proffesor-for-testing__agentic-qe/docs/architecture/phase3-architecture.md

# Phase 3 Architecture: QUIC Transport + Neural Training Integration

**Version:** 1.0.0
**Date:** 2025-10-20
**Status:** Design Complete
**Author:** System Architecture Team

---

## Executive Summary

This document defines the comprehensive architecture for integrating AgentDB's advanced features into the Agentic QE Fleet system. AgentDB replaces custom QUIC transport and neural training implementations with battle-tested, production-ready solutions. The design ensures zero breaking changes, maintains backward compatibility, and provides simple APIs for QE agents.

### Key Objectives

1. **AgentDB QUIC Sync**: Sub-millisecond distributed memory synchronization using AgentDB's built-in QUIC transport with automatic encryption, retry, and multiplexing
2. **AgentDB Learning Plugins**: 9 reinforcement learning algorithms (Decision Transformer, Q-Learning, SARSA, Actor-Critic, etc.) for intelligent pattern prediction
3. **Simple Agent Integration**: Provide transparent APIs through BaseAgent mixins and optional configuration
4. **Zero Breaking Changes**: All features opt-in with feature flags
5. **Performance Targets**: <1ms QUIC sync latency, 150x faster vector search, 85%+ prediction accuracy with proven algorithms

---

## Table of Contents

1. [System Overview](#1-system-overview)
2. [QUIC Transport Architecture](#2-quic-transport-architecture)
3. [Neural Training Architecture](#3-neural-training-architecture)
4. [Agent Integration Pattern](#4-agent-integration-pattern)
5. [Data Flow Architecture](#5-data-flow-architecture)
6. [Configuration Schema](#6-configuration-schema)
7. [Implementation Roadmap](#7-implementation-roadmap)
8. [Performance Characteristics](#8-performance-characteristics)
9. [Testing Strategy](#9-testing-strategy)

---

## 1. System Overview

### 1.1 Current Architecture (Phase 1-2)

```
┌─────────────────────────────────────────────────────────────────┐
│                         FleetManager                            │
│  ┌───────────────────────────────────────────────────────────┐ │
│  │  - HTTP-based agent communication                         │ │
│  │  - SwarmMemoryManager (SQLite)                            │ │
│  │  - QEReasoningBank (in-memory patterns)                   │ │
│  │  - LearningEngine (Q-learning)                            │ │
│  └───────────────────────────────────────────────────────────┘ │
│                              │                                  │
│                              ▼                                  │
│  ┌───────────────────────────────────────────────────────────┐ │
│  │                      BaseAgent                            │ │
│  │  - EventBus for agent coordination                        │ │
│  │  - Memory operations via SwarmMemoryManager               │ │
│  │  - Pattern matching via QEReasoningBank                   │ │
│  └───────────────────────────────────────────────────────────┘ │
└─────────────────────────────────────────────────────────────────┘
```

### 1.2 Target Architecture (Phase 3 - AgentDB Powered)

```
┌─────────────────────────────────────────────────────────────────────────────┐
│                              FleetManager                                   │
│  ┌────────────────────────────────────────────────────────────────────────┐ │
│  │  Configuration with AgentDB Integration                                │ │
│  │  {                                                                     │ │
│  │    features: {                                                         │ │
│  │      agentDBSync: false,          // v1.1.0 (opt-in)                  │ │
│  │      agentDBLearning: false        // v1.1.0 (opt-in)                 │ │
│  │    },                                                                  │ │
│  │    agentdb: {                                                          │ │
│  │      dbPath: '.agentdb/fleet.db',                                      │ │
│  │      enableQUICSync: true,                                             │ │
│  │      syncPort: 4433,                                                   │ │
│  │      syncPeers: ['node1:4433', 'node2:4433'],                         │ │
│  │      enableLearning: true,                                             │ │
│  │      learningAlgorithm: 'decision-transformer'  // 9 algorithms       │ │
│  │    }                                                                   │ │
│  │  }                                                                     │ │
│  └────────────────────────────────────────────────────────────────────────┘ │
│                                     │                                       │
│                                     ▼                                       │
│  ┌─────────────────────────────────────────────────────────────────────┐  │
│  │                      AgentDB Core (Production)                      │  │
│  │  ┌──────────────────┬──────────────────┬─────────────────────┐     │  │
│  │  │ QUIC Sync        │  Vector Search   │  Learning Plugins   │     │  │
│  │  │ - <1ms latency   │  - 150x faster   │  - 9 RL algorithms  │     │  │
│  │  │ - TLS 1.3        │  - Hybrid search │  - WASM accelerated │     │  │
│  │  │ - Auto-retry     │  - Custom metrics│  - Pre-trained      │     │  │
│  │  │ - Multiplexing   │  - Metadata      │  - Decision Transf. │     │  │
│  │  └──────────────────┴──────────────────┴─────────────────────┘     │  │
│  └─────────────────────────────────────────────────────────────────────┘  │
│                                     │                                       │
│                                     ▼                                       │
│  ┌─────────────────────────────────────────────────────────────────────┐  │
│  │                  AgentDB ReasoningBank Adapter                       │  │
│  │  ┌──────────────────┬──────────────────┬─────────────────────┐     │  │
│  │  │  Pattern Storage │  Learning Engine │  Sync Manager       │     │  │
│  │  │  - Vector index  │  - 9 algorithms  │  - QUIC broadcast   │     │  │
│  │  │  - Metadata      │  - Auto-train    │  - Peer discovery   │     │  │
│  │  │  - Similarity    │  - Experience    │  - Conflict resolve │     │  │
│  │  └──────────────────┴──────────────────┴─────────────────────┘     │  │
│  └─────────────────────────────────────────────────────────────────────┘  │
│                                     │                                       │
│                                     ▼                                       │
│  ┌─────────────────────────────────────────────────────────────────────┐  │
│  │                      BaseAgent (AgentDB Enhanced)                   │  │
│  │  ┌──────────────────┬──────────────────┬─────────────────────┐     │  │
│  │  │  AgentDBMixin    │  LearningMixin   │  LegacySupport      │     │  │
│  │  │  - syncPattern() │  - predictAction │  - Fallback mode    │     │  │
│  │  │  - queryPattern()│  - learnFromExp  │  - Graceful degrade │     │  │
│  │  │  - auto-sync     │  - 9 algorithms  │  - Zero breaking    │     │  │
│  │  └──────────────────┴──────────────────┴─────────────────────┘     │  │
│  └─────────────────────────────────────────────────────────────────────┘  │
└─────────────────────────────────────────────────────────────────────────────┘
```

---

## 2. QUIC Transport Architecture

### 2.1 Overview

QUIC (Quick UDP Internet Connections) provides faster connection establishment, multiplexed streams, and built-in encryption compared to TCP/HTTP.

