saorsa_core/

network.rs

// Copyright 2024 Saorsa Labs Limited
//
// This software is dual-licensed under:
// - GNU Affero General Public License v3.0 or later (AGPL-3.0-or-later)
// - Commercial License
//
// For AGPL-3.0 license, see LICENSE-AGPL-3.0
// For commercial licensing, contact: david@saorsalabs.com
//
// Unless required by applicable law or agreed to in writing, software
// distributed under these licenses is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

//! Network module
//!
//! This module provides core networking functionality for the P2P Foundation.
//! It handles peer connections, network events, and node lifecycle management.

use crate::bgp_geo_provider::BgpGeoProvider;
use crate::bootstrap::{BootstrapManager, ContactEntry, QualityMetrics};
use crate::config::Config;
use crate::control::RejectionMessage;
use crate::dht::DHT;
use crate::error::{NetworkError, P2PError, P2pResult as Result};
use crate::identity::rejection::RejectionReason;
use crate::security::GeoProvider;

use crate::production::{ProductionConfig, ResourceManager, ResourceMetrics};
use crate::transport::ant_quic_adapter::DualStackNetworkNode;
#[allow(unused_imports)] // Temporarily unused during migration
use crate::transport::{TransportOptions, TransportType};
use crate::validation::RateLimitConfig;
use crate::validation::RateLimiter;
use crate::{NetworkAddress, PeerId};
use serde::{Deserialize, Serialize};
use std::collections::{HashMap, HashSet};
use std::sync::Arc;
use std::sync::atomic::{AtomicBool, Ordering};
use std::time::Duration;
use tokio::sync::{RwLock, broadcast};
use tokio::time::Instant;
use tracing::{debug, info, trace, warn};

/// Configuration for a P2P node
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct NodeConfig {
    /// Local peer ID for this node
    pub peer_id: Option<PeerId>,

    /// Addresses to listen on for incoming connections
    pub listen_addrs: Vec<std::net::SocketAddr>,

    /// Primary listen address (for compatibility)
    pub listen_addr: std::net::SocketAddr,

    /// Bootstrap peers to connect to on startup (legacy)
    pub bootstrap_peers: Vec<std::net::SocketAddr>,

    /// Bootstrap peers as strings (for integration tests)
    pub bootstrap_peers_str: Vec<String>,

    /// Enable IPv6 support
    pub enable_ipv6: bool,

    // MCP removed; will be redesigned later
    /// Connection timeout duration
    pub connection_timeout: Duration,

    /// Keep-alive interval for connections
    pub keep_alive_interval: Duration,

    /// Maximum number of concurrent connections
    pub max_connections: usize,

    /// Maximum number of incoming connections
    pub max_incoming_connections: usize,

    /// DHT configuration
    pub dht_config: DHTConfig,

    /// Security configuration
    pub security_config: SecurityConfig,

    /// Production hardening configuration
    pub production_config: Option<ProductionConfig>,

    /// Bootstrap cache configuration
    pub bootstrap_cache_config: Option<crate::bootstrap::CacheConfig>,

    /// Optional IP diversity configuration for Sybil protection tuning.
    ///
    /// When set, this configuration is used by bootstrap peer discovery and
    /// other diversity-enforcing subsystems. If `None`, defaults are used.
    pub diversity_config: Option<crate::security::IPDiversityConfig>,
}

/// DHT-specific configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct DHTConfig {
    /// Kademlia K parameter (bucket size)
    pub k_value: usize,

    /// Kademlia alpha parameter (parallelism)
    pub alpha_value: usize,

    /// DHT record TTL
    pub record_ttl: Duration,

    /// DHT refresh interval
    pub refresh_interval: Duration,
}

/// Security configuration
#[derive(Debug, Clone, Serialize, Deserialize)]
pub struct SecurityConfig {
    /// Enable noise protocol for encryption
    pub enable_noise: bool,

    /// Enable TLS for secure transport
    pub enable_tls: bool,

    /// Trust level for peer verification
    pub trust_level: TrustLevel,
}

/// Trust level for peer verification
#[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
pub enum TrustLevel {
    /// No verification required
    None,
    /// Basic peer ID verification
    Basic,
    /// Full cryptographic verification
    Full,
}

impl NodeConfig {
    /// Create a new NodeConfig with default values
    ///
    /// # Errors
    ///
    /// Returns an error if default addresses cannot be parsed
    pub fn new() -> Result<Self> {
        // Load config and use its defaults
        let config = Config::default();

        // Parse the default listen address
        let listen_addr = config.listen_socket_addr()?;

        // Create listen addresses based on config
        let mut listen_addrs = vec![];

        // Add IPv6 address if enabled
        if config.network.ipv6_enabled {
            let ipv6_addr = std::net::SocketAddr::new(
                std::net::IpAddr::V6(std::net::Ipv6Addr::UNSPECIFIED),
                listen_addr.port(),
            );
            listen_addrs.push(ipv6_addr);
        }

        // Always add IPv4
        let ipv4_addr = std::net::SocketAddr::new(
            std::net::IpAddr::V4(std::net::Ipv4Addr::UNSPECIFIED),
            listen_addr.port(),
        );
        listen_addrs.push(ipv4_addr);

        Ok(Self {
            peer_id: None,
            listen_addrs,
            listen_addr,
            bootstrap_peers: Vec::new(),
            bootstrap_peers_str: config.network.bootstrap_nodes.clone(),
            enable_ipv6: config.network.ipv6_enabled,

            connection_timeout: Duration::from_secs(config.network.connection_timeout),
            keep_alive_interval: Duration::from_secs(config.network.keepalive_interval),
            max_connections: config.network.max_connections,
            max_incoming_connections: config.security.connection_limit as usize,
            dht_config: DHTConfig::default(),
            security_config: SecurityConfig::default(),
            production_config: None,
            bootstrap_cache_config: None,
            diversity_config: None,
            // identity_config: None,
        })
    }
}

impl Default for NodeConfig {
    fn default() -> Self {
        // Use config defaults for network settings
        let config = Config::default();

        // Parse the default listen address - use safe fallback if parsing fails
        let listen_addr = config.listen_socket_addr().unwrap_or_else(|_| {
            std::net::SocketAddr::new(
                std::net::IpAddr::V4(std::net::Ipv4Addr::new(0, 0, 0, 0)),
                9000,
            )
        });

        Self {
            peer_id: None,
            listen_addrs: vec![
                std::net::SocketAddr::new(
                    std::net::IpAddr::V6(std::net::Ipv6Addr::UNSPECIFIED),
                    listen_addr.port(),
                ),
                std::net::SocketAddr::new(
                    std::net::IpAddr::V4(std::net::Ipv4Addr::UNSPECIFIED),
                    listen_addr.port(),
                ),
            ],
            listen_addr,
            bootstrap_peers: Vec::new(),
            bootstrap_peers_str: Vec::new(),
            enable_ipv6: config.network.ipv6_enabled,

            connection_timeout: Duration::from_secs(config.network.connection_timeout),
            keep_alive_interval: Duration::from_secs(config.network.keepalive_interval),
            max_connections: config.network.max_connections,
            max_incoming_connections: config.security.connection_limit as usize,
            dht_config: DHTConfig::default(),
            security_config: SecurityConfig::default(),
            production_config: None, // Use default production config if enabled
            bootstrap_cache_config: None,
            diversity_config: None,
            // identity_config: None, // Use default identity config if enabled
        }
    }
}

impl NodeConfig {
    /// Create NodeConfig from Config
    pub fn from_config(config: &Config) -> Result<Self> {
        let listen_addr = config.listen_socket_addr()?;
        let bootstrap_addrs = config.bootstrap_addrs()?;

        let mut node_config = Self {
            peer_id: None,
            listen_addrs: vec![listen_addr],
            listen_addr,
            bootstrap_peers: bootstrap_addrs
                .iter()
                .map(|addr| addr.socket_addr())
                .collect(),
            bootstrap_peers_str: config
                .network
                .bootstrap_nodes
                .iter()
                .map(|addr| addr.to_string())
                .collect(),
            enable_ipv6: config.network.ipv6_enabled,

            connection_timeout: Duration::from_secs(config.network.connection_timeout),
            keep_alive_interval: Duration::from_secs(config.network.keepalive_interval),
            max_connections: config.network.max_connections,
            max_incoming_connections: config.security.connection_limit as usize,
            dht_config: DHTConfig {
                k_value: 20,
                alpha_value: 3,
                record_ttl: Duration::from_secs(3600),
                refresh_interval: Duration::from_secs(900),
            },
            security_config: SecurityConfig {
                enable_noise: true,
                enable_tls: true,
                trust_level: TrustLevel::Basic,
            },
            production_config: Some(ProductionConfig {
                max_connections: config.network.max_connections,
                max_memory_bytes: 0,  // unlimited
                max_bandwidth_bps: 0, // unlimited
                connection_timeout: Duration::from_secs(config.network.connection_timeout),
                keep_alive_interval: Duration::from_secs(config.network.keepalive_interval),
                health_check_interval: Duration::from_secs(30),
                metrics_interval: Duration::from_secs(60),
                enable_performance_tracking: true,
                enable_auto_cleanup: true,
                shutdown_timeout: Duration::from_secs(30),
                rate_limits: crate::production::RateLimitConfig::default(),
            }),
            bootstrap_cache_config: None,
            diversity_config: None,
            // identity_config: Some(IdentityManagerConfig {
            //     cache_ttl: Duration::from_secs(3600),
            //     challenge_timeout: Duration::from_secs(30),
            // }),
        };

        // Add IPv6 listen address if enabled
        if config.network.ipv6_enabled {
            node_config.listen_addrs.push(std::net::SocketAddr::new(
                std::net::IpAddr::V6(std::net::Ipv6Addr::UNSPECIFIED),
                listen_addr.port(),
            ));
        }

        Ok(node_config)
    }

    /// Try to build a NodeConfig from a listen address string
    pub fn with_listen_addr(addr: &str) -> Result<Self> {
        let listen_addr: std::net::SocketAddr = addr
            .parse()
            .map_err(|e: std::net::AddrParseError| {
                NetworkError::InvalidAddress(e.to_string().into())
            })
            .map_err(P2PError::Network)?;
        let cfg = NodeConfig {
            listen_addr,
            listen_addrs: vec![listen_addr],
            diversity_config: None,
            ..Default::default()
        };
        Ok(cfg)
    }
}

impl Default for DHTConfig {
    fn default() -> Self {
        Self {
            k_value: 20,
            alpha_value: 5,
            record_ttl: Duration::from_secs(3600), // 1 hour
            refresh_interval: Duration::from_secs(600), // 10 minutes
        }
    }
}

impl Default for SecurityConfig {
    fn default() -> Self {
        Self {
            enable_noise: true,
            enable_tls: true,
            trust_level: TrustLevel::Basic,
        }
    }
}

/// Information about a connected peer
#[derive(Debug, Clone)]
pub struct PeerInfo {
    /// Peer identifier
    pub peer_id: PeerId,

    /// Peer's addresses
    pub addresses: Vec<String>,

    /// Connection timestamp
    pub connected_at: Instant,

    /// Last seen timestamp
    pub last_seen: Instant,

    /// Connection status
    pub status: ConnectionStatus,

    /// Supported protocols
    pub protocols: Vec<String>,

    /// Number of heartbeats received
    pub heartbeat_count: u64,
}

/// Connection status for a peer
#[derive(Debug, Clone, PartialEq)]
pub enum ConnectionStatus {
    /// Connection is being established
    Connecting,
    /// Connection is established and active
    Connected,
    /// Connection is being closed
    Disconnecting,
    /// Connection is closed
    Disconnected,
    /// Connection failed
    Failed(String),
}

/// Network events that can occur
#[derive(Debug, Clone)]
pub enum NetworkEvent {
    /// A new peer has connected
    PeerConnected {
        /// The identifier of the newly connected peer
        peer_id: PeerId,
        /// The network addresses where the peer can be reached
        addresses: Vec<String>,
    },

    /// A peer has disconnected
    PeerDisconnected {
        /// The identifier of the disconnected peer
        peer_id: PeerId,
        /// The reason for the disconnection
        reason: String,
    },

    /// A message was received from a peer
    MessageReceived {
        /// The identifier of the sending peer
        peer_id: PeerId,
        /// The protocol used for the message
        protocol: String,
        /// The raw message data
        data: Vec<u8>,
    },

    /// A connection attempt failed
    ConnectionFailed {
        /// The identifier of the peer (if known)
        peer_id: Option<PeerId>,
        /// The address where connection was attempted
        address: String,
        /// The error message describing the failure
        error: String,
    },

    /// DHT record was stored
    DHTRecordStored {
        /// The DHT key where the record was stored
        key: Vec<u8>,
        /// The value that was stored
        value: Vec<u8>,
    },

    /// DHT record was retrieved
    DHTRecordRetrieved {
        /// The DHT key that was queried
        key: Vec<u8>,
        /// The retrieved value, if found
        value: Option<Vec<u8>>,
    },
}

/// Network events that can occur in the P2P system
///
/// Events are broadcast to all listeners and provide real-time
/// notifications of network state changes and message arrivals.
#[derive(Debug, Clone)]
pub enum P2PEvent {
    /// Message received from a peer on a specific topic
    Message {
        /// Topic or channel the message was sent on
        topic: String,
        /// Peer ID of the message sender
        source: PeerId,
        /// Raw message data payload
        data: Vec<u8>,
    },
    /// A new peer has connected to the network
    PeerConnected(PeerId),
    /// A peer has disconnected from the network
    PeerDisconnected(PeerId),
}

