//! Node lifecycle management: start, stop, and peer connection initiation.

use super::{Node, NodeError, NodeState};
use crate::node::wire::build_msg1;
use crate::peer::PeerConnection;
use crate::protocol::{Disconnect, DisconnectReason};
use crate::transport::{Link, LinkDirection, LinkId, TransportAddr, TransportId, packet_channel};
use crate::upper::tun::{TunDevice, TunState, run_tun_reader, shutdown_tun_interface};
use crate::{NodeAddr, PeerIdentity};
use std::thread;
use std::time::Duration;
use tracing::{debug, info, warn};

impl Node {
    /// Initiate connections to configured static peers.
    ///
    /// For each peer configured with AutoConnect policy, creates a link and
    /// peer entry, then starts the Noise handshake by sending the first message.
    pub(super) async fn initiate_peer_connections(&mut self) {
        // Build display name map from all configured peers (alias or short npub),
        // and pre-seed the identity cache from each peer's npub so that TUN packets
        // addressed to a configured peer can be dispatched (and trigger session
        // initiation) immediately on startup — without waiting for the link-layer
        // handshake to complete first.
        let peer_identities: Vec<(PeerIdentity, Option<String>)> = self
            .config
            .peers()
            .iter()
            .filter_map(|pc| {
                PeerIdentity::from_npub(&pc.npub)
                    .ok()
                    .map(|id| (id, pc.alias.clone()))
            })
            .collect();

        for (identity, alias) in peer_identities {
            let name = alias.unwrap_or_else(|| identity.short_npub());
            self.peer_aliases.insert(*identity.node_addr(), name);
            // Pre-seed identity cache. The parity may be wrong (npub is x-only)
            // but will be corrected to the real value when the peer is promoted
            // after a successful Noise handshake.
            self.register_identity(*identity.node_addr(), identity.pubkey_full());
        }

        // Collect peer configs to avoid borrow conflicts
        let peer_configs: Vec<_> = self.config.auto_connect_peers().cloned().collect();

        if peer_configs.is_empty() {
            debug!("No static peers configured");
            return;
        }

        debug!(
            count = peer_configs.len(),
            "Initiating static peer connections"
        );

        for peer_config in peer_configs {
            if let Err(e) = self.initiate_peer_connection(&peer_config).await {
                warn!(
                    npub = %peer_config.npub,
                    alias = ?peer_config.alias,
                    error = %e,
                    "Failed to initiate peer connection"
                );
            }
        }
    }

    /// Initiate a connection to a single peer.
    ///
    /// Creates a link, starts the Noise handshake, and sends the first message.
    pub(super) async fn initiate_peer_connection(
        &mut self,
        peer_config: &crate::config::PeerConfig,
    ) -> Result<(), NodeError> {
        // Parse the peer's npub to get their identity
        let peer_identity =
            PeerIdentity::from_npub(&peer_config.npub).map_err(|e| NodeError::InvalidPeerNpub {
                npub: peer_config.npub.clone(),
                reason: e.to_string(),
            })?;

        let peer_node_addr = *peer_identity.node_addr();

        // Check if peer already exists (fully authenticated)
        if self.peers.contains_key(&peer_node_addr) {
            debug!(
                npub = %peer_config.npub,
                "Peer already exists, skipping"
            );
            return Ok(());
        }

        // Check if connection already in progress to this peer
        let already_connecting = self.connections.values().any(|conn| {
            conn.expected_identity()
                .map(|id| id.node_addr() == &peer_node_addr)
                .unwrap_or(false)
        });
        if already_connecting {
            debug!(
                npub = %peer_config.npub,
                "Connection already in progress, skipping"
            );
            return Ok(());
        }

