# Development Guide - Neural Nexus

## Table of Contents

1. [Project Overview](#project-overview)
2. [Architecture](#architecture)
3. [Technology Stack](#technology-stack)
4. [Development Setup](#development-setup)
5. [Project Structure](#project-structure)
6. [Development Workflow](#development-workflow)
7. [Game Design Guidelines](#game-design-guidelines)
8. [Code Standards](#code-standards)
9. [Testing Strategy](#testing-strategy)
10. [Performance Guidelines](#performance-guidelines)
11. [Deployment Process](#deployment-process)
12. [Troubleshooting](#troubleshooting)

## Project Overview

### Vision
Neural Nexus is a modern HTML5 puzzle game that challenges players to connect neural network nodes in specific patterns. We're building an engaging, visually appealing game that combines contemporary themes with accessible gameplay mechanics.

### Goals
- **Primary:** Create a polished, addictive puzzle game with 50+ levels
- **Secondary:** Achieve smooth 60fps performance across all modern devices
- **Success Metrics:** 
  - 5+ minute average session time
  - 80%+ level completion rate for first 10 levels
  - <3 second load time on mobile devices

### Target Users
- **Primary Users:** Casual puzzle game players aged 16-45
- **Use Cases:** Quick gaming sessions, brain training, stress relief
- **User Needs:** Engaging mental challenge without complexity overload

## Architecture

### System Design
```
┌─────────────────┐     ┌─────────────────┐
│   Game UI       │────▶│   Game State    │
│ (Canvas/HTML)   │     │   Manager       │
└─────────────────┘     └─────────────────┘
         │                       │
         ▼                       ▼
┌─────────────────┐     ┌─────────────────┐
│  Render Engine  │     │   Game Logic    │
│ (Canvas 2D API) │     │ (Nodes/Levels)  │
└─────────────────┘     └─────────────────┘
         │                       │
         ▼                       ▼
┌─────────────────┐     ┌─────────────────┐
│  Input Handler  │     │  Local Storage  │
│(Mouse/Touch)    │     │  (Save Data)    │
└─────────────────┘     └─────────────────┘
```

### Component Relationships
- **Game State:** Central store for level progress, score, timer
- **Rendering:** Canvas-based with CSS for UI overlays
- **Input System:** Unified mouse/touch handling for connections
- **Game Objects:** Node and Connection classes with physics

### Design Decisions
| Decision | Choice | Rationale |
|----------|--------|-----------|
| Graphics API | Canvas 2D | Excellent performance, wide compatibility, simpler than WebGL |
| State Management | Single Global Object | Sufficient for game scope, easy debugging |
| Input Handling | Event-based | Responsive feel, works across devices |
| Styling | CSS + Canvas | Leverage CSS for UI, Canvas for game graphics |

## Technology Stack

### Core Technologies
- **Frontend:** Vanilla HTML5, JavaScript ES6+, CSS3
- **Graphics:** Canvas 2D API with CSS animations
- **Architecture:** Object-oriented game components
- **Storage:** LocalStorage for save data and preferences

### Key Libraries
```json
{
  "dependencies": {
    "No external dependencies": "Vanilla JS for maximum performance and control"
  }
}
```

### Development Tools
- **Browser DevTools:** Performance profiling and debugging
- **Testing:** Manual testing across browsers and devices
- **Version Control:** Git with feature branching
- **Performance:** Lighthouse for optimization audits

## Game Design Guidelines

### Core Mechanics Principles
1. **Clarity:** Player immediately understands connection system
2. **Progressive Difficulty:** Each level introduces manageable challenge increase
3. **Feedback:** Visual and audio cues for all player actions
4. **Flow State:** Difficulty curve maintains engagement without frustration

### Level Design Standards
```javascript
// Level generation guidelines
const levelDesign = {
  nodes: {
    minimum: 3,
    maximum: 12,
    progression: "gradual increase with occasional easier levels"
  },
  connections: {
    formula: "nodeCount - 1 + Math.floor(level / 3)",
    maxComplexity: "avoid overly complex patterns"
  },
  timing: {
    baseTime: 60,
    adjustment: "decrease by 2 seconds every 3 levels",
    minimum: 30
  }
};
```

## Performance Guidelines

### Target Metrics
- **Frame Rate:** 60fps on desktop, 30fps+ on mobile
- **Load Time:** <3 seconds on 3G connection
- **Memory Usage:** <50MB on mobile devices
- **Bundle Size:** <1MB total (including assets)

### Optimization Techniques

1. **Rendering Optimization**
   ```javascript
   // Efficient canvas clearing
   function clearCanvas() {
     ctx.clearRect(0, 0, canvas.width, canvas.height);
     // Better than: ctx.fillRect() for transparency
   }

   // Object pooling for particles
   class ParticlePool {
     constructor(size = 100) {
       this.pool = [];
       this.active = [];
       for (let i = 0; i < size; i++) {
         this.pool.push(new Particle());
       }
     }
     
     acquire() {
       return this.pool.pop() || new Particle();
     }
     
     release(particle) {
       particle.reset();
       this.pool.push(particle);
     }
   }
   ```

2. **Event Handling Optimization**
   ```javascript
   // Throttle mouse move events
   function throttle(func, delay) {
     let timeoutId;
     return (...args) => {
       clearTimeout(timeoutId);
       timeoutId = setTimeout(() => func(...args), delay);
     };
   }

   const throttledMouseMove = throttle(handleMouseMove, 16); // ~60fps
   ```

## Troubleshooting

### Common Development Issues

#### Performance Problems
**Problem:** Game running slowly, stuttering animations
```javascript
// Debug: Check frame time
function debugFrameTime() {
  const times = [];
  let lastTime = performance.now();
  
  function measureFrame() {
    const now = performance.now();
    times.push(now - lastTime);
    lastTime = now;
    
    if (times.length > 60) {
      const avg = times.reduce((a, b) => a + b) / times.length;
      console.log(`Average frame time: ${avg.toFixed(2)}ms`);
      times.length = 0;
    }
    
    requestAnimationFrame(measureFrame);
  }
  
  measureFrame();
}
```

**Solutions:**
- Reduce particle count
- Optimize drawing operations
- Use `requestAnimationFrame` properly
- Check for memory leaks

### Debug Tools
```javascript
// Development debug helper
if (location.hostname === 'localhost') {
  window.gameDebug = {
    state: () => console.table(gameState),
    skipLevel: () => showLevelComplete(),
    addTime: (seconds) => gameState.timeLeft += seconds,
    setLevel: (level) => {
      gameState.level = level;
      generateLevel(level);
    },
    performance: () => {
      console.log('Nodes:', gameState.nodes.length);
      console.log('Connections:', gameState.connections.length);
      console.log('Memory:', performance.memory?.usedJSHeapSize);
    }
  };
}
```

---

**Remember:** This is a living document. Update it as the game evolves and you discover new patterns or solutions!