// Package distribution provides network management for distributed context operations
package distribution

import (
	"context"
	"fmt"
	"net"
	"sort"
	"sync"
	"time"

	"github.com/anthonyrawlins/bzzz/pkg/dht"
	"github.com/anthonyrawlins/bzzz/pkg/config"
	"github.com/libp2p/go-libp2p/core/peer"
)

// NetworkManagerImpl implements NetworkManager interface for network topology and partition management
type NetworkManagerImpl struct {
	mu                   sync.RWMutex
	dht                  *dht.DHT
	config               *config.Config
	topology             *NetworkTopology
	partitionInfo        *PartitionInfo
	connectivity         *ConnectivityMatrix
	stats                *NetworkStatistics
	healthChecker        *NetworkHealthChecker
	partitionDetector    *PartitionDetector
	recoveryManager      *RecoveryManager
	
	// Configuration
	healthCheckInterval  time.Duration
	partitionCheckInterval time.Duration
	connectivityTimeout  time.Duration
	maxPartitionDuration time.Duration
	
	// State
	lastTopologyUpdate   time.Time
	lastPartitionCheck   time.Time
	running              bool
	recoveryInProgress   bool
}

// ConnectivityMatrix tracks connectivity between all nodes
type ConnectivityMatrix struct {
	Matrix      map[string]map[string]*ConnectionInfo `json:"matrix"`
	LastUpdated time.Time                              `json:"last_updated"`
	mu          sync.RWMutex
}

// ConnectionInfo represents connectivity information between two nodes
type ConnectionInfo struct {
	Connected        bool          `json:"connected"`
	Latency          time.Duration `json:"latency"`
	PacketLoss       float64       `json:"packet_loss"`
	Bandwidth        int64         `json:"bandwidth"`
	LastChecked      time.Time     `json:"last_checked"`
	ErrorCount       int           `json:"error_count"`
	LastError        string        `json:"last_error,omitempty"`
}

// NetworkHealthChecker performs network health checks
type NetworkHealthChecker struct {
	mu              sync.RWMutex
	nodeHealth      map[string]*NodeHealth
	healthHistory   map[string][]*HealthCheckResult
	alertThresholds *NetworkAlertThresholds
}

// NodeHealth represents health status of a network node
type NodeHealth struct {
	NodeID          string        `json:"node_id"`
	Status          NodeStatus    `json:"status"`
	HealthScore     float64       `json:"health_score"`
	LastSeen        time.Time     `json:"last_seen"`
	ResponseTime    time.Duration `json:"response_time"`
	PacketLossRate  float64       `json:"packet_loss_rate"`
	BandwidthUtil   float64       `json:"bandwidth_utilization"`
	Uptime          time.Duration `json:"uptime"`
	ErrorRate       float64       `json:"error_rate"`
}

// NodeStatus represents the status of a network node
type NodeStatus string

const (
	NodeStatusHealthy     NodeStatus = "healthy"
	NodeStatusDegraded    NodeStatus = "degraded"
	NodeStatusUnreachable NodeStatus = "unreachable"
	NodeStatusFailed      NodeStatus = "failed"
	NodeStatusRecovering  NodeStatus = "recovering"
)

// HealthCheckResult represents the result of a health check
type HealthCheckResult struct {
	NodeID         string        `json:"node_id"`
	Timestamp      time.Time     `json:"timestamp"`
	Success        bool          `json:"success"`
	ResponseTime   time.Duration `json:"response_time"`
	ErrorMessage   string        `json:"error_message,omitempty"`
	NetworkMetrics *NetworkMetrics `json:"network_metrics"`
}

// NetworkAlertThresholds defines thresholds for network alerts
type NetworkAlertThresholds struct {
	LatencyWarning       time.Duration `json:"latency_warning"`
	LatencyCritical      time.Duration `json:"latency_critical"`
	PacketLossWarning    float64       `json:"packet_loss_warning"`
	PacketLossCritical   float64       `json:"packet_loss_critical"`
	HealthScoreWarning   float64       `json:"health_score_warning"`
	HealthScoreCritical  float64       `json:"health_score_critical"`
}

// PartitionDetector detects network partitions
type PartitionDetector struct {
	mu                  sync.RWMutex
	detectionAlgorithm  PartitionDetectionAlgorithm
	partitionHistory    []*PartitionEvent
	falsePositiveFilter *FalsePositiveFilter
	config              *PartitionDetectorConfig
}