        // Try addresses in priority order until one works
        for addr in peer_config.addresses_by_priority() {
            // For Ethernet addresses ("interface/mac"), find the transport
            // instance matching the interface name and parse the MAC.
            let (transport_id, remote_addr) = if addr.transport == "ethernet" {
                match self.resolve_ethernet_addr(&addr.addr) {
                    Ok(result) => result,
                    Err(e) => {
                        debug!(
                            transport = %addr.transport,
                            addr = %addr.addr,
                            error = %e,
                            "Failed to resolve Ethernet address"
                        );
                        continue;
                    }
                }
            } else if addr.transport == "ble" {
                #[cfg(target_os = "linux")]
                {
                    match self.resolve_ble_addr(&addr.addr) {
                        Ok(result) => result,
                        Err(e) => {
                            debug!(
                                transport = %addr.transport,
                                addr = %addr.addr,
                                error = %e,
                                "Failed to resolve BLE address"
                            );
                            continue;
                        }
                    }
                }
                #[cfg(not(target_os = "linux"))]
                {
                    debug!(
                        transport = %addr.transport,
                        "BLE transport not available on this platform"
                    );
                    continue;
                }
            } else {
                // Find a transport matching this address type
                let tid = match self.find_transport_for_type(&addr.transport) {
                    Some(id) => id,
                    None => {
                        debug!(
                            transport = %addr.transport,
                            addr = %addr.addr,
                            "No operational transport for address type"
                        );
                        continue;
                    }
                };
                (tid, TransportAddr::from_string(&addr.addr))
            };

            match self
                .initiate_connection(transport_id, remote_addr, peer_identity)
                .await
            {
                Ok(()) => return Ok(()),
                Err(e) => {
                    debug!(
                        npub = %peer_config.npub,
                        transport_id = %transport_id,
                        error = %e,
                        "Connection attempt failed, trying next address"
                    );
                    continue;
                }
            }
        }

        // No address worked
        Err(NodeError::NoTransportForType(format!(
            "no operational transport for any of {}'s addresses",
            peer_config.npub
        )))
    }

    /// Initiate a connection to a peer on a specific transport and address.
    ///
    /// For connectionless transports (UDP, Ethernet): allocates a link, starts
    /// the Noise IK handshake, sends msg1, and registers the connection for
    /// msg2 dispatch.
    ///
    /// For connection-oriented transports (TCP, Tor): allocates a link and
    /// starts a non-blocking transport connect. The handshake is deferred
    /// until the transport connection is established — the tick handler
    /// polls `connection_state()` and initiates the handshake when ready.
    pub(super) async fn initiate_connection(
        &mut self,
        transport_id: TransportId,
        remote_addr: TransportAddr,
        peer_identity: PeerIdentity,
    ) -> Result<(), NodeError> {
        let peer_node_addr = *peer_identity.node_addr();

        let is_connection_oriented = self
            .transports
            .get(&transport_id)
            .map(|t| t.transport_type().connection_oriented)
            .unwrap_or(false);

        // Allocate link ID and create link
        let link_id = self.allocate_link_id();

        let link = if is_connection_oriented {
            Link::new(
                link_id,
                transport_id,
                remote_addr.clone(),
                LinkDirection::Outbound,
                Duration::from_millis(self.config.node.base_rtt_ms),
            )
        } else {
            Link::connectionless(
                link_id,
                transport_id,
                remote_addr.clone(),
                LinkDirection::Outbound,
                Duration::from_millis(self.config.node.base_rtt_ms),
            )
        };

        self.links.insert(link_id, link);

        // Add reverse lookup for packet dispatch
        self.addr_to_link
            .insert((transport_id, remote_addr.clone()), link_id);

        if is_connection_oriented {
            // Connection-oriented: start non-blocking connect, defer handshake
            if let Some(transport) = self.transports.get(&transport_id) {
                match transport.connect(&remote_addr).await {
                    Ok(()) => {
                        debug!(
                            peer = %self.peer_display_name(&peer_node_addr),
                            transport_id = %transport_id,
                            remote_addr = %remote_addr,
                            link_id = %link_id,
                            "Transport connect initiated (non-blocking)"
                        );
                        self.pending_connects.push(super::PendingConnect {
                            link_id,
                            transport_id,
                            remote_addr,
                            peer_identity,
                        });
                    }
                    Err(e) => {
                        // Clean up link
                        self.links.remove(&link_id);
                        self.addr_to_link.remove(&(transport_id, remote_addr));
                        return Err(NodeError::TransportError(e.to_string()));
                    }
                }
            }
            Ok(())
        } else {
            // Connectionless: proceed with immediate handshake
            self.start_handshake(link_id, transport_id, remote_addr, peer_identity)
                .await
        }
    }

