AppleHillsProduction/docs/scenemanagerservice_review_and_migration_opportunities.md

SceneManagerService Independent Review & Migration Opportunities

Date: November 4, 2025
Reviewer: AI Assistant
Context: Post-BootCompletionService migration, lifecycle system fully operational

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Executive Summary

SceneManagerService is currently partially integrated with the lifecycle system but is missing critical lifecycle orchestration as outlined in the roadmap. The service manages scene loading/unloading effectively but doesn't broadcast lifecycle events to ManagedBehaviour components during scene transitions.

Key Finding: ⚠️ Phase 3 of the roadmap (Scene Orchestration) was never implemented

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Part 1: SceneManagerService Review

Current State Analysis

✅ Strengths

1. ManagedBehaviour Migration Complete

   • Inherits from ManagedBehaviour ✅
   • Priority: 15 (core infrastructure) ✅
   • Uses OnManagedAwake() properly ✅
   • Removed BootCompletionService dependency ✅

2. Solid Event-Driven Architecture

   • 6 public events for scene lifecycle
   • Clean async/await pattern
   • Progress reporting support
   • Loading screen integration

3. Good Scene Management Features

   • Additive scene loading
   • Multi-scene support
   • Bootstrap scene tracking
   • Current scene tracking

⚠️ Critical Gaps

1. Missing Lifecycle Orchestration

   • ❌ Does NOT call LifecycleManager.BroadcastSceneUnloading()
   • ❌ Does NOT call LifecycleManager.BroadcastSaveRequested()
   • ❌ Does NOT call LifecycleManager.BroadcastSceneReady()
   • ❌ Does NOT call LifecycleManager.BroadcastRestoreRequested()

2. No Save/Load Integration

   • Scene transitions don't trigger automatic saves
   • No restoration hooks after scene load
   • SaveLoadManager not invoked during transitions

3. Incomplete Scene Transition Flow

   // CURRENT (Incomplete):
   SwitchSceneAsync() {
       1. Show loading screen
       2. Destroy AstarPath
       3. Unload old scene
       4. Load new scene
       5. Hide loading screen
   }
   
   // MISSING (Per Roadmap Phase 3):
   SwitchSceneAsync() {
       1. Show loading screen
       2. BroadcastSceneUnloading(oldScene)     ❌ MISSING
       3. BroadcastSaveRequested(oldScene)      ❌ MISSING
       4. SaveLoadManager.Save()                ❌ MISSING
       5. Destroy AstarPath
       6. Unload old scene (Unity OnDestroy)
       7. Load new scene
       8. BroadcastSceneReady(newScene)         ❌ MISSING
       9. BroadcastRestoreRequested(newScene)   ❌ MISSING
       10. Hide loading screen
   }
   

📊 Code Quality Assessment

Good:

• Clean separation of concerns
• Well-documented public API
• Null safety checks
• Proper async handling
• DontDestroyOnLoad handled correctly

Could Improve:

• Add lifecycle orchestration (critical)
• Integrate SaveLoadManager
• Add scene validation before transitions
• Consider cancellation token support
• Add scene transition state tracking

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Recommended Changes to SceneManagerService

Priority 1: Add Lifecycle Orchestration (Critical)

Location: SwitchSceneAsync() method

Changes Needed:

public async Task SwitchSceneAsync(string newSceneName, IProgress<float> progress = null, bool autoHideLoadingScreen = true)
{
    // PHASE 1: Show loading screen
    if (_loadingScreen != null && !_loadingScreen.IsActive)
    {
        _loadingScreen.ShowLoadingScreen();
    }

    string oldSceneName = CurrentGameplayScene;
    
    // PHASE 2: Broadcast scene unloading (NEW)
    LogDebugMessage($"Broadcasting scene unloading for: {oldSceneName}");
    LifecycleManager.Instance?.BroadcastSceneUnloading(oldSceneName);
    
    // PHASE 3: Broadcast save request (NEW)
    LogDebugMessage($"Broadcasting save request for: {oldSceneName}");
    LifecycleManager.Instance?.BroadcastSaveRequested(oldSceneName);
    
    // PHASE 4: Trigger global save (NEW)
    if (SaveLoadManager.Instance != null && 
        DeveloperSettingsProvider.Instance.GetSettings<DebugSettings>().useSaveLoadSystem)
    {
        LogDebugMessage("Saving global game state");
        SaveLoadManager.Instance.Save();
    }
    