/// Main P2P node structure
/// Main P2P network node that manages connections, routing, and communication
///
/// This struct represents a complete P2P network participant that can:
/// - Connect to other peers via QUIC transport
/// - Participate in distributed hash table (DHT) operations
/// - Send and receive messages through various protocols
/// - Handle network events and peer lifecycle
/// - Provide MCP (Model Context Protocol) services
pub struct P2PNode {
    /// Node configuration
    config: NodeConfig,

    /// Our peer ID
    peer_id: PeerId,

    /// Connected peers
    peers: Arc<RwLock<HashMap<PeerId, PeerInfo>>>,

    /// Network event broadcaster
    event_tx: broadcast::Sender<P2PEvent>,

    /// Listen addresses
    listen_addrs: RwLock<Vec<std::net::SocketAddr>>,

    /// Node start time
    start_time: Instant,

    /// Running state
    running: RwLock<bool>,

    /// DHT instance (optional)
    dht: Option<Arc<RwLock<DHT>>>,

    /// Production resource manager (optional)
    resource_manager: Option<Arc<ResourceManager>>,

    /// Bootstrap cache manager for peer discovery
    bootstrap_manager: Option<Arc<RwLock<BootstrapManager>>>,

    /// Dual-stack ant-quic nodes (IPv6 + IPv4) with Happy Eyeballs dialing
    dual_node: Arc<DualStackNetworkNode>,

    /// Rate limiter for connection and request throttling
    #[allow(dead_code)]
    rate_limiter: Arc<RateLimiter>,

    /// Active connections (tracked by peer_id)
    /// This set is synchronized with ant-quic's connection state via event monitoring
    active_connections: Arc<RwLock<HashSet<PeerId>>>,

    /// Security dashboard for monitoring
    pub security_dashboard: Option<Arc<crate::dht::metrics::SecurityDashboard>>,

    /// Connection lifecycle monitor task handle
    #[allow(dead_code)]
    connection_monitor_handle: Arc<RwLock<Option<tokio::task::JoinHandle<()>>>>,

    /// Keepalive task handle
    #[allow(dead_code)]
    keepalive_handle: Arc<RwLock<Option<tokio::task::JoinHandle<()>>>>,

    /// Shutdown flag for background tasks
    #[allow(dead_code)]
    shutdown: Arc<AtomicBool>,

    /// GeoIP provider for connection validation
    #[allow(dead_code)]
    geo_provider: Arc<BgpGeoProvider>,
}

/// Normalize wildcard bind addresses to localhost loopback addresses
///
/// ant-quic correctly rejects "unspecified" addresses (0.0.0.0 and [::]) for remote connections
/// because you cannot connect TO an unspecified address - these are only valid for BINDING.
///
/// This function converts wildcard addresses to appropriate loopback addresses for local connections:
/// - IPv6 [::]:port → ::1:port (IPv6 loopback)
/// - IPv4 0.0.0.0:port → 127.0.0.1:port (IPv4 loopback)
/// - All other addresses pass through unchanged
///
/// # Arguments
/// * `addr` - The SocketAddr to normalize
///
/// # Returns
/// * Normalized SocketAddr suitable for remote connections
fn normalize_wildcard_to_loopback(addr: std::net::SocketAddr) -> std::net::SocketAddr {
    use std::net::{IpAddr, Ipv4Addr, Ipv6Addr};

    if addr.ip().is_unspecified() {
        // Convert unspecified addresses to loopback
        let loopback_ip = match addr {
            std::net::SocketAddr::V6(_) => IpAddr::V6(Ipv6Addr::LOCALHOST), // ::1
            std::net::SocketAddr::V4(_) => IpAddr::V4(Ipv4Addr::LOCALHOST), // 127.0.0.1
        };
        std::net::SocketAddr::new(loopback_ip, addr.port())
    } else {
        // Not a wildcard address, pass through unchanged
        addr
    }
}

impl P2PNode {
    /// Minimal constructor for tests that avoids real networking
    pub fn new_for_tests() -> Result<Self> {
        let (event_tx, _) = broadcast::channel(16);
        Ok(Self {
            config: NodeConfig::default(),
            peer_id: "test_peer".to_string(),
            peers: Arc::new(RwLock::new(HashMap::new())),
            event_tx,
            listen_addrs: RwLock::new(Vec::new()),
            start_time: Instant::now(),
            running: RwLock::new(false),
            dht: None,
            resource_manager: None,
            bootstrap_manager: None,
            dual_node: {
                // Bind dual-stack nodes on ephemeral ports for tests
                let v6: Option<std::net::SocketAddr> = "[::1]:0"
                    .parse()
                    .ok()
                    .or(Some(std::net::SocketAddr::from(([0, 0, 0, 0], 0))));
                let v4: Option<std::net::SocketAddr> = "127.0.0.1:0".parse().ok();
                let handle = tokio::runtime::Handle::current();
                let dual_attempt = handle.block_on(
                    crate::transport::ant_quic_adapter::DualStackNetworkNode::new(v6, v4),
                );
                let dual = match dual_attempt {
                    Ok(d) => d,
                    Err(_e1) => {
                        // Fallback to IPv4-only ephemeral bind
                        let fallback = handle.block_on(
                            crate::transport::ant_quic_adapter::DualStackNetworkNode::new(
                                None,
                                "127.0.0.1:0".parse().ok(),
                            ),
                        );
                        match fallback {
                            Ok(d) => d,
                            Err(e2) => {
                                return Err(P2PError::Network(NetworkError::BindError(
                                    format!("Failed to create dual-stack network node: {}", e2)
                                        .into(),
                                )));
                            }
                        }
                    }
                };
                Arc::new(dual)
            },
            rate_limiter: Arc::new(RateLimiter::new(RateLimitConfig {
                max_requests: 100,
                burst_size: 100,
                window: std::time::Duration::from_secs(1),
                ..Default::default()
            })),
            active_connections: Arc::new(RwLock::new(HashSet::new())),
            connection_monitor_handle: Arc::new(RwLock::new(None)),
            keepalive_handle: Arc::new(RwLock::new(None)),
            shutdown: Arc::new(AtomicBool::new(false)),
            geo_provider: Arc::new(BgpGeoProvider::new()),
            security_dashboard: None,
        })
    }
    /// Create a new P2P node with the given configuration
    pub async fn new(config: NodeConfig) -> Result<Self> {
        let peer_id = config.peer_id.clone().unwrap_or_else(|| {
            // Generate a random peer ID for now
            format!("peer_{}", &uuid::Uuid::new_v4().to_string()[..8])
        });

        let (event_tx, _) = broadcast::channel(1000);

        // Initialize and register a TrustWeightedKademlia DHT for the global API
        // Use a deterministic local NodeId derived from the peer_id
        {
            use blake3::Hasher;
            let mut hasher = Hasher::new();
            hasher.update(peer_id.as_bytes());
            let digest = hasher.finalize();
            let mut nid = [0u8; 32];
            nid.copy_from_slice(digest.as_bytes());
            let _twdht = std::sync::Arc::new(crate::dht::TrustWeightedKademlia::new(
                crate::identity::node_identity::NodeId::from_bytes(nid),
            ));
            // TODO: Update to use new clean API
            // let _ = crate::api::set_dht_instance(twdht);
        }

        // Initialize DHT if needed
        let (dht, security_dashboard) = if true {
            // Assuming DHT is always enabled for now, or check config
            let _dht_config = crate::dht::DHTConfig {
                replication_factor: config.dht_config.k_value,
                bucket_size: config.dht_config.k_value,
                alpha: config.dht_config.alpha_value,
                record_ttl: config.dht_config.record_ttl,
                bucket_refresh_interval: config.dht_config.refresh_interval,
                republish_interval: config.dht_config.refresh_interval,
                max_distance: 160,
            };
            // Convert peer_id String to NodeId
            let peer_bytes = peer_id.as_bytes();
            let mut node_id_bytes = [0u8; 32];
            let len = peer_bytes.len().min(32);
            node_id_bytes[..len].copy_from_slice(&peer_bytes[..len]);
            let node_id = crate::dht::core_engine::NodeId::from_bytes(node_id_bytes);
            let dht_instance = DHT::new(node_id).map_err(|e| {
                crate::error::P2PError::Dht(crate::error::DhtError::StoreFailed(
                    e.to_string().into(),
                ))
            })?;
            dht_instance.start_maintenance_tasks();

            // Create Security Dashboard
            let security_metrics = dht_instance.security_metrics();
            let dashboard = crate::dht::metrics::SecurityDashboard::new(
                security_metrics,
                Arc::new(crate::dht::metrics::DhtMetricsCollector::new()),
                Arc::new(crate::dht::metrics::TrustMetricsCollector::new()),
                Arc::new(crate::dht::metrics::PlacementMetricsCollector::new()),
            );

            (
                Some(Arc::new(RwLock::new(dht_instance))),
                Some(Arc::new(dashboard)),
            )
        } else {
            (None, None)
        };

        // MCP removed

        // Initialize production resource manager if configured
        let resource_manager = config
            .production_config
            .clone()
            .map(|prod_config| Arc::new(ResourceManager::new(prod_config)));

        // Initialize bootstrap cache manager
        let diversity_config = config.diversity_config.clone().unwrap_or_default();
        let bootstrap_manager = if let Some(ref cache_config) = config.bootstrap_cache_config {
            match BootstrapManager::with_full_config(
                cache_config.clone(),
                crate::rate_limit::JoinRateLimiterConfig::default(),
                diversity_config.clone(),
            )
            .await
            {
                Ok(manager) => Some(Arc::new(RwLock::new(manager))),
                Err(e) => {
                    warn!(
                        "Failed to initialize bootstrap manager: {}, continuing without cache",
                        e
                    );
                    None
                }
            }
        } else {
            match BootstrapManager::with_full_config(
                crate::bootstrap::CacheConfig::default(),
                crate::rate_limit::JoinRateLimiterConfig::default(),
                diversity_config,
            )
            .await
            {
                Ok(manager) => Some(Arc::new(RwLock::new(manager))),
                Err(e) => {
                    warn!(
                        "Failed to initialize bootstrap manager: {}, continuing without cache",
                        e
                    );
                    None
                }
            }
        };

        // Initialize dual-stack ant-quic nodes
        // Determine bind addresses
        let (v6_opt, v4_opt) = {
            let port = config.listen_addr.port();
            let ip = config.listen_addr.ip();

            let v4_addr = if ip.is_ipv4() {
                Some(std::net::SocketAddr::new(ip, port))
            } else {
                // If config is IPv6, we still might want IPv4 on UNSPECIFIED if dual stack is desired
                // But for now let's just stick to defaults if not specified
                Some(std::net::SocketAddr::new(
                    std::net::IpAddr::V4(std::net::Ipv4Addr::UNSPECIFIED),
                    port,
                ))
            };

            let v6_addr = if config.enable_ipv6 {
                if ip.is_ipv6() {
                    Some(std::net::SocketAddr::new(ip, port))
                } else {
                    Some(std::net::SocketAddr::new(
                        std::net::IpAddr::V6(std::net::Ipv6Addr::UNSPECIFIED),
                        port,
                    ))
                }
            } else {
                None
            };
            (v6_addr, v4_addr)
        };

        let dual_node = Arc::new(
            DualStackNetworkNode::new(v6_opt, v4_opt)
                .await
                .map_err(|e| {
                    P2PError::Transport(crate::error::TransportError::SetupFailed(
                        format!("Failed to create dual-stack network nodes: {}", e).into(),
                    ))
                })?,
        );

        // Initialize rate limiter with default config
        let rate_limiter = Arc::new(RateLimiter::new(
            crate::validation::RateLimitConfig::default(),
        ));

        // Create active connections tracker
        let active_connections = Arc::new(RwLock::new(HashSet::new()));

        // Initialize GeoIP provider
        let geo_provider = Arc::new(BgpGeoProvider::new());

        // Create peers map
        let peers = Arc::new(RwLock::new(HashMap::new()));

        // Start connection lifecycle monitor
        let connection_monitor_handle = {
            let active_conns = Arc::clone(&active_connections);
            let peers_map = Arc::clone(&peers);
            let event_tx_clone = event_tx.clone();
            let dual_node_clone = Arc::clone(&dual_node);
            let geo_provider_clone = Arc::clone(&geo_provider);
            let peer_id_clone = peer_id.clone();

            let handle = tokio::spawn(async move {
                Self::connection_lifecycle_monitor(
                    dual_node_clone,
                    active_conns,
                    peers_map,
                    event_tx_clone,
                    geo_provider_clone,
                    peer_id_clone,
                )
                .await;
            });

            Arc::new(RwLock::new(Some(handle)))
        };

        // Spawn keepalive task
        let shutdown = Arc::new(AtomicBool::new(false));
        let keepalive_handle = {
            let active_conns = Arc::clone(&active_connections);
            let dual_node_clone = Arc::clone(&dual_node);
            let shutdown_clone = Arc::clone(&shutdown);

            let handle = tokio::spawn(async move {
                Self::keepalive_task(active_conns, dual_node_clone, shutdown_clone).await;
            });

            Arc::new(RwLock::new(Some(handle)))
        };

        let node = Self {
            config,
            peer_id,
            peers,
            event_tx,
            listen_addrs: RwLock::new(Vec::new()),
            start_time: Instant::now(),
            running: RwLock::new(false),
            dht,
            resource_manager,
            bootstrap_manager,
            dual_node,
            rate_limiter,
            active_connections,
            security_dashboard,
            connection_monitor_handle,
            keepalive_handle,
            shutdown,
            geo_provider,
        };
        info!("Created P2P node with peer ID: {}", node.peer_id);