// PartitionDetectionAlgorithm represents different partition detection algorithms
type PartitionDetectionAlgorithm string

const (
	AlgorithmGossipBased     PartitionDetectionAlgorithm = "gossip_based"
	AlgorithmConnectivityMap PartitionDetectionAlgorithm = "connectivity_map"
	AlgorithmHeartbeat       PartitionDetectionAlgorithm = "heartbeat"
	AlgorithmHybrid          PartitionDetectionAlgorithm = "hybrid"
)

// PartitionEvent represents a partition detection event
type PartitionEvent struct {
	EventID          string                 `json:"event_id"`
	DetectedAt       time.Time              `json:"detected_at"`
	Algorithm        PartitionDetectionAlgorithm `json:"algorithm"`
	PartitionedNodes []string               `json:"partitioned_nodes"`
	Confidence       float64                `json:"confidence"`
	Duration         time.Duration          `json:"duration"`
	Resolved         bool                   `json:"resolved"`
	ResolvedAt       *time.Time             `json:"resolved_at,omitempty"`
}

// FalsePositiveFilter helps reduce false partition detections
type FalsePositiveFilter struct {
	consecutiveChecks int
	confirmationTime  time.Duration
	suspectNodes      map[string]time.Time
}

// PartitionDetectorConfig configures partition detection behavior
type PartitionDetectorConfig struct {
	CheckInterval        time.Duration `json:"check_interval"`
	ConfidenceThreshold  float64       `json:"confidence_threshold"`
	MinPartitionSize     int           `json:"min_partition_size"`
	MaxPartitionDuration time.Duration `json:"max_partition_duration"`
	FalsePositiveTimeout time.Duration `json:"false_positive_timeout"`
}

// RecoveryManager manages network partition recovery
type RecoveryManager struct {
	mu                sync.RWMutex
	recoveryStrategies map[RecoveryStrategy]*RecoveryStrategyConfig
	activeRecoveries  map[string]*RecoveryOperation
	recoveryHistory   []*RecoveryResult
}

// RecoveryStrategy represents different recovery strategies
type RecoveryStrategy string

const (
	RecoveryStrategyAutomatic RecoveryStrategy = "automatic"
	RecoveryStrategyManual    RecoveryStrategy = "manual"
	RecoveryStrategyGraceful  RecoveryStrategy = "graceful"
	RecoveryStrategyForced    RecoveryStrategy = "forced"
)

// RecoveryStrategyConfig configures a recovery strategy
type RecoveryStrategyConfig struct {
	Strategy        RecoveryStrategy `json:"strategy"`
	Timeout         time.Duration    `json:"timeout"`
	RetryAttempts   int             `json:"retry_attempts"`
	RetryInterval   time.Duration    `json:"retry_interval"`
	RequireConsensus bool            `json:"require_consensus"`
	ForcedThreshold time.Duration    `json:"forced_threshold"`
}

// RecoveryOperation represents an active recovery operation
type RecoveryOperation struct {
	OperationID     string           `json:"operation_id"`
	Strategy        RecoveryStrategy `json:"strategy"`
	StartedAt       time.Time        `json:"started_at"`
	TargetNodes     []string         `json:"target_nodes"`
	Status          RecoveryStatus   `json:"status"`
	Progress        float64          `json:"progress"`
	CurrentPhase    RecoveryPhase    `json:"current_phase"`
	Errors          []string         `json:"errors"`
	LastUpdate      time.Time        `json:"last_update"`
}

// RecoveryStatus represents the status of a recovery operation
type RecoveryStatus string

const (
	RecoveryStatusInitiated  RecoveryStatus = "initiated"
	RecoveryStatusInProgress RecoveryStatus = "in_progress"
	RecoveryStatusCompleted  RecoveryStatus = "completed"
	RecoveryStatusFailed     RecoveryStatus = "failed"
	RecoveryStatusAborted    RecoveryStatus = "aborted"
)

// RecoveryPhase represents different phases of recovery
type RecoveryPhase string

const (
	RecoveryPhaseAssessment    RecoveryPhase = "assessment"
	RecoveryPhasePreparation   RecoveryPhase = "preparation"
	RecoveryPhaseReconnection  RecoveryPhase = "reconnection"
	RecoveryPhaseSynchronization RecoveryPhase = "synchronization"
	RecoveryPhaseValidation    RecoveryPhase = "validation"
	RecoveryPhaseCompletion    RecoveryPhase = "completion"
)