**Benefits for AQE Fleet:**
- **50-70% latency reduction** for agent-to-agent messaging
- **0-RTT connection resumption** for known peers
- **Built-in TLS 1.3** encryption for security
- **Stream multiplexing** without head-of-line blocking
- **Automatic TCP fallback** when QUIC unavailable

### 2.2 Component Design

#### 2.2.1 QUICTransportManager

```typescript
/**
 * QUICTransportManager - Manages QUIC connections between agents
 *
 * Features:
 * - Automatic peer discovery via SwarmMemoryManager
 * - Connection pooling with configurable limits
 * - Health monitoring and automatic failover
 * - Graceful degradation to TCP when QUIC unavailable
 */
export class QUICTransportManager {
  private server?: QuicServer;
  private connections: Map<string, QuicConnection>;
  private peerRegistry: PeerRegistry;
  private fallbackHandler: FallbackHandler;
  private config: QUICConfig;

  constructor(config: QUICConfig, memoryManager: SwarmMemoryManager);

  /**
   * Initialize QUIC server and start listening
   * - Binds to configured port (default: 4433)
   * - Loads TLS certificates
   * - Registers with peer discovery
   *
   * @throws {QUICError} if port unavailable or certs invalid
   */
  async initialize(): Promise<void>;

  /**
   * Connect to a remote agent via QUIC
   * - Auto-discovers peer address from SwarmMemoryManager
   * - Establishes QUIC connection or falls back to TCP
   * - Pools connection for reuse
   *
   * @param agentId - Target agent identifier
   * @returns Connection handle
   */
  async connectToPeer(agentId: string): Promise<Connection>;

  /**
   * Send message to peer agent
   * - Uses existing connection or creates new one
   * - Automatically retries on transient failures
   * - Falls back to TCP if QUIC fails
   *
   * @param agentId - Target agent
   * @param message - AgentMessage payload
   * @returns Promise resolving when message delivered
   */
  async sendMessage(agentId: string, message: AgentMessage): Promise<void>;

  /**
   * Subscribe to messages from peer agents
   * - Receives messages via QUIC streams
   * - Deserializes and validates messages
   * - Emits events to EventBus
   *
   * @param messageType - Message type filter
   * @param handler - Callback for received messages
   */
  async subscribe(
    messageType: MessageType,
    handler: (message: AgentMessage) => void
  ): Promise<void>;

  /**
   * Gracefully shutdown QUIC server
   * - Closes all active connections
   * - Waits for in-flight messages
   * - Deregisters from peer discovery
   */
  async shutdown(): Promise<void>;
}
```

#### 2.2.2 PeerRegistry

```typescript
/**
 * PeerRegistry - Maintains active peer list for connection pooling
 *
 * Integrates with SwarmMemoryManager agent_registry table:
 * - Reads active agents from agent_registry
 * - Stores QUIC address info in metadata column
 * - Monitors agent status changes via events
 */
export class PeerRegistry {
  private peers: Map<string, PeerInfo>;
  private memoryManager: SwarmMemoryManager;
  private eventBus: EventEmitter;

  /**
   * PeerInfo structure stored in agent_registry.metadata:
   * {
   *   quicAddress: string;  // "127.0.0.1:4433"
   *   quicEnabled: boolean;
   *   lastSeen: number;
   *   latency: number;      // Moving average (ms)
   *   reliability: number;  // Success rate (0-1)
   * }
   */

  /**
   * Discover active peers from agent_registry
   * - Queries agent_registry for status='active'
   * - Extracts QUIC address from metadata
   * - Tests connectivity via ping
   */
  async discoverPeers(): Promise<PeerInfo[]>;

  /**
   * Register this agent in agent_registry
   * - Stores QUIC address in metadata
   * - Sets status to 'active'
   * - Starts heartbeat timer
   */
  async registerSelf(agentId: string, quicAddress: string): Promise<void>;

  /**
   * Update peer metrics based on connection performance
   * - Updates latency (exponential moving average)
   * - Updates reliability (success rate)
   * - Stores in agent_registry.performance column
   */
  async updatePeerMetrics(
    peerId: string,
    latency: number,
    success: boolean
  ): Promise<void>;

  /**
   * Get optimal peer for load balancing
   * - Considers latency, reliability, current load
   * - Returns peer with best composite score
   */
  getOptimalPeer(peers: string[]): string | null;
}
```

#### 2.2.3 FallbackHandler

```typescript
/**
 * FallbackHandler - Manages automatic TCP fallback when QUIC fails
 *
 * Fallback scenarios:
 * 1. QUIC port blocked by firewall
 * 2. UDP packet loss exceeds threshold
 * 3. TLS certificate validation fails
 * 4. Connection timeout after retries
 */
export class FallbackHandler {
  private fallbackMode: Map<string, TransportMode>; // per-peer fallback state
  private circuitBreaker: CircuitBreaker;

  /**
   * Attempt connection with automatic fallback
   *
   * Strategy:
   * 1. Try QUIC first (if enabled and not failed previously)
   * 2. On failure, switch to TCP for this peer
   * 3. Retry QUIC after cooldown period (5min)
   * 4. Circuit breaker opens after 5 consecutive failures
   */
  async connectWithFallback(
    peerId: string,
    quicConnect: () => Promise<Connection>,
    tcpConnect: () => Promise<Connection>
  ): Promise<Connection>;

  /**
   * Check if we should attempt QUIC for this peer
   * - Returns false if circuit breaker open
   * - Returns false if peer previously failed QUIC
   * - Returns true otherwise
   */
  shouldAttemptQUIC(peerId: string): boolean;

  /**
   * Record connection success/failure for circuit breaker
   */
  recordResult(peerId: string, success: boolean, protocol: 'QUIC' | 'TCP'): void;
}
```

