From e8e4c4ab9baaa1334c662bc9ef2a5a3b04e65095 Mon Sep 17 00:00:00 2001
From: Age Manning <Age@AgeManning.com>
Date: Thu, 7 Mar 2019 11:43:55 +1100
Subject: [PATCH] Adds basic structure for swarm behaviour and topology.

---
 beacon_node/libp2p/Cargo.toml     |  1 +
 beacon_node/libp2p/src/service.rs | 33 ++++++++++++++++++++++++-------
 2 files changed, 27 insertions(+), 7 deletions(-)

diff --git a/beacon_node/libp2p/Cargo.toml b/beacon_node/libp2p/Cargo.toml
index b32eed1a6..fff7dc82d 100644
--- a/beacon_node/libp2p/Cargo.toml
+++ b/beacon_node/libp2p/Cargo.toml
@@ -9,3 +9,4 @@ edition = "2018"
 libp2p =  { git = "https://github.com/SigP/rust-libp2p", branch = "gossipsub" }
 slog = "2.4.1"
 version = { path = "../version" }
+tokio = "0.1.16"
diff --git a/beacon_node/libp2p/src/service.rs b/beacon_node/libp2p/src/service.rs
index 53c566187..528d24ce8 100644
--- a/beacon_node/libp2p/src/service.rs
+++ b/beacon_node/libp2p/src/service.rs
@@ -1,14 +1,17 @@
 use crate::NetworkConfig;
-use libp2p::gossipsub::GossipsubEvent;
-use libp2p::PeerId;
+use libp2p::core::{muxing::StreamMuxer, nodes::Substream};
+use libp2p::gossipsub::{Gossipsub, GossipsubConfig, GossipsubEvent};
 use libp2p::{build_tcp_ws_secio_mplex_yamux, core, secio, Transport};
+use libp2p::{core::swarm::NetworkBehaviour, PeerId, Swarm};
 use slog::debug;
 use std::error;
 
 /// The configuration and state of the libp2p components for the beacon node.
 pub struct Service {
+    /// The libp2p Swarm handler.
+    swarm: String,
     /// This node's PeerId.
-    peer_id: PeerId,
+    local_peer_id: PeerId,
 }
 
 impl Service {
@@ -16,15 +19,22 @@ impl Service {
         debug!(log, "Libp2p Service starting");
 
         let local_private_key = config.local_private_key;
-        let peer_id = local_private_key.to_peer_id();
-        debug!(log, "Local peer id: {:?}", peer_id);
+        let local_peer_id = local_private_key.to_peer_id();
+        debug!(log, "Local peer id: {:?}", local_peer_id);
 
         // Set up the transport
         let transport = build_transport(local_private_key);
+        // Set up gossipsub routing
+        let behaviour = build_behaviour(local_peer_id, config.gs_config);
+        // Set up Topology
+        let topology = local_peer_id;
 
-        //let transport = libp2p::
+        let swarm = Swarm::new(transport, behaviour, topology);
 
-        Service { peer_id }
+        Service {
+            local_peer_id,
+            swarm,
+        }
     }
 }
 
@@ -48,3 +58,12 @@ fn build_transport(
     // in the future.
     build_tcp_ws_secio_mplex_yamux(local_private_key)
 }
+
+/// Builds the network behaviour for the libp2p Swarm.
+fn build_behaviour<TSubstream>(
+    local_peer_id: PeerId,
+    config: GossipsubConfig,
+) -> impl NetworkBehaviour {
+    // TODO: Add Kademlia/Peer discovery
+    Gossipsub::new(local_peer_id, config)
+}