//! This module handles incoming network messages.
//!
//! It routes the messages to appropriate services.
//! It handles requests at the application layer in its associated processor and directs
//! syncing-related responses to the Sync manager.
#![allow(clippy::unit_arg)]

use crate::network_beacon_processor::{InvalidBlockStorage, NetworkBeaconProcessor};
use crate::service::NetworkMessage;
use crate::status::status_message;
use crate::sync::SyncMessage;
use beacon_chain::{BeaconChain, BeaconChainTypes};
use beacon_processor::{BeaconProcessorSend, DuplicateCache};
use futures::prelude::*;
use lighthouse_network::rpc::*;
use lighthouse_network::{
    MessageId, NetworkGlobals, PeerId, PubsubMessage, Response,
    service::api_types::{AppRequestId, SyncRequestId},
};
use logging::TimeLatch;
use logging::crit;
use std::sync::Arc;
use std::time::{Duration, SystemTime, UNIX_EPOCH};
use tokio::sync::mpsc;
use tokio_stream::wrappers::UnboundedReceiverStream;
use tracing::{debug, error, trace, warn};
use types::{BlobSidecar, DataColumnSidecar, EthSpec, ForkContext, SignedBeaconBlock};

/// Handles messages from the network and routes them to the appropriate service to be handled.
pub struct Router<T: BeaconChainTypes> {
    /// Access to the peer db and network information.
    network_globals: Arc<NetworkGlobals<T::EthSpec>>,
    /// A reference to the underlying beacon chain.
    chain: Arc<BeaconChain<T>>,
    /// A channel to the syncing thread.
    sync_send: mpsc::UnboundedSender<SyncMessage<T::EthSpec>>,
    /// A network context to return and handle RPC requests.
    network: HandlerNetworkContext<T::EthSpec>,
    /// A multi-threaded, non-blocking processor for applying messages to the beacon chain.
    network_beacon_processor: Arc<NetworkBeaconProcessor<T>>,
    /// Provides de-bounce functionality for logging.
    logger_debounce: TimeLatch,
}

/// Types of messages the router can receive.
#[derive(Debug)]
pub enum RouterMessage<E: EthSpec> {
    /// Peer has disconnected.
    PeerDisconnected(PeerId),
    /// An RPC request has been received.
    RPCRequestReceived {
        peer_id: PeerId,
        inbound_request_id: InboundRequestId,
        request_type: RequestType<E>,
    },
    /// An RPC response has been received.
    RPCResponseReceived {
        peer_id: PeerId,
        app_request_id: AppRequestId,
        response: Response<E>,
    },
    /// An RPC request failed
    RPCFailed {
        peer_id: PeerId,
        app_request_id: AppRequestId,
        error: RPCError,
    },
    /// A gossip message has been received. The fields are: message id, the peer that sent us this
    /// message, the message itself and a bool which indicates if the message should be processed
    /// by the beacon chain after successful verification.
    PubsubMessage(MessageId, PeerId, PubsubMessage<E>, bool),
    /// The peer manager has requested we re-status a peer.
    StatusPeer(PeerId),
    /// The peer has an updated custody group count from METADATA.
    PeerUpdatedCustodyGroupCount(PeerId),
}

impl<T: BeaconChainTypes> Router<T> {
    /// Initializes and runs the Router.
    #[allow(clippy::too_many_arguments)]
    pub fn spawn(
        beacon_chain: Arc<BeaconChain<T>>,
        network_globals: Arc<NetworkGlobals<T::EthSpec>>,
        network_send: mpsc::UnboundedSender<NetworkMessage<T::EthSpec>>,
        executor: task_executor::TaskExecutor,
        invalid_block_storage: InvalidBlockStorage,
        beacon_processor_send: BeaconProcessorSend<T::EthSpec>,
        fork_context: Arc<ForkContext>,
    ) -> Result<mpsc::UnboundedSender<RouterMessage<T::EthSpec>>, String> {
        trace!("Service starting");

        let (handler_send, handler_recv) = mpsc::unbounded_channel();

        // generate the message channel
        let (sync_send, sync_recv) = mpsc::unbounded_channel::<SyncMessage<T::EthSpec>>();

        let network_beacon_processor = NetworkBeaconProcessor {
            beacon_processor_send,
            duplicate_cache: DuplicateCache::default(),
            chain: beacon_chain.clone(),
            network_tx: network_send.clone(),
            sync_tx: sync_send.clone(),
            network_globals: network_globals.clone(),
            invalid_block_storage,
            executor: executor.clone(),
        };
        let network_beacon_processor = Arc::new(network_beacon_processor);

