using System;
using System.Collections.Generic;
using System.IO;
using MCPForUnity.Editor.Helpers;
using Newtonsoft.Json.Linq;
using UnityEditor;
using UnityEditor.SceneManagement;
using UnityEngine;
using UnityEngine.SceneManagement;
namespace MCPForUnity.Editor.Tools.Prefabs
{
[McpForUnityTool("manage_prefabs", AutoRegister = false)]
///
/// Tool to manage Unity Prefab stages and create prefabs from GameObjects.
///
public static class ManagePrefabs
{
// Action constants
private const string ACTION_OPEN_STAGE = "open_stage";
private const string ACTION_CLOSE_STAGE = "close_stage";
private const string ACTION_SAVE_OPEN_STAGE = "save_open_stage";
private const string ACTION_CREATE_FROM_GAMEOBJECT = "create_from_gameobject";
private const string ACTION_GET_INFO = "get_info";
private const string ACTION_GET_HIERARCHY = "get_hierarchy";
private const string SupportedActions = ACTION_OPEN_STAGE + ", " + ACTION_CLOSE_STAGE + ", " + ACTION_SAVE_OPEN_STAGE + ", " + ACTION_CREATE_FROM_GAMEOBJECT + ", " + ACTION_GET_INFO + ", " + ACTION_GET_HIERARCHY;
public static object HandleCommand(JObject @params)
{
if (@params == null)
{
return new ErrorResponse("Parameters cannot be null.");
}
string action = @params["action"]?.ToString()?.ToLowerInvariant();
if (string.IsNullOrEmpty(action))
{
return new ErrorResponse($"Action parameter is required. Valid actions are: {SupportedActions}.");
}
try
{
switch (action)
{
case ACTION_OPEN_STAGE:
return OpenStage(@params);
case ACTION_CLOSE_STAGE:
return CloseStage(@params);
case ACTION_SAVE_OPEN_STAGE:
return SaveOpenStage(@params);
case ACTION_CREATE_FROM_GAMEOBJECT:
return CreatePrefabFromGameObject(@params);
case ACTION_GET_INFO:
return GetInfo(@params);
case ACTION_GET_HIERARCHY:
return GetHierarchy(@params);
default:
return new ErrorResponse($"Unknown action: '{action}'. Valid actions are: {SupportedActions}.");
}
}
catch (Exception e)
{
McpLog.Error($"[ManagePrefabs] Action '{action}' failed: {e}");
return new ErrorResponse($"Internal error: {e.Message}");
}
}
///
/// Opens a prefab in prefab mode for editing.
///
private static object OpenStage(JObject @params)
{
string prefabPath = @params["prefabPath"]?.ToString();
if (string.IsNullOrEmpty(prefabPath))
{
return new ErrorResponse("'prefabPath' parameter is required for open_stage.");
}
string sanitizedPath = AssetPathUtility.SanitizeAssetPath(prefabPath);
if (string.IsNullOrEmpty(sanitizedPath))
{
return new ErrorResponse($"Invalid prefab path: '{prefabPath}'.");
}
GameObject prefabAsset = AssetDatabase.LoadAssetAtPath(sanitizedPath);
if (prefabAsset == null)
{
return new ErrorResponse($"No prefab asset found at path '{sanitizedPath}'.");
}
PrefabStage stage = PrefabStageUtility.OpenPrefab(sanitizedPath);
if (stage == null)
{
return new ErrorResponse($"Failed to open prefab stage for '{sanitizedPath}'.");
}
return new SuccessResponse($"Opened prefab stage for '{sanitizedPath}'.", SerializeStage(stage));
}
///
/// Closes the currently open prefab stage, optionally saving first.
///
private static object CloseStage(JObject @params)
{
PrefabStage stage = PrefabStageUtility.GetCurrentPrefabStage();
if (stage == null)
{
return new SuccessResponse("No prefab stage was open.");
}
string assetPath = stage.assetPath;
bool saveBeforeClose = @params["saveBeforeClose"]?.ToObject() ?? false;
if (saveBeforeClose && stage.scene.isDirty)
{
try
{
SaveAndRefreshStage(stage);
}
catch (Exception e)
{
return new ErrorResponse($"Failed to save prefab before closing: {e.Message}");
}
}
StageUtility.GoToMainStage();
return new SuccessResponse($"Closed prefab stage for '{assetPath}'.");
}
///
/// Saves changes to the currently open prefab stage.
