# CHORUS Distributed Hash Table (DHT) Package

## Overview

The `pkg/dht` package provides a complete distributed hash table implementation for CHORUS, enabling peer discovery, content routing, and decentralized storage with encryption. Built on LibP2P's Kademlia DHT, it extends the foundation with encrypted storage, automatic replication, and CHORUS-specific content management.

**Package Path**: `/home/tony/chorus/project-queues/active/CHORUS/pkg/dht/`

**Key Dependencies**:
- `github.com/libp2p/go-libp2p-kad-dht` - Kademlia DHT implementation
- `github.com/libp2p/go-libp2p/core` - LibP2P core types
- `filippo.io/age` - Modern encryption (via crypto package)
- `chorus/pkg/crypto` - Age encryption integration
- `chorus/pkg/ucxl` - UCXL address validation
- `chorus/pkg/config` - Configuration and role management

## Architecture

```
┌──────────────────────────────────────────────────────────────────┐
│                     Application Layer                            │
│              (UCXL Content Storage/Retrieval)                    │
└────────────────────────┬─────────────────────────────────────────┘
                         │
┌────────────────────────▼─────────────────────────────────────────┐
│                  EncryptedDHTStorage                             │
│  - UCXL address validation                                       │
│  - Age encryption/decryption                                     │
│  - Local caching with TTL                                        │
│  - Role-based access control                                     │
│  - Audit logging                                                 │
└────────────────────────┬─────────────────────────────────────────┘
                         │
┌────────────────────────▼─────────────────────────────────────────┐
│                     LibP2PDHT                                    │
│  - Kademlia DHT operations                                       │
│  - Peer discovery and bootstrap                                  │
│  - Provider records management                                   │
│  - Role announcement                                             │
│  - Routing table management                                      │
└────────────────────────┬─────────────────────────────────────────┘
                         │
┌────────────────────────▼─────────────────────────────────────────┐
│                 ReplicationManager                               │
│  - Content replication tracking                                  │
│  - Provider record caching                                       │
│  - Periodic reproviding                                          │
│  - Health monitoring                                             │
│  - Metrics collection                                            │
└────────────────────────┬─────────────────────────────────────────┘
                         │
┌────────────────────────▼─────────────────────────────────────────┐
│              LibP2P Network Layer                                │
│  - P2P transport protocols                                       │
│  - Peer connections                                              │
│  - Content routing                                               │
└──────────────────────────────────────────────────────────────────┘
```

## Core Components

### 1. LibP2PDHT - Kademlia DHT Implementation

**File**: `dht.go`

The main DHT implementation providing distributed peer discovery and content routing.

#### Key Features

- **Kademlia Protocol**: XOR-based distributed routing
- **Bootstrap Process**: Connects to initial peer network
- **Peer Discovery**: Continuous peer finding and registration
- **Provider Records**: Announces content availability
- **Role-Based Discovery**: CHORUS-specific role announcements

#### Configuration

```go
type Config struct {
    // Bootstrap nodes for initial DHT discovery
    BootstrapPeers []multiaddr.Multiaddr

    // Protocol prefix for CHORUS DHT
    ProtocolPrefix string  // Default: "/CHORUS"

    // Bootstrap timeout
    BootstrapTimeout time.Duration  // Default: 30s

    // Peer discovery interval
    DiscoveryInterval time.Duration  // Default: 60s

    // DHT mode (client, server, auto)
    Mode dht.ModeOpt  // Default: ModeAuto

    // Enable automatic bootstrap
    AutoBootstrap bool  // Default: true
}
```

#### Core Operations

**Initialization and Bootstrap**:

```go
// Create new DHT instance
dht, err := dht.NewLibP2PDHT(ctx, host,
    dht.WithBootstrapPeers(bootstrapPeers),
    dht.WithProtocolPrefix("/CHORUS"),
    dht.WithMode(dht.ModeAuto),
)

// Bootstrap connects to DHT network
err = dht.Bootstrap()

// Check bootstrap status
if dht.IsBootstrapped() {
    log.Println("DHT ready")
}
```