        // spawn the sync thread
        crate::sync::manager::spawn(
            executor.clone(),
            beacon_chain.clone(),
            network_send.clone(),
            network_beacon_processor.clone(),
            sync_recv,
            fork_context,
        );

        // generate the Message handler
        let mut handler = Router {
            network_globals,
            chain: beacon_chain,
            sync_send,
            network: HandlerNetworkContext::new(network_send),
            network_beacon_processor,
            logger_debounce: TimeLatch::default(),
        };

        // spawn handler task and move the message handler instance into the spawned thread
        executor.spawn(
            async move {
                debug!("Network message router started");
                UnboundedReceiverStream::new(handler_recv)
                    .for_each(move |msg| future::ready(handler.handle_message(msg)))
                    .await;
            },
            "router",
        );

        Ok(handler_send)
    }

    /// Handle all messages incoming from the network service.
    fn handle_message(&mut self, message: RouterMessage<T::EthSpec>) {
        match message {
            // we have initiated a connection to a peer or the peer manager has requested a
            // re-status
            RouterMessage::StatusPeer(peer_id) => {
                self.send_status(peer_id);
            }
            // A peer has disconnected
            RouterMessage::PeerDisconnected(peer_id) => {
                self.send_to_sync(SyncMessage::Disconnect(peer_id));
            }
            // A peer has updated CGC
            RouterMessage::PeerUpdatedCustodyGroupCount(peer_id) => {
                self.send_to_sync(SyncMessage::UpdatedPeerCgc(peer_id));
            }
            RouterMessage::RPCRequestReceived {
                peer_id,
                inbound_request_id,
                request_type,
            } => {
                self.handle_rpc_request(peer_id, inbound_request_id, request_type);
            }
            RouterMessage::RPCResponseReceived {
                peer_id,
                app_request_id,
                response,
            } => {
                self.handle_rpc_response(peer_id, app_request_id, response);
            }
            RouterMessage::RPCFailed {
                peer_id,
                app_request_id,
                error,
            } => {
                self.on_rpc_error(peer_id, app_request_id, error);
            }
            RouterMessage::PubsubMessage(id, peer_id, gossip, should_process) => {
                self.handle_gossip(id, peer_id, gossip, should_process);
            }
        }
    }

    /* RPC - Related functionality */

    /// A new RPC request has been received from the network.
    fn handle_rpc_request(
        &mut self,
        peer_id: PeerId,
        inbound_request_id: InboundRequestId, // Use ResponseId here
        request_type: RequestType<T::EthSpec>,
    ) {
        if !self.network_globals.peers.read().is_connected(&peer_id) {
            debug!(%peer_id, request = ?request_type, "Dropping request of disconnected peer");
            return;
        }
        match request_type {
            RequestType::Status(status_message) => {
                self.on_status_request(peer_id, inbound_request_id, status_message)
            }
            RequestType::BlocksByRange(request) => {
                let mut count = *request.count();
                if *request.step() > 1 {
                    count = 1;
                }
                let blocks_request = match request {
                    methods::OldBlocksByRangeRequest::V1(req) => {
                        BlocksByRangeRequest::new_v1(req.start_slot, count)
                    }
                    methods::OldBlocksByRangeRequest::V2(req) => {
                        BlocksByRangeRequest::new(req.start_slot, count)
                    }
                };