### 2.3 Integration with SwarmMemoryManager

QUIC transport integrates seamlessly with existing SwarmMemoryManager:

```typescript
// Store peer connection info in agent_registry table
await memoryManager.registerAgent({
  id: agentId,
  type: 'qe-test-generator',
  capabilities: ['test-generation'],
  status: 'active',
  performance: {
    quicAddress: '127.0.0.1:4433',
    quicEnabled: true,
    latency: 12.5,        // ms
    reliability: 0.98     // 98% success rate
  }
});

// Query active peers for QUIC connections
const activePeers = await memoryManager.queryAgentsByStatus('active');
for (const peer of activePeers) {
  const perf = peer.performance;
  if (perf.quicEnabled) {
    await quicManager.connectToPeer(peer.id);
  }
}
```

### 2.4 Message Protocol

QUIC messages use same AgentMessage interface as HTTP:

```typescript
interface AgentMessage {
  id: string;
  from: AgentId;
  to: AgentId;
  type: MessageType;
  payload: any;
  timestamp: Date;
  priority: 'low' | 'medium' | 'high' | 'critical';

  // Phase 3 additions
  transport?: 'QUIC' | 'TCP';      // Transport used
  streamId?: number;                // QUIC stream ID
  retryCount?: number;              // Retry attempts
}
```

### 2.5 Performance Characteristics

| Metric | HTTP (Current) | QUIC (Target) | Improvement |
|--------|----------------|---------------|-------------|
| Connection handshake | 100-200ms | <10ms | 90-95% |
| Message latency | 20-50ms | 10-15ms | 50-70% |
| Throughput | 1000 msg/s | 5000 msg/s | 5x |
| Connection overhead | High (TCP+TLS) | Low (QUIC) | 60% |
| Reliability | 99.5% | 99.9% | 0.4% |

---

## 3. Neural Training Architecture

### 3.1 Overview

Neural training enables agents to learn optimal patterns from historical test data and predict best strategies for new tasks.

**Benefits for AQE Fleet:**
- **85%+ prediction accuracy** for test generation strategies
- **30-40% reduction** in manual test case creation
- **Continuous learning** from test execution results
- **Transfer learning** across similar projects

### 3.2 Component Design

#### 3.2.1 NeuralPatternMatcher

```typescript
/**
 * NeuralPatternMatcher - Neural network-based pattern prediction
 *
 * Features:
 * - Trains on historical test patterns from QEReasoningBank
 * - Predicts optimal test patterns for new code
 * - Provides confidence scores for recommendations
 * - Supports online learning (updates as new data arrives)
 */
export class NeuralPatternMatcher {
  private model?: TensorFlowModel;
  private reasoningBank: QEReasoningBank;
  private trainingPipeline: TrainingPipeline;
  private inferenceEngine: InferenceEngine;
  private cache: PatternCache;
  private config: NeuralConfig;

  constructor(
    config: NeuralConfig,
    reasoningBank: QEReasoningBank,
    memoryManager: SwarmMemoryManager
  );

  /**
   * Initialize neural model
   * - Loads pre-trained model if available
   * - Otherwise initializes new model
   * - Warms up cache with common patterns
   *
   * @param modelPath - Path to saved model (optional)
   */
  async initialize(modelPath?: string): Promise<void>;

  /**
   * Train model on historical patterns
   * - Ingests patterns from QEReasoningBank
   * - Extracts features (keywords, complexity, success rate)
   * - Trains neural network via backpropagation
   * - Validates on hold-out set (20% of data)
   *
   * @param patterns - Training data from QEReasoningBank
   * @returns Training metrics (loss, accuracy, validation score)
   */
  async train(patterns: TestPattern[]): Promise<TrainingMetrics>;

  /**
   * Predict optimal pattern for code context
   * - Extracts features from code/task description
   * - Runs inference through neural network
   * - Returns top-K patterns with confidence scores
   * - Caches prediction for similar contexts
   *
   * @param context - Code context (same as QEReasoningBank)
   * @param topK - Number of predictions to return
   * @returns Predicted patterns with confidence
   */
  async predict(
    context: {
      codeType: string;
      framework?: string;
      language?: string;
      keywords?: string[];
      codeSnippet?: string;  // New: actual code for deeper analysis
    },
    topK: number = 5
  ): Promise<NeuralPrediction[]>;

  /**
   * Update model with new task result (online learning)
   * - Records task outcome (success/failure)
   * - Updates model weights incrementally
   * - No need for full retraining
   *
   * @param taskId - Task identifier
   * @param patternId - Pattern used
   * @param success - Whether task succeeded
   */
  async learnFromTask(
    taskId: string,
    patternId: string,
    success: boolean
  ): Promise<void>;

  /**
   * Save trained model to disk
   * - Serializes model weights
   * - Saves metadata (version, accuracy, timestamp)
   * - Creates checkpoint for rollback
   */
  async saveModel(path: string): Promise<void>;

  /**
   * Get model performance metrics
   * - Accuracy, precision, recall, F1
   * - Training/validation loss
   * - Inference latency (p50, p95, p99)
   */
  async getMetrics(): Promise<ModelMetrics>;
}
```

#### 3.2.2 TrainingPipeline

```typescript
/**
 * TrainingPipeline - Manages model training workflow
 *
 * Steps:
 * 1. Data ingestion from QEReasoningBank
 * 2. Feature extraction (tokenization, embeddings)
 * 3. Model training (batch gradient descent)
 * 4. Validation and evaluation
 * 5. Model persistence
 */
export class TrainingPipeline {
  private featureExtractor: FeatureExtractor;
  private dataLoader: DataLoader;
  private validator: ModelValidator;

  /**
   * Extract features from test patterns
   *
   * Features:
   * - Text embeddings (via pre-trained BERT model)
   * - Pattern metadata (category, framework, language)
   * - Success metrics (confidence, success rate, usage count)
   * - Code complexity metrics (cyclomatic, LOC, dependencies)
   */
  extractFeatures(pattern: TestPattern): Float32Array;

  /**
   * Load training data in batches
   * - Prevents memory overflow with large datasets
   * - Shuffles data for better training
   * - Splits into train/validation/test sets (70/20/10)
   */
  async loadData(
    patterns: TestPattern[],
    batchSize: number = 32
  ): Promise<DataBatch[]>;

  /**
   * Train model on batch
   * - Forward pass (prediction)
   * - Backward pass (gradient calculation)
   * - Weight update (Adam optimizer)
   * - Loss calculation (cross-entropy)
   */
  async trainBatch(
    model: TensorFlowModel,
    batch: DataBatch
  ): Promise<{ loss: number; accuracy: number }>;

  /**
   * Validate model on hold-out set
   * - Calculates accuracy, precision, recall, F1
   * - Generates confusion matrix
   * - Identifies misclassified patterns
   */
  async validate(
    model: TensorFlowModel,
    validationData: DataBatch[]
  ): Promise<ValidationMetrics>;
}
```

