// Copyright 2018 Parity Technologies (UK) Ltd.
//
// 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
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// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

//! Ping example
//!
//! See ../src/tutorial.rs for a step-by-step guide building the example below.
//!
//! In the first terminal window, run:
//!
//! ```sh
//! cargo run --example ping --features=full
//! ```
//!
//! It will print the PeerId and the listening addresses, e.g. `Listening on
//! "/ip4/0.0.0.0/tcp/24915"`
//!
//! In the second terminal window, start a new instance of the example with:
//!
//! ```sh
//! cargo run --example ping --features=full -- /ip4/127.0.0.1/tcp/24915
//! ```
//!
//! The two nodes establish a connection, negotiate the ping protocol
//! and begin pinging each other.

use libp2p::futures::StreamExt;
use libp2p::ping::Success;
use libp2p::swarm::{keep_alive, NetworkBehaviour, SwarmEvent};
use libp2p::{identity, ping, Multiaddr, PeerId};
use log::{debug, info, LevelFilter};
use nym_sdk::mixnet::MixnetClient;
use std::error::Error;
use std::time::Duration;

#[path = "../libp2p_shared/lib.rs"]
mod rust_libp2p_nym;

#[tokio::main]
async fn main() -> Result<(), Box<dyn Error>> {
    pretty_env_logger::formatted_timed_builder()
        .filter_level(LevelFilter::Warn)
        .filter(Some("libp2p_ping"), LevelFilter::Debug)
        .init();

    let local_key = identity::Keypair::generate_ed25519();
    let local_peer_id = PeerId::from(local_key.public());
    info!("Local peer id: {local_peer_id:?}");

    #[cfg(not(feature = "libp2p-vanilla"))]
    let mut swarm = {
        debug!("Running `ping` example using NymTransport");
        use libp2p::core::{muxing::StreamMuxerBox, transport::Transport};
        use libp2p::swarm::SwarmBuilder;
        use rust_libp2p_nym::transport::NymTransport;

        let client = MixnetClient::connect_new().await.unwrap();

        let transport = NymTransport::new(client, local_key.clone()).await?;
        SwarmBuilder::with_tokio_executor(
            transport
                .map(|a, _| (a.0, StreamMuxerBox::new(a.1)))
                .boxed(),
            Behaviour::default(),
            local_peer_id,
        )
        .build()
    };

    #[cfg(feature = "libp2p-vanilla")]
    let mut swarm = {
        debug!("Running `ping` example using the vanilla libp2p tokio_development_transport");
        let transport = libp2p::tokio_development_transport(local_key)?;
        let mut swarm =
            libp2p::Swarm::with_tokio_executor(transport, Behaviour::default(), local_peer_id);
        swarm.listen_on("/ip4/0.0.0.0/tcp/0".parse()?)?;
        swarm
    };

    // Dial the peer identified by the multi-address given as the second
    // command-line argument, if any.
    if let Some(addr) = std::env::args().nth(1) {
        let remote: Multiaddr = addr.parse()?;
        swarm.dial(remote)?;
        info!("Dialed {addr}")
    }

    let mut total_ping_rtt: Duration = Duration::from_micros(0);
    let mut counter: u128 = 0;
    loop {
        match swarm.select_next_some().await {
            SwarmEvent::NewListenAddr { address, .. } => info!("Listening on {address:?}"),
            SwarmEvent::Behaviour(event) => {
                // Get the round-trip duration for the pings.
                // This value is already captured in the BehaviourEvent::Ping's `Success::Ping`
                // field.
                debug!("{event:?}");
                if let BehaviourEvent::Ping(ping_event) = event {
                    let result: Success = ping_event.result?;
                    match result {
                        Success::Ping { rtt } => {
                            counter += 1;
                            total_ping_rtt += rtt;
                            let average_ping_rtt = Duration::from_micros(
                                (total_ping_rtt.as_micros() / counter).try_into().unwrap(),
                            );
                            info!("Ping RTT: {rtt:?} AVERAGE RTT: ({counter} pings): {average_ping_rtt:?}");
                        }
                        Success::Pong => info!("Pong Event"),
                    }
                }
            }
            _ => {}
        }
    }
}

/// Our network behaviour.
///
/// For illustrative purposes, this includes the [`KeepAlive`](behaviour::KeepAlive) behaviour so a continuous sequence of
/// pings can be observed.
#[derive(NetworkBehaviour, Default)]
struct Behaviour {
    keep_alive: keep_alive::Behaviour,
    ping: ping::Behaviour,
}
