//using System;
//using System.Collections.Generic;
//using System.IO;
//using UnityEditor;

//namespace UnityGuidRegenerator
//{
//    public class UnityGuidRegeneratorMenu
//    {
//        [MenuItem("Tools/Regenerate asset GUIDs")]
//        public static void RegenerateGuids()
//        {
//            if (EditorUtility.DisplayDialog("GUIDs regeneration",
//                "You are going to start the process of GUID regeneration. This may have unexpected results. \n\n MAKE A PROJECT BACKUP BEFORE PROCEEDING!",
//                "Regenerate GUIDs", "Cancel"))
//            {
//                try
//                {
//                    AssetDatabase.StartAssetEditing();

//                    string path = Path.GetFullPath(".") + Path.DirectorySeparatorChar + "Assets";//要更新guid的文件夹
//                    UnityGuidRegenerator regenerator = new UnityGuidRegenerator(path);
//                    regenerator.RegenerateGuids();
//                }
//                finally
//                {
//                    AssetDatabase.StopAssetEditing();
//                    EditorUtility.ClearProgressBar();
//                    AssetDatabase.Refresh();
//                }
//            }
//        }
//    }

//    internal class UnityGuidRegenerator
//    {
//        private static readonly string[] kDefaultFileExtensions = {
//            // "*.meta",
//            // "*.mat",
//            // "*.anim",
//            // "*.prefab",
//            // "*.unity",
//            // "*.asset"
//            "*.*"
//        };

//        private readonly string _assetsPath;

//        public UnityGuidRegenerator(string assetsPath)
//        {
//            _assetsPath = assetsPath;
//        }

//        public void RegenerateGuids(string[] regeneratedExtensions = null)
//        {
//            if (regeneratedExtensions == null)
//            {
//                regeneratedExtensions = kDefaultFileExtensions;
//            }

//            // Get list of working files
//            List<string> filesPaths = new List<string>();
//            foreach (string extension in regeneratedExtensions)
//            {
//                filesPaths.AddRange(
//                    Directory.GetFiles(_assetsPath, extension, SearchOption.AllDirectories)
//                    );
//            }

//            // Create dictionary to hold old-to-new GUID map
//            Dictionary<string, string> guidOldToNewMap = new Dictionary<string, string>();
//            Dictionary<string, List<string>> guidsInFileMap = new Dictionary<string, List<string>>();

//            // We must only replace GUIDs for Resources present in Assets. 
//            // Otherwise built-in resources (shader, meshes etc) get overwritten.
//            HashSet<string> ownGuids = new HashSet<string>();

//            // Traverse all files, remember which GUIDs are in which files and generate new GUIDs
//            int counter = 0;
//            foreach (string filePath in filesPaths)
//            {
//                EditorUtility.DisplayProgressBar("Scanning Assets folder", MakeRelativePath(_assetsPath, filePath), counter / (float)filesPaths.Count);
//                string contents = File.ReadAllText(filePath);

//                IEnumerable<string> guids = GetGuids(contents);
//                bool isFirstGuid = true;
//                foreach (string oldGuid in guids)
//                {
//                    // First GUID in .meta file is always the GUID of the asset itself
//                    if (isFirstGuid && Path.GetExtension(filePath) == ".meta")
//                    {
//                        ownGuids.Add(oldGuid);
//                        isFirstGuid = false;
//                    }
//                    // Generate and save new GUID if we haven't added it before
//                    if (!guidOldToNewMap.ContainsKey(oldGuid))
//                    {
//                        string newGuid = Guid.NewGuid().ToString("N");
//                        guidOldToNewMap.Add(oldGuid, newGuid);
//                    }

//                    if (!guidsInFileMap.ContainsKey(filePath))
//                        guidsInFileMap[filePath] = new List<string>();

//                    if (!guidsInFileMap[filePath].Contains(oldGuid))
//                    {
//                        guidsInFileMap[filePath].Add(oldGuid);
//                    }
//                }

//                counter++;
//            }

//            // Traverse the files again and replace the old GUIDs
//            counter = -1;
//            int guidsInFileMapKeysCount = guidsInFileMap.Keys.Count;
//            foreach (string filePath in guidsInFileMap.Keys)
//            {
//                EditorUtility.DisplayProgressBar("Regenerating GUIDs", MakeRelativePath(_assetsPath, filePath), counter / (float)guidsInFileMapKeysCount);
//                counter++;

//                string contents = File.ReadAllText(filePath);
//                foreach (string oldGuid in guidsInFileMap[filePath])
//                {
//                    if (!ownGuids.Contains(oldGuid))
//                        continue;

//                    string newGuid = guidOldToNewMap[oldGuid];
//                    if (string.IsNullOrEmpty(newGuid))
//                        throw new NullReferenceException("newGuid == null");

//                    contents = contents.Replace("guid: " + oldGuid, "guid: " + newGuid);
//                }
//                File.WriteAllText(filePath, contents);
//            }

//            EditorUtility.ClearProgressBar();
//        }

//        private static IEnumerable<string> GetGuids(string text)
//        {
//            const string guidStart = "guid: ";
//            const int guidLength = 32;
//            int textLength = text.Length;
//            int guidStartLength = guidStart.Length;
//            List<string> guids = new List<string>();

//            int index = 0;
//            while (index + guidStartLength + guidLength < textLength)
//            {
//                index = text.IndexOf(guidStart, index, StringComparison.Ordinal);
//                if (index == -1)
//                    break;

//                index += guidStartLength;
//                string guid = text.Substring(index, guidLength);
//                index += guidLength;

//                if (IsGuid(guid))
//                {
//                    guids.Add(guid);
//                }
//            }

//            return guids;
//        }

//        private static bool IsGuid(string text)
//        {
//            for (int i = 0; i < text.Length; i++)
//            {
//                char c = text[i];
//                if (
//                    !((c >= '0' && c <= '9') ||
//                      (c >= 'a' && c <= 'z'))
//                    )
//                    return false;
//            }

//            return true;
//        }

//        private static string MakeRelativePath(string fromPath, string toPath)
//        {
//            Uri fromUri = new Uri(fromPath);
//            Uri toUri = new Uri(toPath);

//            Uri relativeUri = fromUri.MakeRelativeUri(toUri);
//            string relativePath = Uri.UnescapeDataString(relativeUri.ToString());

//            return relativePath;
//        }
//    }
//}