# Implementation Summary - Agent Intelligence & UI Refactor

**Date:** 2026-09-09  
**Cost:** ~$0.90 USD (well under budget)

## What Was Implemented

### 1. ✅ Monster Health Display Fix
- **File:** `BattleArenaView.cs:448`
- **Issue:** Monster health bars displayed "100" as max health even when stats differed
- **Fix:** Changed `slot.Combatant.MaxHealth` → `slot.Combatant.Sheet.Stats.MaxHealth`
- **Impact:** Fight visualization now shows accurate health percentages

### 2. ✅ Inventory Display for Agents
- **Files:** `HUD/InfoPanelUI.cs` (new file)
- **Location:** Right-side info panel when following an agent
- **Features:**
  - Lists all items in agent's inventory
  - Shows item type (Weapon/Armor/Consumable)
  - Displays stat bonuses (ATK, DEF, HP)
  - Color-coded for clarity
- **Access:** Click an agent in the left panel to follow and see inventory

### 3. ✅ GUI Refactoring
- **Created 4 new UI panel classes** (extracted from MazeSceneBuilder):
  - `HUD/StatusPanelUI.cs` — Elapsed time, agent counts, simulation controls
  - `HUD/FightPanelUI.cs` — Live fights with join-window countdown
  - `HUD/AgentPanelUI.cs` — Agent list, click-to-follow
  - `HUD/InfoPanelUI.cs` — Detailed agent info, thoughts, inventory, combat log

- **Benefits:**
  - Reduced MazeSceneBuilder by ~300 lines
  - Each panel owns its own scroll state and drawing logic
  - Easy to customize UI without touching scene logic
  - Reusable components

### 4. ✅ Health-Aware Retreat System
- **Implementation:** Encapsulated in decision classes
- **Behavior:**
  - **Below 30% health:** Retreat threshold cut in half (very defensive)
  - **30-50% health:** Gradually more cautious (linear lerp)
  - **Above 50% health:** Normal threshold applies
  
- **Impact:** 
  - Low-health agents actively avoid dangerous fights
  - Encourages tactical retreat when wounded
  - Reduces suicide charges by wounded agents

### 5. ✅ Automatic Health Potion Usage
- **Class:** `UseHealthPotionDecision`
- **Trigger:** When health falls below 50% (outside combat)
- **Behavior:**
  - Checks inventory for health potions
  - Uses the first potion found
  - Narrates the action to thought log
  - Only executes outside of active fights

- **Extensibility:** Can modify `LowHealthThreshold` constant to adjust trigger point

### 6. ✅ Decision Tree System (Major Architecture Change)

#### Core Classes:
- **`AgentDecision.cs`** — Abstract base class
  - `CanExecute(agent)` — Precondition check
  - `Execute(agent)` — Perform action, return if consumed
  - `Think(agent)` — Narrate to thought log
  - `DecisionName` — Human-readable label

- **`AgentDecisionTree.cs`** — Priority-ordered decision manager
  - `Add(decision)` — Register a decision
  - `TryDecide(agent)` — Evaluate tree, execute first valid decision
  - `FindApplicableDecision()` — Debug helper to see available choices
  - `GetAvailableDecisions()` — List all executable decisions

#### Concrete Decision Classes:
1. **`UseHealthPotionDecision`**
   - Uses health potions when HP < 50%
   
2. **`HandleExistingFightDecision`**
   - Joins or sneaks past fights already mustering
   
3. **`DeclareFightDecision`**
   - Starts a new fight if threat is acceptable
   
4. **`SneakAwayDecision`**
   - Attempts to sneak past overwhelming forces
   - Falls into forced fight if sneak fails
   
5. **`MoveOnDecision`**
   - Explores/follows/backtracks based on exit type
   - Filters by threat level
   - Catch-all that always succeeds

#### Execution Flow:
```
Update() 
  → _decisionTree.TryDecide(agent)
    → For each decision in priority order:
      → If CanExecute():
         → Execute()  (modifies state)
         → Think()    (narrates to thought log)
         → Return true (decision consumed this turn)
    → Return false if no decision could execute
```

## How to Extend Agent Behavior

### Adding a New Decision Type
1. Create a new class inheriting from `AgentDecision`
2. Implement `CanExecute()`, `Execute()`, `Think()`, `DecisionName`
3. Add it to `BuildDecisionTree()` in the priority order you want
4. That's it! No need to modify Update() or narration logic

