Sprint 4: Pause / Save / New Game

# 🎉 Sprint 4: Save/Load System - COMPLETED

**Sprint Duration:** Week 4  

**Status:** ✅ COMPLETE  

**Completion Date:** November 29, 2025

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## 📋 Sprint Goal

Implement a complete save/load system that persists all game state between sessions, including visit counts, building activations, and animal discoveries.

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## ✅ Completed Features

### 1. Save/Load Core System

- ✅ JSON-based serialization using Unity's JsonUtility

- ✅ GameSaveData structure with visit counts, animals, and buildings

- ✅ Auto-save every 2 minutes

- ✅ Manual save via pause menu "Save Game" button

- ✅ Auto-save on application quit

- ✅ Save file path: `Application.persistentDataPath/outback_save.json`

### 2. Visit System Persistence

- ✅ All zone visit counts save/load correctly

- ✅ Visit data restored to VisitManager on game start

- ✅ Buildings activate based on loaded visit thresholds

### 3. Building Activation Persistence

- ✅ Activated building IDs tracked at runtime

- ✅ Buildings restore activation state on load

- ✅ BuildingIDHelper for easy ID assignment in Inspector

- ✅ Integration with ActivatableObject component

### 4. Animal Discovery Persistence

- ✅ Discovered animals save/load correctly

- ✅ Discovery HUD updates after loading save data

- ✅ Animal icons show correct discovered/undiscovered state

- ✅ "X/4 Animals Discovered" counter persists

### 5. Pause Menu with Save/Load UI

- ✅ ESC key opens pause menu

- ✅ "Resume" button returns to game

- ✅ "Save Game" button triggers manual save

- ✅ "New Game" button resets game state

- ✅ "Instructions" panel with game controls

- ✅ Time.timeScale pauses game properly

### 6. New Game Functionality

- ✅ Deletes save file

- ✅ Resets all manager states

- ✅ Reloads scene cleanly without crashes

- ✅ Destroys DontDestroyOnLoad singletons before reload

### 7. Debug Features

- ✅ F5 = Manual save

- ✅ F6 = Manual load

- ✅ F7 = Delete save

- ✅ F8 = New game

- ✅ Comprehensive console logging

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## 🐛 Bugs Fixed

### Bug #1: New Game Crash 💥 → ✅ FIXED

**Problem:** Clicking "New Game" crashed Unity with duplicate singleton warnings

**Root Cause:** DontDestroyOnLoad singletons (VisitManager, AnimalDiscoveryManager, GameSaveManager) persisted across scene reload, creating duplicate instances

**Solution:** Modified `GameSaveManager.StartNewGame()` to destroy all DontDestroyOnLoad singletons BEFORE calling `SceneManager.LoadScene()`

**Files Modified:** `GameSaveManager.cs`

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### Bug #2: Animal Discovery UI Reset 🦘 → ✅ FIXED

**Problem:** After save/load, HUD showed "0/4 Animals Discovered" instead of correct count

**Root Cause:** Save data loaded correctly into AnimalDiscoveryManager, but HUD never updated because no events were fired during load

**Solution:** Added `Start()` method to HUDController that queries discovery count after save data loads (delayed by one frame to ensure load completes first)

**Files Modified:** `HUDController.cs`

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## 📊 Technical Implementation

### Architecture Pattern: Observer Pattern

- GameSaveManager observes ActivatableObject activations

- HUDController observes AnimalDiscoveryManager events

- Clean separation of concerns

### Design Patterns Used

- **Singleton:** GameSaveManager, VisitManager, AnimalDiscoveryManager

- **Observer:** Event-driven updates for UI and state changes

- **Serialization:** GameSaveData as data transfer object

### Code Quality

- ✅ Follows OOP principles

- ✅ Follows SOLID principles

- ✅ Comprehensive error handling

- ✅ Defensive null checks

- ✅ Clear code comments

- ✅ Consistent naming conventions

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## 🧪 Testing Completed

### Test Case 1: Basic Save/Load

1. Started game (fresh)

2. Discovered 2 animals → HUD shows "2/4"

3. Visited zones to activate 2 buildings

4. Clicked ESC → "Save Game"

5. Quit game

6. Restarted game

7. ✅ HUD showed "2/4 Animals Discovered"