#### 3.2.3 InferenceEngine

```typescript
/**
 * InferenceEngine - Fast inference for prediction requests
 *
 * Optimizations:
 * - Batch inference for multiple requests
 * - GPU acceleration (if available)
 * - Result caching (LRU cache)
 * - Warm cache on startup
 */
export class InferenceEngine {
  private model: TensorFlowModel;
  private cache: LRUCache<string, NeuralPrediction[]>;
  private batchQueue: InferenceRequest[];
  private batchTimer?: NodeJS.Timeout;

  /**
   * Run inference on code context
   * - Extracts features
   * - Runs model prediction
   * - Post-processes results (top-K, confidence threshold)
   * - Caches result
   *
   * @param context - Code context
   * @param topK - Number of predictions
   * @returns Predictions with confidence scores
   */
  async infer(
    context: CodeContext,
    topK: number
  ): Promise<NeuralPrediction[]>;

  /**
   * Batch multiple inference requests for efficiency
   * - Queues requests for batching
   * - Triggers batch after timeout or queue full
   * - Distributes results to original requesters
   */
  async batchInfer(
    contexts: CodeContext[]
  ): Promise<NeuralPrediction[][]>;

  /**
   * Warm cache with common patterns
   * - Pre-loads frequent code contexts
   * - Reduces cold-start latency
   */
  async warmCache(commonContexts: CodeContext[]): Promise<void>;
}
```

### 3.3 Integration with QEReasoningBank

Neural training extends QEReasoningBank without replacing it:

```typescript
// QEReasoningBank continues to work without neural features
const reasoningBank = new QEReasoningBank();
await reasoningBank.storePattern(pattern);
const matches = await reasoningBank.findMatchingPatterns(context);

// Neural adds prediction capability when enabled
const neuralMatcher = new NeuralPatternMatcher(
  config,
  reasoningBank,
  memoryManager
);
await neuralMatcher.initialize();

// Train on existing patterns
const patterns = Array.from(reasoningBank['patterns'].values());
await neuralMatcher.train(patterns);

// Predict with neural (higher accuracy than rule-based)
const predictions = await neuralMatcher.predict(context, 5);

// predictions[0] = {
//   pattern: TestPattern,
//   confidence: 0.92,      // Neural confidence (higher than rule-based 0.75)
//   reasoning: "Neural model trained on 500+ similar patterns",
//   modelVersion: "1.0.0",
//   inferenceTime: 8       // ms
// }
```

### 3.4 Training Data Flow

```
┌─────────────────────────────────────────────────────────────┐
│                    QEReasoningBank                          │
│  ┌───────────────────────────────────────────────────────┐ │
│  │  TestPattern storage (in-memory Map)                  │ │
│  │  - 100+ patterns per project                          │ │
│  │  - Success metrics (confidence, usage, success rate)  │ │
│  └───────────────────────────────────────────────────────┘ │
└────────────────────────────┬────────────────────────────────┘
                             │
                             ▼
┌─────────────────────────────────────────────────────────────┐
│                   TrainingPipeline                          │
│  ┌───────────────────────────────────────────────────────┐ │
│  │  1. Ingest patterns from ReasoningBank                │ │
│  │  2. Extract features (embeddings, metadata)           │ │
│  │  3. Split train/val/test (70/20/10)                   │ │
│  │  4. Train neural network                              │ │
│  │  5. Validate on hold-out set                          │ │
│  └───────────────────────────────────────────────────────┘ │
└────────────────────────────┬────────────────────────────────┘
                             │
                             ▼
┌─────────────────────────────────────────────────────────────┐
│                  TensorFlow Model                           │
│  ┌───────────────────────────────────────────────────────┐ │
│  │  Architecture: Multi-layer perceptron                 │ │
│  │  - Input: 512-dim feature vector                      │ │
│  │  - Hidden: [256, 128, 64] neurons                     │ │
│  │  - Output: Softmax over pattern classes              │ │
│  │  - Optimizer: Adam (lr=0.001)                         │ │
│  │  - Loss: Categorical cross-entropy                    │ │
│  └───────────────────────────────────────────────────────┘ │
└────────────────────────────┬────────────────────────────────┘
                             │
                             ▼
┌─────────────────────────────────────────────────────────────┐
│                  InferenceEngine                            │
│  ┌───────────────────────────────────────────────────────┐ │
│  │  - Fast prediction (<50ms p95)                        │ │
│  │  - Batch inference for efficiency                     │ │
│  │  - LRU cache (1000 entries)                           │ │
│  │  - Returns top-K patterns with confidence            │ │
│  └───────────────────────────────────────────────────────┘ │
└─────────────────────────────────────────────────────────────┘
```

### 3.5 Model Architecture

```typescript
/**
 * Neural Network Architecture for Pattern Prediction
 *
 * Input Layer: 512 dimensions
 * - Text embeddings: 384 dims (BERT mini)
 * - Metadata features: 64 dims
 * - Code complexity: 32 dims
 * - Success metrics: 32 dims
 *
 * Hidden Layers:
 * - Dense(256) + ReLU + Dropout(0.2)
 * - Dense(128) + ReLU + Dropout(0.2)
 * - Dense(64) + ReLU + Dropout(0.1)
 *
 * Output Layer:
 * - Dense(num_patterns) + Softmax
 * - Returns probability distribution over patterns
 *
 * Training:
 * - Optimizer: Adam (lr=0.001, beta1=0.9, beta2=0.999)
 * - Loss: Categorical cross-entropy
 * - Batch size: 32
 * - Epochs: 50 (with early stopping)
 * - Validation split: 20%
 *
 * Expected Performance:
 * - Training time: 5-10 minutes (100 patterns)
 * - Inference time: <50ms (p95)
 * - Accuracy: 85-90% (on validation set)
 * - Memory: ~50MB (model weights)
 */
```

---

## 4. Agent Integration Pattern

### 4.1 Overview

QE agents leverage QUIC and Neural features through simple APIs added to BaseAgent. All features are opt-in and backward compatible.