                self.handle_beacon_processor_send_result(
                    self.network_beacon_processor.send_blocks_by_range_request(
                        peer_id,
                        inbound_request_id,
                        blocks_request,
                    ),
                )
            }
            RequestType::BlocksByRoot(request) => self.handle_beacon_processor_send_result(
                self.network_beacon_processor.send_blocks_by_roots_request(
                    peer_id,
                    inbound_request_id,
                    request,
                ),
            ),
            RequestType::BlobsByRange(request) => self.handle_beacon_processor_send_result(
                self.network_beacon_processor.send_blobs_by_range_request(
                    peer_id,
                    inbound_request_id,
                    request,
                ),
            ),
            RequestType::BlobsByRoot(request) => self.handle_beacon_processor_send_result(
                self.network_beacon_processor.send_blobs_by_roots_request(
                    peer_id,
                    inbound_request_id,
                    request,
                ),
            ),
            RequestType::DataColumnsByRoot(request) => self.handle_beacon_processor_send_result(
                self.network_beacon_processor
                    .send_data_columns_by_roots_request(peer_id, inbound_request_id, request),
            ),
            RequestType::DataColumnsByRange(request) => self.handle_beacon_processor_send_result(
                self.network_beacon_processor
                    .send_data_columns_by_range_request(peer_id, inbound_request_id, request),
            ),
            RequestType::LightClientBootstrap(request) => self.handle_beacon_processor_send_result(
                self.network_beacon_processor
                    .send_light_client_bootstrap_request(peer_id, inbound_request_id, request),
            ),
            RequestType::LightClientOptimisticUpdate => self.handle_beacon_processor_send_result(
                self.network_beacon_processor
                    .send_light_client_optimistic_update_request(peer_id, inbound_request_id),
            ),
            RequestType::LightClientFinalityUpdate => self.handle_beacon_processor_send_result(
                self.network_beacon_processor
                    .send_light_client_finality_update_request(peer_id, inbound_request_id),
            ),
            RequestType::LightClientUpdatesByRange(request) => self
                .handle_beacon_processor_send_result(
                    self.network_beacon_processor
                        .send_light_client_updates_by_range_request(
                            peer_id,
                            inbound_request_id,
                            request,
                        ),
                ),
            _ => {}
        }
    }

    /// An RPC response has been received from the network.
    fn handle_rpc_response(
        &mut self,
        peer_id: PeerId,
        app_request_id: AppRequestId,
        response: Response<T::EthSpec>,
    ) {
        match response {
            Response::Status(status_message) => {
                debug!(%peer_id, ?status_message,"Received Status Response");
                self.handle_beacon_processor_send_result(
                    self.network_beacon_processor
                        .send_status_message(peer_id, status_message),
                )
            }
            Response::BlocksByRange(beacon_block) => {
                self.on_blocks_by_range_response(peer_id, app_request_id, beacon_block);
            }
            Response::BlocksByRoot(beacon_block) => {
                self.on_blocks_by_root_response(peer_id, app_request_id, beacon_block);
            }
            Response::BlobsByRange(blob) => {
                self.on_blobs_by_range_response(peer_id, app_request_id, blob);
            }
            Response::BlobsByRoot(blob) => {
                self.on_blobs_by_root_response(peer_id, app_request_id, blob);
            }
            Response::DataColumnsByRoot(data_column) => {
                self.on_data_columns_by_root_response(peer_id, app_request_id, data_column);
            }
            Response::DataColumnsByRange(data_column) => {
                self.on_data_columns_by_range_response(peer_id, app_request_id, data_column);
            }
            // Light client responses should not be received
            Response::LightClientBootstrap(_)
            | Response::LightClientOptimisticUpdate(_)
            | Response::LightClientFinalityUpdate(_)
            | Response::LightClientUpdatesByRange(_) => unreachable!(),
        }
    }