/// Supports a 'force' parameter for automated workflows where isDirty may not be set.
///
private static object SaveOpenStage(JObject @params)
{
PrefabStage stage = PrefabStageUtility.GetCurrentPrefabStage();
if (stage == null)
{
return new ErrorResponse("No prefab stage is currently open.");
}
if (!ValidatePrefabStageForSave(stage))
{
return new ErrorResponse("Prefab stage validation failed. Cannot save.");
}
// Check for force parameter (useful for automated workflows)
bool force = @params?["force"]?.ToObject() ?? false;
// Check if there are actual changes to save
bool wasDirty = stage.scene.isDirty;
if (!wasDirty && !force)
{
return new SuccessResponse($"Prefab stage for '{stage.assetPath}' has no unsaved changes.", SerializeStage(stage));
}
try
{
SaveAndRefreshStage(stage, force);
return new SuccessResponse($"Saved prefab stage for '{stage.assetPath}'.", SerializeStage(stage));
}
catch (Exception e)
{
return new ErrorResponse($"Failed to save prefab: {e.Message}");
}
}
#region Prefab Save Operations
///
/// Saves the prefab stage and refreshes the asset database.
/// Uses PrefabUtility.SaveAsPrefabAsset for reliable prefab saving without dialogs.
///
/// The prefab stage to save.
/// If true, marks the prefab dirty before saving to ensure changes are captured.
private static void SaveAndRefreshStage(PrefabStage stage, bool force = false)
{
if (stage == null)
{
throw new ArgumentNullException(nameof(stage), "Prefab stage cannot be null.");
}
if (stage.prefabContentsRoot == null)
{
throw new InvalidOperationException("Cannot save prefab stage without a prefab root.");
}
if (string.IsNullOrEmpty(stage.assetPath))
{
throw new InvalidOperationException("Prefab stage has invalid asset path.");
}
// When force=true, mark the prefab root dirty to ensure changes are saved
// This is useful for automated workflows where isDirty may not be set correctly
if (force)
{
EditorUtility.SetDirty(stage.prefabContentsRoot);
EditorSceneManager.MarkSceneDirty(stage.scene);
}
// Mark all children as dirty to ensure their changes are captured
foreach (Transform child in stage.prefabContentsRoot.GetComponentsInChildren(true))
{
if (child != stage.prefabContentsRoot.transform)
{
EditorUtility.SetDirty(child.gameObject);
}
}
// Use PrefabUtility.SaveAsPrefabAsset which saves without dialogs
// This is more reliable for automated workflows than EditorSceneManager.SaveScene
bool success;
PrefabUtility.SaveAsPrefabAsset(stage.prefabContentsRoot, stage.assetPath, out success);
if (!success)
{
throw new InvalidOperationException($"Failed to save prefab asset for '{stage.assetPath}'.");
}
// Ensure changes are persisted to disk
AssetDatabase.SaveAssets();
AssetDatabase.Refresh();
McpLog.Info($"[ManagePrefabs] Successfully saved prefab '{stage.assetPath}'.");
}
///
/// Validates prefab stage before saving.
///
private static bool ValidatePrefabStageForSave(PrefabStage stage)
{
if (stage == null)
{
McpLog.Warn("[ManagePrefabs] No prefab stage is open.");
return false;
}
if (stage.prefabContentsRoot == null)
{
McpLog.Error($"[ManagePrefabs] Prefab stage '{stage.assetPath}' has no root object.");
return false;
}
if (string.IsNullOrEmpty(stage.assetPath))
{
McpLog.Error("[ManagePrefabs] Prefab stage has invalid asset path.");
return false;
}
return true;
}
#endregion
#region Create Prefab from GameObject
///
/// Creates a prefab asset from a GameObject in the scene.