        // Start the network listeners to populate listen addresses
        node.start_network_listeners().await?;

        // Update the connection monitor with actual peers reference
        node.start_connection_monitor().await;

        Ok(node)
    }

    /// Create a new node builder
    pub fn builder() -> NodeBuilder {
        NodeBuilder::new()
    }

    /// Get the peer ID of this node
    pub fn peer_id(&self) -> &PeerId {
        &self.peer_id
    }

    pub fn local_addr(&self) -> Option<String> {
        self.listen_addrs
            .try_read()
            .ok()
            .and_then(|addrs| addrs.first().map(|a| a.to_string()))
    }

    pub async fn subscribe(&self, topic: &str) -> Result<()> {
        // In a real implementation, this would register the topic with the pubsub mechanism.
        // For now, we just log it.
        info!("Subscribed to topic: {}", topic);
        Ok(())
    }

    pub async fn publish(&self, topic: &str, data: &[u8]) -> Result<()> {
        info!(
            "Publishing message to topic: {} ({} bytes)",
            topic,
            data.len()
        );

        // Get list of connected peers
        let peer_list: Vec<PeerId> = {
            let peers_guard = self.peers.read().await;
            peers_guard.keys().cloned().collect()
        };

        if peer_list.is_empty() {
            debug!("No peers connected, message will only be sent to local subscribers");
        } else {
            // Send message to all connected peers
            let mut send_count = 0;
            for peer_id in &peer_list {
                match self.send_message(peer_id, topic, data.to_vec()).await {
                    Ok(_) => {
                        send_count += 1;
                        debug!("Sent message to peer: {}", peer_id);
                    }
                    Err(e) => {
                        warn!("Failed to send message to peer {}: {}", peer_id, e);
                    }
                }
            }
            info!(
                "Published message to {}/{} connected peers",
                send_count,
                peer_list.len()
            );
        }

        // Also send to local subscribers (for local echo and testing)
        let event = P2PEvent::Message {
            topic: topic.to_string(),
            source: self.peer_id.clone(),
            data: data.to_vec(),
        };
        let _ = self.event_tx.send(event);

        Ok(())
    }

    /// Get the node configuration
    pub fn config(&self) -> &NodeConfig {
        &self.config
    }

    /// Start the P2P node
    pub async fn start(&self) -> Result<()> {
        info!("Starting P2P node...");

        // Start production resource manager if configured
        if let Some(ref resource_manager) = self.resource_manager {
            resource_manager.start().await.map_err(|e| {
                P2PError::Network(crate::error::NetworkError::ProtocolError(
                    format!("Failed to start resource manager: {e}").into(),
                ))
            })?;
            info!("Production resource manager started");
        }

        // Start bootstrap manager background tasks
        if let Some(ref bootstrap_manager) = self.bootstrap_manager {
            let mut manager = bootstrap_manager.write().await;
            manager.start_background_tasks().await.map_err(|e| {
                P2PError::Network(crate::error::NetworkError::ProtocolError(
                    format!("Failed to start bootstrap manager: {e}").into(),
                ))
            })?;
            info!("Bootstrap cache manager started");
        }

        // Set running state
        *self.running.write().await = true;

        // Start listening on configured addresses using transport layer
        self.start_network_listeners().await?;

        // Log current listen addresses
        let listen_addrs = self.listen_addrs.read().await;
        info!("P2P node started on addresses: {:?}", *listen_addrs);

        // MCP removed

        // Start message receiving system
        self.start_message_receiving_system().await?;

        // Connect to bootstrap peers
        self.connect_bootstrap_peers().await?;

        Ok(())
    }

    /// Start network listeners on configured addresses
    async fn start_network_listeners(&self) -> Result<()> {
        info!("Starting dual-stack listeners (ant-quic)...");
        // Update our listen_addrs from the dual node bindings
        let addrs = self.dual_node.local_addrs().await.map_err(|e| {
            P2PError::Transport(crate::error::TransportError::SetupFailed(
                format!("Failed to get local addresses: {}", e).into(),
            ))
        })?;
        {
            let mut la = self.listen_addrs.write().await;
            *la = addrs.clone();
        }

        // Spawn a background accept loop that handles incoming connections from either stack
        let event_tx = self.event_tx.clone();
        let peers = self.peers.clone();
        let active_connections = self.active_connections.clone();
        let rate_limiter = self.rate_limiter.clone();
        let dual = self.dual_node.clone();
        tokio::spawn(async move {
            loop {
                match dual.accept_any().await {
                    Ok((ant_peer_id, remote_sock)) => {
                        let peer_id =
                            crate::transport::ant_quic_adapter::ant_peer_id_to_string(&ant_peer_id);
                        let remote_addr = NetworkAddress::from(remote_sock);
                        // Optional: basic IP rate limiting
                        let _ = rate_limiter.check_ip(&remote_sock.ip());
                        let _ = event_tx.send(P2PEvent::PeerConnected(peer_id.clone()));
                        register_new_peer(&peers, &peer_id, &remote_addr).await;
                        active_connections.write().await.insert(peer_id);
                    }
                    Err(e) => {
                        warn!("Accept failed: {}", e);
                        tokio::time::sleep(std::time::Duration::from_millis(200)).await;
                    }
                }
            }
        });

        info!("Dual-stack listeners active on: {:?}", addrs);
        Ok(())
    }

    /// Start a listener on a specific socket address
    #[allow(dead_code)]
    async fn start_listener_on_address(&self, addr: std::net::SocketAddr) -> Result<()> {
        // use crate::transport::{Transport}; // Unused during migration

        // DISABLED during ant-quic migration - TODO: Reimplement using AntQuicAdapter
        /*
        // Try QUIC first (preferred transport)
        match crate::transport::QuicTransport::new(Default::default()) {
            Ok(quic_transport) => {
                match quic_transport.listen(NetworkAddress::new(addr)).await {
                    Ok(listen_addrs) => {
                        info!("QUIC listener started on {} -> {:?}", addr, listen_addrs);

                        // Store the actual listening addresses in the node
                        {
                            let mut node_listen_addrs = self.listen_addrs.write().await;
                            // Don't clear - accumulate addresses from multiple listeners
                            node_listen_addrs.push(listen_addrs.socket_addr());
                        }

                        // Start accepting connections in background
                        self.start_connection_acceptor(
                            Arc::new(quic_transport),
                            addr,
                            crate::transport::TransportType::QUIC
                        ).await?;

                        return Ok(());
                    }
                    Err(e) => {
                        warn!("Failed to start QUIC listener on {}: {}", addr, e);
                    }
                }
            }
            Err(e) => {
                warn!("Failed to create QUIC transport for listening: {}", e);
            }
        }
        */

        warn!("QUIC transport temporarily disabled during ant-quic migration");
        // No TCP fallback - QUIC only
        Err(crate::P2PError::Transport(
            crate::error::TransportError::SetupFailed(
                format!(
                    "Failed to start QUIC listener on {addr} - transport disabled during migration"
                )
                .into(),
            ),
        ))
    }

    /// Start connection acceptor background task
    #[allow(dead_code)] // Deprecated during ant-quic migration
    async fn start_connection_acceptor(
        &self,
        transport: Arc<dyn crate::transport::Transport>,
        addr: std::net::SocketAddr,
        transport_type: crate::transport::TransportType,
    ) -> Result<()> {
        info!(
            "Starting connection acceptor for {:?} on {}",
            transport_type, addr
        );

        // Clone necessary data for the background task
        let event_tx = self.event_tx.clone();
        let _peer_id = self.peer_id.clone();
        let peers = Arc::clone(&self.peers);
        // ant-quic dual-stack node is managed separately; accept loop started in start_network_listeners

        let rate_limiter = Arc::clone(&self.rate_limiter);

        // Spawn background task to accept incoming connections
        tokio::spawn(async move {
            loop {
                match transport.accept().await {
                    Ok(connection) => {
                        let remote_addr = connection.remote_addr();
                        let connection_peer_id =
                            format!("peer_from_{}", remote_addr.to_string().replace(":", "_"));

                        // Apply rate limiting for incoming connections
                        let socket_addr = remote_addr.socket_addr();
                        if check_rate_limit(&rate_limiter, &socket_addr, &remote_addr).is_err() {
                            // Connection dropped automatically when it goes out of scope
                            continue;
                        }

                        info!(
                            "Accepted {:?} connection from {} (peer: {})",
                            transport_type, remote_addr, connection_peer_id
                        );

                        // Generate peer connected event
                        let _ = event_tx.send(P2PEvent::PeerConnected(connection_peer_id.clone()));

                        // Store the peer connection
                        register_new_peer(&peers, &connection_peer_id, &remote_addr).await;

                        // Spawn task to handle this specific connection's messages
                        spawn_connection_handler(
                            connection,
                            connection_peer_id,
                            event_tx.clone(),
                            Arc::clone(&peers),
                        );
                    }
                    Err(e) => {
                        warn!(
                            "Failed to accept {:?} connection on {}: {}",
                            transport_type, addr, e
                        );

                        // Brief pause before retrying to avoid busy loop
                        tokio::time::sleep(std::time::Duration::from_millis(1000)).await;
                    }
                }
            }
        });

        info!(
            "Connection acceptor background task started for {:?} on {}",
            transport_type, addr
        );
        Ok(())
    }

    /// Start the message receiving system with background tasks
    async fn start_message_receiving_system(&self) -> Result<()> {
        info!("Starting message receiving system");
        let dual = self.dual_node.clone();
        let event_tx = self.event_tx.clone();

        tokio::spawn(async move {
            loop {
                match dual.receive_any().await {
                    Ok((_peer_id, bytes)) => {
                        // Expect the JSON message wrapper from create_protocol_message
                        #[allow(clippy::collapsible_if)]
                        if let Ok(value) = serde_json::from_slice::<serde_json::Value>(&bytes) {
                            if let (Some(protocol), Some(data), Some(from)) = (
                                value.get("protocol").and_then(|v| v.as_str()),
                                value.get("data").and_then(|v| v.as_array()),
                                value.get("from").and_then(|v| v.as_str()),
                            ) {
                                let payload: Vec<u8> = data
                                    .iter()
                                    .filter_map(|v| v.as_u64().map(|n| n as u8))
                                    .collect();
                                let _ = event_tx.send(P2PEvent::Message {
                                    topic: protocol.to_string(),
                                    source: from.to_string(),
                                    data: payload,
                                });
                            }
                        }
                    }
                    Err(e) => {
                        warn!("Receive error: {}", e);
                        tokio::time::sleep(std::time::Duration::from_millis(50)).await;
                    }
                }
            }
        });

        Ok(())
    }

    /// Handle a received message and generate appropriate events
    #[allow(dead_code)]
    async fn handle_received_message(
        &self,
        message_data: Vec<u8>,
        peer_id: &PeerId,
        _protocol: &str,
        event_tx: &broadcast::Sender<P2PEvent>,
    ) -> Result<()> {
        // MCP removed: no special protocol handling

        // Parse the message format we created in create_protocol_message
        match serde_json::from_slice::<serde_json::Value>(&message_data) {
            Ok(message) => {
                if let (Some(protocol), Some(data), Some(from)) = (
                    message.get("protocol").and_then(|v| v.as_str()),
                    message.get("data").and_then(|v| v.as_array()),
                    message.get("from").and_then(|v| v.as_str()),
                ) {
                    // Convert data array back to bytes
                    let data_bytes: Vec<u8> = data
                        .iter()
                        .filter_map(|v| v.as_u64().map(|n| n as u8))
                        .collect();

                    // Generate message event
                    let event = P2PEvent::Message {
                        topic: protocol.to_string(),
                        source: from.to_string(),
                        data: data_bytes,
                    };

                    let _ = event_tx.send(event);
                    debug!("Generated message event from peer: {}", peer_id);
                }
            }
            Err(e) => {
                warn!("Failed to parse received message from {}: {}", peer_id, e);
            }
        }

        Ok(())
    }

    // MCP removed

    // MCP removed

    /// Run the P2P node (blocks until shutdown)
    pub async fn run(&self) -> Result<()> {
        if !*self.running.read().await {
            self.start().await?;
        }

        info!("P2P node running...");

        // Main event loop
        loop {
            if !*self.running.read().await {
                break;
            }

            // Perform periodic tasks
            self.periodic_tasks().await?;

            // Sleep for a short interval
            tokio::time::sleep(Duration::from_millis(100)).await;
        }

        info!("P2P node stopped");
        Ok(())
    }

    /// Stop the P2P node
    pub async fn stop(&self) -> Result<()> {
        info!("Stopping P2P node...");

        // Set running state to false
        *self.running.write().await = false;

        // Disconnect all peers
        self.disconnect_all_peers().await?;

        // Shutdown production resource manager if configured
        if let Some(ref resource_manager) = self.resource_manager {
            resource_manager.shutdown().await.map_err(|e| {
                P2PError::Network(crate::error::NetworkError::ProtocolError(
                    format!("Failed to shutdown resource manager: {e}").into(),
                ))
            })?;
            info!("Production resource manager stopped");
        }

        info!("P2P node stopped");
        Ok(())
    }

    /// Graceful shutdown alias for tests
    pub async fn shutdown(&self) -> Result<()> {
        self.stop().await
    }

    /// Check if the node is running
    pub async fn is_running(&self) -> bool {
        *self.running.read().await
    }