    /// Handle RPC messages.
    /// Note: `should_process` is currently only useful for the `Attestation` variant.
    /// if `should_process` is `false`, we only propagate the message on successful verification,
    /// else, we propagate **and** import into the beacon chain.
    fn handle_gossip(
        &mut self,
        message_id: MessageId,
        peer_id: PeerId,
        gossip_message: PubsubMessage<T::EthSpec>,
        should_process: bool,
    ) {
        match gossip_message {
            PubsubMessage::AggregateAndProofAttestation(aggregate_and_proof) => self
                .handle_beacon_processor_send_result(
                    self.network_beacon_processor.send_aggregated_attestation(
                        message_id,
                        peer_id,
                        *aggregate_and_proof,
                        timestamp_now(),
                    ),
                ),
            PubsubMessage::Attestation(subnet_attestation) => self
                .handle_beacon_processor_send_result(
                    self.network_beacon_processor.send_unaggregated_attestation(
                        message_id,
                        peer_id,
                        subnet_attestation.1,
                        subnet_attestation.0,
                        should_process,
                        timestamp_now(),
                    ),
                ),
            PubsubMessage::BeaconBlock(block) => self.handle_beacon_processor_send_result(
                self.network_beacon_processor.send_gossip_beacon_block(
                    message_id,
                    peer_id,
                    self.network_globals.client(&peer_id),
                    block,
                    timestamp_now(),
                ),
            ),
            PubsubMessage::BlobSidecar(data) => {
                let (blob_index, blob_sidecar) = *data;
                self.handle_beacon_processor_send_result(
                    self.network_beacon_processor.send_gossip_blob_sidecar(
                        message_id,
                        peer_id,
                        self.network_globals.client(&peer_id),
                        blob_index,
                        blob_sidecar,
                        timestamp_now(),
                    ),
                )
            }
            PubsubMessage::DataColumnSidecar(data) => {
                let (subnet_id, column_sidecar) = *data;
                self.handle_beacon_processor_send_result(
                    self.network_beacon_processor
                        .send_gossip_data_column_sidecar(
                            message_id,
                            peer_id,
                            subnet_id,
                            column_sidecar,
                            timestamp_now(),
                        ),
                )
            }
            PubsubMessage::VoluntaryExit(exit) => {
                debug!(%peer_id, "Received a voluntary exit");
                self.handle_beacon_processor_send_result(
                    self.network_beacon_processor
                        .send_gossip_voluntary_exit(message_id, peer_id, exit),
                )
            }
            PubsubMessage::ProposerSlashing(proposer_slashing) => {
                debug!(
                    %peer_id,
                    "Received a proposer slashing"
                );
                self.handle_beacon_processor_send_result(
                    self.network_beacon_processor.send_gossip_proposer_slashing(
                        message_id,
                        peer_id,
                        proposer_slashing,
                    ),
                )
            }
            PubsubMessage::AttesterSlashing(attester_slashing) => {
                debug!(
                    %peer_id,
                    "Received a attester slashing"
                );
                self.handle_beacon_processor_send_result(
                    self.network_beacon_processor.send_gossip_attester_slashing(
                        message_id,
                        peer_id,
                        attester_slashing,
                    ),
                )
            }
            PubsubMessage::SignedContributionAndProof(contribution_and_proof) => {
                trace!(
                    %peer_id,
                    "Received sync committee aggregate"
                );
                self.handle_beacon_processor_send_result(
                    self.network_beacon_processor.send_gossip_sync_contribution(
                        message_id,
                        peer_id,
                        *contribution_and_proof,
                        timestamp_now(),
                    ),
                )
            }
            PubsubMessage::SyncCommitteeMessage(sync_committtee_msg) => {
                trace!(
                    %peer_id,
                    "Received sync committee signature"
                );
                self.handle_beacon_processor_send_result(
                    self.network_beacon_processor.send_gossip_sync_signature(
                        message_id,
                        peer_id,
                        sync_committtee_msg.1,
                        sync_committtee_msg.0,
                        timestamp_now(),
                    ),
                )
            }
            PubsubMessage::LightClientFinalityUpdate(light_client_finality_update) => {
                trace!(
                    %peer_id,
                    "Received light client finality update"
                );
                self.handle_beacon_processor_send_result(
                    self.network_beacon_processor
                        .send_gossip_light_client_finality_update(
                            message_id,
                            peer_id,
                            *light_client_finality_update,
                            timestamp_now(),
                        ),
                )
            }
            PubsubMessage::LightClientOptimisticUpdate(light_client_optimistic_update) => {
                trace!(
                    %peer_id,
                    "Received light client optimistic update"

                );
                self.handle_beacon_processor_send_result(
                    self.network_beacon_processor
                        .send_gossip_light_client_optimistic_update(
                            message_id,
                            peer_id,
                            *light_client_optimistic_update,
                            timestamp_now(),
                        ),
                )
            }
            PubsubMessage::BlsToExecutionChange(bls_to_execution_change) => self
                .handle_beacon_processor_send_result(
                    self.network_beacon_processor
                        .send_gossip_bls_to_execution_change(
                            message_id,
                            peer_id,
                            bls_to_execution_change,
                        ),
                ),
        }
    }

    fn send_status(&mut self, peer_id: PeerId) {
        let status_message = status_message(&self.chain);
        debug!(%peer_id, ?status_message, "Sending Status Request");
        self.network
            .send_processor_request(peer_id, RequestType::Status(status_message));
    }

    fn send_to_sync(&mut self, message: SyncMessage<T::EthSpec>) {
        self.sync_send.send(message).unwrap_or_else(|e| {
            warn!(
                error = %e,
                "Could not send message to the sync service"
            )
        });
    }