**Key-Value Operations**:

```go
// Store value in DHT
key := "CHORUS:data:example"
value := []byte("encrypted content")
err = dht.PutValue(ctx, key, value)

// Retrieve value from DHT
retrievedValue, err := dht.GetValue(ctx, key)

// Announce content availability
err = dht.Provide(ctx, key)

// Find content providers
providers, err := dht.FindProviders(ctx, key, 10)
for _, provider := range providers {
    log.Printf("Provider: %s", provider.ID)
}
```

**Role Management**:

```go
// Register peer with role information
dht.RegisterPeer(
    peerID,
    "chorus-agent/1.0",
    "backend_developer",
    []string{"ucxl-storage", "decision-making"},
)

// Announce role to DHT
err = dht.AnnounceRole(ctx, "backend_developer")

// Announce capability
err = dht.AnnounceCapability(ctx, "ucxl-storage")

// Find peers by role
peers, err := dht.FindPeersByRole(ctx, "backend_developer")
for _, peer := range peers {
    log.Printf("Found peer: %s with role: %s", peer.ID, peer.Role)
}
```

#### Bootstrap Process Flow

```
1. Initialize DHT
   ↓
2. Connect to Bootstrap Peers
   - Use configured peers or IPFS defaults
   - Establish libp2p connections
   ↓
3. DHT Bootstrap
   - Populate routing table
   - Discover nearby peers
   ↓
4. Background Tasks Start
   - Auto-bootstrap (if enabled)
   - Periodic discovery
   - Peer cleanup
   ↓
5. DHT Ready for Operations
```

#### Background Maintenance

The DHT runs several background tasks:

1. **Auto-Bootstrap** (30s interval):
   - Retries bootstrap if not connected
   - Ensures DHT stays connected

2. **Periodic Discovery** (configurable, default 60s):
   - Searches for "CHORUS:peer" providers
   - Updates known peer information

3. **Peer Cleanup** (5 minute interval):
   - Removes stale peer entries (>1 hour old)
   - Checks peer connection status

#### Statistics and Monitoring

```go
type DHTStats struct {
    TotalPeers int           // Connected peers count
    TotalKeys  int           // Managed keys count
    Uptime     time.Duration // DHT uptime
}

stats := dht.GetStats()
log.Printf("DHT Stats: peers=%d, keys=%d, uptime=%v",
    stats.TotalPeers, stats.TotalKeys, stats.Uptime)

// Get routing table size
rtSize := dht.GetDHTSize()

// Get connected peer list
peerIDs := dht.GetConnectedPeers()
```

### 2. EncryptedDHTStorage - Encrypted Content Layer

**File**: `encrypted_storage.go`

Provides encrypted UCXL content storage with role-based access control.

#### Key Features

- **Age Encryption**: Modern encryption using filippo.io/age
- **Role-Based Access**: Content encrypted for specific roles
- **UCXL Integration**: Validates UCXL addresses
- **Local Caching**: Performance optimization with TTL
- **Audit Logging**: Comprehensive access tracking
- **Metadata Management**: Rich content metadata

#### Data Structures

```go
type EncryptedDHTStorage struct {
    ctx       context.Context
    host      host.Host
    dht       *LibP2PDHT
    crypto    *crypto.AgeCrypto
    config    *config.Config
    nodeID    string
    cache     map[string]*CachedEntry  // Local cache
    metrics   *StorageMetrics
}

type UCXLMetadata struct {
    Address           string      // UCXL address
    CreatorRole       string      // Role that created content
    EncryptedFor      []string    // Roles that can decrypt
    ContentType       string      // decision, suggestion, etc
    Timestamp         time.Time   // Creation time
    Size              int          // Content size
    Hash              string      // SHA256 of encrypted content
    DHTPeers          []string    // Peers with this content
    ReplicationFactor int         // Target replication count
}

type CachedEntry struct {
    Content   []byte
    Metadata  *UCXLMetadata
    CachedAt  time.Time
    ExpiresAt time.Time  // Cache TTL
}
```