    /// Start the Noise handshake on a link and send msg1.
    ///
    /// Called immediately for connectionless transports, or after the
    /// transport connection is established for connection-oriented transports.
    pub(super) async fn start_handshake(
        &mut self,
        link_id: LinkId,
        transport_id: TransportId,
        remote_addr: TransportAddr,
        peer_identity: PeerIdentity,
    ) -> Result<(), NodeError> {
        let peer_node_addr = *peer_identity.node_addr();

        // Create connection in handshake phase (outbound knows expected identity)
        let current_time_ms = std::time::SystemTime::now()
            .duration_since(std::time::UNIX_EPOCH)
            .map(|d| d.as_millis() as u64)
            .unwrap_or(0);
        let mut connection = PeerConnection::outbound(link_id, peer_identity, current_time_ms);

        // Allocate a session index for this handshake
        let our_index = match self.index_allocator.allocate() {
            Ok(idx) => idx,
            Err(e) => {
                // Clean up the link we just created
                self.links.remove(&link_id);
                self.addr_to_link.remove(&(transport_id, remote_addr));
                return Err(NodeError::IndexAllocationFailed(e.to_string()));
            }
        };

        // Start the Noise handshake and get message 1
        let our_keypair = self.identity.keypair();
        let noise_msg1 =
            match connection.start_handshake(our_keypair, self.startup_epoch, current_time_ms) {
                Ok(msg) => msg,
                Err(e) => {
                    // Clean up the index and link
                    let _ = self.index_allocator.free(our_index);
                    self.links.remove(&link_id);
                    self.addr_to_link.remove(&(transport_id, remote_addr));
                    return Err(NodeError::HandshakeFailed(e.to_string()));
                }
            };

        // Set index and transport info on the connection
        connection.set_our_index(our_index);
        connection.set_transport_id(transport_id);
        connection.set_source_addr(remote_addr.clone());

        // Build wire format msg1: [0x01][sender_idx:4 LE][noise_msg1:82]
        let wire_msg1 = build_msg1(our_index, &noise_msg1);

        debug!(
            peer = %self.peer_display_name(&peer_node_addr),
            transport_id = %transport_id,
            remote_addr = %remote_addr,
            link_id = %link_id,
            our_index = %our_index,
            "Connection initiated"
        );

        // Store msg1 for resend and schedule first resend
        let resend_interval = self.config.node.rate_limit.handshake_resend_interval_ms;
        connection.set_handshake_msg1(wire_msg1.clone(), current_time_ms + resend_interval);

        // Track in pending_outbound for msg2 dispatch
        self.pending_outbound
            .insert((transport_id, our_index.as_u32()), link_id);
        self.connections.insert(link_id, connection);

        // Send the wire format handshake message
        if let Some(transport) = self.transports.get(&transport_id) {
            match transport.send(&remote_addr, &wire_msg1).await {
                Ok(bytes) => {
                    debug!(
                        link_id = %link_id,
                        our_index = %our_index,
                        bytes,
                        "Sent Noise handshake message 1 (wire format)"
                    );
                }
                Err(e) => {
                    warn!(
                        link_id = %link_id,
                        error = %e,
                        "Failed to send handshake message"
                    );
                    // Mark connection as failed but don't remove it yet
                    // The event loop can handle retry logic
                    if let Some(conn) = self.connections.get_mut(&link_id) {
                        conn.mark_failed();
                    }
                }
            }
        }

        Ok(())
    }

    /// Poll all transports for discovered peers and auto-connect.
    ///
    /// Called from the tick handler. Iterates operational transports,
    /// drains their discovery buffers, and initiates connections to
    /// newly discovered peers (if auto_connect is enabled).
    pub(super) async fn poll_transport_discovery(&mut self) {
        // Collect discoveries first to avoid borrow conflict with self
        let mut to_connect = Vec::new();

        for (transport_id, transport) in &self.transports {
            if !transport.is_operational() {
                continue;
            }
            if !transport.auto_connect() {
                // Still drain the buffer so it doesn't grow unbounded
                let _ = transport.discover();
                continue;
            }
            let discovered = match transport.discover() {
                Ok(peers) => peers,
                Err(_) => continue,
            };
            for peer in discovered {
                let pubkey = match peer.pubkey_hint {
                    Some(pk) => pk,
                    None => continue,
                };
                let identity = PeerIdentity::from_pubkey(pubkey);
                let node_addr = *identity.node_addr();

