using System.Text;
using UnityEditor;
using UnityEditor.SceneManagement;
using UnityEngine;
using UnityEngine.SceneManagement;

/// <summary>
/// Removes orphaned MonoBehaviour components whose script asset no longer exists
/// (the "The referenced script on this Behaviour is missing!" warnings seen in the
/// WebGPU build console). Operates on every GameObject in the currently open scene(s),
/// including inactive ones. Safe: only removes components Unity already reports as missing.
/// </summary>
public static class RemoveMissingScripts
{
    [MenuItem("Tools/Cleanup/Remove Missing Scripts In Open Scene(s)")]
    public static void RemoveInOpenScenes()
    {
        int totalRemoved = 0;
        int objectsAffected = 0;
        var report = new StringBuilder();

        for (int s = 0; s < SceneManager.sceneCount; s++)
        {
            Scene scene = SceneManager.GetSceneAt(s);
            if (!scene.isLoaded) continue;

            foreach (GameObject root in scene.GetRootGameObjects())
            {
                foreach (Transform t in root.GetComponentsInChildren<Transform>(true))
                {
                    GameObject go = t.gameObject;
                    int count = GameObjectUtility.GetMonoBehavioursWithMissingScriptCount(go);
                    if (count == 0) continue;

                    Undo.RegisterCompleteObjectUndo(go, "Remove Missing Scripts");
                    int removed = GameObjectUtility.RemoveMonoBehavioursWithMissingScript(go);
                    if (removed > 0)
                    {
                        totalRemoved += removed;
                        objectsAffected++;
                        report.AppendLine($"  {removed} on '{GetPath(go)}'");
                        EditorSceneManager.MarkSceneDirty(scene);
                    }
                }
            }
        }

        if (totalRemoved == 0)
            Debug.Log("[RemoveMissingScripts] No missing scripts found in the open scene(s).");
        else
            Debug.Log($"[RemoveMissingScripts] Removed {totalRemoved} missing script component(s) from {objectsAffected} object(s):\n{report}\nSave the scene (Ctrl+S) to persist.");
    }

    private static string GetPath(GameObject go)
    {
        string path = go.name;
        Transform p = go.transform.parent;
        while (p != null)
        {
            path = p.name + "/" + path;
            p = p.parent;
        }
        return path;
    }
}