    /// An error occurred during an RPC request. The state is maintained by the sync manager, so
    /// this function notifies the sync manager of the error.
    pub fn on_rpc_error(&mut self, peer_id: PeerId, app_request_id: AppRequestId, error: RPCError) {
        // Check if the failed RPC belongs to sync
        if let AppRequestId::Sync(sync_request_id) = app_request_id {
            self.send_to_sync(SyncMessage::RpcError {
                peer_id,
                sync_request_id,
                error,
            });
        }
    }

    /// Handle a `Status` request.
    ///
    /// Processes the `Status` from the remote peer and sends back our `Status`.
    pub fn on_status_request(
        &mut self,
        peer_id: PeerId,
        inbound_request_id: InboundRequestId, // Use ResponseId here
        status: StatusMessage,
    ) {
        debug!(%peer_id, ?status, "Received Status Request");

        // Say status back.
        self.network.send_response(
            peer_id,
            inbound_request_id,
            Response::Status(status_message(&self.chain)),
        );

        self.handle_beacon_processor_send_result(
            self.network_beacon_processor
                .send_status_message(peer_id, status),
        )
    }

    /// Handle a `BlocksByRange` response from the peer.
    /// A `beacon_block` behaves as a stream which is terminated on a `None` response.
    pub fn on_blocks_by_range_response(
        &mut self,
        peer_id: PeerId,
        app_request_id: AppRequestId,
        beacon_block: Option<Arc<SignedBeaconBlock<T::EthSpec>>>,
    ) {
        let sync_request_id = match app_request_id {
            AppRequestId::Sync(sync_request_id) => match sync_request_id {
                id @ SyncRequestId::BlocksByRange { .. } => id,
                other => {
                    crit!(request = ?other, "BlocksByRange response on incorrect request");
                    return;
                }
            },
            AppRequestId::Router => {
                crit!(%peer_id, "All BBRange requests belong to sync");
                return;
            }
            AppRequestId::Internal => unreachable!("Handled internally"),
        };

        trace!(
            %peer_id,
            "Received BlocksByRange Response"

        );

        self.send_to_sync(SyncMessage::RpcBlock {
            peer_id,
            sync_request_id,
            beacon_block,
            seen_timestamp: timestamp_now(),
        });
    }

    pub fn on_blobs_by_range_response(
        &mut self,
        peer_id: PeerId,
        app_request_id: AppRequestId,
        blob_sidecar: Option<Arc<BlobSidecar<T::EthSpec>>>,
    ) {
        trace!(
            %peer_id,
            "Received BlobsByRange Response"
        );

        if let AppRequestId::Sync(sync_request_id) = app_request_id {
            self.send_to_sync(SyncMessage::RpcBlob {
                peer_id,
                sync_request_id,
                blob_sidecar,
                seen_timestamp: timestamp_now(),
            });
        } else {
            crit!("All blobs by range responses should belong to sync");
        }
    }

    /// Handle a `BlocksByRoot` response from the peer.
    pub fn on_blocks_by_root_response(
        &mut self,
        peer_id: PeerId,
        app_request_id: AppRequestId,
        beacon_block: Option<Arc<SignedBeaconBlock<T::EthSpec>>>,
    ) {
        let sync_request_id = match app_request_id {
            AppRequestId::Sync(sync_id) => match sync_id {
                id @ SyncRequestId::SingleBlock { .. } => id,
                other => {
                    crit!(request = ?other, "BlocksByRoot response on incorrect request");
                    return;
                }
            },
            AppRequestId::Router => {
                crit!(%peer_id, "All BBRoot requests belong to sync");
                return;
            }
            AppRequestId::Internal => unreachable!("Handled internally"),
        };

        trace!(
            %peer_id,
            "Received BlocksByRoot Response"
        );
        self.send_to_sync(SyncMessage::RpcBlock {
            peer_id,
            sync_request_id,
            beacon_block,
            seen_timestamp: timestamp_now(),
        });
    }

