chess/docs/review/performance-report.md

# Performance Report - Chess Game Implementation

**Report Date**: 2025-11-22
**Reviewer**: Reviewer Agent (Performance Analysis)
**Swarm ID**: swarm-chess-game
**Status**: ❌ **CANNOT ASSESS - NO IMPLEMENTATION**

---

## Executive Summary

**CRITICAL**: Performance analysis cannot be performed because no implementation exists.

**Performance Metrics Status**:
- Lighthouse Score: ❌ **N/A - No app to test**
- Bundle Size: ❌ **N/A - No build**
- Rendering Performance: ❌ **N/A - No UI**
- Move Validation Speed: ❌ **N/A - No game logic**
- Browser Compatibility: ❌ **N/A - No code**

**Overall Performance Rating**: **0/10 - CANNOT MEASURE**

---

## 1. Lighthouse Performance Analysis

### 1.1 Desktop Performance

**Target**: Lighthouse Score >90

**Metrics**:
- [ ] Performance: >90
- [ ] Accessibility: >90
- [ ] Best Practices: >90
- [ ] SEO: >90

**Actual**: ❌ **CANNOT MEASURE - No HTML page exists**

**Status**: ❌ **BLOCKED**

---

### 1.2 Mobile Performance

**Target**: Lighthouse Score >85 (mobile)

**Metrics**:
- [ ] Performance: >85
- [ ] First Contentful Paint: <1.8s
- [ ] Largest Contentful Paint: <2.5s
- [ ] Time to Interactive: <3.8s
- [ ] Cumulative Layout Shift: <0.1

**Actual**: ❌ **CANNOT MEASURE**

**Status**: ❌ **BLOCKED**

---

## 2. Bundle Size Analysis

### 2.1 JavaScript Bundle

**Target**: <150KB gzipped

**Expected Breakdown**:
```
Total Bundle: 120KB (gzipped)
├── Core Game Logic: 45KB
│   ├── Models: 15KB
│   ├── Controllers: 12KB
│   ├── Views: 10KB
│   └── Utils: 8KB
├── Move Validation Engine: 35KB
├── UI Components: 25KB
├── AI Engine (Optional): 40KB
└── Dependencies: 15KB
```

**Actual**: ❌ **NO BUILD - Cannot measure**

**Status**: ❌ **BLOCKED**

---

### 2.2 Asset Size

**Target**: <50KB total

**Expected Assets**:
- Piece images (SVG): 12 pieces × 2KB = 24KB
- Sound effects: 5 files × 3KB = 15KB
- CSS: ~10KB
- Total: ~49KB

**Actual**: ❌ **NO ASSETS - Cannot measure**

**Status**: ❌ **BLOCKED**

---

## 3. Runtime Performance

### 3.1 Move Validation Speed

**Target**: <100ms per move validation

**Test Scenarios**:
- Simple pawn move: <10ms
- Knight move: <15ms
- Complex queen move: <30ms
- Check detection: <50ms
- Checkmate detection: <100ms
- Position evaluation (AI): <200ms

**Actual**: ❌ **NO IMPLEMENTATION - Cannot measure**

**Status**: ❌ **BLOCKED**

---

### 3.2 Rendering Performance

**Target**: 60 FPS (16.67ms per frame)

**Test Scenarios**:
- Board initial render: <50ms
- Piece movement animation: 60 FPS
- Highlight updates: <16ms
- Move history scroll: 60 FPS
- Simultaneous animations: 60 FPS

**Actual**: ❌ **NO UI - Cannot measure**

**Status**: ❌ **BLOCKED**

---

### 3.3 Memory Usage

**Target**: <100MB RAM usage

**Expected Memory Profile**:
- Game state: ~2MB
- Board representation: ~1MB
- Move history (100 moves): ~5MB
- UI elements: ~10MB
- Total baseline: ~20MB

**Actual**: ❌ **NO APP - Cannot measure**

**Status**: ❌ **BLOCKED**

---

## 4. Browser Compatibility Matrix

### 4.1 Desktop Browsers

**Target**: 100% compatibility on modern browsers

| Browser | Version | Status | Performance | Notes |
|---------|---------|--------|-------------|-------|
| Chrome | Latest | ❌ N/A | ❌ N/A | Not tested |
| Firefox | Latest | ❌ N/A | ❌ N/A | Not tested |
| Safari | Latest | ❌ N/A | ❌ N/A | Not tested |
| Edge | Latest | ❌ N/A | ❌ N/A | Not tested |
| Opera | Latest | ❌ N/A | ❌ N/A | Not tested |