    /// Get the current listen addresses
    pub async fn listen_addrs(&self) -> Vec<std::net::SocketAddr> {
        self.listen_addrs.read().await.clone()
    }

    /// Get connected peers
    pub async fn connected_peers(&self) -> Vec<PeerId> {
        self.peers.read().await.keys().cloned().collect()
    }

    /// Get peer count
    pub async fn peer_count(&self) -> usize {
        self.peers.read().await.len()
    }

    /// Get peer info
    pub async fn peer_info(&self, peer_id: &PeerId) -> Option<PeerInfo> {
        self.peers.read().await.get(peer_id).cloned()
    }

    /// Get the peer ID for a given socket address, if connected
    ///
    /// This method searches through all connected peers to find one that has
    /// the specified address in its address list.
    ///
    /// # Arguments
    /// * `addr` - The socket address to search for (e.g., "192.168.1.100:9000")
    ///
    /// # Returns
    /// * `Some(PeerId)` - The peer ID if a matching connected peer is found
    /// * `None` - If no peer with this address is currently connected
    pub async fn get_peer_id_by_address(&self, addr: &str) -> Option<PeerId> {
        // Parse the address to a SocketAddr for comparison
        let socket_addr: std::net::SocketAddr = addr.parse().ok()?;

        let peers = self.peers.read().await;

        // Search through all connected peers
        for (peer_id, peer_info) in peers.iter() {
            // Check if this peer has a matching address
            for peer_addr in &peer_info.addresses {
                if let Ok(peer_socket) = peer_addr.parse::<std::net::SocketAddr>()
                    && peer_socket == socket_addr
                {
                    return Some(peer_id.clone());
                }
            }
        }

        None
    }

    /// List all active connections with their peer IDs and addresses
    ///
    /// # Returns
    /// A vector of tuples containing (PeerId, Vec<String>) where the Vec<String>
    /// contains all known addresses for that peer.
    pub async fn list_active_connections(&self) -> Vec<(PeerId, Vec<String>)> {
        let peers = self.peers.read().await;

        peers
            .iter()
            .map(|(peer_id, peer_info)| (peer_id.clone(), peer_info.addresses.clone()))
            .collect()
    }

    /// Remove a peer from the peers map
    ///
    /// This method removes a peer from the internal peers map. It should be used
    /// when a connection is no longer valid (e.g., after detecting that the underlying
    /// ant-quic connection has closed).
    ///
    /// # Arguments
    /// * `peer_id` - The ID of the peer to remove
    ///
    /// # Returns
    /// `true` if the peer was found and removed, `false` if the peer was not in the map
    pub async fn remove_peer(&self, peer_id: &PeerId) -> bool {
        // Remove from active connections tracking
        self.active_connections.write().await.remove(peer_id);
        // Remove from peers map and return whether it existed
        self.peers.write().await.remove(peer_id).is_some()
    }

    /// Check if a peer is connected
    ///
    /// This method checks if the peer ID exists in the peers map. Note that this
    /// only verifies the peer is registered - it does not guarantee the underlying
    /// ant-quic connection is still active. For connection validation, use `send_message`
    /// which will fail if the connection is closed.
    ///
    /// # Arguments
    /// * `peer_id` - The ID of the peer to check
    ///
    /// # Returns
    /// `true` if the peer exists in the peers map, `false` otherwise
    pub async fn is_peer_connected(&self, peer_id: &PeerId) -> bool {
        self.peers.read().await.contains_key(peer_id)
    }

    /// Connect to a peer
    pub async fn connect_peer(&self, address: &str) -> Result<PeerId> {
        info!("Connecting to peer at: {}", address);

        // Check production limits if resource manager is enabled
        let _connection_guard = if let Some(ref resource_manager) = self.resource_manager {
            Some(resource_manager.acquire_connection().await?)
        } else {
            None
        };

        // Parse the address to SocketAddr format
        let socket_addr: std::net::SocketAddr = address.parse().map_err(|e| {
            P2PError::Network(crate::error::NetworkError::InvalidAddress(
                format!("{}: {}", address, e).into(),
            ))
        })?;

        // Normalize wildcard addresses to loopback for local connections
        // This converts [::]:port → ::1:port and 0.0.0.0:port → 127.0.0.1:port
        let normalized_addr = normalize_wildcard_to_loopback(socket_addr);
        if normalized_addr != socket_addr {
            info!(
                "Normalized wildcard address {} to loopback {}",
                socket_addr, normalized_addr
            );
        }

        // Establish a real connection via dual-stack Happy Eyeballs, but cap the wait
        let addr_list = vec![normalized_addr];
        let peer_id = match tokio::time::timeout(
            self.config.connection_timeout,
            self.dual_node.connect_happy_eyeballs(&addr_list),
        )
        .await
        {
            Ok(Ok(peer)) => {
                let connected_peer_id =
                    crate::transport::ant_quic_adapter::ant_peer_id_to_string(&peer);
                info!("Successfully connected to peer: {}", connected_peer_id);
                connected_peer_id
            }
            Ok(Err(e)) => {
                warn!("Failed to connect to peer at {}: {}", address, e);
                let sanitized_address = address.replace(['/', ':'], "_");
                let demo_peer_id = format!("peer_from_{}", sanitized_address);
                warn!(
                    "Using demo peer ID: {} (transport connection failed)",
                    demo_peer_id
                );
                demo_peer_id
            }
            Err(_) => {
                warn!(
                    "Timed out connecting to peer at {} after {:?}",
                    address, self.config.connection_timeout
                );
                let sanitized_address = address.replace(['/', ':'], "_");
                let demo_peer_id = format!("peer_from_{}", sanitized_address);
                demo_peer_id
            }
        };

        // Create peer info with connection details
        let peer_info = PeerInfo {
            peer_id: peer_id.clone(),
            addresses: vec![address.to_string()],
            connected_at: Instant::now(),
            last_seen: Instant::now(),
            status: ConnectionStatus::Connected,
            protocols: vec!["p2p-foundation/1.0".to_string()],
            heartbeat_count: 0,
        };

        // Store peer information
        self.peers.write().await.insert(peer_id.clone(), peer_info);

        // Add to active connections tracking
        // This is critical for is_connection_active() to work correctly
        self.active_connections
            .write()
            .await
            .insert(peer_id.clone());

        // Record bandwidth usage if resource manager is enabled
        if let Some(ref resource_manager) = self.resource_manager {
            resource_manager.record_bandwidth(0, 0); // Placeholder for handshake data
        }

        // Emit connection event
        let _ = self.event_tx.send(P2PEvent::PeerConnected(peer_id.clone()));

        info!("Connected to peer: {}", peer_id);
        Ok(peer_id)
    }

    /// Disconnect from a peer
    pub async fn disconnect_peer(&self, peer_id: &PeerId) -> Result<()> {
        info!("Disconnecting from peer: {}", peer_id);

        // Remove from active connections
        self.active_connections.write().await.remove(peer_id);

        if let Some(mut peer_info) = self.peers.write().await.remove(peer_id) {
            peer_info.status = ConnectionStatus::Disconnected;

            // Emit event
            let _ = self
                .event_tx
                .send(P2PEvent::PeerDisconnected(peer_id.clone()));

            info!("Disconnected from peer: {}", peer_id);
        }

        Ok(())
    }

    /// Check if a connection to a peer is active
    pub async fn is_connection_active(&self, peer_id: &str) -> bool {
        self.active_connections.read().await.contains(peer_id)
    }

    /// Send a message to a peer
    pub async fn send_message(
        &self,
        peer_id: &PeerId,
        protocol: &str,
        data: Vec<u8>,
    ) -> Result<()> {
        debug!(
            "Sending message to peer {} on protocol {}",
            peer_id, protocol
        );

        // Check rate limits if resource manager is enabled
        if let Some(ref resource_manager) = self.resource_manager
            && !resource_manager
                .check_rate_limit(peer_id, "message")
                .await?
        {
            return Err(P2PError::ResourceExhausted(
                format!("Rate limit exceeded for peer {}", peer_id).into(),
            ));
        }

        // Check if peer exists in peers map
        if !self.peers.read().await.contains_key(peer_id) {
            return Err(P2PError::Network(crate::error::NetworkError::PeerNotFound(
                peer_id.to_string().into(),
            )));
        }

        // **NEW**: Check if the ant-quic connection is actually active
        // This is the critical fix for the connection state synchronization issue
        if !self.is_connection_active(peer_id).await {
            debug!(
                "Connection to peer {} exists in peers map but ant-quic connection is closed",
                peer_id
            );

            // Clean up stale peer entry
            self.remove_peer(peer_id).await;

            return Err(P2PError::Network(
                crate::error::NetworkError::ConnectionClosed {
                    peer_id: peer_id.to_string().into(),
                },
            ));
        }

        // MCP removed: no special-case protocol validation

        // Record bandwidth usage if resource manager is enabled
        if let Some(ref resource_manager) = self.resource_manager {
            resource_manager.record_bandwidth(data.len() as u64, 0);
        }

        // Create protocol message wrapper
        let _message_data = self.create_protocol_message(protocol, data)?;

        // Send via ant-quic dual-node
        let send_fut = self.dual_node.send_to_peer_string(peer_id, &_message_data);
        tokio::time::timeout(self.config.connection_timeout, send_fut)
            .await
            .map_err(|_| {
                P2PError::Transport(crate::error::TransportError::StreamError(
                    "Timed out sending message".into(),
                ))
            })?
            .map_err(|e| {
                P2PError::Transport(crate::error::TransportError::StreamError(
                    e.to_string().into(),
                ))
            })
    }

    /// Create a protocol message wrapper
    fn create_protocol_message(&self, protocol: &str, data: Vec<u8>) -> Result<Vec<u8>> {
        use serde_json::json;

        let timestamp = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .map_err(|e| {
                P2PError::Network(NetworkError::ProtocolError(
                    format!("System time error: {}", e).into(),
                ))
            })?
            .as_secs();

        // Create a simple message format for P2P communication
        let message = json!({
            "protocol": protocol,
            "data": data,
            "from": self.peer_id,
            "timestamp": timestamp
        });

        serde_json::to_vec(&message).map_err(|e| {
            P2PError::Transport(crate::error::TransportError::StreamError(
                format!("Failed to serialize message: {e}").into(),
            ))
        })
    }

    // Note: async listen_addrs() already exists above for fetching listen addresses
}

/// Create a protocol message wrapper (static version for background tasks)
#[allow(dead_code)]
fn create_protocol_message_static(protocol: &str, data: Vec<u8>) -> Result<Vec<u8>> {
    use serde_json::json;

    let timestamp = std::time::SystemTime::now()
        .duration_since(std::time::UNIX_EPOCH)
        .map_err(|e| {
            P2PError::Network(NetworkError::ProtocolError(
                format!("System time error: {}", e).into(),
            ))
        })?
        .as_secs();

    // Create a simple message format for P2P communication
    let message = json!({
        "protocol": protocol,
        "data": data,
        "timestamp": timestamp
    });

    serde_json::to_vec(&message).map_err(|e| {
        P2PError::Transport(crate::error::TransportError::StreamError(
            format!("Failed to serialize message: {e}").into(),
        ))
    })
}

impl P2PNode {
    /// Subscribe to network events
    pub fn subscribe_events(&self) -> broadcast::Receiver<P2PEvent> {
        self.event_tx.subscribe()
    }

    /// Backwards-compat event stream accessor for tests
    pub fn events(&self) -> broadcast::Receiver<P2PEvent> {
        self.subscribe_events()
    }

    /// Get node uptime
    pub fn uptime(&self) -> Duration {
        self.start_time.elapsed()
    }

    // MCP removed: all MCP tool/service methods removed

    // /// Handle MCP remote tool call with network integration

    // /// List tools available on a specific remote peer

    // /// Get MCP server statistics

    /// Get production resource metrics
    pub async fn resource_metrics(&self) -> Result<ResourceMetrics> {
        if let Some(ref resource_manager) = self.resource_manager {
            Ok(resource_manager.get_metrics().await)
        } else {
            Err(P2PError::Network(
                crate::error::NetworkError::ProtocolError(
                    "Production resource manager not enabled".to_string().into(),
                ),
            ))
        }
    }

    /// Connection lifecycle monitor task - processes ant-quic connection events
    /// and updates active_connections HashSet and peers map
    async fn connection_lifecycle_monitor(
        dual_node: Arc<DualStackNetworkNode>,
        active_connections: Arc<RwLock<HashSet<String>>>,
        peers: Arc<RwLock<HashMap<String, PeerInfo>>>,
        event_tx: broadcast::Sender<P2PEvent>,
        geo_provider: Arc<BgpGeoProvider>,
        local_peer_id: String,
    ) {
        use crate::transport::ant_quic_adapter::ConnectionEvent;

        let mut event_rx = dual_node.subscribe_connection_events();

        info!("Connection lifecycle monitor started");

        loop {
            match event_rx.recv().await {
                Ok(event) => {
                    match event {
                        ConnectionEvent::Established {
                            peer_id,
                            remote_address,
                        } => {
                            let peer_id_str =
                                crate::transport::ant_quic_adapter::ant_peer_id_to_string(&peer_id);
                            debug!(
                                "Connection established: peer={}, addr={}",
                                peer_id_str, remote_address
                            );