### 4.2 BaseAgent Enhancements

```typescript
/**
 * BaseAgent enhancements for Phase 3
 *
 * New capabilities:
 * 1. QUIC messaging (via QUICMixin)
 * 2. Neural pattern prediction (via NeuralMixin)
 * 3. Automatic fallback (via graceful degradation)
 */

// Add to BaseAgentConfig interface
export interface BaseAgentConfig {
  // ... existing fields ...

  // Phase 3 additions
  enableQuic?: boolean;              // Enable QUIC transport (default: false)
  enableNeural?: boolean;            // Enable neural predictions (default: false)
  quicConfig?: QUICConfig;           // QUIC configuration
  neuralConfig?: NeuralConfig;       // Neural configuration
}

// Enhance BaseAgent class
export abstract class BaseAgent extends EventEmitter {
  // ... existing fields ...

  // Phase 3 additions
  protected quicManager?: QUICTransportManager;
  protected neuralMatcher?: NeuralPatternMatcher;
  protected readonly enableQuic: boolean;
  protected readonly enableNeural: boolean;

  constructor(config: BaseAgentConfig) {
    super();
    // ... existing initialization ...

    this.enableQuic = config.enableQuic ?? false;
    this.enableNeural = config.enableNeural ?? false;
  }

  /**
   * Initialize agent (enhanced for Phase 3)
   */
  public async initialize(): Promise<void> {
    // ... existing initialization ...

    // Initialize QUIC transport if enabled
    if (this.enableQuic && this.memoryStore instanceof SwarmMemoryManager) {
      this.quicManager = new QUICTransportManager(
        this.config.quicConfig || {},
        this.memoryStore
      );
      await this.quicManager.initialize();
      console.info(`[QUIC] Enabled for agent ${this.agentId.id}`);
    }

    // Initialize neural matcher if enabled
    if (this.enableNeural && this.memoryStore instanceof SwarmMemoryManager) {
      const reasoningBank = new QEReasoningBank();
      this.neuralMatcher = new NeuralPatternMatcher(
        this.config.neuralConfig || {},
        reasoningBank,
        this.memoryStore
      );
      await this.neuralMatcher.initialize();
      console.info(`[Neural] Enabled for agent ${this.agentId.id}`);
    }

    // ... rest of initialization ...
  }

  /**
   * Send message to another agent (QUIC-aware)
   *
   * Automatically uses QUIC if available, falls back to EventBus
   */
  protected async sendMessageToAgent(
    targetAgentId: string,
    message: AgentMessage
  ): Promise<void> {
    if (this.quicManager) {
      try {
        await this.quicManager.sendMessage(targetAgentId, message);
        return;
      } catch (error) {
        console.warn(`[QUIC] Failed to send message, falling back to EventBus:`, error);
      }
    }

    // Fallback to EventBus (existing behavior)
    this.eventBus.emit('agent.message', message);
  }

  /**
   * Subscribe to messages from other agents (QUIC-aware)
   */
  protected async subscribeToMessages(
    messageType: MessageType,
    handler: (message: AgentMessage) => void
  ): Promise<void> {
    if (this.quicManager) {
      await this.quicManager.subscribe(messageType, handler);
    }

    // Also subscribe via EventBus for backward compatibility
    this.registerEventHandler({
      eventType: 'agent.message',
      handler: async (event: QEEvent) => {
        const msg = event.data as AgentMessage;
        if (msg.type === messageType) {
          handler(msg);
        }
      }
    });
  }

  /**
   * Get pattern recommendation using neural prediction
   *
   * Falls back to QEReasoningBank if neural disabled
   */
  protected async getPatternRecommendation(
    context: {
      codeType: string;
      framework?: string;
      language?: string;
      keywords?: string[];
      codeSnippet?: string;
    }
  ): Promise<PatternMatch[]> {
    // Try neural prediction first (if enabled)
    if (this.neuralMatcher) {
      try {
        const predictions = await this.neuralMatcher.predict(context, 5);
        return predictions.map(pred => ({
          pattern: pred.pattern,
          confidence: pred.confidence,
          reasoning: pred.reasoning,
          applicability: pred.confidence * pred.pattern.successRate
        }));
      } catch (error) {
        console.warn(`[Neural] Prediction failed, falling back to rule-based:`, error);
      }
    }

    // Fallback to QEReasoningBank (existing behavior)
    const reasoningBank = new QEReasoningBank();
    return await reasoningBank.findMatchingPatterns(context, 5);
  }

  /**
   * Report task outcome for neural learning
   */
  protected async reportTaskOutcome(
    taskId: string,
    patternId: string,
    success: boolean
  ): Promise<void> {
    if (this.neuralMatcher) {
      await this.neuralMatcher.learnFromTask(taskId, patternId, success);
    }
  }
}
```

### 4.3 Usage Example: TestGeneratorAgent

```typescript
/**
 * Example: Using Phase 3 features in TestGeneratorAgent
 */
export class TestGeneratorAgent extends BaseAgent {
  constructor(config: BaseAgentConfig) {
    super({
      ...config,
      type: 'test-generator',
      enableQuic: true,      // Opt-in to QUIC
      enableNeural: true,    // Opt-in to neural predictions
      quicConfig: {
        port: 4433,
        cert: './certs/agent.crt',
        key: './certs/agent.key'
      },
      neuralConfig: {
        modelPath: './models/test-pattern-v1.0.0.h5'
      }
    });
  }

  protected async performTask(task: QETask): Promise<any> {
    // Get neural pattern recommendation (automatic fallback to rule-based)
    const recommendations = await this.getPatternRecommendation({
      codeType: 'test',
      framework: 'jest',
      language: 'typescript',
      keywords: ['api', 'controller'],
      codeSnippet: task.metadata?.codeSnippet
    });

    const bestPattern = recommendations[0];
    console.log(`Using pattern: ${bestPattern.pattern.name} (confidence: ${bestPattern.confidence})`);

    // Generate tests using pattern
    const tests = await this.generateTests(bestPattern.pattern, task);

    // Send results to coverage analyzer via QUIC (automatic fallback to EventBus)
    await this.sendMessageToAgent('coverage-analyzer-1', {
      id: generateId(),
      from: this.agentId,
      to: { id: 'coverage-analyzer-1', type: 'coverage-analyzer', created: new Date() },
      type: 'test-results',
      payload: { tests, patternId: bestPattern.pattern.id },
      timestamp: new Date(),
      priority: 'medium'
    });

    // Report outcome for neural learning
    await this.reportTaskOutcome(
      task.id,
      bestPattern.pattern.id,
      tests.length > 0 // Success if tests generated
    );

    return { tests, pattern: bestPattern };
  }
}

// Initialize and run agent
const agent = new TestGeneratorAgent({
  memoryStore: new SwarmMemoryManager('./fleet.db'),
  eventBus: new EventEmitter(),
  capabilities: [/* ... */],
  context: { projectName: 'my-app' },
  enableQuic: true,
  enableNeural: true
});

await agent.initialize();
await agent.executeTask(task);
```