    /// Handle a `BlobsByRoot` response from the peer.
    pub fn on_blobs_by_root_response(
        &mut self,
        peer_id: PeerId,
        app_request_id: AppRequestId,
        blob_sidecar: Option<Arc<BlobSidecar<T::EthSpec>>>,
    ) {
        let sync_request_id = match app_request_id {
            AppRequestId::Sync(sync_id) => match sync_id {
                id @ SyncRequestId::SingleBlob { .. } => id,
                other => {
                    crit!(request = ?other, "BlobsByRoot response on incorrect request");
                    return;
                }
            },
            AppRequestId::Router => {
                crit!(%peer_id, "All BlobsByRoot requests belong to sync");
                return;
            }
            AppRequestId::Internal => unreachable!("Handled internally"),
        };

        trace!(
            %peer_id,
            "Received BlobsByRoot Response"
        );
        self.send_to_sync(SyncMessage::RpcBlob {
            sync_request_id,
            peer_id,
            blob_sidecar,
            seen_timestamp: timestamp_now(),
        });
    }

    /// Handle a `DataColumnsByRoot` response from the peer.
    pub fn on_data_columns_by_root_response(
        &mut self,
        peer_id: PeerId,
        app_request_id: AppRequestId,
        data_column: Option<Arc<DataColumnSidecar<T::EthSpec>>>,
    ) {
        let sync_request_id = match app_request_id {
            AppRequestId::Sync(sync_id) => match sync_id {
                id @ SyncRequestId::DataColumnsByRoot { .. } => id,
                other => {
                    crit!(request = ?other, "DataColumnsByRoot response on incorrect request");
                    return;
                }
            },
            AppRequestId::Router => {
                crit!(%peer_id, "All DataColumnsByRoot requests belong to sync");
                return;
            }
            AppRequestId::Internal => unreachable!("Handled internally"),
        };

        trace!(
            %peer_id,
            "Received DataColumnsByRoot Response"
        );
        self.send_to_sync(SyncMessage::RpcDataColumn {
            sync_request_id,
            peer_id,
            data_column,
            seen_timestamp: timestamp_now(),
        });
    }

    pub fn on_data_columns_by_range_response(
        &mut self,
        peer_id: PeerId,
        app_request_id: AppRequestId,
        data_column: Option<Arc<DataColumnSidecar<T::EthSpec>>>,
    ) {
        trace!(
            %peer_id,
            "Received DataColumnsByRange Response"
        );

        if let AppRequestId::Sync(sync_request_id) = app_request_id {
            self.send_to_sync(SyncMessage::RpcDataColumn {
                peer_id,
                sync_request_id,
                data_column,
                seen_timestamp: timestamp_now(),
            });
        } else {
            crit!("All data columns by range responses should belong to sync");
        }
    }

    fn handle_beacon_processor_send_result(
        &mut self,
        result: Result<(), crate::network_beacon_processor::Error<T::EthSpec>>,
    ) {
        if let Err(e) = result {
            let work_type = match &e {
                mpsc::error::TrySendError::Closed(work) | mpsc::error::TrySendError::Full(work) => {
                    work.work_type_str()
                }
            };

            if self.logger_debounce.elapsed() {
                error!(error = %e, work_type, "Unable to send message to the beacon processor")
            }
        }
    }
}

/// Wraps a Network Channel to employ various RPC related network functionality for the
/// processor.
#[derive(Clone)]
pub struct HandlerNetworkContext<E: EthSpec> {
    /// The network channel to relay messages to the Network service.
    network_send: mpsc::UnboundedSender<NetworkMessage<E>>,
}

impl<E: EthSpec> HandlerNetworkContext<E> {
    pub fn new(network_send: mpsc::UnboundedSender<NetworkMessage<E>>) -> Self {
        Self { network_send }
    }

    /// Sends a message to the network task.
    fn inform_network(&mut self, msg: NetworkMessage<E>) {
        self.network_send
            .send(msg)
            .unwrap_or_else(|e| warn!(error = %e,"Could not send message to the network service"))
    }

    /// Sends a request to the network task.
    pub fn send_processor_request(&mut self, peer_id: PeerId, request: RequestType<E>) {
        self.inform_network(NetworkMessage::SendRequest {
            peer_id,
            app_request_id: AppRequestId::Router,
            request,
        })
    }

    /// Sends a response to the network task.
    pub fn send_response(
        &mut self,
        peer_id: PeerId,
        inbound_request_id: InboundRequestId,
        response: Response<E>,
    ) {
        self.inform_network(NetworkMessage::SendResponse {
            peer_id,
            inbound_request_id,
            response,
        })
    }
}

fn timestamp_now() -> Duration {
    SystemTime::now()
        .duration_since(UNIX_EPOCH)
        .unwrap_or_else(|_| Duration::from_secs(0))
}