///
private static object CreatePrefabFromGameObject(JObject @params)
{
// 1. Validate and parse parameters
var validation = ValidateCreatePrefabParams(@params);
if (!validation.isValid)
{
return new ErrorResponse(validation.errorMessage);
}
string targetName = validation.targetName;
string finalPath = validation.finalPath;
bool includeInactive = validation.includeInactive;
bool replaceExisting = validation.replaceExisting;
bool unlinkIfInstance = validation.unlinkIfInstance;
// 2. Find the source object
GameObject sourceObject = FindSceneObjectByName(targetName, includeInactive);
if (sourceObject == null)
{
return new ErrorResponse($"GameObject '{targetName}' not found in the active scene or prefab stage{(includeInactive ? " (including inactive objects)" : "")}.");
}
// 3. Validate source object state
var objectValidation = ValidateSourceObjectForPrefab(sourceObject, unlinkIfInstance);
if (!objectValidation.isValid)
{
return new ErrorResponse(objectValidation.errorMessage);
}
// 4. Check for path conflicts and track if file will be replaced
bool fileExistedAtPath = AssetDatabase.LoadAssetAtPath(finalPath) != null;
if (!replaceExisting && fileExistedAtPath)
{
finalPath = AssetDatabase.GenerateUniqueAssetPath(finalPath);
McpLog.Info($"[ManagePrefabs] Generated unique path: {finalPath}");
}
// 5. Ensure directory exists
EnsureAssetDirectoryExists(finalPath);
// 6. Unlink from existing prefab if needed
if (unlinkIfInstance && objectValidation.shouldUnlink)
{
try
{
// UnpackPrefabInstance requires the prefab instance root, not a child object
GameObject rootToUnlink = PrefabUtility.GetOutermostPrefabInstanceRoot(sourceObject);
if (rootToUnlink != null)
{
PrefabUtility.UnpackPrefabInstance(rootToUnlink, PrefabUnpackMode.Completely, InteractionMode.AutomatedAction);
McpLog.Info($"[ManagePrefabs] Unpacked prefab instance '{rootToUnlink.name}' before creating new prefab.");
}
}
catch (Exception e)
{
return new ErrorResponse($"Failed to unlink prefab instance: {e.Message}");
}
}
// 7. Create the prefab
try
{
GameObject result = CreatePrefabAsset(sourceObject, finalPath, replaceExisting);
if (result == null)
{
return new ErrorResponse($"Failed to create prefab asset at '{finalPath}'.");
}
// 8. Select the newly created instance
Selection.activeGameObject = result;
return new SuccessResponse(
$"Prefab created at '{finalPath}' and instance linked.",
new
{
prefabPath = finalPath,
instanceId = result.GetInstanceID(),
instanceName = result.name,
wasUnlinked = unlinkIfInstance && objectValidation.shouldUnlink,
wasReplaced = replaceExisting && fileExistedAtPath,
componentCount = result.GetComponents().Length,
childCount = result.transform.childCount
}
);
}
catch (Exception e)
{
McpLog.Error($"[ManagePrefabs] Error creating prefab at '{finalPath}': {e}");
return new ErrorResponse($"Error saving prefab asset: {e.Message}");
}
}
///
/// Validates parameters for creating a prefab from GameObject.
