// 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::{
    identify, noise, ping, rendezvous,
    swarm::{NetworkBehaviour, SwarmEvent},
    tcp, yamux, Multiaddr,
};
use std::time::Duration;
use tracing_subscriber::EnvFilter;

#[tokio::main]
async fn main() {
    let _ = tracing_subscriber::fmt()
        .with_env_filter(EnvFilter::from_default_env())
        .try_init();

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

    let mut swarm = libp2p::SwarmBuilder::with_new_identity()
        .with_tokio()
        .with_tcp(
            tcp::Config::default(),
            noise::Config::new,
            yamux::Config::default,
        )
        .unwrap()
        .with_behaviour(|key| MyBehaviour {
            identify: identify::Behaviour::new(identify::Config::new(
                "rendezvous-example/1.0.0".to_string(),
                key.public(),
            )),
            rendezvous: rendezvous::client::Behaviour::new(key.clone()),
            ping: ping::Behaviour::new(ping::Config::new().with_interval(Duration::from_secs(1))),
        })
        .unwrap()
        .with_swarm_config(|cfg| cfg.with_idle_connection_timeout(Duration::from_secs(5)))
        .build();

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

    swarm.dial(rendezvous_point_address.clone()).unwrap();

    while let Some(event) = swarm.next().await {
        match event {
            SwarmEvent::NewListenAddr { address, .. } => {
                tracing::info!("Listening on {}", address);
            }
            SwarmEvent::ConnectionClosed {
                peer_id,
                cause: Some(error),
                ..
            } if peer_id == rendezvous_point => {
                tracing::error!("Lost connection to rendezvous point {}", error);
            }
            // once `/identify` did its job, we know our external address and can register
            SwarmEvent::Behaviour(MyBehaviourEvent::Identify(identify::Event::Received {
                info,
                ..
            })) => {
                // Register our external address. Needs to be done explicitly
                // for this case, as it's a local address.
                swarm.add_external_address(info.observed_addr);
                if let Err(error) = swarm.behaviour_mut().rendezvous.register(
                    rendezvous::Namespace::from_static("rendezvous"),
                    rendezvous_point,
                    None,
                ) {
                    tracing::error!("Failed to register: {error}");
                    return;
                }
            }
            SwarmEvent::Behaviour(MyBehaviourEvent::Rendezvous(
                rendezvous::client::Event::Registered {
                    namespace,
                    ttl,
                    rendezvous_node,
                },
            )) => {
                tracing::info!(
                    "Registered for namespace '{}' at rendezvous point {} for the next {} seconds",
                    namespace,
                    rendezvous_node,
                    ttl
                );
            }
            SwarmEvent::Behaviour(MyBehaviourEvent::Rendezvous(
                rendezvous::client::Event::RegisterFailed {
                    rendezvous_node,
                    namespace,
                    error,
                },
            )) => {
                tracing::error!(
                    "Failed to register: rendezvous_node={}, namespace={}, error_code={:?}",
                    rendezvous_node,
                    namespace,
                    error
                );
                return;
            }
            SwarmEvent::Behaviour(MyBehaviourEvent::Ping(ping::Event {
                peer,
                result: Ok(rtt),
                ..
            })) if peer != rendezvous_point => {
                tracing::info!("Ping to {} is {}ms", peer, rtt.as_millis())
            }
            other => {
                tracing::debug!("Unhandled {:?}", other);
            }
        }
    }
}

#[derive(NetworkBehaviour)]
struct MyBehaviour {
    identify: identify::Behaviour,
    rendezvous: rendezvous::client::Behaviour,
    ping: ping::Behaviour,
}