                            // **GeoIP Validation**
                            // Check if the peer's IP is allowed
                            let ip = remote_address.ip();
                            let is_rejected = match ip {
                                std::net::IpAddr::V4(v4) => {
                                    // Check if it's a hosting provider or VPN
                                    if let Some(asn) = geo_provider.lookup_ipv4_asn(v4) {
                                        geo_provider.is_hosting_asn(asn)
                                            || geo_provider.is_vpn_asn(asn)
                                    } else {
                                        false
                                    }
                                }
                                std::net::IpAddr::V6(v6) => {
                                    let info = geo_provider.lookup(v6);
                                    info.is_hosting_provider || info.is_vpn_provider
                                }
                            };

                            if is_rejected {
                                info!(
                                    "Rejecting connection from {} ({}) due to GeoIP policy (Hosting/VPN)",
                                    peer_id_str, remote_address
                                );

                                // Create rejection message
                                let rejection = RejectionMessage {
                                    reason: RejectionReason::GeoIpPolicy,
                                    message:
                                        "Connection rejected: Hosting/VPN providers not allowed"
                                            .to_string(),
                                    suggested_target: None, // Could suggest a different region if we knew more
                                };

                                // Serialize message
                                if let Ok(data) = serde_json::to_vec(&rejection) {
                                    // Create protocol message
                                    let timestamp = std::time::SystemTime::now()
                                        .duration_since(std::time::UNIX_EPOCH)
                                        .unwrap_or_default()
                                        .as_secs();

                                    let message = serde_json::json!({
                                        "protocol": "control",
                                        "data": data,
                                        "from": local_peer_id,
                                        "timestamp": timestamp
                                    });

                                    if let Ok(msg_bytes) = serde_json::to_vec(&message) {
                                        // Send rejection message
                                        // We use send_to_peer directly on dual_node to avoid the checks in P2PNode::send_message
                                        // which might fail if we haven't fully registered the peer yet
                                        let _ = dual_node.send_to_peer(&peer_id, &msg_bytes).await;

                                        // Give it a moment to send before disconnecting?
                                        // ant-quic might handle this, but a small yield is safe
                                        tokio::task::yield_now().await;
                                    }
                                }

                                // Disconnect (TODO: Add disconnect method to dual_node or just drop?)
                                // For now, we just don't add it to active connections, effectively ignoring it
                                // Ideally we should actively close the connection
                                continue;
                            }

                            // Add to active connections
                            active_connections.write().await.insert(peer_id_str.clone());

                            // Update peer info or insert new
                            let mut peers_lock = peers.write().await;
                            if let Some(peer_info) = peers_lock.get_mut(&peer_id_str) {
                                peer_info.status = ConnectionStatus::Connected;
                                peer_info.connected_at = Instant::now();
                            } else {
                                // New incoming peer
                                debug!("Registering new incoming peer: {}", peer_id_str);
                                peers_lock.insert(
                                    peer_id_str.clone(),
                                    PeerInfo {
                                        peer_id: peer_id_str.clone(),
                                        addresses: vec![remote_address.to_string()],
                                        status: ConnectionStatus::Connected,
                                        last_seen: Instant::now(),
                                        connected_at: Instant::now(),
                                        protocols: Vec::new(),
                                        heartbeat_count: 0,
                                    },
                                );
                            }

                            // Broadcast connection event
                            let _ = event_tx.send(P2PEvent::PeerConnected(peer_id_str));
                        }
                        ConnectionEvent::Lost { peer_id, reason } => {
                            let peer_id_str =
                                crate::transport::ant_quic_adapter::ant_peer_id_to_string(&peer_id);
                            debug!("Connection lost: peer={}, reason={}", peer_id_str, reason);

                            // Remove from active connections
                            active_connections.write().await.remove(&peer_id_str);

                            // Update peer info status
                            if let Some(peer_info) = peers.write().await.get_mut(&peer_id_str) {
                                peer_info.status = ConnectionStatus::Disconnected;
                                peer_info.last_seen = Instant::now();
                            }

                            // Broadcast disconnection event
                            let _ = event_tx.send(P2PEvent::PeerDisconnected(peer_id_str));
                        }
                        ConnectionEvent::Failed { peer_id, reason } => {
                            let peer_id_str =
                                crate::transport::ant_quic_adapter::ant_peer_id_to_string(&peer_id);
                            warn!("Connection failed: peer={}, reason={}", peer_id_str, reason);

                            // Remove from active connections
                            active_connections.write().await.remove(&peer_id_str);

                            // Update peer info status
                            if let Some(peer_info) = peers.write().await.get_mut(&peer_id_str) {
                                peer_info.status = ConnectionStatus::Failed(reason.clone());
                            }

                            // Broadcast disconnection event
                            let _ = event_tx.send(P2PEvent::PeerDisconnected(peer_id_str));
                        }
                    }
                }
                Err(broadcast::error::RecvError::Lagged(skipped)) => {
                    warn!(
                        "Connection event monitor lagged, skipped {} events",
                        skipped
                    );
                    continue;
                }
                Err(broadcast::error::RecvError::Closed) => {
                    info!("Connection event channel closed, stopping monitor");
                    break;
                }
            }
        }

        info!("Connection lifecycle monitor stopped");
    }

    /// Start connection monitor (called after node initialization)
    async fn start_connection_monitor(&self) {
        // The monitor task is already spawned in new() with a temporary peers map
        // This method is a placeholder for future enhancements where we might
        // need to restart the monitor or provide it with updated references
        debug!("Connection monitor already running from initialization");
    }

    /// Keepalive task - sends periodic pings to prevent 30-second idle timeout
    ///
    /// ant-quic has a 30-second max_idle_timeout. This task sends a small keepalive
    /// message every 15 seconds (half the timeout) to all active connections to prevent
    /// them from timing out during periods of inactivity.
    async fn keepalive_task(
        active_connections: Arc<RwLock<HashSet<String>>>,
        dual_node: Arc<DualStackNetworkNode>,
        shutdown: Arc<AtomicBool>,
    ) {
        use tokio::time::{Duration, interval};

        const KEEPALIVE_INTERVAL_SECS: u64 = 15; // Half of 30-second timeout
        const KEEPALIVE_PAYLOAD: &[u8] = b"keepalive"; // Small payload

        let mut interval = interval(Duration::from_secs(KEEPALIVE_INTERVAL_SECS));
        interval.set_missed_tick_behavior(tokio::time::MissedTickBehavior::Skip);

        info!(
            "Keepalive task started (interval: {}s)",
            KEEPALIVE_INTERVAL_SECS
        );

        loop {
            // Check shutdown flag first
            if shutdown.load(Ordering::Relaxed) {
                info!("Keepalive task shutting down");
                break;
            }

            interval.tick().await;

            // Get snapshot of active connections
            let peers: Vec<String> = { active_connections.read().await.iter().cloned().collect() };

            if peers.is_empty() {
                trace!("Keepalive: no active connections");
                continue;
            }

            debug!("Sending keepalive to {} active connections", peers.len());

            // Send keepalive to each peer
            for peer_id in peers {
                match dual_node
                    .send_to_peer_string(&peer_id, KEEPALIVE_PAYLOAD)
                    .await
                {
                    Ok(_) => {
                        trace!("Keepalive sent to peer: {}", peer_id);
                    }
                    Err(e) => {
                        debug!(
                            "Failed to send keepalive to peer {}: {} (connection may have closed)",
                            peer_id, e
                        );
                        // Don't remove from active_connections here - let the lifecycle monitor handle it
                    }
                }
            }
        }

        info!("Keepalive task stopped");
    }

    /// Check system health
    pub async fn health_check(&self) -> Result<()> {
        if let Some(ref resource_manager) = self.resource_manager {
            resource_manager.health_check().await
        } else {
            // Basic health check without resource manager
            let peer_count = self.peer_count().await;
            if peer_count > self.config.max_connections {
                Err(P2PError::Network(
                    crate::error::NetworkError::ProtocolError(
                        format!("Too many connections: {peer_count}").into(),
                    ),
                ))
            } else {
                Ok(())
            }
        }
    }

    /// Get production configuration (if enabled)
    pub fn production_config(&self) -> Option<&ProductionConfig> {
        self.config.production_config.as_ref()
    }

    /// Check if production hardening is enabled
    pub fn is_production_mode(&self) -> bool {
        self.resource_manager.is_some()
    }

    /// Get DHT reference
    pub fn dht(&self) -> Option<&Arc<RwLock<DHT>>> {
        self.dht.as_ref()
    }

    /// Store a value in the DHT
    pub async fn dht_put(&self, key: crate::dht::Key, value: Vec<u8>) -> Result<()> {
        if let Some(ref dht) = self.dht {
            let mut dht_instance = dht.write().await;
            let dht_key = crate::dht::DhtKey::from_bytes(key);
            dht_instance
                .store(&dht_key, value.clone())
                .await
                .map_err(|e| {
                    P2PError::Dht(crate::error::DhtError::StoreFailed(
                        format!("{:?}: {e}", key).into(),
                    ))
                })?;

            Ok(())
        } else {
            Err(P2PError::Dht(crate::error::DhtError::RoutingError(
                "DHT not enabled".to_string().into(),
            )))
        }
    }

    /// Retrieve a value from the DHT
    pub async fn dht_get(&self, key: crate::dht::Key) -> Result<Option<Vec<u8>>> {
        if let Some(ref dht) = self.dht {
            let dht_instance = dht.read().await;
            let dht_key = crate::dht::DhtKey::from_bytes(key);
            let record_result = dht_instance.retrieve(&dht_key).await.map_err(|e| {
                P2PError::Dht(crate::error::DhtError::StoreFailed(
                    format!("Retrieve failed: {e}").into(),
                ))
            })?;

            Ok(record_result)
        } else {
            Err(P2PError::Dht(crate::error::DhtError::RoutingError(
                "DHT not enabled".to_string().into(),
            )))
        }
    }

    /// Add a discovered peer to the bootstrap cache
    pub async fn add_discovered_peer(&self, peer_id: PeerId, addresses: Vec<String>) -> Result<()> {
        if let Some(ref bootstrap_manager) = self.bootstrap_manager {
            let mut manager = bootstrap_manager.write().await;
            let socket_addresses: Vec<std::net::SocketAddr> = addresses
                .iter()
                .filter_map(|addr| addr.parse().ok())
                .collect();
            let contact = ContactEntry::new(peer_id, socket_addresses);
            manager.add_contact(contact).await.map_err(|e| {
                P2PError::Network(crate::error::NetworkError::ProtocolError(
                    format!("Failed to add peer to bootstrap cache: {e}").into(),
                ))
            })?;
        }
        Ok(())
    }

    /// Update connection metrics for a peer in the bootstrap cache
    pub async fn update_peer_metrics(
        &self,
        peer_id: &PeerId,
        success: bool,
        latency_ms: Option<u64>,
        _error: Option<String>,
    ) -> Result<()> {
        if let Some(ref bootstrap_manager) = self.bootstrap_manager {
            let mut manager = bootstrap_manager.write().await;

            // Create quality metrics based on the connection result
            let metrics = QualityMetrics {
                success_rate: if success { 1.0 } else { 0.0 },
                avg_latency_ms: latency_ms.unwrap_or(0) as f64,
                quality_score: if success { 0.8 } else { 0.2 }, // Initial score
                last_connection_attempt: chrono::Utc::now(),
                last_successful_connection: if success {
                    chrono::Utc::now()
                } else {
                    chrono::Utc::now() - chrono::Duration::hours(1)
                },
                uptime_score: 0.5,
            };

            manager
                .update_contact_metrics(peer_id, metrics)
                .await
                .map_err(|e| {
                    P2PError::Network(crate::error::NetworkError::ProtocolError(
                        format!("Failed to update peer metrics: {e}").into(),
                    ))
                })?;
        }
        Ok(())
    }

    /// Get bootstrap cache statistics
    pub async fn get_bootstrap_cache_stats(&self) -> Result<Option<crate::bootstrap::CacheStats>> {
        if let Some(ref bootstrap_manager) = self.bootstrap_manager {
            let manager = bootstrap_manager.read().await;
            let stats = manager.get_stats().await.map_err(|e| {
                P2PError::Network(crate::error::NetworkError::ProtocolError(
                    format!("Failed to get bootstrap stats: {e}").into(),
                ))
            })?;
            Ok(Some(stats))
        } else {
            Ok(None)
        }
    }

    /// Get the number of cached bootstrap peers
    pub async fn cached_peer_count(&self) -> usize {
        if let Some(ref _bootstrap_manager) = self.bootstrap_manager
            && let Ok(Some(stats)) = self.get_bootstrap_cache_stats().await
        {
            return stats.total_contacts;
        }
        0
    }

    /// Connect to bootstrap peers
    async fn connect_bootstrap_peers(&self) -> Result<()> {
        let mut bootstrap_contacts = Vec::new();
        let mut used_cache = false;
        let mut seen_addresses = std::collections::HashSet::new();

        // CLI-provided bootstrap peers take priority - always include them first
        let cli_bootstrap_peers = if !self.config.bootstrap_peers_str.is_empty() {
            self.config.bootstrap_peers_str.clone()
        } else {
            // Convert Multiaddr to strings
            self.config
                .bootstrap_peers
                .iter()
                .map(|addr| addr.to_string())
                .collect::<Vec<_>>()
        };

        if !cli_bootstrap_peers.is_empty() {
            info!(
                "Using {} CLI-provided bootstrap peers (priority)",
                cli_bootstrap_peers.len()
            );
            for addr in &cli_bootstrap_peers {
                if let Ok(socket_addr) = addr.parse::<std::net::SocketAddr>() {
                    seen_addresses.insert(socket_addr);
                    let contact = ContactEntry::new(
                        format!("cli_peer_{}", addr.chars().take(8).collect::<String>()),
                        vec![socket_addr],
                    );
                    bootstrap_contacts.push(contact);
                } else {
                    warn!("Invalid bootstrap address format: {}", addr);
                }
            }
        }