### 4.4 Configuration Options

Users control Phase 3 features via configuration files:

#### .agentic-qe/config/fleet.json

```json
{
  "features": {
    "quicTransport": false,    // Disabled by default (opt-in)
    "neuralTraining": false     // Disabled by default (opt-in)
  },
  "quic": {
    "enabled": false,
    "port": 4433,
    "cert": "./certs/agent.crt",
    "key": "./certs/agent.key",
    "maxConnections": 100,
    "connectionTimeout": 30000,  // 30 seconds
    "autoFallback": true,
    "peerDiscovery": {
      "enabled": true,
      "interval": 60000          // 1 minute
    }
  },
  "neural": {
    "enabled": false,
    "modelPath": "./models/test-pattern-v1.0.0.h5",
    "trainingInterval": 86400000,  // 24 hours
    "minPatterns": 50,              // Minimum patterns for training
    "batchSize": 32,
    "epochs": 50,
    "validationSplit": 0.2,
    "cacheSize": 1000,
    "warmCache": true
  }
}
```

#### Environment Variables

```bash
# QUIC configuration
export AQE_QUIC_ENABLED=false
export AQE_QUIC_PORT=4433
export AQE_QUIC_CERT_PATH=./certs/agent.crt
export AQE_QUIC_KEY_PATH=./certs/agent.key

# Neural configuration
export AQE_NEURAL_ENABLED=false
export AQE_NEURAL_MODEL_PATH=./models/test-pattern-v1.0.0.h5
export AQE_NEURAL_TRAINING_INTERVAL=86400000
```

---

## 5. Data Flow Architecture

### 5.1 QUIC Message Flow

```
Agent A (Test Generator)
  │
  │ 1. Generate tests using neural prediction
  │
  ▼
NeuralPatternMatcher
  │
  │ 2. Predict optimal pattern (confidence: 0.92)
  │
  ▼
Agent A
  │
  │ 3. sendMessageToAgent('coverage-analyzer-1', results)
  │
  ▼
QUICTransportManager
  │
  │ 4. Check if QUIC available for peer
  │
  ▼
PeerRegistry
  │
  │ 5. Lookup peer in agent_registry
  │    - quicAddress: "127.0.0.1:4434"
  │    - quicEnabled: true
  │
  ▼
QUICTransportManager
  │
  │ 6. Establish QUIC connection (or reuse existing)
  │    - 0-RTT if peer previously connected
  │    - <10ms handshake if new peer
  │
  ▼
QUIC Stream
  │
  │ 7. Send message over QUIC stream
  │    - Serialize AgentMessage to JSON
  │    - Compress with gzip
  │    - Send over stream ID
  │
  ▼
Agent B (Coverage Analyzer)
  │
  │ 8. Receive message via QUIC
  │
  ▼
QUICTransportManager
  │
  │ 9. Deserialize and validate message
  │
  ▼
Agent B
  │
  │ 10. Process test results
  │
  ▼
SwarmMemoryManager
  │
  │ 11. Store results in memory_entries
  │
  └─────────────────────────────────────────────
```

### 5.2 Neural Training Flow

```
QEReasoningBank
  │
  │ 1. Store 100+ test patterns
  │    - Each with success metrics
  │
  ▼
TrainingPipeline (triggered every 24 hours)
  │
  │ 2. Ingest patterns from ReasoningBank
  │
  ▼
FeatureExtractor
  │
  │ 3. Extract features
  │    - Text embeddings (BERT)
  │    - Metadata (category, framework)
  │    - Success metrics (confidence, rate)
  │
  ▼
TensorFlow Model
  │
  │ 4. Train neural network
  │    - 50 epochs
  │    - Batch size 32
  │    - Adam optimizer
  │
  ▼
ModelValidator
  │
  │ 5. Validate on hold-out set
  │    - Accuracy: 88%
  │    - Precision: 0.87
  │    - Recall: 0.85
  │
  ▼
NeuralPatternMatcher
  │
  │ 6. Save model checkpoint
  │    - ./models/test-pattern-v1.0.1.h5
  │
  ▼
InferenceEngine
  │
  │ 7. Warm cache with common patterns
  │
  └─────────────────────────────────────────────

Later: Prediction Flow

Agent (Test Generator)
  │
  │ 1. Request pattern recommendation
  │
  ▼
InferenceEngine
  │
  │ 2. Check cache
  │    - Cache hit: return cached result
  │    - Cache miss: run inference
  │
  ▼
TensorFlow Model
  │
  │ 3. Run inference
  │    - Extract features
  │    - Forward pass
  │    - Top-K selection
  │
  ▼
NeuralPatternMatcher
  │
  │ 4. Return predictions with confidence
  │    - Pattern A: 0.92
  │    - Pattern B: 0.78
  │    - Pattern C: 0.65
  │
  ▼
Agent
  │
  │ 5. Use highest confidence pattern
  │
  │ 6. Generate tests
  │
  ▼
NeuralPatternMatcher
  │
  │ 7. Learn from outcome (online learning)
  │    - Update model weights incrementally
  │
  └─────────────────────────────────────────────
```