8. ✅ Buildings remained activated

9. ✅ Visit counts persisted

### Test Case 2: New Game

1. Loaded game with progress

2. Clicked ESC → "New Game"

3. ✅ Scene reloaded cleanly (no crash)

4. ✅ HUD showed "0/4 Animals Discovered"

5. ✅ All buildings deactivated

6. ✅ No duplicate manager warnings

### Test Case 3: Auto-Save

1. Played for 3 minutes

2. Observed console logs

3. ✅ Auto-save triggered at 2-minute mark

4. ✅ Save file updated successfully

### Test Case 4: Debug Keys

1. Pressed F5 → ✅ Manual save worked

2. Pressed F6 → ✅ Manual load worked

3. Pressed F7 → ✅ Save deleted

4. Pressed F8 → ✅ New game started

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## 📁 Files Created/Modified

### New Files Created

- `GameSaveData.cs` - Serializable save data structure

- `GameSaveManager.cs` - Save/load system manager

- `BuildingIDHelper.cs` - Inspector helper for assigning building IDs

### Files Modified

- `ActivatableObject.cs` - Added save system integration

- `VisitManager.cs` - Added LoadVisitData() and GetAllVisitData()

- `AnimalDiscoveryManager.cs` - Added LoadDiscoveryData() and ResetAllDiscoveries()

- `HUDController.cs` - Added pause menu, save/load buttons, discovery HUD update on load

- `HUD.uxml` - Added pause menu UI structure

- `HUD.uss` - Added pause menu styling

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## 📈 Metrics

**Lines of Code Added:** ~800 lines  

**Files Created:** 3  

**Files Modified:** 6  

**Bugs Fixed:** 2 critical  

**Test Cases Passed:** 4/4  

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## 🎯 Definition of Done - Sprint 4

- [x] Save system persists visit counts

- [x] Save system persists building states

- [x] Save system persists discovered animals

- [x] Auto-save works every 2 minutes

- [x] Manual save/load works via pause menu

- [x] Save on quit works

- [x] New Game button works without crash

- [x] Animal discovery UI updates after loading

- [x] Debug keys functional (F5/F6/F7/F8)

- [x] Code follows OOP/SOLID principles

- [x] No compiler errors/warnings

- [x] All features tested in Play mode

- [x] Code committed to Git with clear messages

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## 🚀 Ready for Sprint 5

Sprint 4 is complete with all features working as expected. The save/load system is robust, tested, and ready for production.

**Next Sprint Focus:** Add 3 new animals (Koala, Frillneck Lizard, Platypus) to expand discovery content.

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## 📝 Lessons Learned

### What Went Well ✅

- Observer pattern made event-driven updates clean and maintainable

- Singleton managers kept global state management simple

- GameSaveData structure with helper methods made serialization straightforward

- Comprehensive logging made debugging efficient

### Challenges Overcome 🔧

- DontDestroyOnLoad singleton lifecycle during scene reload (fixed with proper destruction)

- Event firing during save data load (fixed with delayed UI update)

- Method naming consistency across codebase (resolved with compatibility aliases)

### Future Improvements 💡

- Consider player position save/load for spawn location

- Add save file backup system

- Implement save file version migration for future updates

- Add cloud save integration (future feature)

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## 🎮 Player Experience

The save/load system is completely transparent to players:

- Game automatically saves progress every 2 minutes

- Progress persists between sessions without player action

- Manual save available via pause menu for peace of mind

- New Game option allows fresh starts

- No loading screens or save confirmations interrupt gameplay

**Sprint 4 delivers a polished, production-ready save system!** ✨

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**Sprint Completed By:** Andrew (Developer) + Claude (AI Assistant)  

**Sprint Review Date:** November 29, 2025  

**Status:** APPROVED - Ready for Sprint 5