    // PHASE 5: Cleanup (existing)
    var astarPaths = FindObjectsByType<AstarPath>(FindObjectsSortMode.None);
    foreach (var astar in astarPaths)
    {
        if (Application.isPlaying)
            Destroy(astar.gameObject);
        else
            DestroyImmediate(astar.gameObject);
    }
    
    // PHASE 6: Unload old scene (existing)
    if (!string.IsNullOrEmpty(oldSceneName) && oldSceneName != BootstrapSceneName)
    {
        var prevScene = SceneManager.GetSceneByName(oldSceneName);
        if (prevScene.isLoaded)
        {
            await UnloadSceneAsync(oldSceneName);
            // Unity automatically calls OnDestroy → OnManagedDestroy()
        }
    }
    
    // PHASE 7: Ensure bootstrap loaded (existing)
    var bootstrap = SceneManager.GetSceneByName(BootstrapSceneName);
    if (!bootstrap.isLoaded)
    {
        SceneManager.LoadScene(BootstrapSceneName, LoadSceneMode.Additive);
    }
    
    // PHASE 8: Load new scene (existing)
    await LoadSceneAsync(newSceneName, progress);
    CurrentGameplayScene = newSceneName;
    
    // PHASE 9: Broadcast scene ready (NEW)
    LogDebugMessage($"Broadcasting scene ready for: {newSceneName}");
    LifecycleManager.Instance?.BroadcastSceneReady(newSceneName);
    
    // PHASE 10: Broadcast restore request (NEW)
    LogDebugMessage($"Broadcasting restore request for: {newSceneName}");
    LifecycleManager.Instance?.BroadcastRestoreRequested(newSceneName);
    
    // PHASE 11: Hide loading screen (existing)
    if (autoHideLoadingScreen && _loadingScreen != null)
    {
        _loadingScreen.HideLoadingScreen();
    }
}

Impact: 🔴 HIGH - Critical for proper lifecycle integration

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Part 2: Components Depending on Scene Loading Events

Analysis Results

I found 6 components that currently subscribe to SceneManagerService events. Here's the breakdown:

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Component 1: PauseMenu ✅ Already Using Lifecycle

Current Implementation:

protected override void OnSceneReady()
{
    SceneManagerService.Instance.SceneLoadCompleted += SetPauseMenuByLevel;
    // ...
}

Status: ✅ ALREADY OPTIMAL

• Uses OnSceneReady() hook
• Subscribes to SceneLoadCompleted for per-scene visibility logic
• No migration needed - dual approach is appropriate here

Rationale: PauseMenu needs to know about EVERY scene load (not just transitions), so event subscription is correct.

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Component 2: QuickAccess ⚠️ Should Migrate to Lifecycle

File: Assets/Scripts/Core/QuickAccess.cs

Current Implementation:

public class QuickAccess : MonoBehaviour  // ← Not ManagedBehaviour!
{
    private void Awake()
    {
        _instance = this;
        
        if (!_initialized)
        {
            if (SceneManager != null)
            {
                SceneManager.SceneLoadCompleted += OnSceneLoadCompleted;
            }
            _initialized = true;
        }
    }

    private void OnSceneLoadCompleted(string sceneName)
    {
        ClearReferences();  // Invalidates cached GameObjects
    }
}

Issues:

• ❌ Not using ManagedBehaviour
• ❌ Manual event subscription in Awake
• ❌ No automatic cleanup
• ❌ Uses event for scene transitions

Recommended Migration:

public class QuickAccess : ManagedBehaviour
{
    public override int ManagedAwakePriority => 5; // Very early
    
    protected override void OnManagedAwake()
    {
        _instance = this;
        _initialized = true;
    }
    
    protected override void OnSceneUnloading(string sceneName)
    {
        // Clear references BEFORE scene unloads
        ClearReferences();
    }
    
    // REMOVE: Awake() method
    // REMOVE: OnSceneLoadCompleted() method
    // REMOVE: SceneLoadCompleted subscription
}

Benefits:

• ✅ Automatic cleanup (no manual unsubscribe)
• ✅ Clear references at proper time (before unload, not after load)
• ✅ Consistent with lifecycle pattern
• ✅ One less event subscription

Impact: 🟡 MEDIUM - Improves cleanup timing and consistency

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Component 3: CardSystemSceneVisibility ✅ Already Migrated

