// Copyright 2021 COMIT Network.
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

use futures::StreamExt;
use libp2p::core::identity;
use libp2p::core::PeerId;
use libp2p::ping;
use libp2p::swarm::{NetworkBehaviour, Swarm, SwarmEvent};
use libp2p::Multiaddr;
use libp2p::{development_transport, rendezvous};
use libp2p_swarm::AddressScore;
use std::time::Duration;

#[tokio::main]
async fn main() {
    env_logger::init();

    let rendezvous_point_address = "/ip4/127.0.0.1/tcp/62649".parse::<Multiaddr>().unwrap();
    let rendezvous_point = "12D3KooWDpJ7As7BWAwRMfu1VU2WCqNjvq387JEYKDBj4kx6nXTN"
        .parse()
        .unwrap();

    let identity = identity::Keypair::generate_ed25519();

    let mut swarm = Swarm::new(
        development_transport(identity.clone()).await.unwrap(),
        MyBehaviour {
            rendezvous: rendezvous::client::Behaviour::new(identity.clone()),
            ping: ping::Behaviour::new(ping::Config::new().with_interval(Duration::from_secs(1))),
        },
        PeerId::from(identity.public()),
    );

    // In production the external address should be the publicly facing IP address of the rendezvous point.
    // This address is recorded in the registration entry by the rendezvous point.
    let external_address = "/ip4/127.0.0.1/tcp/0".parse::<Multiaddr>().unwrap();
    swarm.add_external_address(external_address, AddressScore::Infinite);

    log::info!("Local peer id: {}", swarm.local_peer_id());

    let _ = swarm.listen_on("/ip4/0.0.0.0/tcp/0".parse().unwrap());

    swarm.dial(rendezvous_point_address).unwrap();

    while let Some(event) = swarm.next().await {
        match event {
            SwarmEvent::NewListenAddr { address, .. } => {
                log::info!("Listening on {}", address);
            }
            SwarmEvent::ConnectionClosed {
                peer_id,
                cause: Some(error),
                ..
            } if peer_id == rendezvous_point => {
                log::error!("Lost connection to rendezvous point {}", error);
            }
            SwarmEvent::ConnectionEstablished { peer_id, .. } if peer_id == rendezvous_point => {
                swarm.behaviour_mut().rendezvous.register(
                    rendezvous::Namespace::from_static("rendezvous"),
                    rendezvous_point,
                    None,
                );
                log::info!("Connection established with rendezvous point {}", peer_id);
            }
            // once `/identify` did its job, we know our external address and can register
            SwarmEvent::Behaviour(MyEvent::Rendezvous(rendezvous::client::Event::Registered {
                namespace,
                ttl,
                rendezvous_node,
            })) => {
                log::info!(
                    "Registered for namespace '{}' at rendezvous point {} for the next {} seconds",
                    namespace,
                    rendezvous_node,
                    ttl
                );
            }
            SwarmEvent::Behaviour(MyEvent::Rendezvous(
                rendezvous::client::Event::RegisterFailed(error),
            )) => {
                log::error!("Failed to register {}", error);
                return;
            }
            SwarmEvent::Behaviour(MyEvent::Ping(ping::Event {
                peer,
                result: Ok(ping::Success::Ping { rtt }),
            })) if peer != rendezvous_point => {
                log::info!("Ping to {} is {}ms", peer, rtt.as_millis())
            }
            other => {
                log::debug!("Unhandled {:?}", other);
            }
        }
    }
}

#[derive(Debug)]
enum MyEvent {
    Rendezvous(rendezvous::client::Event),
    Ping(ping::Event),
}

impl From<rendezvous::client::Event> for MyEvent {
    fn from(event: rendezvous::client::Event) -> Self {
        MyEvent::Rendezvous(event)
    }
}

impl From<ping::Event> for MyEvent {
    fn from(event: ping::Event) -> Self {
        MyEvent::Ping(event)
    }
}

#[derive(NetworkBehaviour)]
#[behaviour(event_process = false)]
#[behaviour(out_event = "MyEvent")]
struct MyBehaviour {
    rendezvous: rendezvous::client::Behaviour,
    ping: ping::Behaviour,
}