                // Skip self
                if node_addr == *self.identity.node_addr() {
                    continue;
                }
                // Skip if already connected
                if self.peers.contains_key(&node_addr) {
                    continue;
                }
                // Skip if connection already in progress
                let connecting = self.connections.values().any(|c| {
                    c.expected_identity()
                        .map(|id| id.node_addr() == &node_addr)
                        .unwrap_or(false)
                });
                if connecting {
                    continue;
                }

                to_connect.push((*transport_id, peer.addr, identity));
            }
        }

        for (transport_id, remote_addr, identity) in to_connect {
            info!(
                peer = %self.peer_display_name(identity.node_addr()),
                transport_id = %transport_id,
                remote_addr = %remote_addr,
                "Auto-connecting to discovered peer"
            );
            if let Err(e) = self
                .initiate_connection(transport_id, remote_addr, identity)
                .await
            {
                warn!(error = %e, "Failed to auto-connect to discovered peer");
            }
        }
    }

    /// Poll pending transport connects and initiate handshakes for ready ones.
    ///
    /// Called from the tick handler. For each pending connect, queries the
    /// transport's connection state. When a connection is established,
    /// marks the link as Connected and starts the Noise handshake.
    /// Failed connections are cleaned up and scheduled for retry.
    pub(super) async fn poll_pending_connects(&mut self) {
        if self.pending_connects.is_empty() {
            return;
        }

        let mut completed = Vec::new();

        for (i, pending) in self.pending_connects.iter().enumerate() {
            let state = if let Some(transport) = self.transports.get(&pending.transport_id) {
                transport.connection_state(&pending.remote_addr)
            } else {
                crate::transport::ConnectionState::Failed("transport removed".into())
            };

            match state {
                crate::transport::ConnectionState::Connected => {
                    completed.push((i, true, None));
                }
                crate::transport::ConnectionState::Failed(reason) => {
                    completed.push((i, false, Some(reason)));
                }
                crate::transport::ConnectionState::Connecting => {
                    // Still in progress, check on next tick
                }
                crate::transport::ConnectionState::None => {
                    // Shouldn't happen — treat as failure
                    completed.push((i, false, Some("no connection attempt found".into())));
                }
            }
        }

        // Process completions in reverse order to preserve indices
        for (i, success, reason) in completed.into_iter().rev() {
            let pending = self.pending_connects.remove(i);

            if success {
                // Mark link as Connected
                if let Some(link) = self.links.get_mut(&pending.link_id) {
                    link.set_connected();
                }

                debug!(
                    peer = %self.peer_display_name(pending.peer_identity.node_addr()),
                    transport_id = %pending.transport_id,
                    remote_addr = %pending.remote_addr,
                    link_id = %pending.link_id,
                    "Transport connected, starting handshake"
                );

                // Start the handshake now that the transport is connected
                if let Err(e) = self
                    .start_handshake(
                        pending.link_id,
                        pending.transport_id,
                        pending.remote_addr.clone(),
                        pending.peer_identity,
                    )
                    .await
                {
                    warn!(
                        link_id = %pending.link_id,
                        error = %e,
                        "Failed to start handshake after transport connect"
                    );
                    // Clean up link on handshake failure
                    self.remove_link(&pending.link_id);
                }
            } else {
                let reason = reason.unwrap_or_default();
                warn!(
                    peer = %self.peer_display_name(pending.peer_identity.node_addr()),
                    transport_id = %pending.transport_id,
                    remote_addr = %pending.remote_addr,
                    link_id = %pending.link_id,
                    reason = %reason,
                    "Transport connect failed"
                );

                // Clean up link and schedule retry
                self.remove_link(&pending.link_id);
                self.links.remove(&pending.link_id);
                let now_ms = std::time::SystemTime::now()
                    .duration_since(std::time::UNIX_EPOCH)
                    .map(|d| d.as_millis() as u64)
                    .unwrap_or(0);
                self.schedule_retry(*pending.peer_identity.node_addr(), now_ms);
            }
        }
    }