File: Assets/Scripts/UI/CardSystem/CardSystemSceneVisibility.cs

Current Implementation:

protected override void OnSceneReady()
{
    // Replaces SceneLoadCompleted subscription
    SetVisibilityForScene(sceneName);
}

Status: ✅ ALREADY MIGRATED

• Uses OnSceneReady() lifecycle hook
• No event subscription
• No action needed

---

Component 4: PuzzleManager ✅ Already Migrated

File: Assets/Scripts/PuzzleS/PuzzleManager.cs

Current Implementation:

protected override void OnSceneReady()
{
    // Replaces SceneLoadCompleted subscription
    string sceneName = SceneManagerService.Instance.CurrentGameplayScene;
    OnSceneLoadCompleted(sceneName);
}

public void OnSceneLoadCompleted(string sceneName)
{
    // Load puzzle data for scene
    // ...
}

Status: ✅ ALREADY MIGRATED

• Uses OnSceneReady() lifecycle hook
• Method renamed but could be cleaned up
• Minor cleanup recommended (rename OnSceneLoadCompleted → LoadPuzzlesForScene)

---

Component 5: InputManager ✅ Already Migrated

File: Assets/Scripts/Input/InputManager.cs

Current Implementation:

protected override void OnSceneReady()
{
    // Replaces SceneLoadCompleted subscription
    UpdateInputModeForScene();
}

Status: ✅ ALREADY MIGRATED

• Uses OnSceneReady() lifecycle hook
• No action needed

---

Component 6: ItemManager ✅ Already Migrated

File: Assets/Scripts/Core/ItemManager.cs

Current Implementation:

protected override void OnSceneUnloading(string sceneName)
{
    // Replaces SceneLoadStarted subscription for clearing registrations
    ClearItemRegistrations();
}

Status: ✅ ALREADY MIGRATED

• Uses OnSceneUnloading() lifecycle hook
• No action needed

---

Component 7: SaveLoadManager ⚠️ Has Orphaned Methods

File: Assets/Scripts/Core/SaveLoad/SaveLoadManager.cs

Current Implementation:

protected override void OnSceneReady()
{
    // Replaces SceneLoadCompleted event subscription
    string sceneName = SceneManagerService.Instance.CurrentGameplayScene;
    OnSceneLoadCompleted(sceneName);
}

private void OnSceneLoadCompleted(string sceneName)
{
    // Restore global save data
    // ...
}

private void OnSceneUnloadStarted(string sceneName)
{
    // Save global data before unload
    // ...
}

Issues:

• ⚠️ Has OnSceneUnloadStarted() method but doesn't override OnSceneUnloading()
• ⚠️ Should use OnSaveRequested() instead of custom method
• ⚠️ Method naming inconsistent with lifecycle pattern

Recommended Changes:

protected override void OnSceneReady()
{
    string sceneName = SceneManagerService.Instance.CurrentGameplayScene;
    RestoreGlobalData(sceneName); // Renamed for clarity
}

protected override void OnSaveRequested(string sceneName)
{
    // Replaces OnSceneUnloadStarted
    SaveGlobalData(sceneName);
}

// REMOVE: OnSceneLoadCompleted() - rename to RestoreGlobalData()
// REMOVE: OnSceneUnloadStarted() - replace with OnSaveRequested()

Impact: 🟡 MEDIUM - Cleanup and consistency

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Part 3: Migration Summary & Recommendations

Components Needing Migration

Component	Current State	Action Required	Priority	Estimated Time
SceneManagerService	Missing lifecycle broadcasts	Add lifecycle orchestration	🔴 CRITICAL	30 min
QuickAccess	MonoBehaviour, uses events	Migrate to ManagedBehaviour	🟡 MEDIUM	20 min
SaveLoadManager	Has orphaned methods	Cleanup and use lifecycle hooks	🟡 MEDIUM	15 min
PuzzleManager	Minor naming issue	Rename method	🟢 LOW	5 min

Total Estimated Time: ~70 minutes

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Migration Benefits

After Full Migration:

1. Proper Scene Lifecycle Flow

   Scene Transition Triggers:
   1. OnSceneUnloading() - Components clean up
   2. OnSaveRequested() - Save level-specific data
   3. SaveLoadManager.Save() - Save global data
   4. [Scene Unload] - Unity OnDestroy
   5. [Scene Load] - Unity Awake
   6. OnSceneReady() - Components initialize
   7. OnRestoreRequested() - Restore level-specific data
   

2. Fewer Event Subscriptions

   • Current: 7 event subscriptions across 6 components
   • After: 1 event subscription (PauseMenu only)
   • Reduction: ~86%