        // Supplement with cached bootstrap peers (after CLI peers)
        if let Some(ref bootstrap_manager) = self.bootstrap_manager {
            let manager = bootstrap_manager.read().await;
            match manager.get_bootstrap_peers(20).await {
                // Try to get top 20 quality peers
                Ok(contacts) => {
                    if !contacts.is_empty() {
                        let mut added_from_cache = 0;
                        for contact in contacts {
                            // Only add if we haven't already added this address from CLI
                            let new_addresses: Vec<_> = contact
                                .addresses
                                .iter()
                                .filter(|addr| !seen_addresses.contains(addr))
                                .copied()
                                .collect();

                            if !new_addresses.is_empty() {
                                for addr in &new_addresses {
                                    seen_addresses.insert(*addr);
                                }
                                let mut contact = contact.clone();
                                contact.addresses = new_addresses;
                                bootstrap_contacts.push(contact);
                                added_from_cache += 1;
                            }
                        }
                        if added_from_cache > 0 {
                            info!(
                                "Added {} cached bootstrap peers (supplementing CLI peers)",
                                added_from_cache
                            );
                            used_cache = true;
                        }
                    }
                }
                Err(e) => {
                    warn!("Failed to get cached bootstrap peers: {}", e);
                }
            }
        }

        if bootstrap_contacts.is_empty() {
            info!("No bootstrap peers configured and no cached peers available");
            return Ok(());
        }

        // Connect to bootstrap peers
        let mut successful_connections = 0;
        for contact in bootstrap_contacts {
            for addr in &contact.addresses {
                match self.connect_peer(&addr.to_string()).await {
                    Ok(peer_id) => {
                        info!("Connected to bootstrap peer: {} ({})", peer_id, addr);
                        successful_connections += 1;

                        // Update bootstrap cache with successful connection
                        if let Some(ref bootstrap_manager) = self.bootstrap_manager {
                            let mut manager = bootstrap_manager.write().await;
                            let mut updated_contact = contact.clone();
                            updated_contact.peer_id = peer_id.clone();
                            updated_contact.update_connection_result(true, Some(100), None); // Assume 100ms latency for now

                            if let Err(e) = manager.add_contact(updated_contact).await {
                                warn!("Failed to update bootstrap cache: {}", e);
                            }
                        }
                        break; // Successfully connected, move to next contact
                    }
                    Err(e) => {
                        warn!("Failed to connect to bootstrap peer {}: {}", addr, e);

                        // Update bootstrap cache with failed connection
                        if used_cache && let Some(ref bootstrap_manager) = self.bootstrap_manager {
                            let mut manager = bootstrap_manager.write().await;
                            let mut updated_contact = contact.clone();
                            updated_contact.update_connection_result(
                                false,
                                None,
                                Some(e.to_string()),
                            );

                            if let Err(e) = manager.add_contact(updated_contact).await {
                                warn!("Failed to update bootstrap cache: {}", e);
                            }
                        }
                    }
                }
            }
        }

        if successful_connections == 0 {
            if !used_cache {
                warn!("Failed to connect to any bootstrap peers");
            }
            return Err(P2PError::Network(NetworkError::ConnectionFailed {
                addr: std::net::SocketAddr::from(([0, 0, 0, 0], 0)), // Placeholder for bootstrap ensemble
                reason: "Failed to connect to any bootstrap peers".into(),
            }));
        }
        info!(
            "Successfully connected to {} bootstrap peers",
            successful_connections
        );

        Ok(())
    }

    /// Disconnect from all peers
    async fn disconnect_all_peers(&self) -> Result<()> {
        let peer_ids: Vec<PeerId> = self.peers.read().await.keys().cloned().collect();

        for peer_id in peer_ids {
            self.disconnect_peer(&peer_id).await?;
        }

        Ok(())
    }

    /// Perform periodic maintenance tasks
    async fn periodic_tasks(&self) -> Result<()> {
        // Update peer last seen timestamps
        // Remove stale connections
        // Perform DHT maintenance
        // This is a placeholder for now

        Ok(())
    }
}

/// Network sender trait for sending messages
#[async_trait::async_trait]
pub trait NetworkSender: Send + Sync {
    /// Send a message to a specific peer
    async fn send_message(&self, peer_id: &PeerId, protocol: &str, data: Vec<u8>) -> Result<()>;

    /// Get our local peer ID
    fn local_peer_id(&self) -> &PeerId;
}

/// Lightweight wrapper for P2PNode to implement NetworkSender
#[derive(Clone)]
pub struct P2PNetworkSender {
    peer_id: PeerId,
    // Use channels for async communication with the P2P node
    send_tx: tokio::sync::mpsc::UnboundedSender<(PeerId, String, Vec<u8>)>,
}

impl P2PNetworkSender {
    pub fn new(
        peer_id: PeerId,
        send_tx: tokio::sync::mpsc::UnboundedSender<(PeerId, String, Vec<u8>)>,
    ) -> Self {
        Self { peer_id, send_tx }
    }
}

/// Implementation of NetworkSender trait for P2PNetworkSender
#[async_trait::async_trait]
impl NetworkSender for P2PNetworkSender {
    /// Send a message to a specific peer via the P2P network
    async fn send_message(&self, peer_id: &PeerId, protocol: &str, data: Vec<u8>) -> Result<()> {
        self.send_tx
            .send((peer_id.clone(), protocol.to_string(), data))
            .map_err(|_| {
                P2PError::Network(crate::error::NetworkError::ProtocolError(
                    "Failed to send message via channel".to_string().into(),
                ))
            })?;
        Ok(())
    }

    /// Get our local peer ID
    fn local_peer_id(&self) -> &PeerId {
        &self.peer_id
    }
}

/// Builder pattern for creating P2P nodes
pub struct NodeBuilder {
    config: NodeConfig,
}

impl Default for NodeBuilder {
    fn default() -> Self {
        Self::new()
    }
}

impl NodeBuilder {
    /// Create a new node builder
    pub fn new() -> Self {
        Self {
            config: NodeConfig::default(),
        }
    }

    /// Set the peer ID
    pub fn with_peer_id(mut self, peer_id: PeerId) -> Self {
        self.config.peer_id = Some(peer_id);
        self
    }

    /// Add a listen address
    pub fn listen_on(mut self, addr: &str) -> Self {
        if let Ok(multiaddr) = addr.parse() {
            self.config.listen_addrs.push(multiaddr);
        }
        self
    }

    /// Add a bootstrap peer
    pub fn with_bootstrap_peer(mut self, addr: &str) -> Self {
        if let Ok(multiaddr) = addr.parse() {
            self.config.bootstrap_peers.push(multiaddr);
        }
        self.config.bootstrap_peers_str.push(addr.to_string());
        self
    }

    /// Enable IPv6 support
    pub fn with_ipv6(mut self, enable: bool) -> Self {
        self.config.enable_ipv6 = enable;
        self
    }

    // MCP removed: builder methods deleted

    /// Set connection timeout
    pub fn with_connection_timeout(mut self, timeout: Duration) -> Self {
        self.config.connection_timeout = timeout;
        self
    }

    /// Set maximum connections
    pub fn with_max_connections(mut self, max: usize) -> Self {
        self.config.max_connections = max;
        self
    }

    /// Enable production mode with default configuration
    pub fn with_production_mode(mut self) -> Self {
        self.config.production_config = Some(ProductionConfig::default());
        self
    }

    /// Configure production settings
    pub fn with_production_config(mut self, production_config: ProductionConfig) -> Self {
        self.config.production_config = Some(production_config);
        self
    }

    /// Configure IP diversity limits for Sybil protection.
    pub fn with_diversity_config(
        mut self,
        diversity_config: crate::security::IPDiversityConfig,
    ) -> Self {
        self.config.diversity_config = Some(diversity_config);
        self
    }

    /// Configure DHT settings
    pub fn with_dht(mut self, dht_config: DHTConfig) -> Self {
        self.config.dht_config = dht_config;
        self
    }

    /// Enable DHT with default configuration
    pub fn with_default_dht(mut self) -> Self {
        self.config.dht_config = DHTConfig::default();
        self
    }

    /// Build the P2P node
    pub async fn build(self) -> Result<P2PNode> {
        P2PNode::new(self.config).await
    }
}

#[cfg(test)]
#[allow(clippy::unwrap_used, clippy::expect_used)]
mod diversity_tests {
    use super::*;
    use crate::security::IPDiversityConfig;

    async fn build_bootstrap_manager_like_prod(config: &NodeConfig) -> BootstrapManager {
        let diversity_config = config.diversity_config.clone().unwrap_or_default();
        if let Some(ref cache_config) = config.bootstrap_cache_config {
            BootstrapManager::with_full_config(
                cache_config.clone(),
                crate::rate_limit::JoinRateLimiterConfig::default(),
                diversity_config,
            )
            .await
            .expect("bootstrap manager")
        } else {
            BootstrapManager::with_full_config(
                crate::bootstrap::CacheConfig::default(),
                crate::rate_limit::JoinRateLimiterConfig::default(),
                diversity_config,
            )
            .await
            .expect("bootstrap manager")
        }
    }

    #[tokio::test]
    async fn test_nodeconfig_diversity_config_used_for_bootstrap() {
        let config = NodeConfig {
            diversity_config: Some(IPDiversityConfig::testnet()),
            ..Default::default()
        };

        let manager = build_bootstrap_manager_like_prod(&config).await;
        assert!(manager.diversity_config().is_relaxed());
        assert_eq!(manager.diversity_config().max_nodes_per_asn, 5000);
    }
}

/// Standalone function to handle received messages without borrowing self
#[allow(dead_code)] // Deprecated during ant-quic migration
async fn handle_received_message_standalone(
    message_data: Vec<u8>,
    peer_id: &PeerId,
    _protocol: &str,
    event_tx: &broadcast::Sender<P2PEvent>,
) -> Result<()> {
    // Parse the message format
    match serde_json::from_slice::<serde_json::Value>(&message_data) {
        Ok(message) => {
            if let (Some(protocol), Some(data), Some(from)) = (
                message.get("protocol").and_then(|v| v.as_str()),
                message.get("data").and_then(|v| v.as_array()),
                message.get("from").and_then(|v| v.as_str()),
            ) {
                // Convert data array back to bytes
                let data_bytes: Vec<u8> = data
                    .iter()
                    .filter_map(|v| v.as_u64().map(|n| n as u8))
                    .collect();

                // Generate message event
                let event = P2PEvent::Message {
                    topic: protocol.to_string(),
                    source: from.to_string(),
                    data: data_bytes,
                };

                let _ = event_tx.send(event);
                debug!("Generated message event from peer: {}", peer_id);
            }
        }
        Err(e) => {
            warn!("Failed to parse received message from {}: {}", peer_id, e);
        }
    }

    Ok(())
}

// MCP removed: standalone MCP handler deleted

/// Helper function to handle protocol message creation
#[allow(dead_code)]
fn handle_protocol_message_creation(protocol: &str, data: Vec<u8>) -> Option<Vec<u8>> {
    match create_protocol_message_static(protocol, data) {
        Ok(msg) => Some(msg),
        Err(e) => {
            warn!("Failed to create protocol message: {}", e);
            None
        }
    }
}

/// Helper function to handle message send result
#[allow(dead_code)]
async fn handle_message_send_result(result: crate::error::P2pResult<()>, peer_id: &PeerId) {
    match result {
        Ok(_) => {
            debug!("Message sent to peer {} via transport layer", peer_id);
        }
        Err(e) => {
            warn!("Failed to send message to peer {}: {}", peer_id, e);
        }
    }
}

/// Helper function to check rate limit
#[allow(dead_code)] // Deprecated during ant-quic migration
fn check_rate_limit(
    rate_limiter: &RateLimiter,
    socket_addr: &std::net::SocketAddr,
    remote_addr: &NetworkAddress,
) -> Result<()> {
    rate_limiter.check_ip(&socket_addr.ip()).map_err(|e| {
        warn!("Rate limit exceeded for {}: {}", remote_addr, e);
        e
    })
}

/// Helper function to register a new peer
#[allow(dead_code)] // Deprecated during ant-quic migration
async fn register_new_peer(
    peers: &Arc<RwLock<HashMap<PeerId, PeerInfo>>>,
    peer_id: &PeerId,
    remote_addr: &NetworkAddress,
) {
    let mut peers_guard = peers.write().await;
    let peer_info = PeerInfo {
        peer_id: peer_id.clone(),
        addresses: vec![remote_addr.to_string()],
        connected_at: tokio::time::Instant::now(),
        last_seen: tokio::time::Instant::now(),
        status: ConnectionStatus::Connected,
        protocols: vec!["p2p-chat/1.0.0".to_string()],
        heartbeat_count: 0,
    };
    peers_guard.insert(peer_id.clone(), peer_info);
}

/// Helper function to spawn connection handler
#[allow(dead_code)] // Deprecated during ant-quic migration
fn spawn_connection_handler(
    connection: Box<dyn crate::transport::Connection>,
    peer_id: PeerId,
    event_tx: broadcast::Sender<P2PEvent>,
    peers: Arc<RwLock<HashMap<PeerId, PeerInfo>>>,
) {
    tokio::spawn(async move {
        handle_peer_connection(connection, peer_id, event_tx, peers).await;
    });
}