**Status**: ❌ **NO TESTS RUN**

---

### 4.2 Mobile Browsers

**Target**: 100% compatibility on iOS Safari and Chrome Android

| Browser | Platform | Status | Performance | Notes |
|---------|----------|--------|-------------|-------|
| Safari | iOS 15+ | ❌ N/A | ❌ N/A | Not tested |
| Chrome | Android 10+ | ❌ N/A | ❌ N/A | Not tested |
| Firefox | Android | ❌ N/A | ❌ N/A | Not tested |
| Samsung Browser | Android | ❌ N/A | ❌ N/A | Not tested |

**Status**: ❌ **NO TESTS RUN**

---

### 4.3 Feature Support

**Target**: All ES6+ features supported with polyfills if needed

| Feature | Chrome | Firefox | Safari | Edge | Polyfill Needed |
|---------|--------|---------|--------|------|-----------------|
| ES6 Classes | ❌ N/A | ❌ N/A | ❌ N/A | ❌ N/A | N/A |
| Arrow Functions | ❌ N/A | ❌ N/A | ❌ N/A | ❌ N/A | N/A |
| Destructuring | ❌ N/A | ❌ N/A | ❌ N/A | ❌ N/A | N/A |
| Template Literals | ❌ N/A | ❌ N/A | ❌ N/A | ❌ N/A | N/A |
| Promises | ❌ N/A | ❌ N/A | ❌ N/A | ❌ N/A | N/A |
| LocalStorage | ❌ N/A | ❌ N/A | ❌ N/A | ❌ N/A | N/A |
| Drag & Drop API | ❌ N/A | ❌ N/A | ❌ N/A | ❌ N/A | N/A |

**Status**: ❌ **CANNOT TEST**

---

## 5. Responsive Design Performance

### 5.1 Viewport Testing

**Target**: Smooth performance at all viewport sizes

| Viewport | Size | Performance | Layout | Notes |
|----------|------|-------------|--------|-------|
| Mobile Portrait | 320×568 | ❌ N/A | ❌ N/A | Not tested |
| Mobile Landscape | 568×320 | ❌ N/A | ❌ N/A | Not tested |
| Tablet Portrait | 768×1024 | ❌ N/A | ❌ N/A | Not tested |
| Tablet Landscape | 1024×768 | ❌ N/A | ❌ N/A | Not tested |
| Desktop Small | 1280×720 | ❌ N/A | ❌ N/A | Not tested |
| Desktop Large | 1920×1080 | ❌ N/A | ❌ N/A | Not tested |
| 4K | 2560×1440 | ❌ N/A | ❌ N/A | Not tested |

**Status**: ❌ **NO UI TO TEST**

---

## 6. Network Performance

### 6.1 Load Time Analysis

**Target**: <2s on 3G, <1s on 4G

**Metrics**:
- [ ] Initial HTML: <100ms
- [ ] CSS load: <200ms
- [ ] JS load: <500ms
- [ ] Assets load: <300ms
- [ ] Total time to interactive: <1s (4G), <2s (3G)

**Actual**: ❌ **NO APP TO TEST**

**Status**: ❌ **BLOCKED**

---

### 6.2 Caching Strategy

**Expected**:
- [ ] Service Worker implemented
- [ ] Static assets cached
- [ ] App Shell cached
- [ ] Offline fallback available

**Actual**: ❌ **NOT IMPLEMENTED**

**Status**: ❌ **BLOCKED**

---

## 7. Optimization Opportunities (For Future Implementation)

### 7.1 Code Optimizations

**Recommended Optimizations**:

**1. Bitboards for Position Checking**
```javascript
// Instead of array iteration
// Use bitboards for O(1) position checks
class BitboardOptimizer {
  // Fast position checking
  // ~10x faster than array iteration
}
```

**2. Move Caching**
```javascript
// Cache valid moves for current position
// Invalidate on position change
class MoveCache {
  // Reduce redundant calculations
  // ~5x speedup for AI
}
```

**3. Lazy Loading**
```javascript
// Load AI engine only when needed
// Reduce initial bundle size
const AIEngine = () => import('./ai/AIEngine.js');
```