    // === State Transitions ===

    /// Start the node.
    ///
    /// Initializes the TUN interface (if configured), spawns I/O threads,
    /// and transitions to the Running state.
    pub async fn start(&mut self) -> Result<(), NodeError> {
        if !self.state.can_start() {
            return Err(NodeError::AlreadyStarted);
        }
        self.state = NodeState::Starting;

        // Create packet channel for transport -> Node communication
        let packet_buffer_size = self.config.node.buffers.packet_channel;
        let (packet_tx, packet_rx) = packet_channel(packet_buffer_size);
        self.packet_tx = Some(packet_tx.clone());
        self.packet_rx = Some(packet_rx);

        // Initialize transports first (before TUN)
        let transport_handles = self.create_transports(&packet_tx).await;

        for mut handle in transport_handles {
            let transport_id = handle.transport_id();
            let transport_type = handle.transport_type().name;
            let name = handle.name().map(|s| s.to_string());

            match handle.start().await {
                Ok(()) => {
                    self.transports.insert(transport_id, handle);
                }
                Err(e) => {
                    if let Some(ref n) = name {
                        warn!(transport_type, name = %n, error = %e, "Transport failed to start");
                    } else {
                        warn!(transport_type, error = %e, "Transport failed to start");
                    }
                }
            }
        }

        if !self.transports.is_empty() {
            info!(count = self.transports.len(), "Transports initialized");
        }

        // Connect to static peers before TUN is active
        // This allows handshake messages to be sent before we start accepting packets
        self.initiate_peer_connections().await;

        // Initialize TUN interface last, after transports and peers are ready
        if self.config.tun.enabled {
            let address = *self.identity.address();
            match TunDevice::create(&self.config.tun, address).await {
                Ok(device) => {
                    let mtu = device.mtu();
                    let name = device.name().to_string();
                    let our_addr = *device.address();

                    info!("TUN device active:");
                    info!("     name: {}", name);
                    info!("  address: {}", device.address());
                    info!("      mtu: {}", mtu);

                    // Calculate max MSS for TCP clamping
                    let effective_mtu = self.effective_ipv6_mtu();
                    let max_mss = effective_mtu.saturating_sub(40).saturating_sub(20); // IPv6 + TCP headers

                    info!("effective MTU: {} bytes", effective_mtu);
                    debug!("   max TCP MSS: {} bytes", max_mss);

                    // On macOS, create a shutdown pipe. Writing to it unblocks the
                    // reader thread's select() loop without closing the TUN fd
                    // (which would cause a double-close when TunDevice drops).
                    #[cfg(target_os = "macos")]
                    let (shutdown_read_fd, shutdown_write_fd) = {
                        let mut fds = [0i32; 2];
                        if unsafe { libc::pipe(fds.as_mut_ptr()) } < 0 {
                            return Err(NodeError::Tun(crate::upper::tun::TunError::Configure(
                                "failed to create shutdown pipe".into(),
                            )));
                        }
                        (fds[0], fds[1])
                    };

                    // Create writer (dups the fd for independent write access)
                    let (writer, tun_tx) = device.create_writer(max_mss)?;

                    // Spawn writer thread
                    let writer_handle = thread::spawn(move || {
                        writer.run();
                    });

                    // Clone tun_tx for the reader
                    let reader_tun_tx = tun_tx.clone();

                    // Create outbound channel for TUN reader → Node
                    let tun_channel_size = self.config.node.buffers.tun_channel;
                    let (outbound_tx, outbound_rx) = tokio::sync::mpsc::channel(tun_channel_size);