/// Helper function to handle peer connection
#[allow(dead_code)] // Deprecated during ant-quic migration
async fn handle_peer_connection(
    mut connection: Box<dyn crate::transport::Connection>,
    peer_id: PeerId,
    event_tx: broadcast::Sender<P2PEvent>,
    peers: Arc<RwLock<HashMap<PeerId, PeerInfo>>>,
) {
    loop {
        match connection.receive().await {
            Ok(message_data) => {
                debug!(
                    "Received {} bytes from peer: {}",
                    message_data.len(),
                    peer_id
                );

                // Handle the received message
                if let Err(e) = handle_received_message_standalone(
                    message_data,
                    &peer_id,
                    "unknown", // TODO: Extract protocol from message
                    &event_tx,
                )
                .await
                {
                    warn!("Failed to handle message from peer {}: {}", peer_id, e);
                }
            }
            Err(e) => {
                warn!("Failed to receive message from {}: {}", peer_id, e);

                // Check if connection is still alive
                if !connection.is_alive().await {
                    info!("Connection to {} is dead, removing peer", peer_id);

                    // Remove dead peer
                    remove_peer(&peers, &peer_id).await;

                    // Generate peer disconnected event
                    let _ = event_tx.send(P2PEvent::PeerDisconnected(peer_id.clone()));

                    break; // Exit the message receiving loop
                }

                // Brief pause before retrying
                tokio::time::sleep(std::time::Duration::from_millis(100)).await;
            }
        }
    }
}

/// Helper function to remove a peer
#[allow(dead_code)] // Deprecated during ant-quic migration
async fn remove_peer(peers: &Arc<RwLock<HashMap<PeerId, PeerInfo>>>, peer_id: &PeerId) {
    let mut peers_guard = peers.write().await;
    peers_guard.remove(peer_id);
}

/// Helper function to update peer heartbeat
#[allow(dead_code)]
async fn update_peer_heartbeat(
    peers: &Arc<RwLock<HashMap<PeerId, PeerInfo>>>,
    peer_id: &PeerId,
) -> Result<()> {
    let mut peers_guard = peers.write().await;
    match peers_guard.get_mut(peer_id) {
        Some(peer_info) => {
            peer_info.last_seen = Instant::now();
            peer_info.heartbeat_count += 1;
            Ok(())
        }
        None => {
            warn!("Received heartbeat from unknown peer: {}", peer_id);
            Err(P2PError::Network(NetworkError::PeerNotFound(
                format!("Peer {} not found", peer_id).into(),
            )))
        }
    }
}

/// Helper function to get resource metrics
#[allow(dead_code)]
async fn get_resource_metrics(resource_manager: &Option<Arc<ResourceManager>>) -> (u64, f64) {
    if let Some(manager) = resource_manager {
        let metrics = manager.get_metrics().await;
        (metrics.memory_used, metrics.cpu_usage)
    } else {
        (0, 0.0)
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    // MCP removed from tests
    use std::time::Duration;
    use tokio::time::timeout;

    // Test tool handler for network tests

    // MCP removed

    /// Helper function to create a test node configuration
    fn create_test_node_config() -> NodeConfig {
        NodeConfig {
            peer_id: Some("test_peer_123".to_string()),
            listen_addrs: vec![
                std::net::SocketAddr::new(std::net::IpAddr::V6(std::net::Ipv6Addr::LOCALHOST), 0),
                std::net::SocketAddr::new(std::net::IpAddr::V4(std::net::Ipv4Addr::LOCALHOST), 0),
            ],
            listen_addr: std::net::SocketAddr::new(
                std::net::IpAddr::V4(std::net::Ipv4Addr::LOCALHOST),
                0,
            ),
            bootstrap_peers: vec![],
            bootstrap_peers_str: vec![],
            enable_ipv6: true,

            connection_timeout: Duration::from_millis(300),
            keep_alive_interval: Duration::from_secs(30),
            max_connections: 100,
            max_incoming_connections: 50,
            dht_config: DHTConfig::default(),
            security_config: SecurityConfig::default(),
            production_config: None,
            bootstrap_cache_config: None,
            diversity_config: None,
            // identity_config: None,
        }
    }

    /// Helper function to create a test tool
    // MCP removed: test tool helper deleted

    #[tokio::test]
    async fn test_node_config_default() {
        let config = NodeConfig::default();

        assert!(config.peer_id.is_none());
        assert_eq!(config.listen_addrs.len(), 2);
        assert!(config.enable_ipv6);
        assert_eq!(config.max_connections, 10000); // Fixed: matches actual default
        assert_eq!(config.max_incoming_connections, 100);
        assert_eq!(config.connection_timeout, Duration::from_secs(30));
    }

    #[tokio::test]
    async fn test_dht_config_default() {
        let config = DHTConfig::default();

        assert_eq!(config.k_value, 20);
        assert_eq!(config.alpha_value, 5);
        assert_eq!(config.record_ttl, Duration::from_secs(3600));
        assert_eq!(config.refresh_interval, Duration::from_secs(600));
    }

    #[tokio::test]
    async fn test_security_config_default() {
        let config = SecurityConfig::default();

        assert!(config.enable_noise);
        assert!(config.enable_tls);
        assert_eq!(config.trust_level, TrustLevel::Basic);
    }

    #[test]
    fn test_trust_level_variants() {
        // Test that all trust level variants can be created
        let _none = TrustLevel::None;
        let _basic = TrustLevel::Basic;
        let _full = TrustLevel::Full;

        // Test equality
        assert_eq!(TrustLevel::None, TrustLevel::None);
        assert_eq!(TrustLevel::Basic, TrustLevel::Basic);
        assert_eq!(TrustLevel::Full, TrustLevel::Full);
        assert_ne!(TrustLevel::None, TrustLevel::Basic);
    }

    #[test]
    fn test_connection_status_variants() {
        let connecting = ConnectionStatus::Connecting;
        let connected = ConnectionStatus::Connected;
        let disconnecting = ConnectionStatus::Disconnecting;
        let disconnected = ConnectionStatus::Disconnected;
        let failed = ConnectionStatus::Failed("test error".to_string());

        assert_eq!(connecting, ConnectionStatus::Connecting);
        assert_eq!(connected, ConnectionStatus::Connected);
        assert_eq!(disconnecting, ConnectionStatus::Disconnecting);
        assert_eq!(disconnected, ConnectionStatus::Disconnected);
        assert_ne!(connecting, connected);

        if let ConnectionStatus::Failed(msg) = failed {
            assert_eq!(msg, "test error");
        } else {
            panic!("Expected Failed status");
        }
    }

    #[tokio::test]
    async fn test_node_creation() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        assert_eq!(node.peer_id(), "test_peer_123");
        assert!(!node.is_running().await);
        assert_eq!(node.peer_count().await, 0);
        assert!(node.connected_peers().await.is_empty());

        Ok(())
    }

    #[tokio::test]
    async fn test_node_creation_without_peer_id() -> Result<()> {
        let mut config = create_test_node_config();
        config.peer_id = None;

        let node = P2PNode::new(config).await?;

        // Should have generated a peer ID
        assert!(node.peer_id().starts_with("peer_"));
        assert!(!node.is_running().await);

        Ok(())
    }

    #[tokio::test]
    async fn test_node_lifecycle() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        // Initially not running
        assert!(!node.is_running().await);

        // Start the node
        node.start().await?;
        assert!(node.is_running().await);

        // Check listen addresses were set (at least one)
        let listen_addrs = node.listen_addrs().await;
        assert!(
            !listen_addrs.is_empty(),
            "Expected at least one listening address"
        );

        // Stop the node
        node.stop().await?;
        assert!(!node.is_running().await);

        Ok(())
    }

    #[tokio::test]
    async fn test_peer_connection() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        let peer_addr = "127.0.0.1:0";

        // Connect to a peer
        let peer_id = node.connect_peer(peer_addr).await?;
        assert!(peer_id.starts_with("peer_from_"));

        // Check peer count
        assert_eq!(node.peer_count().await, 1);

        // Check connected peers
        let connected_peers = node.connected_peers().await;
        assert_eq!(connected_peers.len(), 1);
        assert_eq!(connected_peers[0], peer_id);

        // Get peer info
        let peer_info = node.peer_info(&peer_id).await;
        assert!(peer_info.is_some());
        let info = peer_info.expect("Peer info should exist after adding peer");
        assert_eq!(info.peer_id, peer_id);
        assert_eq!(info.status, ConnectionStatus::Connected);
        assert!(info.protocols.contains(&"p2p-foundation/1.0".to_string()));

        // Disconnect from peer
        node.disconnect_peer(&peer_id).await?;
        assert_eq!(node.peer_count().await, 0);

        Ok(())
    }

    #[tokio::test]
    async fn test_event_subscription() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        let mut events = node.subscribe_events();
        let peer_addr = "127.0.0.1:0";

        // Connect to a peer (this should emit an event)
        let peer_id = node.connect_peer(peer_addr).await?;

        // Check for PeerConnected event
        let event = timeout(Duration::from_millis(100), events.recv()).await;
        assert!(event.is_ok());

        let event_result = event
            .expect("Should receive event")
            .expect("Event should not be error");
        match event_result {
            P2PEvent::PeerConnected(event_peer_id) => {
                assert_eq!(event_peer_id, peer_id);
            }
            _ => panic!("Expected PeerConnected event"),
        }

        // Disconnect from peer (this should emit another event)
        node.disconnect_peer(&peer_id).await?;

        // Check for PeerDisconnected event
        let event = timeout(Duration::from_millis(100), events.recv()).await;
        assert!(event.is_ok());

        let event_result = event
            .expect("Should receive event")
            .expect("Event should not be error");
        match event_result {
            P2PEvent::PeerDisconnected(event_peer_id) => {
                assert_eq!(event_peer_id, peer_id);
            }
            _ => panic!("Expected PeerDisconnected event"),
        }

        Ok(())
    }

    #[tokio::test]
    async fn test_message_sending() -> Result<()> {
        // Create two nodes
        let mut config1 = create_test_node_config();
        config1.listen_addr =
            std::net::SocketAddr::new(std::net::IpAddr::V4(std::net::Ipv4Addr::LOCALHOST), 0);
        let node1 = P2PNode::new(config1).await?;
        node1.start().await?;

        let mut config2 = create_test_node_config();
        config2.listen_addr =
            std::net::SocketAddr::new(std::net::IpAddr::V4(std::net::Ipv4Addr::LOCALHOST), 0);
        let node2 = P2PNode::new(config2).await?;
        node2.start().await?;

        // Wait a bit for nodes to start listening
        tokio::time::sleep(tokio::time::Duration::from_millis(50)).await;

        // Get actual listening address of node2
        let node2_addr = node2.local_addr().ok_or_else(|| {
            P2PError::Network(crate::error::NetworkError::ProtocolError(
                "No listening address".to_string().into(),
            ))
        })?;

        // Connect node1 to node2
        let peer_id =
            match timeout(Duration::from_millis(500), node1.connect_peer(&node2_addr)).await {
                Ok(res) => res?,
                Err(_) => return Err(P2PError::Network(NetworkError::Timeout)),
            };

        // Wait a bit for connection to establish
        tokio::time::sleep(tokio::time::Duration::from_millis(30)).await;

        // Send a message
        let message_data = b"Hello, peer!".to_vec();
        let result = match timeout(
            Duration::from_millis(500),
            node1.send_message(&peer_id, "test-protocol", message_data),
        )
        .await
        {
            Ok(res) => res,
            Err(_) => return Err(P2PError::Network(NetworkError::Timeout)),
        };
        // For now, we'll just check that we don't get a "not connected" error
        // The actual send might fail due to no handler on the other side
        if let Err(e) = &result {
            assert!(!e.to_string().contains("not connected"), "Got error: {}", e);
        }

        // Try to send to non-existent peer
        let non_existent_peer = "non_existent_peer".to_string();
        let result = node1
            .send_message(&non_existent_peer, "test-protocol", vec![])
            .await;
        assert!(result.is_err(), "Sending to non-existent peer should fail");

        Ok(())
    }

    #[tokio::test]
    async fn test_remote_mcp_operations() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        // MCP removed; test reduced to simple start/stop
        node.start().await?;
        node.stop().await?;
        Ok(())
    }

    #[tokio::test]
    async fn test_health_check() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        // Health check should pass with no connections
        let result = node.health_check().await;
        assert!(result.is_ok());

        // Note: We're not actually connecting to real peers here
        // since that would require running bootstrap nodes.
        // The health check should still pass with no connections.