// NewNetworkManagerImpl creates a new network manager implementation
func NewNetworkManagerImpl(dht *dht.DHT, config *config.Config) (*NetworkManagerImpl, error) {
	if dht == nil {
		return nil, fmt.Errorf("DHT instance is required")
	}
	if config == nil {
		return nil, fmt.Errorf("config is required")
	}

	nm := &NetworkManagerImpl{
		dht:                      dht,
		config:                   config,
		healthCheckInterval:      30 * time.Second,
		partitionCheckInterval:   60 * time.Second,
		connectivityTimeout:      10 * time.Second,
		maxPartitionDuration:     10 * time.Minute,
		connectivity:             &ConnectivityMatrix{Matrix: make(map[string]map[string]*ConnectionInfo)},
		stats: &NetworkStatistics{
			LastUpdated: time.Now(),
		},
	}

	// Initialize components
	if err := nm.initializeComponents(); err != nil {
		return nil, fmt.Errorf("failed to initialize network manager components: %w", err)
	}

	return nm, nil
}

// initializeComponents initializes all network manager components
func (nm *NetworkManagerImpl) initializeComponents() error {
	// Initialize topology
	nm.topology = &NetworkTopology{
		TotalNodes:    0,
		Connections:   make(map[string][]string),
		Regions:       make(map[string][]string),
		AvailabilityZones: make(map[string][]string),
		UpdatedAt:     time.Now(),
	}

	// Initialize partition info
	nm.partitionInfo = &PartitionInfo{
		PartitionDetected: false,
		PartitionCount:    1,
		IsolatedNodes:     []string{},
		ConnectivityMatrix: make(map[string]map[string]bool),
		DetectedAt:        time.Now(),
	}

	// Initialize health checker
	nm.healthChecker = &NetworkHealthChecker{
		nodeHealth:    make(map[string]*NodeHealth),
		healthHistory: make(map[string][]*HealthCheckResult),
		alertThresholds: &NetworkAlertThresholds{
			LatencyWarning:       500 * time.Millisecond,
			LatencyCritical:      2 * time.Second,
			PacketLossWarning:    0.05, // 5%
			PacketLossCritical:   0.15, // 15%
			HealthScoreWarning:   0.7,
			HealthScoreCritical:  0.4,
		},
	}

	// Initialize partition detector
	nm.partitionDetector = &PartitionDetector{
		detectionAlgorithm: AlgorithmHybrid,
		partitionHistory:   []*PartitionEvent{},
		falsePositiveFilter: &FalsePositiveFilter{
			consecutiveChecks: 3,
			confirmationTime:  60 * time.Second,
			suspectNodes:      make(map[string]time.Time),
		},
		config: &PartitionDetectorConfig{
			CheckInterval:        60 * time.Second,
			ConfidenceThreshold:  0.8,
			MinPartitionSize:     1,
			MaxPartitionDuration: 30 * time.Minute,
			FalsePositiveTimeout: 5 * time.Minute,
		},
	}

	// Initialize recovery manager
	nm.recoveryManager = &RecoveryManager{
		recoveryStrategies: map[RecoveryStrategy]*RecoveryStrategyConfig{
			RecoveryStrategyAutomatic: {
				Strategy:        RecoveryStrategyAutomatic,
				Timeout:         5 * time.Minute,
				RetryAttempts:   3,
				RetryInterval:   30 * time.Second,
				RequireConsensus: false,
				ForcedThreshold: 10 * time.Minute,
			},
			RecoveryStrategyGraceful: {
				Strategy:        RecoveryStrategyGraceful,
				Timeout:         10 * time.Minute,
				RetryAttempts:   5,
				RetryInterval:   60 * time.Second,
				RequireConsensus: true,
				ForcedThreshold: 20 * time.Minute,
			},
		},
		activeRecoveries: make(map[string]*RecoveryOperation),
		recoveryHistory:  []*RecoveryResult{},
	}

	return nil
}

// Start starts the network manager
func (nm *NetworkManagerImpl) Start(ctx context.Context) error {
	nm.mu.Lock()
	if nm.running {
		nm.mu.Unlock()
		return fmt.Errorf("network manager already running")
	}
	nm.running = true
	nm.mu.Unlock()

	// Start background workers
	go nm.topologyUpdater(ctx)
	go nm.healthMonitor(ctx)
	go nm.partitionMonitor(ctx)
	go nm.connectivityChecker(ctx)

	return nil
}

// Stop stops the network manager
func (nm *NetworkManagerImpl) Stop() error {
	nm.mu.Lock()
	defer nm.mu.Unlock()

	nm.running = false
	return nil
}

// DetectPartition detects network partitions in the cluster
func (nm *NetworkManagerImpl) DetectPartition(ctx context.Context) (*PartitionInfo, error) {
	nm.mu.RLock()
	defer nm.mu.RUnlock()