#### Storing Encrypted Content

```go
// Create encrypted storage
storage := dht.NewEncryptedDHTStorage(
    ctx,
    host,
    libp2pDHT,
    config,
    "node001",
)

// Store UCXL content
ucxlAddress := "ucxl://agent001/backend_developer/project123/task456/decision"
content := []byte("Decision: Implement feature X using pattern Y")
creatorRole := "backend_developer"
contentType := "decision"

err := storage.StoreUCXLContent(
    ucxlAddress,
    content,
    creatorRole,
    contentType,
)

// Content is:
// 1. UCXL address validated
// 2. Encrypted for creator role and authorized roles
// 3. Stored in DHT with metadata
// 4. Cached locally for 10 minutes
// 5. Audit logged
```

#### Retrieving Encrypted Content

```go
// Retrieve and decrypt content
content, metadata, err := storage.RetrieveUCXLContent(ucxlAddress)

if err != nil {
    log.Printf("Failed to retrieve: %v", err)
} else {
    log.Printf("Content: %s", string(content))
    log.Printf("Creator: %s", metadata.CreatorRole)
    log.Printf("Type: %s", metadata.ContentType)
    log.Printf("Size: %d bytes", metadata.Size)
}

// Retrieval process:
// 1. Check local cache first (cache hit optimization)
// 2. If not cached, query DHT
// 3. Verify role permissions
// 4. Decrypt with role key
// 5. Cache for future use
// 6. Audit log access
```

#### Cache Management

The storage layer implements automatic cache management:

```go
type CachedEntry struct {
    Content   []byte
    Metadata  *UCXLMetadata
    CachedAt  time.Time
    ExpiresAt time.Time  // Default: 10 minutes
}

// Start automatic cache cleanup
storage.StartCacheCleanup(5 * time.Minute)

// Manual cleanup
storage.CleanupCache()

// Cache behavior:
// - Entries expire after 10 minutes
// - Periodic cleanup every 5 minutes
// - Automatic invalidation on decryption errors
// - LRU-style management
```

#### DHT Key Generation

```go
// Generate consistent DHT key from UCXL address
func (eds *EncryptedDHTStorage) generateDHTKey(ucxlAddress string) string {
    hash := sha256.Sum256([]byte(ucxlAddress))
    return "/CHORUS/ucxl/" + base64.URLEncoding.EncodeToString(hash[:])
}

// Example:
// ucxl://agent001/backend_developer/project123/task456/decision
//   ↓ SHA256 hash
//   ↓ Base64 URL encoding
// /CHORUS/ucxl/R4nd0mH4sh3dStr1ngH3r3...
```

#### Encryption Flow

```
User Content
    ↓
[UCXL Address Validation]
    ↓
[Determine Decryptable Roles]
    ↓
[Age Encryption for Multiple Recipients]
    ↓
[Create Storage Entry with Metadata]
    ↓
[Generate DHT Key]
    ↓
[Store in DHT]
    ↓
[Cache Locally]
    ↓
[Audit Log]
```

#### Role-Based Access Policy

```go
// checkStoreAccessPolicy validates storage permissions
func (eds *EncryptedDHTStorage) checkStoreAccessPolicy(
    creatorRole, ucxlAddress, contentType string,
) error {
    roles := config.GetPredefinedRoles()
    role, exists := roles[creatorRole]

    // Read-only roles cannot store content
    if role.AuthorityLevel == config.AuthorityReadOnly {
        return fmt.Errorf("role %s has read-only authority", creatorRole)
    }

    return nil
}

// checkRetrieveAccessPolicy validates retrieval permissions
func (eds *EncryptedDHTStorage) checkRetrieveAccessPolicy(
    currentRole, ucxlAddress string,
) error {
    // All valid roles can retrieve (encryption handles access)
    // Decryption will fail if role lacks permission
    return nil
}
```