**4. Virtual Scrolling for History**
```javascript
// Only render visible moves
// Handle 1000+ moves smoothly
class VirtualMoveHistory {
  // Constant memory usage
}
```

**Status**: ⚠️ **RECOMMENDATIONS ONLY - No implementation to optimize**

---

### 7.2 Rendering Optimizations

**Recommended**:

**1. RequestAnimationFrame for Animations**
```javascript
// Smooth 60 FPS animations
function animatePieceMove(piece, from, to) {
  requestAnimationFrame(updatePosition);
}
```

**2. CSS Transforms for Movement**
```css
/* Hardware-accelerated animations */
.piece {
  transform: translate3d(x, y, 0);
  will-change: transform;
}
```

**3. Debounced Window Resize**
```javascript
// Prevent excessive reflows
const handleResize = debounce(() => {
  resizeBoard();
}, 100);
```

**Status**: ⚠️ **RECOMMENDATIONS ONLY**

---

### 7.3 Memory Optimizations

**Recommended**:

**1. Object Pooling for Positions**
```javascript
// Reuse position objects
// Reduce GC pressure
class PositionPool {
  // ~50% memory reduction
}
```

**2. Efficient Move History**
```javascript
// Store deltas instead of full positions
class CompressedHistory {
  // ~80% memory reduction
}
```

**Status**: ⚠️ **RECOMMENDATIONS ONLY**

---

## 8. Performance Benchmarks (Cannot Run)

### 8.1 Expected Benchmarks

**Core Operations** (Expected performance):
- Board initialization: <10ms
- Piece creation: <1ms per piece
- Move validation: <50ms
- Legal moves generation: <30ms
- Check detection: <20ms
- Checkmate detection: <100ms
- Position evaluation: <200ms

**UI Operations** (Expected performance):
- Initial render: <50ms
- Piece selection: <5ms
- Move highlight: <10ms
- Animation frame: <16ms (60 FPS)
- History update: <20ms

**Actual Benchmarks**: ❌ **CANNOT RUN - No implementation**

---

### 8.2 AI Performance (If Implemented)

**Expected AI Performance**:
- Depth 1 search: <50ms
- Depth 2 search: <200ms
- Depth 3 search: <1000ms
- Depth 4 search: <5000ms
- Depth 5 search: <30000ms

**Optimizations**:
- Alpha-beta pruning: ~10x speedup
- Move ordering: ~2x speedup
- Transposition table: ~3x speedup
- Web Worker: No UI blocking

**Actual Performance**: ❌ **NO AI IMPLEMENTED**

---

## 9. Critical Performance Issues (None Found - No Code)

### No Issues Detected

**Reason**: No implementation exists to analyze for performance issues.

**Potential Issues to Watch For** (during implementation):

**1. N+1 Query Problem in Move Validation**
```javascript
// ❌ BAD: Checking each square individually
for (let square of allSquares) {
  if (isPieceAt(square)) { /* ... */ }
}

// ✅ GOOD: Single position lookup
const positions = getPiecePositions(); // O(1) lookup
```

**2. Unnecessary Re-renders**
```javascript
// ❌ BAD: Re-rendering entire board on every move
function updateBoard() {
  renderEntireBoard(); // Slow
}

// ✅ GOOD: Update only changed squares
function updateBoard(move) {
  updateSquare(move.from);
  updateSquare(move.to);
}
```

**3. Memory Leaks in Event Listeners**
```javascript
// ❌ BAD: Not removing listeners
squares.forEach(sq => {
  sq.addEventListener('click', handler);
});

// ✅ GOOD: Clean up on destroy
class BoardView {
  destroy() {
    this.squares.forEach(sq => {
      sq.removeEventListener('click', this.handler);
    });
  }
}
```

---

## 10. Performance Testing Plan

### 10.1 Automated Performance Tests

**To Implement**:

```javascript
// Lighthouse CI Configuration
module.exports = {
  ci: {
    collect: {
      numberOfRuns: 3,
      url: ['http://localhost:8080']
    },
    assert: {
      assertions: {
        'categories:performance': ['error', { minScore: 0.9 }],
        'categories:accessibility': ['error', { minScore: 0.9 }],
        'categories:best-practices': ['error', { minScore: 0.9 }]
      }
    }
  }
};
```