                    // Spawn reader thread
                    let transport_mtu = self.transport_mtu();
                    #[cfg(target_os = "macos")]
                    let reader_handle = thread::spawn(move || {
                        run_tun_reader(
                            device,
                            mtu,
                            our_addr,
                            reader_tun_tx,
                            outbound_tx,
                            transport_mtu,
                            shutdown_read_fd,
                        );
                    });
                    #[cfg(not(target_os = "macos"))]
                    let reader_handle = thread::spawn(move || {
                        run_tun_reader(
                            device,
                            mtu,
                            our_addr,
                            reader_tun_tx,
                            outbound_tx,
                            transport_mtu,
                        );
                    });

                    self.tun_state = TunState::Active;
                    self.tun_name = Some(name);
                    self.tun_tx = Some(tun_tx);
                    self.tun_outbound_rx = Some(outbound_rx);
                    self.tun_reader_handle = Some(reader_handle);
                    self.tun_writer_handle = Some(writer_handle);
                    #[cfg(target_os = "macos")]
                    {
                        self.tun_shutdown_fd = Some(shutdown_write_fd);
                    }
                }
                Err(e) => {
                    self.tun_state = TunState::Failed;
                    warn!(error = %e, "Failed to initialize TUN, continuing without it");
                }
            }
        }

        // Initialize DNS responder (independent of TUN)
        if self.config.dns.enabled {
            let bind = format!("{}:{}", self.config.dns.bind_addr(), self.config.dns.port());
            match tokio::net::UdpSocket::bind(&bind).await {
                Ok(socket) => {
                    let dns_channel_size = self.config.node.buffers.dns_channel;
                    let (identity_tx, identity_rx) = tokio::sync::mpsc::channel(dns_channel_size);
                    let dns_ttl = self.config.dns.ttl();
                    let base_hosts =
                        crate::upper::hosts::HostMap::from_peer_configs(self.config.peers());
                    let hosts_path =
                        std::path::PathBuf::from(crate::upper::hosts::DEFAULT_HOSTS_PATH);
                    let reloader =
                        crate::upper::hosts::HostMapReloader::new(base_hosts, hosts_path);
                    info!(bind = %bind, hosts = reloader.hosts().len(), "DNS responder started for .fips domain (auto-reload enabled)");
                    let handle = tokio::spawn(crate::upper::dns::run_dns_responder(
                        socket,
                        identity_tx,
                        dns_ttl,
                        reloader,
                    ));
                    self.dns_identity_rx = Some(identity_rx);
                    self.dns_task = Some(handle);
                }
                Err(e) => {
                    warn!(bind = %bind, error = %e, "Failed to start DNS responder");
                }
            }
        }

        self.state = NodeState::Running;
        info!("Node started:");
        info!("       state: {}", self.state);
        info!("  transports: {}", self.transports.len());
        info!(" connections: {}", self.connections.len());
        Ok(())
    }

    /// Stop the node.
    ///
    /// Shuts down TUN interface, stops I/O threads, and transitions to
    /// the Stopped state.
    pub async fn stop(&mut self) -> Result<(), NodeError> {
        if !self.state.can_stop() {
            return Err(NodeError::NotStarted);
        }
        self.state = NodeState::Stopping;
        info!(state = %self.state, "Node stopping");

        // Stop DNS responder
        if let Some(handle) = self.dns_task.take() {
            handle.abort();
            debug!("DNS responder stopped");
        }

        // Send disconnect notifications to all active peers before closing transports
        self.send_disconnect_to_all_peers(DisconnectReason::Shutdown)
            .await;

        // Shutdown transports (they're packet producers)
        let transport_ids: Vec<_> = self.transports.keys().cloned().collect();
        for transport_id in transport_ids {
            if let Some(mut handle) = self.transports.remove(&transport_id) {
                let transport_type = handle.transport_type().name;
                match handle.stop().await {
                    Ok(()) => {
                        info!(transport_id = %transport_id, transport_type, "Transport stopped");
                    }
                    Err(e) => {
                        warn!(
                            transport_id = %transport_id,
                            transport_type,
                            error = %e,
                            "Transport stop failed"
                        );
                    }
                }
            }
        }

        // Drop packet channels
        self.packet_tx.take();
        self.packet_rx.take();

        // Shutdown TUN interface
        if let Some(name) = self.tun_name.take() {
            info!(name = %name, "Shutting down TUN interface");

            // Drop the tun_tx to signal the writer to stop
            self.tun_tx.take();

            // Delete the interface (on Linux, causes reader to get EFAULT)
            if let Err(e) = shutdown_tun_interface(&name).await {
                warn!(name = %name, error = %e, "Failed to shutdown TUN interface");
            }