///
private static (bool isValid, string errorMessage, string targetName, string finalPath, bool includeInactive, bool replaceExisting, bool unlinkIfInstance)
ValidateCreatePrefabParams(JObject @params)
{
string targetName = @params["target"]?.ToString() ?? @params["name"]?.ToString();
if (string.IsNullOrEmpty(targetName))
{
return (false, "'target' parameter is required for create_from_gameobject.", null, null, false, false, false);
}
string requestedPath = @params["prefabPath"]?.ToString();
if (string.IsNullOrWhiteSpace(requestedPath))
{
return (false, "'prefabPath' parameter is required for create_from_gameobject.", targetName, null, false, false, false);
}
string sanitizedPath = AssetPathUtility.SanitizeAssetPath(requestedPath);
if (sanitizedPath == null)
{
return (false, $"Invalid prefab path (path traversal detected): '{requestedPath}'", targetName, null, false, false, false);
}
if (string.IsNullOrEmpty(sanitizedPath))
{
return (false, $"Invalid prefab path '{requestedPath}'. Path cannot be empty.", targetName, null, false, false, false);
}
if (!sanitizedPath.EndsWith(".prefab", StringComparison.OrdinalIgnoreCase))
{
sanitizedPath += ".prefab";
}
// Validate path is within Assets folder
if (!sanitizedPath.StartsWith("Assets/", StringComparison.OrdinalIgnoreCase))
{
return (false, $"Prefab path must be within the Assets folder. Got: '{sanitizedPath}'", targetName, null, false, false, false);
}
bool includeInactive = @params["searchInactive"]?.ToObject() ?? false;
bool replaceExisting = @params["allowOverwrite"]?.ToObject() ?? false;
bool unlinkIfInstance = @params["unlinkIfInstance"]?.ToObject() ?? false;
return (true, null, targetName, sanitizedPath, includeInactive, replaceExisting, unlinkIfInstance);
}
///
/// Validates source object can be converted to prefab.
///
private static (bool isValid, string errorMessage, bool shouldUnlink, string existingPrefabPath)
ValidateSourceObjectForPrefab(GameObject sourceObject, bool unlinkIfInstance)
{
// Check if this is a Prefab Asset (the .prefab file itself in the editor)
if (PrefabUtility.IsPartOfPrefabAsset(sourceObject))
{
return (false,
$"GameObject '{sourceObject.name}' is part of a prefab asset. " +
"Open the prefab stage to save changes instead.",
false, null);
}
// Check if this is already a Prefab Instance
PrefabInstanceStatus status = PrefabUtility.GetPrefabInstanceStatus(sourceObject);
if (status != PrefabInstanceStatus.NotAPrefab)
{
string existingPath = PrefabUtility.GetPrefabAssetPathOfNearestInstanceRoot(sourceObject);
if (!unlinkIfInstance)
{
return (false,
$"GameObject '{sourceObject.name}' is already linked to prefab '{existingPath}'. " +
"Set 'unlinkIfInstance' to true to unlink it first, or modify the existing prefab instead.",
false, existingPath);
}
// Needs to be unlinked
return (true, null, true, existingPath);
}
return (true, null, false, null);
}
///
/// Creates a prefab asset from a GameObject.
///
private static GameObject CreatePrefabAsset(GameObject sourceObject, string path, bool replaceExisting)
{
GameObject result = PrefabUtility.SaveAsPrefabAssetAndConnect(
sourceObject,
path,
InteractionMode.AutomatedAction
);
string action = replaceExisting ? "Replaced existing" : "Created new";
McpLog.Info($"[ManagePrefabs] {action} prefab at '{path}'.");
if (result != null)
{
AssetDatabase.SaveAssets();
AssetDatabase.Refresh();
}
return result;
}
#endregion
///
/// Ensures the directory for an asset path exists, creating it if necessary.
///
private static void EnsureAssetDirectoryExists(string assetPath)
{
string directory = Path.GetDirectoryName(assetPath);
if (string.IsNullOrEmpty(directory))
{
return;
}
// Use Application.dataPath for more reliable path resolution
// Application.dataPath points to the Assets folder (e.g., ".../ProjectName/Assets")
string assetsPath = Application.dataPath;
string projectRoot = Path.GetDirectoryName(assetsPath);
string fullDirectory = Path.Combine(projectRoot, directory);
if (!Directory.Exists(fullDirectory))
{
Directory.CreateDirectory(fullDirectory);
AssetDatabase.Refresh(ImportAssetOptions.ForceSynchronousImport);
McpLog.Info($"[ManagePrefabs] Created directory: {directory}");
}
}
///
/// Finds a GameObject by name in the active scene or current prefab stage.