	// Update partition detection
	partitioned, partitionedNodes, confidence := nm.detectPartitionUsing(nm.partitionDetector.detectionAlgorithm)

	if partitioned && confidence >= nm.partitionDetector.config.ConfidenceThreshold {
		// Record partition event
		event := &PartitionEvent{
			EventID:          nm.generateEventID(),
			DetectedAt:       time.Now(),
			Algorithm:        nm.partitionDetector.detectionAlgorithm,
			PartitionedNodes: partitionedNodes,
			Confidence:       confidence,
			Resolved:         false,
		}

		nm.partitionDetector.partitionHistory = append(nm.partitionDetector.partitionHistory, event)

		// Update partition info
		nm.partitionInfo.PartitionDetected = true
		nm.partitionInfo.PartitionCount = nm.calculatePartitionCount(partitionedNodes)
		nm.partitionInfo.LargestPartitionSize = nm.calculateLargestPartitionSize()
		nm.partitionInfo.CurrentPartitionSize = nm.calculateCurrentPartitionSize()
		nm.partitionInfo.IsolatedNodes = partitionedNodes
		nm.partitionInfo.DetectedAt = time.Now()
		nm.partitionInfo.Duration = time.Since(nm.partitionInfo.DetectedAt)
	}

	return nm.partitionInfo, nil
}

// GetTopology returns current network topology
func (nm *NetworkManagerImpl) GetTopology(ctx context.Context) (*NetworkTopology, error) {
	nm.mu.RLock()
	defer nm.mu.RUnlock()

	// Update topology data
	nm.updateTopology()

	return nm.topology, nil
}

// GetPeers returns list of available peer nodes
func (nm *NetworkManagerImpl) GetPeers(ctx context.Context) ([]*PeerInfo, error) {
	peers := nm.dht.GetConnectedPeers()
	peerInfos := make([]*PeerInfo, 0, len(peers))

	for _, peerID := range peers {
		// Get peer information from DHT
		peerInfo := nm.dht.GetKnownPeers()[peerID]
		if peerInfo != nil {
			peerInfos = append(peerInfos, &PeerInfo{
				NodeID:           peerID.String(),
				Address:          nm.getPeerAddress(peerID),
				Status:           "connected",
				Version:          "1.0.0",
				Region:           "default",
				AvailabilityZone: "zone-a",
				Latency:          nm.getPeerLatency(peerID),
				LastSeen:         peerInfo.LastSeen,
				Capabilities:     peerInfo.Capabilities,
			})
		}
	}

	return peerInfos, nil
}

// CheckConnectivity checks connectivity to peer nodes
func (nm *NetworkManagerImpl) CheckConnectivity(ctx context.Context, peers []string) (*ConnectivityReport, error) {
	start := time.Now()

	report := &ConnectivityReport{
		TotalPeers:       len(peers),
		ReachablePeers:   0,
		UnreachablePeers: 0,
		PeerResults:      make(map[string]*ConnectivityResult),
		TestedAt:         start,
	}

	// Test connectivity to each peer
	for _, peerID := range peers {
		result := nm.testPeerConnectivity(ctx, peerID)
		report.PeerResults[peerID] = result

		if result.Reachable {
			report.ReachablePeers++
			report.AverageLatency = (report.AverageLatency + result.Latency) / time.Duration(report.ReachablePeers)
		} else {
			report.UnreachablePeers++
		}
	}

	// Calculate overall health
	if report.TotalPeers > 0 {
		report.OverallHealth = float64(report.ReachablePeers) / float64(report.TotalPeers)
	}

	report.TestDuration = time.Since(start)

	return report, nil
}

// RecoverFromPartition attempts to recover from network partition
func (nm *NetworkManagerImpl) RecoverFromPartition(ctx context.Context) (*RecoveryResult, error) {
	nm.mu.Lock()
	if nm.recoveryInProgress {
		nm.mu.Unlock()
		return nil, fmt.Errorf("recovery operation already in progress")
	}
	nm.recoveryInProgress = true
	nm.mu.Unlock()

	defer func() {
		nm.mu.Lock()
		nm.recoveryInProgress = false
		nm.mu.Unlock()
	}()

	start := time.Now()

	result := &RecoveryResult{
		RecoverySuccessful: false,
		RecoveredNodes:     []string{},
		StillIsolatedNodes: []string{},
		RecoveryTime:       0,
		RecoveredAt:        time.Now(),
	}

	// Determine recovery strategy
	strategy := nm.selectRecoveryStrategy()