---

## 6. Configuration Schema

### 6.1 QUIC Configuration

```typescript
export interface QUICConfig {
  enabled: boolean;
  port: number;
  cert: string;                    // Path to TLS certificate
  key: string;                     // Path to TLS private key
  maxConnections: number;          // Max concurrent connections
  connectionTimeout: number;       // Connection timeout (ms)
  autoFallback: boolean;           // Auto-fallback to TCP
  peerDiscovery: {
    enabled: boolean;
    interval: number;              // Discovery interval (ms)
  };
  performance: {
    maxStreamsPerConnection: number;
    sendBufferSize: number;
    receiveBufferSize: number;
  };
}

export const DEFAULT_QUIC_CONFIG: QUICConfig = {
  enabled: false,
  port: 4433,
  cert: './certs/agent.crt',
  key: './certs/agent.key',
  maxConnections: 100,
  connectionTimeout: 30000,
  autoFallback: true,
  peerDiscovery: {
    enabled: true,
    interval: 60000
  },
  performance: {
    maxStreamsPerConnection: 100,
    sendBufferSize: 1048576,       // 1MB
    receiveBufferSize: 1048576     // 1MB
  }
};
```

### 6.2 Neural Configuration

```typescript
export interface NeuralConfig {
  enabled: boolean;
  modelPath?: string;              // Path to pre-trained model
  trainingInterval: number;        // Training interval (ms)
  minPatterns: number;             // Min patterns for training
  batchSize: number;
  epochs: number;
  validationSplit: number;
  cacheSize: number;               // LRU cache size
  warmCache: boolean;
  architecture: {
    inputDim: number;
    hiddenLayers: number[];
    outputDim: number;
    dropout: number;
    activation: 'relu' | 'sigmoid' | 'tanh';
  };
  optimizer: {
    type: 'adam' | 'sgd' | 'rmsprop';
    learningRate: number;
    beta1?: number;
    beta2?: number;
  };
}

export const DEFAULT_NEURAL_CONFIG: NeuralConfig = {
  enabled: false,
  trainingInterval: 86400000,      // 24 hours
  minPatterns: 50,
  batchSize: 32,
  epochs: 50,
  validationSplit: 0.2,
  cacheSize: 1000,
  warmCache: true,
  architecture: {
    inputDim: 512,
    hiddenLayers: [256, 128, 64],
    outputDim: 100,                // Max pattern classes
    dropout: 0.2,
    activation: 'relu'
  },
  optimizer: {
    type: 'adam',
    learningRate: 0.001,
    beta1: 0.9,
    beta2: 0.999
  }
};
```

---

## 7. Implementation Roadmap

### Phase 3.1: QUIC Transport (Week 1-2)

**Milestone 3.1.1: QUIC Server & Client**
- [ ] Implement QUICTransportManager
- [ ] Implement PeerRegistry (SwarmMemoryManager integration)
- [ ] Implement FallbackHandler with circuit breaker
- [ ] Add QUIC support to BaseAgent
- [ ] Create self-signed certificates for testing
- [ ] Write unit tests (connection, messaging, fallback)

**Milestone 3.1.2: Integration & Testing**
- [ ] Integrate with existing EventBus system
- [ ] Test inter-agent messaging via QUIC
- [ ] Benchmark latency improvements
- [ ] Test automatic TCP fallback
- [ ] Write integration tests

**Deliverables:**
- QUICTransportManager implementation
- BaseAgent enhancements
- Unit tests (>80% coverage)
- Integration tests
- Performance benchmarks

### Phase 3.2: Neural Training (Week 3-4)

**Milestone 3.2.1: Training Pipeline**
- [ ] Implement NeuralPatternMatcher
- [ ] Implement TrainingPipeline
- [ ] Implement FeatureExtractor
- [ ] Integrate with QEReasoningBank
- [ ] Write unit tests for training

**Milestone 3.2.2: Inference Engine**
- [ ] Implement InferenceEngine
- [ ] Implement PatternCache (LRU)
- [ ] Add neural support to BaseAgent
- [ ] Write unit tests for inference
- [ ] Benchmark inference latency

**Milestone 3.2.3: Integration & Validation**
- [ ] Test end-to-end prediction flow
- [ ] Validate model accuracy (>85% target)
- [ ] Test online learning
- [ ] Write integration tests

**Deliverables:**
- NeuralPatternMatcher implementation
- BaseAgent enhancements
- Pre-trained model (if available)
- Unit tests (>80% coverage)
- Integration tests
- Model accuracy report

### Phase 3.3: Documentation & Release (Week 5)

**Milestone 3.3.1: Documentation**
- [ ] User guide for QUIC setup
- [ ] User guide for neural training
- [ ] Configuration reference
- [ ] Migration guide
- [ ] Performance tuning guide

**Milestone 3.3.2: Examples & Samples**
- [ ] Example: QUIC-enabled agent
- [ ] Example: Neural-enabled agent
- [ ] Example: Combined QUIC + Neural
- [ ] Sample configuration files
- [ ] Sample training scripts

**Milestone 3.3.3: Release**
- [ ] Version bump to 1.1.0
- [ ] Update CHANGELOG.md
- [ ] Create release notes
- [ ] Tag release in git
- [ ] Publish npm package

**Deliverables:**
- Complete documentation
- Working examples
- Release v1.1.0

---

## 8. Performance Characteristics

### 8.1 QUIC Performance Targets

| Metric | HTTP (Baseline) | QUIC (Target) | Improvement |
|--------|-----------------|---------------|-------------|
| **Connection Handshake** | 100-200ms (TCP + TLS) | <10ms (QUIC 0-RTT) | 90-95% |
| **Message Latency (p50)** | 30ms | 10ms | 67% |
| **Message Latency (p95)** | 50ms | 15ms | 70% |
| **Message Latency (p99)** | 100ms | 25ms | 75% |
| **Throughput** | 1,000 msg/s | 5,000 msg/s | 5x |
| **Connection Overhead** | 200KB (TCP+TLS) | 50KB (QUIC) | 75% |
| **CPU Usage** | 15% | 12% | 20% |
| **Memory Usage** | 100MB | 80MB | 20% |
| **Reliability** | 99.5% | 99.9% | 0.4% |

### 8.2 Neural Performance Targets

| Metric | Rule-Based (Baseline) | Neural (Target) | Improvement |
|--------|-----------------------|-----------------|-------------|
| **Prediction Accuracy** | 75% | 85-90% | 10-15% |
| **Prediction Latency (p50)** | 20ms | 25ms | -25% slower* |
| **Prediction Latency (p95)** | 40ms | 50ms | -25% slower* |
| **Pattern Recommendations** | Top-5 | Top-5 | Same |
| **Training Time** | N/A | 5-10min (100 patterns) | N/A |
| **Model Size** | N/A | 50MB | N/A |
| **Memory Usage** | 10MB | 60MB | 6x |
| **CPU Usage (inference)** | 5% | 8% | 60% |

*Note: Neural is slightly slower but significantly more accurate, leading to better overall test quality.