#### Content Discovery

```go
// Announce content availability
err := storage.AnnounceContent(ucxlAddress)

// Discover peers with content
peerIDs, err := storage.DiscoverContentPeers(ucxlAddress)
for _, peerID := range peerIDs {
    log.Printf("Peer %s has content", peerID)
}
```

#### Search and Listing

```go
// List content by role
metadata, err := storage.ListContentByRole("backend_developer", 100)

// Search with criteria
query := &storage.SearchQuery{
    Agent:         "agent001",
    Role:          "backend_developer",
    Project:       "project123",
    ContentType:   "decision",
    CreatedAfter:  time.Now().Add(-24 * time.Hour),
    Limit:         50,
}

results, err := storage.SearchContent(query)
for _, meta := range results {
    log.Printf("Found: %s (type: %s, size: %d)",
        meta.Address, meta.ContentType, meta.Size)
}
```

#### Storage Metrics

```go
type StorageMetrics struct {
    StoredItems          int64
    RetrievedItems       int64
    CacheHits            int64
    CacheMisses          int64
    EncryptionOps        int64
    DecryptionOps        int64
    AverageStoreTime     time.Duration
    AverageRetrieveTime  time.Duration
    LastUpdate           time.Time
}

metrics := storage.GetMetrics()
log.Printf("DHT Storage Metrics:")
log.Printf("  Stored: %d, Retrieved: %d",
    metrics["stored_items"], metrics["retrieved_items"])
log.Printf("  Cache hit ratio: %.2f%%",
    float64(metrics["cache_hits"].(int64)) /
    float64(metrics["cache_hits"].(int64) + metrics["cache_misses"].(int64)) * 100)
```

### 3. ReplicationManager - Content Replication

**File**: `replication_manager.go`

Manages DHT content replication, provider tracking, and health monitoring.

#### Key Features

- **Automatic Replication**: Maintains target replication factor
- **Provider Tracking**: Caches provider information
- **Periodic Reproviding**: Keeps content alive in DHT
- **Health Monitoring**: Tracks replication health
- **Concurrent Operations**: Parallel replication with limits

#### Configuration

```go
type ReplicationConfig struct {
    ReplicationFactor         int           // Target replicas: 3
    ReprovideInterval         time.Duration // 12 hours
    CleanupInterval           time.Duration // 1 hour
    ProviderTTL               time.Duration // 24 hours
    MaxProvidersPerKey        int           // 10
    EnableAutoReplication     bool          // true
    EnableReprovide           bool          // true
    MaxConcurrentReplications int           // 5
}

// Use default configuration
config := dht.DefaultReplicationConfig()

// Or customize
config := &dht.ReplicationConfig{
    ReplicationFactor:         5,  // Higher redundancy
    ReprovideInterval:         6 * time.Hour,
    MaxConcurrentReplications: 10,
}
```

#### Managing Content Replication

```go
// Add content for replication management
err := replicationManager.AddContent(
    "ucxl://agent001/backend_developer/project123/task456/decision",
    1024,  // size in bytes
    5,     // priority (higher = more important)
)

// Content is immediately provided to DHT if auto-replication enabled

// Remove from replication
err = replicationManager.RemoveContent(key)

// Manual reprovide
err = replicationManager.ProvideContent(key)
```

#### Finding Providers

```go
// Find providers for content
providers, err := replicationManager.FindProviders(ctx, key, 10)

for _, provider := range providers {
    log.Printf("Provider: %s", provider.PeerID)
    log.Printf("  Added: %s", provider.AddedAt)
    log.Printf("  Last seen: %s", provider.LastSeen)
    log.Printf("  Quality: %.2f", provider.Quality)
    log.Printf("  Distance: %d", provider.Distance)
}

// Provider info includes:
// - PeerID: Unique peer identifier
// - AddedAt: When provider was discovered
// - LastSeen: Last contact time
// - Quality: Provider reliability score (0.0-1.0)
// - Distance: XOR distance from content key
```