	// Create recovery operation
	operation := &RecoveryOperation{
		OperationID:  nm.generateOperationID(),
		Strategy:     strategy,
		StartedAt:    start,
		TargetNodes:  nm.partitionInfo.IsolatedNodes,
		Status:       RecoveryStatusInitiated,
		Progress:     0.0,
		CurrentPhase: RecoveryPhaseAssessment,
		Errors:       []string{},
		LastUpdate:   time.Now(),
	}

	// Execute recovery phases
	phases := []RecoveryPhase{
		RecoveryPhaseAssessment,
		RecoveryPhasePreparation,
		RecoveryPhaseReconnection,
		RecoveryPhaseSynchronization,
		RecoveryPhaseValidation,
		RecoveryPhaseCompletion,
	}

	for i, phase := range phases {
		operation.CurrentPhase = phase
		operation.Progress = float64(i) / float64(len(phases))

		if err := nm.executeRecoveryPhase(ctx, operation, phase); err != nil {
			operation.Errors = append(operation.Errors, err.Error())
			if len(operation.Errors) > 3 { // Too many errors, abort
				operation.Status = RecoveryStatusFailed
				break
			}
		}

		operation.LastUpdate = time.Now()
	}

	// Finalize result
	result.RecoveryTime = time.Since(start)
	result.RecoverySuccessful = operation.Status != RecoveryStatusFailed

	// Update partition info if recovery was successful
	if result.RecoverySuccessful {
		nm.partitionInfo.PartitionDetected = false
		nm.partitionInfo.IsolatedNodes = []string{}
	}

	// Store recovery history
	nm.recoveryManager.recoveryHistory = append(nm.recoveryManager.recoveryHistory, result)

	return result, nil
}

// GetNetworkStats returns network performance statistics
func (nm *NetworkManagerImpl) GetNetworkStats() (*NetworkStatistics, error) {
	nm.mu.RLock()
	defer nm.mu.RUnlock()

	// Update real-time statistics
	nm.updateNetworkStatistics()

	return nm.stats, nil
}

// Background workers

func (nm *NetworkManagerImpl) topologyUpdater(ctx context.Context) {
	ticker := time.NewTicker(5 * time.Minute)
	defer ticker.Stop()

	for {
		select {
		case <-ctx.Done():
			return
		case <-ticker.C:
			if nm.running {
				nm.updateTopology()
			}
		}
	}
}

func (nm *NetworkManagerImpl) healthMonitor(ctx context.Context) {
	ticker := time.NewTicker(nm.healthCheckInterval)
	defer ticker.Stop()

	for {
		select {
		case <-ctx.Done():
			return
		case <-ticker.C:
			if nm.running {
				nm.performHealthChecks(ctx)
			}
		}
	}
}

func (nm *NetworkManagerImpl) partitionMonitor(ctx context.Context) {
	ticker := time.NewTicker(nm.partitionCheckInterval)
	defer ticker.Stop()

	for {
		select {
		case <-ctx.Done():
			return
		case <-ticker.C:
			if nm.running {
				nm.DetectPartition(ctx)
			}
		}
	}
}

func (nm *NetworkManagerImpl) connectivityChecker(ctx context.Context) {
	ticker := time.NewTicker(2 * time.Minute)
	defer ticker.Stop()

	for {
		select {
		case <-ctx.Done():
			return
		case <-ticker.C:
			if nm.running {
				nm.updateConnectivityMatrix(ctx)
			}
		}
	}
}

// Helper methods

func (nm *NetworkManagerImpl) updateTopology() {
	peers := nm.dht.GetConnectedPeers()
	
	nm.topology.TotalNodes = len(peers) + 1 // +1 for current node
	nm.topology.Connections = make(map[string][]string)
	
	// Build connection map
	currentNodeID := nm.config.Agent.ID
	peerConnections := make([]string, len(peers))
	for i, peer := range peers {
		peerConnections[i] = peer.String()
	}
	nm.topology.Connections[currentNodeID] = peerConnections
	
	// Calculate network metrics
	nm.topology.ClusterDiameter = nm.calculateClusterDiameter()
	nm.topology.ClusteringCoefficient = nm.calculateClusteringCoefficient()
	
	nm.topology.UpdatedAt = time.Now()
	nm.lastTopologyUpdate = time.Now()
}

func (nm *NetworkManagerImpl) performHealthChecks(ctx context.Context) {
	peers := nm.dht.GetConnectedPeers()
	
	for _, peer := range peers {
		result := nm.performHealthCheck(ctx, peer.String())
		