3. Consistent Pattern

   • All components use lifecycle hooks
   • Clear separation: boot vs scene lifecycle
   • Predictable execution order

4. Automatic Cleanup

   • No manual event unsubscription
   • ManagedBehaviour handles cleanup
   • Fewer memory leak opportunities

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Part 4: Detailed Implementation Plan

Step 1: Update SceneManagerService (30 min) 🔴 CRITICAL

Priority: Must do this first - enables all other migrations

Changes:

1. Add lifecycle broadcasts to SwitchSceneAsync()
2. Integrate SaveLoadManager.Save() call
3. Add debug logging for lifecycle events
4. Test scene transitions thoroughly

Testing:

• Verify lifecycle order in console logs
• Check save/load triggers correctly
• Ensure OnSceneReady fires after scene fully loaded

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Step 2: Migrate QuickAccess (20 min) 🟡 MEDIUM

Changes:

1. Change base class to ManagedBehaviour
2. Set priority to 5 (very early)
3. Override OnManagedAwake()
4. Override OnSceneUnloading() for cleanup
5. Remove Awake() and event subscription
6. Test reference caching works

Testing:

• Verify references cached correctly
• Check clearing happens before scene unload
• Ensure singleton works across scenes

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Step 3: Cleanup SaveLoadManager (15 min) 🟡 MEDIUM

Changes:

1. Rename OnSceneLoadCompleted() → RestoreGlobalData()
2. Replace OnSceneUnloadStarted() with OnSaveRequested() override
3. Update method documentation
4. Verify save/load flow

Testing:

• Test global data saves before scene unload
• Verify restoration after scene load
• Check ISaveParticipant integration

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Step 4: Minor Cleanups (5 min) 🟢 LOW

PuzzleManager:

• Rename OnSceneLoadCompleted() → LoadPuzzlesForScene()
• Update documentation

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Part 5: Risk Assessment

Low Risk ✅

• PauseMenu, CardSystemSceneVisibility, InputManager, ItemManager already migrated
• Lifecycle system battle-tested from previous migrations

Medium Risk ⚠️

• SceneManagerService changes - Critical path, test thoroughly
• QuickAccess migration - Used throughout codebase, verify references work
• SaveLoadManager cleanup - Save/load is critical, extensive testing needed

Mitigation Strategies

1. Test after each migration - Don't batch changes
2. Use git checkpoints - Commit after each component
3. Playtest thoroughly - Full game loop after SceneManagerService update
4. Keep backups - Copy methods before deleting

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Part 6: Next Steps Recommendation

Immediate Actions (This Session)

Option A: Full Migration (Recommended)

1. ✅ Update SceneManagerService with lifecycle orchestration (30 min)
2. ✅ Migrate QuickAccess to ManagedBehaviour (20 min)
3. ✅ Cleanup SaveLoadManager (15 min)
4. ✅ Test thoroughly (30 min) Total: ~95 minutes

Option B: Critical Path Only

1. ✅ Update SceneManagerService only (30 min)
2. ✅ Test scene transitions (20 min)
3. ⏸️ Defer other migrations Total: ~50 minutes

Option C: Review Only

• ✅ This document completed
• ⏸️ Wait for user approval before proceeding

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Part 7: Expected Outcomes

After Complete Migration:

Architecture:

• ✅ Scene transitions fully orchestrated by LifecycleManager
• ✅ Automatic save/load during scene transitions
• ✅ All components use lifecycle hooks consistently
• ✅ Event subscriptions minimized (7 → 1)

Developer Experience:

• ✅ Clear lifecycle flow for debugging
• ✅ Predictable initialization order
• ✅ Less manual cleanup code
• ✅ Consistent patterns across codebase

Performance:

• ✅ Fewer active event subscriptions
• ✅ Better memory management
• ✅ No change in frame time (lifecycle is event-driven)

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Conclusion

Key Finding: SceneManagerService is missing the critical lifecycle orchestration outlined in Phase 3 of the roadmap. This is the final piece needed to complete the lifecycle system implementation.

Recommendation: Implement SceneManagerService lifecycle orchestration (Step 1) immediately. This unlocks the full potential of the lifecycle system and completes the architectural vision from the roadmap.

Next Action: Await user approval to proceed with implementation.

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Review Completed: November 4, 2025
Status: Ready for implementation
Estimated Total Time: 70-95 minutes