#### Replication Status

```go
type ReplicationStatus struct {
    Key              string
    TargetReplicas   int           // Desired replication count
    ActualReplicas   int           // Current replica count
    HealthyProviders int           // Recently seen providers
    LastReprovided   time.Time     // Last reprovide time
    CreatedAt        time.Time     // Content creation time
    Size             int64         // Content size
    Priority         int           // Replication priority
    Health           string        // "healthy", "degraded", "critical"
    IsLocal          bool          // Stored locally
    Providers        []ProviderInfo
}

// Check replication status
status, err := replicationManager.GetReplicationStatus(key)

log.Printf("Replication Status for %s:", key)
log.Printf("  Health: %s", status.Health)
log.Printf("  Replicas: %d / %d (target)",
    status.ActualReplicas, status.TargetReplicas)
log.Printf("  Healthy providers: %d", status.HealthyProviders)
log.Printf("  Last reprovided: %s", status.LastReprovided)
```

#### Replication Health States

```
healthy:   ActualReplicas >= TargetReplicas
           All systems operational

degraded:  ActualReplicas < TargetReplicas
           Content available but under-replicated

critical:  ActualReplicas == 0
           Content not available in DHT
           Risk of data loss
```

#### Background Tasks

1. **Reprovide Operation** (default: 12 hours):
   ```go
   // Periodically re-announces all content
   // - Processes all local content keys
   // - Respects concurrency limits
   // - Updates metrics
   // - Logs success/failure rates
   ```

2. **Cleanup Operation** (default: 1 hour):
   ```go
   // Removes stale provider records
   // - Expires records older than ProviderTTL
   // - Cleans individual provider entries
   // - Updates metrics
   ```

#### Replication Metrics

```go
type ReplicationMetrics struct {
    TotalKeys              int64     // Managed content keys
    TotalProviders         int64     // Total provider records
    ReprovideOperations    int64     // Completed reprovides
    SuccessfulReplications int64     // Successful operations
    FailedReplications     int64     // Failed operations
    LastReprovideTime      time.Time // Last reprovide run
    LastCleanupTime        time.Time // Last cleanup run
    AverageReplication     float64   // Average replication factor
}

metrics := replicationManager.GetMetrics()
log.Printf("Replication Metrics:")
log.Printf("  Total keys: %d", metrics.TotalKeys)
log.Printf("  Total providers: %d", metrics.TotalProviders)
log.Printf("  Average replication: %.2f", metrics.AverageReplication)
log.Printf("  Success rate: %.2f%%",
    float64(metrics.SuccessfulReplications) /
    float64(metrics.SuccessfulReplications + metrics.FailedReplications) * 100)
```

### 4. HybridDHT - Mock/Real DHT Switching

**File**: `hybrid_dht.go`

Provides development/testing support with automatic fallback between mock and real DHT.

#### Key Features

- **Dual Backend**: Mock DHT for testing, real DHT for production
- **Automatic Fallback**: Falls back to mock on real DHT failures
- **Health Monitoring**: Tracks backend health and errors
- **Metrics Collection**: Per-backend performance tracking
- **Manual Switching**: Override automatic backend selection

#### Backend Health Tracking

```go
type BackendHealth struct {
    Backend     string        // "mock" or "real"
    Status      HealthStatus  // healthy, degraded, failed
    LastCheck   time.Time
    ErrorCount  int
    Latency     time.Duration
    Consecutive int          // Consecutive failures
}

type HealthStatus string
const (
    HealthStatusHealthy  HealthStatus = "healthy"
    HealthStatusDegraded HealthStatus = "degraded"
    HealthStatusFailed   HealthStatus = "failed"
)
```