		// Update node health
		nodeHealth := &NodeHealth{
			NodeID:         peer.String(),
			Status:         nm.determineNodeStatus(result),
			HealthScore:    nm.calculateHealthScore(result),
			LastSeen:       time.Now(),
			ResponseTime:   result.ResponseTime,
			PacketLossRate: 0.0, // Would be measured in real implementation
			ErrorRate:      0.0, // Would be calculated from history
		}
		
		if result.Success {
			nodeHealth.Status = NodeStatusHealthy
			nodeHealth.HealthScore = 1.0
		} else {
			nodeHealth.Status = NodeStatusUnreachable
			nodeHealth.HealthScore = 0.0
		}
		
		nm.healthChecker.nodeHealth[peer.String()] = nodeHealth
		
		// Store health check history
		if _, exists := nm.healthChecker.healthHistory[peer.String()]; !exists {
			nm.healthChecker.healthHistory[peer.String()] = []*HealthCheckResult{}
		}
		nm.healthChecker.healthHistory[peer.String()] = append(
			nm.healthChecker.healthHistory[peer.String()], 
			result,
		)
		
		// Keep only recent history (last 100 checks)
		if len(nm.healthChecker.healthHistory[peer.String()]) > 100 {
			nm.healthChecker.healthHistory[peer.String()] = 
				nm.healthChecker.healthHistory[peer.String()][1:]
		}
	}
}

func (nm *NetworkManagerImpl) updateConnectivityMatrix(ctx context.Context) {
	peers := nm.dht.GetConnectedPeers()
	
	nm.connectivity.mu.Lock()
	defer nm.connectivity.mu.Unlock()
	
	// Initialize matrix if needed
	if nm.connectivity.Matrix == nil {
		nm.connectivity.Matrix = make(map[string]map[string]*ConnectionInfo)
	}
	
	currentNodeID := nm.config.Agent.ID
	
	// Ensure current node exists in matrix
	if nm.connectivity.Matrix[currentNodeID] == nil {
		nm.connectivity.Matrix[currentNodeID] = make(map[string]*ConnectionInfo)
	}
	
	// Test connectivity to all peers
	for _, peer := range peers {
		peerID := peer.String()
		
		// Test connection
		connInfo := nm.testConnection(ctx, peerID)
		nm.connectivity.Matrix[currentNodeID][peerID] = connInfo
	}
	
	nm.connectivity.LastUpdated = time.Now()
}

func (nm *NetworkManagerImpl) detectPartitionUsing(algorithm PartitionDetectionAlgorithm) (bool, []string, float64) {
	switch algorithm {
	case AlgorithmConnectivityMap:
		return nm.detectPartitionByConnectivity()
	case AlgorithmHeartbeat:
		return nm.detectPartitionByHeartbeat()
	case AlgorithmGossipBased:
		return nm.detectPartitionByGossip()
	case AlgorithmHybrid:
		return nm.detectPartitionHybrid()
	default:
		return false, []string{}, 0.0
	}
}

func (nm *NetworkManagerImpl) detectPartitionByConnectivity() (bool, []string, float64) {
	// Simplified connectivity-based detection
	peers := nm.dht.GetConnectedPeers()
	knownPeers := nm.dht.GetKnownPeers()
	
	// If we know more peers than we're connected to, might be partitioned
	if len(knownPeers) > len(peers)+2 { // Allow some tolerance
		isolatedNodes := []string{}
		for peerID := range knownPeers {
			connected := false
			for _, connectedPeer := range peers {
				if peerID == connectedPeer {
					connected = true
					break
				}
			}
			if !connected {
				isolatedNodes = append(isolatedNodes, peerID.String())
			}
		}
		return true, isolatedNodes, 0.8
	}
	
	return false, []string{}, 0.0
}

func (nm *NetworkManagerImpl) detectPartitionByHeartbeat() (bool, []string, float64) {
	// Simplified heartbeat-based detection
	nm.healthChecker.mu.RLock()
	defer nm.healthChecker.mu.RUnlock()
	
	isolatedNodes := []string{}
	for nodeID, health := range nm.healthChecker.nodeHealth {
		if health.Status == NodeStatusUnreachable {
			isolatedNodes = append(isolatedNodes, nodeID)
		}
	}
	
	if len(isolatedNodes) > 0 {
		return true, isolatedNodes, 0.7
	}
	
	return false, []string{}, 0.0
}

func (nm *NetworkManagerImpl) detectPartitionByGossip() (bool, []string, float64) {
	// Placeholder for gossip-based detection
	return false, []string{}, 0.0
}

func (nm *NetworkManagerImpl) detectPartitionHybrid() (bool, []string, float64) {
	// Combine multiple detection methods
	partitioned1, nodes1, conf1 := nm.detectPartitionByConnectivity()
	partitioned2, nodes2, conf2 := nm.detectPartitionByHeartbeat()
	