### 8.3 System-Wide Impact

**With QUIC Enabled:**
- Fleet coordination latency: **-60%**
- Agent spawn time: **-40%**
- Task distribution speed: **+400%**
- Network bandwidth: **-30%**

**With Neural Enabled:**
- Test generation accuracy: **+15%**
- Manual test case creation: **-35%**
- Test quality (bug detection): **+20%**
- Test maintenance effort: **-25%**

---

## 9. Testing Strategy

### 9.1 QUIC Testing

**Unit Tests:**
- QUICTransportManager connection lifecycle
- PeerRegistry peer discovery and metrics
- FallbackHandler circuit breaker logic
- Message serialization/deserialization
- Connection pooling and reuse

**Integration Tests:**
- Agent-to-agent messaging via QUIC
- Automatic TCP fallback on QUIC failure
- Multi-agent coordination via QUIC
- Peer discovery from SwarmMemoryManager
- Connection resilience (peer goes offline)

**Performance Tests:**
- Latency benchmarks (p50, p95, p99)
- Throughput benchmarks (messages/second)
- Connection handshake time
- Memory usage under load
- CPU usage during messaging

**Security Tests:**
- TLS certificate validation
- Encrypted message transmission
- Peer authentication
- Replay attack prevention

### 9.2 Neural Testing

**Unit Tests:**
- FeatureExtractor feature extraction
- TrainingPipeline data loading and batching
- ModelValidator accuracy calculation
- InferenceEngine caching logic
- Online learning weight updates

**Integration Tests:**
- End-to-end training flow
- End-to-end prediction flow
- QEReasoningBank integration
- Model persistence and loading
- Online learning from task outcomes

**Validation Tests:**
- Model accuracy on validation set (>85%)
- Prediction confidence calibration
- Generalization to unseen patterns
- Robustness to noisy inputs
- Transfer learning across projects

**Performance Tests:**
- Inference latency (p50, p95, p99)
- Training time for various dataset sizes
- Memory usage during training/inference
- Cache hit rate
- Batch inference throughput

### 9.3 End-to-End Testing

**Scenario 1: QUIC-Enabled Fleet**
1. Initialize 5 agents with QUIC enabled
2. Agents discover each other via PeerRegistry
3. Send 1000 messages between agents
4. Measure latency and throughput
5. Kill one agent, verify automatic failover
6. Verify TCP fallback when QUIC unavailable

**Scenario 2: Neural-Enabled Test Generation**
1. Initialize TestGeneratorAgent with neural enabled
2. Populate QEReasoningBank with 100 patterns
3. Train neural model
4. Generate tests for 10 different code contexts
5. Measure prediction accuracy
6. Report task outcomes, verify online learning
7. Retrain model, verify accuracy improvement

**Scenario 3: Combined QUIC + Neural**
1. Initialize fleet with both features enabled
2. Generate tests using neural predictions
3. Send results via QUIC to coverage analyzer
4. Measure end-to-end latency
5. Verify learning from test execution outcomes
6. Verify network efficiency with QUIC

---

## 10. Appendix

### 10.1 QUIC Resources

- [QUIC Protocol RFC 9000](https://datatracker.ietf.org/doc/html/rfc9000)
- [Node.js QUIC Implementation](https://nodejs.org/api/quic.html)
- [quiche - Rust QUIC Implementation](https://github.com/cloudflare/quiche)
- [@fails-components/webtransport](https://www.npmjs.com/package/@fails-components/webtransport) - Node.js QUIC library

### 10.2 Neural Training Resources

- [TensorFlow.js](https://www.tensorflow.org/js)
- [Pre-trained BERT Models](https://tfhub.dev/tensorflow/bert_en_uncased_L-12_H-768_A-12/1)
- [Transfer Learning Guide](https://www.tensorflow.org/tutorials/images/transfer_learning)
- [Online Learning Strategies](https://arxiv.org/abs/1802.02871)

### 10.3 Security Considerations

**QUIC Security:**
- All connections use TLS 1.3 with mandatory encryption
- Certificate validation required for peer authentication
- Replay attack protection via connection IDs
- Forward secrecy for session keys

**Neural Security:**
- Model files protected with file system permissions
- No PII stored in training data
- Model versioning for rollback on compromise
- Audit logging for model updates

### 10.4 Migration Path

**From HTTP to QUIC:**
1. Enable QUIC in configuration: `features.quicTransport = true`
2. Deploy certificates to all agents
3. Restart agents to initialize QUIC
4. Monitor logs for successful QUIC connections
5. Verify latency improvements in metrics
6. Disable HTTP after validation period

**From Rule-Based to Neural:**
1. Accumulate 50+ patterns in QEReasoningBank
2. Enable neural in configuration: `features.neuralTraining = true`
3. Trigger initial training via CLI: `aqe neural train`
4. Monitor training metrics (accuracy, loss)
5. Enable neural predictions for agents
6. Monitor prediction accuracy vs rule-based
7. Adjust model hyperparameters if needed

---

## Summary

Phase 3 introduces **QUIC transport** and **Neural training** to the Agentic QE Fleet, providing:

1. **50-70% latency reduction** via QUIC protocol
2. **85%+ prediction accuracy** via neural pattern matching
3. **Simple agent integration** through BaseAgent mixins
4. **Zero breaking changes** with opt-in feature flags
5. **Automatic fallback** for reliability

All features integrate seamlessly with existing components (SwarmMemoryManager, QEReasoningBank, EventBus) while maintaining backward compatibility. Agents can adopt features individually based on their needs, with automatic degradation when features unavailable.

**Key APIs:**
- `sendMessageToAgent()` - QUIC-aware messaging
- `getPatternRecommendation()` - Neural predictions
- `reportTaskOutcome()` - Online learning

**Configuration:**
```json
{
  "features": {
    "quicTransport": false,  // Opt-in
    "neuralTraining": false   // Opt-in
  }
}
```

**Next Steps:**
1. Review architecture with team
2. Begin Phase 3.1 implementation (QUIC)
3. Begin Phase 3.2 implementation (Neural)
4. Release v1.1.0 with Phase 3 features