#### Usage Example

```go
// Initialize hybrid DHT
hybridDHT, err := dht.NewHybridDHT(hybridConfig, logger)

// Operations automatically use appropriate backend
err = hybridDHT.PutValue(ctx, key, value)
value, err := hybridDHT.GetValue(ctx, key)

// Check backend health
health := hybridDHT.GetBackendHealth()
for backend, status := range health {
    log.Printf("%s: %s (errors: %d)",
        backend, status.Status, status.ErrorCount)
}

// Manual backend switch
err = hybridDHT.SwitchBackend("mock")  // Force mock backend
```

## Encryption Integration

The DHT package integrates with `pkg/crypto` for Age encryption:

### Age Encryption Workflow

```go
// Storage layer uses AgeCrypto from crypto package
crypto := crypto.NewAgeCrypto(config)

// Encrypt content for role
encryptedContent, err := crypto.EncryptUCXLContent(
    content,
    creatorRole,
)

// Decrypt content with role
decryptedContent, err := crypto.DecryptWithRole(encryptedContent)

// Check decryption permissions
canDecrypt, err := crypto.CanDecryptContent(targetRole)
```

### Role-Based Encryption

```go
// getDecryptableRoles determines who can decrypt content
func (eds *EncryptedDHTStorage) getDecryptableRoles(
    creatorRole string,
) ([]string, error) {
    roles := config.GetPredefinedRoles()

    // Start with creator role
    decryptableRoles := []string{creatorRole}

    // Add roles with authority to decrypt
    for roleName, role := range roles {
        for _, decryptableRole := range role.CanDecrypt {
            if decryptableRole == creatorRole || decryptableRole == "*" {
                decryptableRoles = append(decryptableRoles, roleName)
            }
        }
    }

    return decryptableRoles, nil
}

// Example:
// Content created by "backend_developer"
// Can be decrypted by:
// - backend_developer (creator)
// - senior_architect (authority: "*")
// - devops_engineer (authority: includes backend_developer)
```

## Cache Cleanup Mechanism

The encrypted storage implements comprehensive cache management:

### Cache Entry Lifecycle

```
Entry Created
    ↓
[Set ExpiresAt = Now + 10 minutes]
    ↓
Entry Cached
    ↓
[Periodic Cleanup Check (5 minutes)]
    ↓
[Is Now > ExpiresAt?]
    ↓
  Yes: Remove Entry
  No:  Keep Entry
    ↓
Entry Expired or Accessed Again
```

### Cleanup Implementation

```go
// CleanupCache removes expired entries
func (eds *EncryptedDHTStorage) CleanupCache() {
    eds.cacheMu.Lock()
    defer eds.cacheMu.Unlock()

    now := time.Now()
    expired := 0

    for address, entry := range eds.cache {
        if now.After(entry.ExpiresAt) {
            delete(eds.cache, address)
            expired++
        }
    }

    log.Printf("Cleaned up %d expired cache entries", expired)
}

// StartCacheCleanup runs cleanup periodically
func (eds *EncryptedDHTStorage) StartCacheCleanup(interval time.Duration) {
    ticker := time.NewTicker(interval)

    go func() {
        defer ticker.Stop()
        for {
            select {
            case <-eds.ctx.Done():
                return
            case <-ticker.C:
                eds.CleanupCache()
            }
        }
    }()
}
```

### Cache Invalidation

```go
// Manual invalidation on errors
func (eds *EncryptedDHTStorage) invalidateCacheEntry(ucxlAddress string) {
    eds.cacheMu.Lock()
    defer eds.cacheMu.Unlock()
    delete(eds.cache, ucxlAddress)
}

// Automatic invalidation on:
// 1. Decryption failures
// 2. Validation errors
// 3. Explicit deletion
// 4. TTL expiration
```

## Security Considerations

### DHT Security

1. **Bootstrap Security**:
   - Verify bootstrap peer identities
   - Use trusted bootstrap nodes
   - Implement peer reputation system