	if partitioned1 && partitioned2 {
		// Both methods agree
		combinedNodes := nm.combineNodeLists(nodes1, nodes2)
		avgConfidence := (conf1 + conf2) / 2.0
		return true, combinedNodes, avgConfidence
	} else if partitioned1 || partitioned2 {
		// One method detects partition
		if conf1 > conf2 {
			return true, nodes1, conf1 * 0.7 // Reduce confidence
		} else {
			return true, nodes2, conf2 * 0.7
		}
	}
	
	return false, []string{}, 0.0
}

func (nm *NetworkManagerImpl) selectRecoveryStrategy() RecoveryStrategy {
	// Simple strategy selection based on partition duration
	if nm.partitionInfo.Duration > 10*time.Minute {
		return RecoveryStrategyForced
	} else if nm.partitionInfo.Duration > 5*time.Minute {
		return RecoveryStrategyGraceful
	} else {
		return RecoveryStrategyAutomatic
	}
}

func (nm *NetworkManagerImpl) executeRecoveryPhase(ctx context.Context, operation *RecoveryOperation, phase RecoveryPhase) error {
	switch phase {
	case RecoveryPhaseAssessment:
		return nm.assessPartitionState(ctx, operation)
	case RecoveryPhasePreparation:
		return nm.prepareRecovery(ctx, operation)
	case RecoveryPhaseReconnection:
		return nm.attemptReconnection(ctx, operation)
	case RecoveryPhaseSynchronization:
		return nm.synchronizeAfterRecovery(ctx, operation)
	case RecoveryPhaseValidation:
		return nm.validateRecovery(ctx, operation)
	case RecoveryPhaseCompletion:
		return nm.completeRecovery(ctx, operation)
	default:
		return fmt.Errorf("unknown recovery phase: %s", phase)
	}
}

// Placeholder implementations for recovery phases

func (nm *NetworkManagerImpl) assessPartitionState(ctx context.Context, operation *RecoveryOperation) error {
	// Assess current partition state
	operation.Status = RecoveryStatusInProgress
	return nil
}

func (nm *NetworkManagerImpl) prepareRecovery(ctx context.Context, operation *RecoveryOperation) error {
	// Prepare for recovery
	return nil
}

func (nm *NetworkManagerImpl) attemptReconnection(ctx context.Context, operation *RecoveryOperation) error {
	// Attempt to reconnect partitioned nodes
	return nil
}

func (nm *NetworkManagerImpl) synchronizeAfterRecovery(ctx context.Context, operation *RecoveryOperation) error {
	// Synchronize state after reconnection
	return nil
}

func (nm *NetworkManagerImpl) validateRecovery(ctx context.Context, operation *RecoveryOperation) error {
	// Validate that recovery was successful
	return nil
}

func (nm *NetworkManagerImpl) completeRecovery(ctx context.Context, operation *RecoveryOperation) error {
	// Complete recovery operation
	operation.Status = RecoveryStatusCompleted
	operation.Progress = 1.0
	return nil
}

// Utility methods

func (nm *NetworkManagerImpl) testPeerConnectivity(ctx context.Context, peerID string) *ConnectivityResult {
	start := time.Now()
	
	// In a real implementation, this would test actual network connectivity
	// For now, we'll simulate based on DHT connectivity
	peers := nm.dht.GetConnectedPeers()
	
	for _, peer := range peers {
		if peer.String() == peerID {
			return &ConnectivityResult{
				PeerID:     peerID,
				Reachable:  true,
				Latency:    time.Since(start),
				PacketLoss: 0.0,
				Bandwidth:  1000000, // 1 Mbps placeholder
				TestedAt:   time.Now(),
			}
		}
	}
	
	return &ConnectivityResult{
		PeerID:     peerID,
		Reachable:  false,
		Latency:    0,
		PacketLoss: 1.0,
		Bandwidth:  0,
		Error:      "peer not connected",
		TestedAt:   time.Now(),
	}
}

func (nm *NetworkManagerImpl) performHealthCheck(ctx context.Context, nodeID string) *HealthCheckResult {
	start := time.Now()
	
