using System.Collections.Generic;
using UnityEditor;
using UnityEngine;

namespace BaseGames.Editor
{
    /// <summary>
    /// 扫描当前场景及 Project 中所有 Prefab，移除丢失（Missing）脚本引用。
    ///
    /// 菜单：BaseGames/Tools/Missing Scripts/
    /// </summary>
    public static class MissingScriptCleaner
    {
        // ──────────────────────────────────────────────
        // 场景
        // ──────────────────────────────────────────────

        [MenuItem("BaseGames/Tools/Maintenance/Missing Scripts/Clear In Scene")]
        public static void ClearMissingScriptsInScene()
        {
            int totalRemoved = 0;
            var affected = new List<GameObject>();

            foreach (var go in GetAllSceneObjects())
            {
                int removed = GameObjectUtility.RemoveMonoBehavioursWithMissingScript(go);
                if (removed > 0)
                {
                    affected.Add(go);
                    totalRemoved += removed;
                    EditorUtility.SetDirty(go);
                    Debug.Log($"[MissingScriptCleaner] 场景已清理：{GetFullPath(go)}", go);
                }
            }

            if (totalRemoved == 0)
                Debug.Log("[MissingScriptCleaner] 场景中未发现丢失脚本。");
            else
                Debug.Log($"[MissingScriptCleaner] 场景完成。共移除 {totalRemoved} 个丢失脚本，影响 {affected.Count} 个 GameObject。");
        }

        [MenuItem("BaseGames/Tools/Maintenance/Missing Scripts/Find In Scene")]
        public static void FindMissingScriptsInScene()
        {
            int totalFound = 0;

            foreach (var go in GetAllSceneObjects())
            {
                foreach (var component in go.GetComponents<Component>())
                {
                    if (component == null)
                    {
                        Debug.LogWarning($"[MissingScriptCleaner] 场景丢失脚本：{GetFullPath(go)}", go);
                        totalFound++;
                        break;
                    }
                }
            }

            if (totalFound == 0)
                Debug.Log("[MissingScriptCleaner] 场景中未发现丢失脚本。");
            else
                Debug.LogWarning($"[MissingScriptCleaner] 场景共发现 {totalFound} 个含丢失脚本的 GameObject。");
        }

        // ──────────────────────────────────────────────
        // Prefab 资产
        // ──────────────────────────────────────────────

        [MenuItem("BaseGames/Tools/Maintenance/Missing Scripts/Clear In All Prefabs")]
        public static void ClearMissingScriptsInPrefabs()
        {
            int totalRemoved = 0;
            int affectedPrefabs = 0;

            string[] guids = AssetDatabase.FindAssets("t:Prefab");
            try
            {
                for (int i = 0; i < guids.Length; i++)
                {
                    string path = AssetDatabase.GUIDToAssetPath(guids[i]);
                    if (!path.StartsWith("Assets/")) continue; // 跳过 Packages 等只读路径

                    if (EditorUtility.DisplayCancelableProgressBar(
                            "清理 Prefab 丢失脚本",
                            path,
                            (float)i / guids.Length))
                        break;

                    int removed = CleanPrefabAtPath(path);
                    if (removed > 0)
                    {
                        totalRemoved += removed;
                        affectedPrefabs++;
                    }
                }
            }
            finally
            {
                EditorUtility.ClearProgressBar();
                AssetDatabase.SaveAssets();
            }

            if (totalRemoved == 0)
                Debug.Log("[MissingScriptCleaner] 所有 Prefab 中未发现丢失脚本。");
            else
                Debug.Log($"[MissingScriptCleaner] Prefab 完成。共移除 {totalRemoved} 个丢失脚本，影响 {affectedPrefabs} 个 Prefab。");
        }

        [MenuItem("BaseGames/Tools/Maintenance/Missing Scripts/Find In All Prefabs")]
        public static void FindMissingScriptsInPrefabs()
        {
            int totalFound = 0;

            string[] guids = AssetDatabase.FindAssets("t:Prefab");
            try
            {
                for (int i = 0; i < guids.Length; i++)
                {
                    string path = AssetDatabase.GUIDToAssetPath(guids[i]);
                    if (!path.StartsWith("Assets/")) continue; // 跳过 Packages 等只读路径

                    if (EditorUtility.DisplayCancelableProgressBar(
                            "查找 Prefab 丢失脚本",
                            path,
                            (float)i / guids.Length))
                        break;

                    var contentsRoot = PrefabUtility.LoadPrefabContents(path);
                    if (contentsRoot == null) continue;

                    try
                    {
                        var tempScene = contentsRoot.scene;
                        foreach (var go in Resources.FindObjectsOfTypeAll<GameObject>())
                        {
                            if (go.scene != tempScene) continue;
                            foreach (var component in go.GetComponents<Component>())
                            {
                                if (component == null)
                                {
                                    Debug.LogWarning($"[MissingScriptCleaner] Prefab 丢失脚本：{path} → {go.name}");
                                    totalFound++;
                                    break;
                                }
                            }
                        }
                    }
                    finally
                    {
                        PrefabUtility.UnloadPrefabContents(contentsRoot);
                    }
                }
            }
            finally
            {
                EditorUtility.ClearProgressBar();
            }

            if (totalFound == 0)
                Debug.Log("[MissingScriptCleaner] 所有 Prefab 中未发现丢失脚本。");
            else
                Debug.LogWarning($"[MissingScriptCleaner] Prefab 共发现 {totalFound} 个含丢失脚本的 GameObject。");
        }

        // ──────────────────────────────────────────────
        // 内部辅助
        // ──────────────────────────────────────────────

        static int CleanPrefabAtPath(string path)
        {
            // LoadPrefabContents 在临时预览场景中打开 Prefab，
            // 此时 Resources.FindObjectsOfTypeAll 可枚举到包括 HideInHierarchy 在内的全部对象。
            // 修改完毕后必须用 SaveAsPrefabAsset 写回，否则隐藏对象的改动不会持久化。
            var contentsRoot = PrefabUtility.LoadPrefabContents(path);
            if (contentsRoot == null) return 0;

            int totalRemoved = 0;
            try
            {
                var tempScene = contentsRoot.scene;
                foreach (var go in Resources.FindObjectsOfTypeAll<GameObject>())
                {
                    if (go.scene != tempScene) continue;
                    int removed = GameObjectUtility.RemoveMonoBehavioursWithMissingScript(go);
                    if (removed > 0)
                    {
                        totalRemoved += removed;
                        Debug.Log($"[MissingScriptCleaner] Prefab 已清理：{path} → {go.name}");
                    }
                }

                if (totalRemoved > 0)
                    PrefabUtility.SaveAsPrefabAsset(contentsRoot, path);
            }
            finally
            {
                PrefabUtility.UnloadPrefabContents(contentsRoot);
            }

            return totalRemoved;
        }

        static GameObject[] GetAllSceneObjects()
        {
            // FindObjectsByType 不返回 HideFlags.HideInHierarchy 的对象，
            // 使用 Resources.FindObjectsOfTypeAll 获取全部对象，再过滤出已加载场景内的实例。
            var all = Resources.FindObjectsOfTypeAll<GameObject>();
            var result = new List<GameObject>();
            foreach (var go in all)
            {
                if (go.scene.IsValid() && go.scene.isLoaded)
                    result.Add(go);
            }
            return result.ToArray();
        }

        static string GetFullPath(GameObject go)
        {
            var path = go.name;
            var parent = go.transform.parent;
            while (parent != null)
            {
                path = parent.name + "/" + path;
                parent = parent.parent;
            }
            return path;
        }
    }
}