///
private static GameObject FindSceneObjectByName(string name, bool includeInactive)
{
// First check if we're in Prefab Stage
PrefabStage stage = PrefabStageUtility.GetCurrentPrefabStage();
if (stage?.prefabContentsRoot != null)
{
foreach (Transform transform in stage.prefabContentsRoot.GetComponentsInChildren(includeInactive))
{
if (transform.name == name && (includeInactive || transform.gameObject.activeSelf))
{
return transform.gameObject;
}
}
}
// Search in the active scene
Scene activeScene = SceneManager.GetActiveScene();
foreach (GameObject root in activeScene.GetRootGameObjects())
{
// Check the root object itself
if (root.name == name && (includeInactive || root.activeSelf))
{
return root;
}
// Check children
foreach (Transform transform in root.GetComponentsInChildren(includeInactive))
{
if (transform.name == name && (includeInactive || transform.gameObject.activeSelf))
{
return transform.gameObject;
}
}
}
return null;
}
#region Read Operations
///
/// Gets basic metadata information about a prefab asset.
///
private static object GetInfo(JObject @params)
{
string prefabPath = @params["prefabPath"]?.ToString() ?? @params["path"]?.ToString();
if (string.IsNullOrEmpty(prefabPath))
{
return new ErrorResponse("'prefabPath' parameter is required for get_info.");
}
string sanitizedPath = AssetPathUtility.SanitizeAssetPath(prefabPath);
if (string.IsNullOrEmpty(sanitizedPath))
{
return new ErrorResponse($"Invalid prefab path: '{prefabPath}'.");
}
GameObject prefabAsset = AssetDatabase.LoadAssetAtPath(sanitizedPath);
if (prefabAsset == null)
{
return new ErrorResponse($"No prefab asset found at path '{sanitizedPath}'.");
}
string guid = PrefabUtilityHelper.GetPrefabGUID(sanitizedPath);
PrefabAssetType assetType = PrefabUtility.GetPrefabAssetType(prefabAsset);
string prefabTypeString = assetType.ToString();
var componentTypes = PrefabUtilityHelper.GetComponentTypeNames(prefabAsset);
int childCount = PrefabUtilityHelper.CountChildrenRecursive(prefabAsset.transform);
var (isVariant, parentPrefab, _) = PrefabUtilityHelper.GetVariantInfo(prefabAsset);
return new SuccessResponse(
$"Successfully retrieved prefab info.",
new
{
assetPath = sanitizedPath,
guid = guid,
prefabType = prefabTypeString,
rootObjectName = prefabAsset.name,
rootComponentTypes = componentTypes,
childCount = childCount,
isVariant = isVariant,
parentPrefab = parentPrefab
}
);
}
///
/// Gets the hierarchical structure of a prefab asset.
/// Returns all objects in the prefab for full client-side filtering and search.
///
private static object GetHierarchy(JObject @params)
{
string prefabPath = @params["prefabPath"]?.ToString() ?? @params["path"]?.ToString();
if (string.IsNullOrEmpty(prefabPath))
{
return new ErrorResponse("'prefabPath' parameter is required for get_hierarchy.");
}
string sanitizedPath = AssetPathUtility.SanitizeAssetPath(prefabPath);
if (string.IsNullOrEmpty(sanitizedPath))
{
return new ErrorResponse($"Invalid prefab path '{prefabPath}'. Path traversal sequences are not allowed.");
}
// Load prefab contents in background (without opening stage UI)
GameObject prefabContents = PrefabUtility.LoadPrefabContents(sanitizedPath);
if (prefabContents == null)
{
return new ErrorResponse($"Failed to load prefab contents from '{sanitizedPath}'.");
}
try
{
// Build complete hierarchy items (no pagination)
var allItems = BuildHierarchyItems(prefabContents.transform, sanitizedPath);
return new SuccessResponse(
$"Successfully retrieved prefab hierarchy. Found {allItems.Count} objects.",
new
{
prefabPath = sanitizedPath,
total = allItems.Count,
items = allItems
}
);
}
finally
{
// Always unload prefab contents to free memory
PrefabUtility.UnloadPrefabContents(prefabContents);
}
}
#endregion
#region Hierarchy Builder
///
/// Builds a flat list of hierarchy items from a transform root.
///
/// The root transform of the prefab.
/// Asset path of the main prefab.
/// List of hierarchy items with prefab information.
private static List