            // On macOS, signal the reader thread to exit by writing to the
            // shutdown pipe. The reader's select() will wake up and break.
            #[cfg(target_os = "macos")]
            if let Some(fd) = self.tun_shutdown_fd.take() {
                unsafe {
                    libc::write(fd, b"x".as_ptr() as *const libc::c_void, 1);
                    libc::close(fd);
                }
            }

            // Wait for threads to finish
            if let Some(handle) = self.tun_reader_handle.take() {
                let _ = handle.join();
            }
            if let Some(handle) = self.tun_writer_handle.take() {
                let _ = handle.join();
            }

            self.tun_state = TunState::Disabled;
        }

        self.state = NodeState::Stopped;
        info!(state = %self.state, "Node stopped");
        Ok(())
    }

    /// Send disconnect notifications to all active peers.
    ///
    /// Best-effort: send failures are logged and ignored since the transport
    /// may already be degraded. This runs before transports are shut down.
    async fn send_disconnect_to_all_peers(&mut self, reason: DisconnectReason) {
        let disconnect = Disconnect::new(reason);
        let plaintext = disconnect.encode();

        // Collect node_addrs to avoid borrow conflict with send helper
        let peer_addrs: Vec<NodeAddr> = self
            .peers
            .iter()
            .filter(|(_, peer)| peer.can_send() && peer.has_session())
            .map(|(addr, _)| *addr)
            .collect();

        if peer_addrs.is_empty() {
            debug!(
                total_peers = self.peers.len(),
                "No sendable peers for disconnect notification"
            );
            return;
        }

        let mut sent = 0usize;
        for node_addr in &peer_addrs {
            match self
                .send_encrypted_link_message(node_addr, &plaintext)
                .await
            {
                Ok(()) => sent += 1,
                Err(e) => {
                    debug!(
                        peer = %self.peer_display_name(node_addr),
                        error = %e,
                        "Failed to send disconnect (transport may be down)"
                    );
                }
            }
        }

        info!(sent, total = peer_addrs.len(), reason = %reason, "Sent disconnect notifications");
    }

    // === Control API methods ===

    /// Connect to a peer via the control API.
    ///
    /// Creates an ephemeral peer connection (not persisted to config, no
    /// auto-reconnect). Reuses the same connection path as auto-connect
    /// peers. Returns JSON data on success or an error message.
    pub(crate) async fn api_connect(
        &mut self,
        npub: &str,
        address: &str,
        transport: &str,
    ) -> Result<serde_json::Value, String> {
        let peer_config = crate::config::PeerConfig {
            npub: npub.to_string(),
            alias: None,
            addresses: vec![crate::config::PeerAddress::new(transport, address)],
            connect_policy: crate::config::ConnectPolicy::Manual,
            auto_reconnect: false,
        };

        // Pre-seed identity cache (same as initiate_peer_connections does)
        if let Ok(identity) = PeerIdentity::from_npub(npub) {
            self.peer_aliases
                .insert(*identity.node_addr(), identity.short_npub());
            self.register_identity(*identity.node_addr(), identity.pubkey_full());
        }

        self.initiate_peer_connection(&peer_config)
            .await
            .map(|()| {
                info!(
                    npub = %npub,
                    address = %address,
                    transport = %transport,
                    "API connect initiated"
                );
                serde_json::json!({
                    "npub": npub,
                    "address": address,
                    "transport": transport,
                })
            })
            .map_err(|e| e.to_string())
    }

    /// Disconnect a peer via the control API.
    ///
    /// Removes the peer and suppresses auto-reconnect.
    pub(crate) fn api_disconnect(&mut self, npub: &str) -> Result<serde_json::Value, String> {
        let peer_identity =
            PeerIdentity::from_npub(npub).map_err(|e| format!("invalid npub '{npub}': {e}"))?;
        let node_addr = *peer_identity.node_addr();

        if !self.peers.contains_key(&node_addr) {
            return Err(format!("peer not found: {npub}"));
        }

        // Remove the peer (full cleanup: sessions, indices, links, tree, bloom)
        self.remove_active_peer(&node_addr);

        // Suppress any pending auto-reconnect
        self.retry_pending.remove(&node_addr);

        info!(npub = %npub, "API disconnect completed");

        Ok(serde_json::json!({
            "npub": npub,
            "disconnected": true,
        }))
    }
}