using System.Collections.Generic;
using Performance.Data;
using UnityEditor;
using UnityEngine;
namespace Performance
{
    public class AutoObjCombine
    {
        
        private GameObject _rootObj;
        
        private Dictionary<Shader, ShaderGroupCombiner> _shaderCombinerDic = new Dictionary<Shader, ShaderGroupCombiner>();
        private string _savePath;
        private string _objName;
        
        public AutoObjCombine(GameObject rootObj)
        {
            _rootObj = rootObj;
            _objName = _rootObj.name;
        }

        public void DoCombine(string savePath)
        {
            _savePath = savePath;
            _ProtectPath();
            _CollectAllRenderers();
            _CombineToNewObj();
        }

        private void _ProtectPath()
        {
            if (!_savePath.EndsWith("/"))
            {
                _savePath += "/";
            }
            _savePath += _rootObj.name + "_Combined";
            AssetDatabase.DeleteAsset(_savePath);
        }

        private void _CombineToNewObj()
        {
            var newObj = Object.Instantiate(_rootObj);

            // 删除所有meshrenderderers和meshfilters
            var allMeshRenderers = newObj.GetComponentsInChildren<MeshRenderer>();
            var allMeshFilters = newObj.GetComponentsInChildren<MeshFilter>();
            for (int i = 0; i < allMeshRenderers.Length; i++)
            {
                Object.DestroyImmediate(allMeshRenderers[i]);
            }
            for (int i = 0; i < allMeshFilters.Length; i++)
            {
                Object.DestroyImmediate(allMeshFilters[i]);
            }
            
            foreach (var kvp in _shaderCombinerDic)
            {
                var combineObj = kvp.Value.CombineToSingleObject(_savePath, new List<Material>());
                if (combineObj == null)
                {
                    DebugUtil.LogError("合并对象失败, 可能是没有找到 MeshFilter 或 MeshRenderer");
                    continue;
                }
                combineObj.transform.SetParent(newObj.transform);
            }

            // 确保_savePath存在, 是从Assets目录开始的
            if (!AssetDatabase.IsValidFolder(_savePath))
            {
                var realPath = Application.dataPath + "/" + _savePath.Replace("Assets/", "");
                System.IO.Directory.CreateDirectory(realPath);
            }
            
            // 把newObj保存到指定路径
            var prefabPath = _savePath + "/" + _objName + ".prefab";
            PrefabUtility.SaveAsPrefabAsset(newObj, prefabPath);
            
            // 清理新创建的 GameObject
            Object.DestroyImmediate(newObj);
            AssetDatabase.Refresh();
        }

        private void _CollectAllRenderers()
        {
            var allMeshRenderers = _rootObj.GetComponentsInChildren<MeshRenderer>();
            for (int i = 0; i < allMeshRenderers.Length; i++)
            {
                var meshRenderer = allMeshRenderers[i];
                if (meshRenderer == null || meshRenderer.sharedMaterial == null)
                {
                    continue;
                }
                var shader = meshRenderer.sharedMaterial.shader;
                if (!_shaderCombinerDic.TryGetValue(shader, out var combiner))
                {
                    combiner = new ShaderGroupCombiner(shader);
                    _shaderCombinerDic[shader] = combiner;
                }
                combiner.AddRenderer(meshRenderer);
            }
            
            DebugUtil.Log($"共收集到 {allMeshRenderers.Length} 个 MeshRenderer, 分别属于 {_shaderCombinerDic.Count} 个 Shader");
        }
        
    }
}