using UnityEngine;
using UnityEditor;
using System.IO;

public class RemoveMissingScriptsFromFolder
{
    [MenuItem("Tools/Cleanup/Remove Missing Scripts (Select Folder)")]
    static void RemoveFromFolder()
    {
        // Ask user to pick a folder
        string absFolder = EditorUtility.OpenFolderPanel(
            "Select folder to clean prefabs",
            Application.dataPath,
            ""
        );

        if (string.IsNullOrEmpty(absFolder))
            return;

        // Must be inside Assets
        if (!absFolder.StartsWith(Application.dataPath))
        {
            EditorUtility.DisplayDialog("Invalid Folder",
                "Please select a folder inside your project's Assets folder.",
                "OK");
            return;
        }

        // Convert to relative path: Assets/...
        string relFolder = "Assets" + absFolder.Substring(Application.dataPath.Length);

        string[] prefabGuids = AssetDatabase.FindAssets("t:Prefab", new[] { relFolder });

        int cleaned = 0;
        int scanned = 0;

        try
        {
            AssetDatabase.StartAssetEditing();

            foreach (string guid in prefabGuids)
            {
                string path = AssetDatabase.GUIDToAssetPath(guid);
                scanned++;

                GameObject instance = PrefabUtility.LoadPrefabContents(path);
                if (!instance) continue;

                bool changed = false;

                // Root
                changed |= GameObjectUtility.RemoveMonoBehavioursWithMissingScript(instance) > 0;

                // Children
                foreach (Transform t in instance.GetComponentsInChildren<Transform>(true))
                {
                    changed |= GameObjectUtility.RemoveMonoBehavioursWithMissingScript(t.gameObject) > 0;
                }

                if (changed)
                {
                    PrefabUtility.SaveAsPrefabAsset(instance, path);
                    cleaned++;
                }

                PrefabUtility.UnloadPrefabContents(instance);
            }
        }
        finally
        {
            AssetDatabase.StopAssetEditing();
            AssetDatabase.SaveAssets();
            AssetDatabase.Refresh();
        }

        EditorUtility.DisplayDialog(
            "Cleanup finished",
            $"Scanned: {scanned}\nCleaned: {cleaned}",
            "OK"
        );
    }
}