2. **Content Security**:
   - All content encrypted before DHT storage
   - DHT keys are hashed UCXL addresses
   - Provider records don't expose content

3. **Network Security**:
   - LibP2P transport encryption
   - Peer identity verification
   - Rate limiting on DHT operations

### Encryption Security

1. **Age Encryption**:
   - Modern X25519 elliptic curve
   - Forward secrecy through key rotation
   - Multi-recipient support

2. **Key Management**:
   - Role-based key isolation
   - Secure key storage (see crypto package)
   - Audit logging of key access

3. **Access Control**:
   - Role-based decryption permissions
   - Authority hierarchy enforcement
   - Audit logging of all access

### Audit Logging

```go
// auditStoreOperation logs storage events
func (eds *EncryptedDHTStorage) auditStoreOperation(
    ucxlAddress, role, contentType string,
    contentSize int, success bool, errorMsg string,
) {
    if !eds.config.Security.AuditLogging {
        return
    }

    auditEntry := map[string]interface{}{
        "timestamp":     time.Now(),
        "operation":     "store",
        "node_id":       eds.nodeID,
        "ucxl_address":  ucxlAddress,
        "role":          role,
        "content_type":  contentType,
        "content_size":  contentSize,
        "success":       success,
        "error_message": errorMsg,
        "audit_trail":   fmt.Sprintf("DHT-STORE-%s-%d",
                           ucxlAddress, time.Now().Unix()),
    }

    log.Printf("AUDIT STORE: %+v", auditEntry)
}
```

## Performance Optimization

### Caching Strategy

1. **Local Cache**:
   - 10-minute TTL by default
   - Reduces DHT queries by ~80%
   - Automatic cleanup every 5 minutes

2. **Provider Cache**:
   - 24-hour TTL for provider records
   - Reduces FindProviders latency
   - Background refresh

### Concurrency Control

```go
// Replication uses semaphore for concurrency limits
semaphore := make(chan struct{}, config.MaxConcurrentReplications)

for _, key := range keys {
    go func(k string) {
        semaphore <- struct{}{}        // Acquire
        defer func() { <-semaphore }() // Release

        provideContent(k)
    }(key)
}
```

### Batch Operations

```go
// Reprovide operation batches content updates
func (rm *ReplicationManager) performReprovide() {
    // Get all content keys
    keys := getAllContentKeys()

    // Process in parallel with limits
    for _, key := range keys {
        go provideContent(key)
    }
}
```

## Monitoring and Debugging

### DHT Statistics

```go
stats := dht.GetStats()
// DHTStats{
//     TotalPeers: 15,
//     TotalKeys:  247,
//     Uptime:     2h15m30s,
// }
```

### Storage Metrics

```go
metrics := storage.GetMetrics()
// map[string]interface{}{
//     "stored_items":     1523,
//     "retrieved_items":  8241,
//     "cache_hits":       6518,
//     "cache_misses":     1723,
//     "encryption_ops":   1523,
//     "decryption_ops":   8241,
//     "cache_size":       142,
// }
```

### Replication Metrics

```go
metrics := replicationManager.GetMetrics()
// &ReplicationMetrics{
//     TotalKeys:              247,
//     TotalProviders:         741,
//     ReprovideOperations:    12,
//     SuccessfulReplications: 2961,
//     FailedReplications:     3,
//     AverageReplication:     3.2,
// }
```

## Best Practices

### 1. DHT Configuration

```go
// Production configuration
config := &dht.Config{
    BootstrapPeers:    productionBootstrapPeers,
    ProtocolPrefix:    "/CHORUS",
    BootstrapTimeout:  30 * time.Second,
    DiscoveryInterval: 5 * time.Minute,
    Mode:              dht.ModeServer,  // Server mode for stable nodes
    AutoBootstrap:     true,
}
```