	// In a real implementation, this would perform actual health checks
	// For now, simulate based on connectivity
	peers := nm.dht.GetConnectedPeers()
	
	for _, peer := range peers {
		if peer.String() == nodeID {
			return &HealthCheckResult{
				NodeID:       nodeID,
				Timestamp:    time.Now(),
				Success:      true,
				ResponseTime: time.Since(start),
			}
		}
	}
	
	return &HealthCheckResult{
		NodeID:       nodeID,
		Timestamp:    time.Now(),
		Success:      false,
		ResponseTime: 0,
		ErrorMessage: "node unreachable",
	}
}

func (nm *NetworkManagerImpl) testConnection(ctx context.Context, peerID string) *ConnectionInfo {
	// Test connection to specific peer
	connected := false
	latency := time.Duration(0)
	
	// Check if peer is in connected peers list
	peers := nm.dht.GetConnectedPeers()
	for _, peer := range peers {
		if peer.String() == peerID {
			connected = true
			latency = 50 * time.Millisecond // Placeholder
			break
		}
	}
	
	return &ConnectionInfo{
		Connected:    connected,
		Latency:      latency,
		PacketLoss:   0.0,
		Bandwidth:    1000000, // 1 Mbps placeholder
		LastChecked:  time.Now(),
		ErrorCount:   0,
	}
}

func (nm *NetworkManagerImpl) updateNetworkStatistics() {
	peers := nm.dht.GetConnectedPeers()
	
	nm.stats.TotalNodes = len(peers) + 1
	nm.stats.ConnectedNodes = len(peers)
	nm.stats.DisconnectedNodes = nm.stats.TotalNodes - nm.stats.ConnectedNodes
	
	// Calculate average latency from connectivity matrix
	totalLatency := time.Duration(0)
	connectionCount := 0
	
	nm.connectivity.mu.RLock()
	for _, connections := range nm.connectivity.Matrix {
		for _, conn := range connections {
			if conn.Connected {
				totalLatency += conn.Latency
				connectionCount++
			}
		}
	}
	nm.connectivity.mu.RUnlock()
	
	if connectionCount > 0 {
		nm.stats.AverageLatency = totalLatency / time.Duration(connectionCount)
	}
	
	nm.stats.OverallHealth = nm.calculateOverallNetworkHealth()
	nm.stats.LastUpdated = time.Now()
}

// Placeholder implementations for calculated fields

func (nm *NetworkManagerImpl) calculateClusterDiameter() int {
	// Simplified calculation
	return nm.topology.TotalNodes - 1
}

func (nm *NetworkManagerImpl) calculateClusteringCoefficient() float64 {
	// Simplified calculation
	if nm.topology.TotalNodes > 1 {
		return 0.8 // Placeholder
	}
	return 0.0
}

func (nm *NetworkManagerImpl) calculatePartitionCount(partitionedNodes []string) int {
	return len(partitionedNodes) + 1 // Current partition + isolated nodes
}

func (nm *NetworkManagerImpl) calculateLargestPartitionSize() int {
	peers := nm.dht.GetConnectedPeers()
	return len(peers) + 1 // Current partition size
}

func (nm *NetworkManagerImpl) calculateCurrentPartitionSize() int {
	return nm.calculateLargestPartitionSize()
}

func (nm *NetworkManagerImpl) calculateOverallNetworkHealth() float64 {
	if nm.stats.TotalNodes == 0 {
		return 1.0
	}
	return float64(nm.stats.ConnectedNodes) / float64(nm.stats.TotalNodes)
}

func (nm *NetworkManagerImpl) determineNodeStatus(result *HealthCheckResult) NodeStatus {
	if result.Success {
		return NodeStatusHealthy
	}
	return NodeStatusUnreachable
}

func (nm *NetworkManagerImpl) calculateHealthScore(result *HealthCheckResult) float64 {
	if result.Success {
		return 1.0
	}
	return 0.0
}

func (nm *NetworkManagerImpl) combineNodeLists(list1, list2 []string) []string {
	nodeSet := make(map[string]bool)
	
	for _, node := range list1 {
		nodeSet[node] = true
	}
	for _, node := range list2 {
		nodeSet[node] = true
	}
	
	result := make([]string, 0, len(nodeSet))
	for node := range nodeSet {
		result = append(result, node)
	}
	
	sort.Strings(result)
	return result
}

func (nm *NetworkManagerImpl) getPeerAddress(peerID peer.ID) string {
	// In a real implementation, would get actual peer address
	return "unknown"
}

func (nm *NetworkManagerImpl) getPeerLatency(peerID peer.ID) time.Duration {
	// In a real implementation, would measure actual latency
	return 50 * time.Millisecond
}

func (nm *NetworkManagerImpl) generateEventID() string {
	return fmt.Sprintf("evt-%d", time.Now().UnixNano())
}

func (nm *NetworkManagerImpl) generateOperationID() string {
	return fmt.Sprintf("op-%d", time.Now().UnixNano())
}