**Status**: ❌ **NOT CONFIGURED**

---

### 10.2 Manual Performance Tests

**Test Scenarios**:
1. Load time on 3G connection
2. 60 FPS animation smoothness
3. Memory usage during 100-move game
4. AI response time at different difficulty levels
5. Rapid piece movements (stress test)
6. Multiple tabs open (memory leak test)

**Status**: ❌ **CANNOT TEST - No app**

---

## 11. Performance Recommendations for Implementation

### Phase 1: MVP (Focus on Correctness)
- ✅ Implement clean, readable code
- ✅ Don't optimize prematurely
- ✅ Get features working first
- ⚠️ Measure baseline performance

### Phase 2: Optimization (After MVP Works)
- ✅ Profile with Chrome DevTools
- ✅ Identify bottlenecks
- ✅ Optimize hot paths
- ✅ Implement caching where beneficial

### Phase 3: Polish (Final optimizations)
- ✅ Code splitting
- ✅ Lazy loading
- ✅ Bundle optimization
- ✅ Service Worker caching

---

## 12. Performance Monitoring Setup

### 12.1 Recommended Tools

**Development**:
- Chrome DevTools Performance Panel
- React DevTools Profiler (if using React)
- Lighthouse
- WebPageTest

**Production**:
- Google Analytics Performance
- Real User Monitoring (RUM)
- Error tracking (Sentry)

**Status**: ❌ **NOT CONFIGURED**

---

### 12.2 Performance Metrics Dashboard

**Key Metrics to Track**:
- Page load time (p50, p95, p99)
- Time to interactive
- Bundle size over time
- Core Web Vitals (LCP, FID, CLS)
- API response times
- Error rates

**Status**: ❌ **NOT IMPLEMENTED**

---

## 13. Verdict

### Performance Rating: **0/10 - CANNOT ASSESS**

**Reason**: No implementation exists to analyze.

**Status**: ❌ **BLOCKED - IMPLEMENTATION REQUIRED**

**Recommendation**:
1. Complete implementation first
2. Run Lighthouse audits
3. Measure bundle size
4. Test browser compatibility
5. Benchmark core operations
6. Optimize based on real data

---

## 14. Performance Checklist (For Future Implementation)

### Build Performance
- [ ] Bundle size <150KB gzipped
- [ ] Code splitting implemented
- [ ] Tree shaking enabled
- [ ] Minification enabled
- [ ] Compression (gzip/brotli) configured

### Runtime Performance
- [ ] Move validation <100ms
- [ ] 60 FPS rendering maintained
- [ ] No memory leaks
- [ ] Efficient event handling
- [ ] Lazy loading for AI

### Network Performance
- [ ] Load time <2s (3G)
- [ ] Service Worker caching
- [ ] Asset optimization
- [ ] CDN for static assets

### Browser Compatibility
- [ ] Chrome (latest) - 100% functional
- [ ] Firefox (latest) - 100% functional
- [ ] Safari (latest) - 100% functional
- [ ] Edge (latest) - 100% functional
- [ ] Mobile browsers tested

### Accessibility Performance
- [ ] Keyboard navigation smooth
- [ ] Screen reader performant
- [ ] High contrast mode supported
- [ ] Reduced motion respected

**Current Status**: 0/25 items completed (0%)

---

## 15. Sign-Off

**Performance Analyst**: Reviewer Agent
**Analysis Type**: Performance & Compatibility Review
**Status**: ❌ **CANNOT COMPLETE - NO IMPLEMENTATION**
**Date**: 2025-11-22

**Critical Finding**: Performance analysis cannot be performed without an implementation. All performance metrics, benchmarks, and compatibility tests are blocked until code is written.

**Action Required**: Complete implementation, then re-run this performance analysis.

---

**FINAL VERDICT**: ❌ **IMPLEMENTATION REQUIRED - PERFORMANCE ANALYSIS BLOCKED**

---

## Appendix A: Performance Budget

### Recommended Performance Budget

**For implementation team to follow:**

```json
{
  "budget": {
    "javascript": {
      "total": 150,
      "vendor": 50,
      "app": 100
    },
    "css": {
      "total": 30
    },
    "images": {
      "total": 50
    },
    "fonts": {
      "total": 20
    }
  },
  "metrics": {
    "loadTime": {
      "3g": 2000,
      "4g": 1000
    },
    "fps": 60,
    "lighthouse": {
      "performance": 90,
      "accessibility": 90,
      "bestPractices": 90
    }
  }
}
```

All values in KB (except loadTime in ms, fps, and lighthouse scores).