePath(r.transform, fbxModel.transform),
                r => r.sharedMaterials
            );

            GameObject instance = (GameObject)PrefabUtility.InstantiatePrefab(prefab);
            bool hasChanged = false;

            foreach (var renderer in instance.GetComponentsInChildren<Renderer>(true))
            {
                string path = GetRelativePath(renderer.transform, instance.transform);
                if (fbxMatMap.TryGetValue(path, out var remappedMats))
                {
                    renderer.sharedMaterials = remappedMats;
                    hasChanged = true;
                    Debug.Log($"✔ 替换 Renderer 材质: {path}");
                }
            }

            if (hasChanged)
            {
                PrefabUtility.SaveAsPrefabAsset(instance, prefabPath);
                Debug.Log($"✅ 已同步材质到 Prefab: {prefabPath}");
            }

            Object.DestroyImmediate(instance);
        }

        AssetDatabase.SaveAssets();
        AssetDatabase.Refresh();
    }

    static string GetRelativePath(Transform current, Transform root)
    {
        if (current == root) return current.name;
        return GetRelativePath(current.parent, root) + "/" + current.name;
    }
}