### Example: Custom Decision
```csharp
public class FleeFromMassiveHorde : AgentDecision
{
    public override string DecisionName => "Flee Horde";
    
    public override bool CanExecute(MazeAgent agent)
    {
        Room room = agent.CurrentRoom;
        if (room?.Encounter == null) return false;
        return room.Encounter.AliveMonsterCount > 8; // Flee if > 8 monsters
    }
    
    public override bool Execute(MazeAgent agent)
    {
        // Attempt panic flee to nearest already-visited room
        // ... implementation ...
        return true; // Consumed this turn
    }
    
    public override void Think(MazeAgent agent)
    {
        agent.Thoughts.Add(ThoughtKind.Avoid, "WAY too many hostiles - RUN!");
    }
}

// Then in BuildDecisionTree():
_decisionTree.Insert(3, new FleeFromMassiveHorde()); // Higher priority than sneaking
```

### Modifying Existing Behavior
- Want to change when potions are used? Edit `UseHealthPotionDecision.LowHealthThreshold`
- Want to change retreat logic? Modify the `GetEffectiveReteatThreshold()` methods in decision classes
- Want to weight exploration differently? Edit `MoveOnDecision` / `_exploreChance`

## Key Design Principles

### 1. Behavior + Narration = Synchronized Pair
- Every action that Execute() performs gets a Think() explanation
- Observer can always understand why the agent did something
- Adding action without narration is a compile-time contract violation (abstract method)

### 2. Preconditions are Explicit
- `CanExecute()` makes it clear when a decision applies
- Easier to debug ("why didn't it do X?") → check if CanExecute() is true
- Prevents logic buried in Execute() that nobody can see

### 3. Priority Order is Visible
- `BuildDecisionTree()` reads top-to-bottom as priority
- First applicable decision wins
- Overriding behavior is easy: Insert a higher-priority decision

### 4. No Global State Pollution
- Each decision is standalone
- Decisions don't depend on magic fields or class-level flags
- Easy to test, compose, and reuse

## Files Changed/Created

### New Files (8)
```
Assets/Scripts/Maze/Visualization/HUD/
├── StatusPanelUI.cs          (165 lines)
├── FightPanelUI.cs           (75 lines)
├── AgentPanelUI.cs           (65 lines)
└── InfoPanelUI.cs            (130 lines) ← Includes inventory display

Assets/Scripts/Maze/Agent/Decisions/
├── AgentDecision.cs          (45 lines)
├── AgentDecisionTree.cs      (120 lines)
├── UseHealthPotionDecision.cs (35 lines)
├── HandleExistingFightDecision.cs (65 lines)
├── DeclareFightDecision.cs   (65 lines)
├── SneakAwayDecision.cs      (80 lines)
└── MoveOnDecision.cs         (230 lines)
```

### Modified Files (3)
```
Assets/Scripts/Maze/Visualization/MazeSceneBuilder.cs
  - Removed: 300+ lines of GUI code
  - Added: UI panel instantiation & delegation
  - Net: -280 lines

Assets/Scripts/Maze/Visualization/BattleArenaView.cs
  - Fixed: Line 448, monster max health display

Assets/Scripts/Maze/Agent/AutonomousAgentBrain.cs
  - Refactored: Entire class to use decision tree
  - Reduced: 470 lines → 95 lines
  - Removed: All decision logic (now in decision classes)
```

## Testing Recommendations

1. **Inventory Display**
   - Follow an agent
   - Verify inventory items display in right panel
   - Confirm equipped/unequipped items both show

2. **Health-Aware Retreat**
   - Damage agent in combat
   - Observe thought log: "threat {X:0.00}, over my limit {Y:0.00}"
   - Verify Y shrinks as health drops (should be ~75% of Y when at 30% health)

3. **Potion Usage**
   - Give agent a health potion
   - Damage agent below 50% health
   - Wait for next decision cycle
   - Verify thought log: "Used health potion..."
   - Confirm HP increased

4. **Monster Health Bar**
   - Trigger a fight
   - Watch the arena
   - Verify monster max health displays correctly (not always 100)

5. **Decision Tree Extension**
   - Create a simple test decision
   - Add to tree in BuildDecisionTree()
   - Verify it executes at the right time
   - Verify thought log shows the narration

## Notes for Future Developers

- The decision tree is intentionally simple to keep overhead minimal
- Agent decisions run every `_decisionInterval` seconds on SimulationClock time
- Decisions can't run multi-frame (coroutines would require restructure)
- Thought log limits itself to ~200 entries, so very old thoughts are pruned
- Health threshold calculations appear in multiple decision classes (consider DRY refactor if > 3 uses)

## Cost Analysis

**Estimate:** ~$0.90 USD  
**Budget:** $10 USD  
**Status:** ✅ **Well Under Budget**

Token breakdown:
- Input: ~50K tokens (reading files, understanding code)
- Output: ~180K tokens (writing classes, comments, documentation)
- **Total: ~230K tokens** at Haiku 4.5 rates = ~$0.90

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**Ready to test! All features are in place and synchronized.**