        Ok(())
    }

    #[tokio::test]
    async fn test_node_uptime() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        let uptime1 = node.uptime();
        assert!(uptime1 >= Duration::from_secs(0));

        // Wait a bit
        tokio::time::sleep(Duration::from_millis(10)).await;

        let uptime2 = node.uptime();
        assert!(uptime2 > uptime1);

        Ok(())
    }

    #[tokio::test]
    async fn test_node_config_access() -> Result<()> {
        let config = create_test_node_config();
        let expected_peer_id = config.peer_id.clone();
        let node = P2PNode::new(config).await?;

        let node_config = node.config();
        assert_eq!(node_config.peer_id, expected_peer_id);
        assert_eq!(node_config.max_connections, 100);
        // MCP removed

        Ok(())
    }

    #[tokio::test]
    async fn test_mcp_server_access() -> Result<()> {
        let config = create_test_node_config();
        let _node = P2PNode::new(config).await?;

        // MCP removed
        Ok(())
    }

    #[tokio::test]
    async fn test_dht_access() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        // Should have DHT
        assert!(node.dht().is_some());

        Ok(())
    }

    #[tokio::test]
    async fn test_node_builder() -> Result<()> {
        // Create a config using the builder but don't actually build a real node
        let builder = P2PNode::builder()
            .with_peer_id("builder_test_peer".to_string())
            .listen_on("/ip4/127.0.0.1/tcp/0")
            .listen_on("/ip6/::1/tcp/0")
            .with_bootstrap_peer("/ip4/127.0.0.1/tcp/9000") // Use a valid port number
            .with_ipv6(true)
            .with_connection_timeout(Duration::from_secs(15))
            .with_max_connections(200);

        // Test the configuration that was built
        let config = builder.config;
        assert_eq!(config.peer_id, Some("builder_test_peer".to_string()));
        assert_eq!(config.listen_addrs.len(), 2); // 2 added by builder (no defaults)
        assert_eq!(config.bootstrap_peers_str.len(), 1); // Check bootstrap_peers_str instead
        assert!(config.enable_ipv6);
        assert_eq!(config.connection_timeout, Duration::from_secs(15));
        assert_eq!(config.max_connections, 200);

        Ok(())
    }

    #[tokio::test]
    async fn test_bootstrap_peers() -> Result<()> {
        let mut config = create_test_node_config();
        config.bootstrap_peers = vec![
            std::net::SocketAddr::new(std::net::IpAddr::V4(std::net::Ipv4Addr::LOCALHOST), 9200),
            std::net::SocketAddr::new(std::net::IpAddr::V4(std::net::Ipv4Addr::LOCALHOST), 9201),
        ];

        let node = P2PNode::new(config).await?;

        // Start node (which attempts to connect to bootstrap peers)
        node.start().await?;

        // In a test environment, bootstrap peers may not be available
        // The test verifies the node starts correctly with bootstrap configuration
        // Peer count may include local/internal tracking, so we just verify it's reasonable
        let _peer_count = node.peer_count().await;

        node.stop().await?;
        Ok(())
    }

    #[tokio::test]
    async fn test_production_mode_disabled() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        assert!(!node.is_production_mode());
        assert!(node.production_config().is_none());

        // Resource metrics should fail when production mode is disabled
        let result = node.resource_metrics().await;
        assert!(result.is_err());
        assert!(result.unwrap_err().to_string().contains("not enabled"));

        Ok(())
    }

    #[tokio::test]
    async fn test_network_event_variants() {
        // Test that all network event variants can be created
        let peer_id = "test_peer".to_string();
        let address = "/ip4/127.0.0.1/tcp/9000".to_string();

        let _peer_connected = NetworkEvent::PeerConnected {
            peer_id: peer_id.clone(),
            addresses: vec![address.clone()],
        };

        let _peer_disconnected = NetworkEvent::PeerDisconnected {
            peer_id: peer_id.clone(),
            reason: "test disconnect".to_string(),
        };

        let _message_received = NetworkEvent::MessageReceived {
            peer_id: peer_id.clone(),
            protocol: "test-protocol".to_string(),
            data: vec![1, 2, 3],
        };

        let _connection_failed = NetworkEvent::ConnectionFailed {
            peer_id: Some(peer_id.clone()),
            address: address.clone(),
            error: "connection refused".to_string(),
        };

        let _dht_stored = NetworkEvent::DHTRecordStored {
            key: vec![1, 2, 3],
            value: vec![4, 5, 6],
        };

        let _dht_retrieved = NetworkEvent::DHTRecordRetrieved {
            key: vec![1, 2, 3],
            value: Some(vec![4, 5, 6]),
        };
    }

    #[tokio::test]
    async fn test_peer_info_structure() {
        let peer_info = PeerInfo {
            peer_id: "test_peer".to_string(),
            addresses: vec!["/ip4/127.0.0.1/tcp/9000".to_string()],
            connected_at: Instant::now(),
            last_seen: Instant::now(),
            status: ConnectionStatus::Connected,
            protocols: vec!["test-protocol".to_string()],
            heartbeat_count: 0,
        };

        assert_eq!(peer_info.peer_id, "test_peer");
        assert_eq!(peer_info.addresses.len(), 1);
        assert_eq!(peer_info.status, ConnectionStatus::Connected);
        assert_eq!(peer_info.protocols.len(), 1);
    }

    #[tokio::test]
    async fn test_serialization() -> Result<()> {
        // Test that configs can be serialized/deserialized
        let config = create_test_node_config();
        let serialized = serde_json::to_string(&config)?;
        let deserialized: NodeConfig = serde_json::from_str(&serialized)?;

        assert_eq!(config.peer_id, deserialized.peer_id);
        assert_eq!(config.listen_addrs, deserialized.listen_addrs);
        assert_eq!(config.enable_ipv6, deserialized.enable_ipv6);

        Ok(())
    }

    #[tokio::test]
    async fn test_get_peer_id_by_address_found() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        // Manually insert a peer for testing
        let test_peer_id = "peer_test_123".to_string();
        let test_address = "192.168.1.100:9000".to_string();

        let peer_info = PeerInfo {
            peer_id: test_peer_id.clone(),
            addresses: vec![test_address.clone()],
            connected_at: Instant::now(),
            last_seen: Instant::now(),
            status: ConnectionStatus::Connected,
            protocols: vec!["test-protocol".to_string()],
            heartbeat_count: 0,
        };

        node.peers
            .write()
            .await
            .insert(test_peer_id.clone(), peer_info);

        // Test: Find peer by address
        let found_peer_id = node.get_peer_id_by_address(&test_address).await;
        assert_eq!(found_peer_id, Some(test_peer_id));

        Ok(())
    }

    #[tokio::test]
    async fn test_get_peer_id_by_address_not_found() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        // Test: Try to find a peer that doesn't exist
        let result = node.get_peer_id_by_address("192.168.1.200:9000").await;
        assert_eq!(result, None);

        Ok(())
    }

    #[tokio::test]
    async fn test_get_peer_id_by_address_invalid_format() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        // Test: Invalid address format should return None
        let result = node.get_peer_id_by_address("invalid-address").await;
        assert_eq!(result, None);

        Ok(())
    }

    #[tokio::test]
    async fn test_get_peer_id_by_address_multiple_peers() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        // Add multiple peers with different addresses
        let peer1_id = "peer_1".to_string();
        let peer1_addr = "192.168.1.101:9001".to_string();

        let peer2_id = "peer_2".to_string();
        let peer2_addr = "192.168.1.102:9002".to_string();

        let peer1_info = PeerInfo {
            peer_id: peer1_id.clone(),
            addresses: vec![peer1_addr.clone()],
            connected_at: Instant::now(),
            last_seen: Instant::now(),
            status: ConnectionStatus::Connected,
            protocols: vec!["test-protocol".to_string()],
            heartbeat_count: 0,
        };

        let peer2_info = PeerInfo {
            peer_id: peer2_id.clone(),
            addresses: vec![peer2_addr.clone()],
            connected_at: Instant::now(),
            last_seen: Instant::now(),
            status: ConnectionStatus::Connected,
            protocols: vec!["test-protocol".to_string()],
            heartbeat_count: 0,
        };

        node.peers
            .write()
            .await
            .insert(peer1_id.clone(), peer1_info);
        node.peers
            .write()
            .await
            .insert(peer2_id.clone(), peer2_info);

        // Test: Find each peer by their unique address
        let found_peer1 = node.get_peer_id_by_address(&peer1_addr).await;
        let found_peer2 = node.get_peer_id_by_address(&peer2_addr).await;

        assert_eq!(found_peer1, Some(peer1_id));
        assert_eq!(found_peer2, Some(peer2_id));

        Ok(())
    }

    #[tokio::test]
    async fn test_list_active_connections_empty() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        // Test: No connections initially
        let connections = node.list_active_connections().await;
        assert!(connections.is_empty());

        Ok(())
    }

    #[tokio::test]
    async fn test_list_active_connections_with_peers() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        // Add multiple peers
        let peer1_id = "peer_1".to_string();
        let peer1_addrs = vec![
            "192.168.1.101:9001".to_string(),
            "192.168.1.101:9002".to_string(),
        ];

        let peer2_id = "peer_2".to_string();
        let peer2_addrs = vec!["192.168.1.102:9003".to_string()];

        let peer1_info = PeerInfo {
            peer_id: peer1_id.clone(),
            addresses: peer1_addrs.clone(),
            connected_at: Instant::now(),
            last_seen: Instant::now(),
            status: ConnectionStatus::Connected,
            protocols: vec!["test-protocol".to_string()],
            heartbeat_count: 0,
        };

        let peer2_info = PeerInfo {
            peer_id: peer2_id.clone(),
            addresses: peer2_addrs.clone(),
            connected_at: Instant::now(),
            last_seen: Instant::now(),
            status: ConnectionStatus::Connected,
            protocols: vec!["test-protocol".to_string()],
            heartbeat_count: 0,
        };

        node.peers
            .write()
            .await
            .insert(peer1_id.clone(), peer1_info);
        node.peers
            .write()
            .await
            .insert(peer2_id.clone(), peer2_info);

        // Test: List all active connections
        let connections = node.list_active_connections().await;
        assert_eq!(connections.len(), 2);

        // Verify peer1 and peer2 are in the list
        let peer1_conn = connections.iter().find(|(id, _)| id == &peer1_id);
        let peer2_conn = connections.iter().find(|(id, _)| id == &peer2_id);

        assert!(peer1_conn.is_some());
        assert!(peer2_conn.is_some());

        // Verify addresses match
        assert_eq!(peer1_conn.unwrap().1, peer1_addrs);
        assert_eq!(peer2_conn.unwrap().1, peer2_addrs);

        Ok(())
    }

    #[tokio::test]
    async fn test_remove_peer_success() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        // Add a peer
        let peer_id = "peer_to_remove".to_string();
        let peer_info = PeerInfo {
            peer_id: peer_id.clone(),
            addresses: vec!["192.168.1.100:9000".to_string()],
            connected_at: Instant::now(),
            last_seen: Instant::now(),
            status: ConnectionStatus::Connected,
            protocols: vec!["test-protocol".to_string()],
            heartbeat_count: 0,
        };

        node.peers.write().await.insert(peer_id.clone(), peer_info);

        // Verify peer exists
        assert!(node.is_peer_connected(&peer_id).await);

        // Remove the peer
        let removed = node.remove_peer(&peer_id).await;
        assert!(removed);

        // Verify peer no longer exists
        assert!(!node.is_peer_connected(&peer_id).await);

        Ok(())
    }

    #[tokio::test]
    async fn test_remove_peer_nonexistent() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        // Try to remove a peer that doesn't exist
        let removed = node.remove_peer(&"nonexistent_peer".to_string()).await;
        assert!(!removed);

        Ok(())
    }

    #[tokio::test]
    async fn test_is_peer_connected() -> Result<()> {
        let config = create_test_node_config();
        let node = P2PNode::new(config).await?;

        let peer_id = "test_peer".to_string();

        // Initially not connected
        assert!(!node.is_peer_connected(&peer_id).await);

        // Add peer
        let peer_info = PeerInfo {
            peer_id: peer_id.clone(),
            addresses: vec!["192.168.1.100:9000".to_string()],
            connected_at: Instant::now(),
            last_seen: Instant::now(),
            status: ConnectionStatus::Connected,
            protocols: vec!["test-protocol".to_string()],
            heartbeat_count: 0,
        };

        node.peers.write().await.insert(peer_id.clone(), peer_info);

        // Now connected
        assert!(node.is_peer_connected(&peer_id).await);

        // Remove peer
        node.remove_peer(&peer_id).await;

        // No longer connected
        assert!(!node.is_peer_connected(&peer_id).await);

        Ok(())
    }

    #[test]
    fn test_normalize_ipv6_wildcard() {
        use std::net::{IpAddr, Ipv6Addr, SocketAddr};

        let wildcard = SocketAddr::new(IpAddr::V6(Ipv6Addr::UNSPECIFIED), 8080);
        let normalized = normalize_wildcard_to_loopback(wildcard);

        assert_eq!(normalized.ip(), IpAddr::V6(Ipv6Addr::LOCALHOST));
        assert_eq!(normalized.port(), 8080);
    }

    #[test]
    fn test_normalize_ipv4_wildcard() {
        use std::net::{IpAddr, Ipv4Addr, SocketAddr};

        let wildcard = SocketAddr::new(IpAddr::V4(Ipv4Addr::UNSPECIFIED), 9000);
        let normalized = normalize_wildcard_to_loopback(wildcard);

        assert_eq!(normalized.ip(), IpAddr::V4(Ipv4Addr::LOCALHOST));
        assert_eq!(normalized.port(), 9000);
    }

    #[test]
    fn test_normalize_specific_address_unchanged() {
        let specific: std::net::SocketAddr = "192.168.1.100:3000".parse().unwrap();
        let normalized = normalize_wildcard_to_loopback(specific);

        assert_eq!(normalized, specific);
    }

    #[test]
    fn test_normalize_loopback_unchanged() {
        use std::net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr};

        let loopback_v6 = SocketAddr::new(IpAddr::V6(Ipv6Addr::LOCALHOST), 5000);
        let normalized_v6 = normalize_wildcard_to_loopback(loopback_v6);
        assert_eq!(normalized_v6, loopback_v6);

        let loopback_v4 = SocketAddr::new(IpAddr::V4(Ipv4Addr::LOCALHOST), 5000);
        let normalized_v4 = normalize_wildcard_to_loopback(loopback_v4);
        assert_eq!(normalized_v4, loopback_v4);
    }
}