### 2. Replication Configuration

```go
// High-availability configuration
replicationConfig := &dht.ReplicationConfig{
    ReplicationFactor:         5,  // Higher redundancy
    ReprovideInterval:         6 * time.Hour,
    CleanupInterval:           30 * time.Minute,
    MaxConcurrentReplications: 10,
    EnableAutoReplication:     true,
    EnableReprovide:           true,
}
```

### 3. Cache Tuning

```go
// Adjust cache TTL based on access patterns
// - Frequently accessed: Longer TTL (30 minutes)
// - Rarely accessed: Shorter TTL (5 minutes)
// - High churn: Aggressive cleanup (2 minutes)
```

### 4. Error Handling

```go
// Retry DHT operations with backoff
func storeWithRetry(ctx context.Context, key string, value []byte) error {
    backoff := time.Second
    maxRetries := 3

    for i := 0; i < maxRetries; i++ {
        err := dht.PutValue(ctx, key, value)
        if err == nil {
            return nil
        }

        log.Printf("DHT store failed (attempt %d): %v", i+1, err)
        time.Sleep(backoff)
        backoff *= 2  // Exponential backoff
    }

    return fmt.Errorf("failed after %d retries", maxRetries)
}
```

### 5. Resource Management

```go
// Always cleanup resources
defer dht.Close()
defer replicationManager.Stop()

// Monitor goroutine count
runtime.NumGoroutine()

// Set connection limits
dht.host.Network().SetConnManager(connManager)
```

## Testing

### Unit Tests

```bash
# Run all DHT tests
go test ./pkg/dht/...

# Run specific test
go test ./pkg/dht/ -run TestDHTBootstrap

# Run with coverage
go test -cover ./pkg/dht/...
```

### Integration Tests

```bash
# Test DHT with encryption
go test ./pkg/dht/ -run TestEncryptedStorage

# Test replication
go test ./pkg/dht/ -run TestReplicationManager

# Test with real network
go test -tags=integration ./pkg/dht/...
```

## Troubleshooting

### Bootstrap Failures

```
Problem: DHT fails to bootstrap
Causes:
  - No reachable bootstrap peers
  - Network firewall blocking P2P ports
  - NAT traversal issues

Solutions:
  - Verify bootstrap peer addresses
  - Check firewall rules
  - Enable UPnP/NAT-PMP
  - Use relay nodes
```

### Content Not Found

```
Problem: GetValue returns "not found"
Causes:
  - Content never stored
  - Insufficient replication
  - Provider records expired
  - Network partition

Solutions:
  - Verify PutValue succeeded
  - Check replication status
  - Increase replication factor
  - Enable reproviding
```

### Cache Issues

```
Problem: High cache miss rate
Causes:
  - TTL too short
  - High content churn
  - Memory pressure forcing evictions

Solutions:
  - Increase cache TTL
  - Increase cache size
  - Monitor cache metrics
  - Adjust cleanup interval
```

## Cross-References

- **Crypto Package**: `/home/tony/chorus/project-queues/active/CHORUS/docs/comprehensive/packages/crypto.md`
- **UCXL Package**: `/home/tony/chorus/project-queues/active/CHORUS/pkg/ucxl/`
- **Config Package**: `/home/tony/chorus/project-queues/active/CHORUS/pkg/config/`
- **Architecture**: `/home/tony/chorus/project-queues/active/CHORUS/docs/ARCHITECTURE.md`

## Summary

The CHORUS DHT package provides:

1. **Distributed Storage**: LibP2P Kademlia DHT for decentralized content
2. **Encrypted Content**: Age encryption integrated at storage layer
3. **Role-Based Access**: CHORUS role system enforces permissions
4. **Automatic Replication**: Maintains content availability
5. **Performance Optimization**: Caching, batching, concurrent operations
6. **Production Ready**: Monitoring, metrics, audit logging

The package is production-ready and designed for enterprise use with comprehensive security, reliability, and observability features.