// Copyright 2018 Parity Technologies (UK) Ltd.
//
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// copy of this software and associated documentation files (the "Software"),
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//
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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//! Demonstrates how to perform Kademlia queries on the IPFS network.
//!
//! You can pass as parameter a base58 peer ID to search for. If you don't pass any parameter, a
//! peer ID will be generated randomly.

use async_std::task;
use mwc_libp2p::{
    Swarm,
    PeerId,
    identity,
    build_development_transport
};
use mwc_libp2p::kad::{
    Kademlia,
    KademliaConfig,
    KademliaEvent,
    GetClosestPeersError,
    QueryResult,
};
use mwc_libp2p::kad::record::store::MemoryStore;
use std::{env, error::Error, time::Duration};

fn main() -> Result<(), Box<dyn Error>> {
    env_logger::init();

    // Create a random key for ourselves.
    let local_key = identity::Keypair::generate_ed25519();
    let local_peer_id = PeerId::from_public_key(local_key.public());

    // Set up a an encrypted DNS-enabled TCP Transport over the Mplex protocol
    let transport = build_development_transport(local_key)?;

    // Create a swarm to manage peers and events.
    let mut swarm = {
        // Create a Kademlia behaviour.
        let mut cfg = KademliaConfig::default();
        cfg.set_query_timeout(Duration::from_secs(5 * 60));
        let store = MemoryStore::new(local_peer_id.clone());
        let mut behaviour = Kademlia::with_config(local_peer_id.clone(), store, cfg);

        // TODO: the /dnsaddr/ scheme is not supported (https://github.com/mwc_libp2p/rust-mwc_libp2p/issues/967)
        /*behaviour.add_address(&"QmNnooDu7bfjPFoTZYxMNLWUQJyrVwtbZg5gBMjTezGAJN".parse().unwrap(), "/dnsaddr/bootstrap.mwc_libp2p.io".parse().unwrap());
        behaviour.add_address(&"QmQCU2EcMqAqQPR2i9bChDtGNJchTbq5TbXJJ16u19uLTa".parse().unwrap(), "/dnsaddr/bootstrap.mwc_libp2p.io".parse().unwrap());
        behaviour.add_address(&"QmbLHAnMoJPWSCR5Zhtx6BHJX9KiKNN6tpvbUcqanj75Nb".parse().unwrap(), "/dnsaddr/bootstrap.mwc_libp2p.io".parse().unwrap());
        behaviour.add_address(&"QmcZf59bWwK5XFi76CZX8cbJ4BhTzzA3gU1ZjYZcYW3dwt".parse().unwrap(), "/dnsaddr/bootstrap.mwc_libp2p.io".parse().unwrap());*/

        // The only address that currently works.
        behaviour.add_address(&"QmaCpDMGvV2BGHeYERUEnRQAwe3N8SzbUtfsmvsqQLuvuJ".parse()?, "/ip4/104.131.131.82/tcp/4001".parse()?);

        // The following addresses always fail signature verification, possibly due to
        // RSA keys with < 2048 bits.
        // behaviour.add_address(&"QmSoLPppuBtQSGwKDZT2M73ULpjvfd3aZ6ha4oFGL1KrGM".parse().unwrap(), "/ip4/104.236.179.241/tcp/4001".parse().unwrap());
        // behaviour.add_address(&"QmSoLSafTMBsPKadTEgaXctDQVcqN88CNLHXMkTNwMKPnu".parse().unwrap(), "/ip4/128.199.219.111/tcp/4001".parse().unwrap());
        // behaviour.add_address(&"QmSoLV4Bbm51jM9C4gDYZQ9Cy3U6aXMJDAbzgu2fzaDs64".parse().unwrap(), "/ip4/104.236.76.40/tcp/4001".parse().unwrap());
        // behaviour.add_address(&"QmSoLer265NRgSp2LA3dPaeykiS1J6DifTC88f5uVQKNAd".parse().unwrap(), "/ip4/178.62.158.247/tcp/4001".parse().unwrap());

        // The following addresses are permanently unreachable:
        // Other(Other(A(Transport(A(Underlying(Os { code: 101, kind: Other, message: "Network is unreachable" }))))))
        // behaviour.add_address(&"QmSoLPppuBtQSGwKDZT2M73ULpjvfd3aZ6ha4oFGL1KrGM".parse().unwrap(), "/ip6/2604:a880:1:20::203:d001/tcp/4001".parse().unwrap());
        // behaviour.add_address(&"QmSoLSafTMBsPKadTEgaXctDQVcqN88CNLHXMkTNwMKPnu".parse().unwrap(), "/ip6/2400:6180:0:d0::151:6001/tcp/4001".parse().unwrap());
        // behaviour.add_address(&"QmSoLV4Bbm51jM9C4gDYZQ9Cy3U6aXMJDAbzgu2fzaDs64".parse().unwrap(), "/ip6/2604:a880:800:10::4a:5001/tcp/4001".parse().unwrap());
        // behaviour.add_address(&"QmSoLer265NRgSp2LA3dPaeykiS1J6DifTC88f5uVQKNAd".parse().unwrap(), "/ip6/2a03:b0c0:0:1010::23:1001/tcp/4001".parse().unwrap());
        Swarm::new(transport, behaviour, local_peer_id)
    };

    // Order Kademlia to search for a peer.
    let to_search: PeerId = if let Some(peer_id) = env::args().nth(1) {
        peer_id.parse()?
    } else {
        PeerId::from_public_key( identity::Keypair::generate_ed25519().public().into())
    };

    println!("Searching for the closest peers to {:?}", to_search);
    swarm.get_closest_peers(to_search.to_bytes());

    // Kick it off!
    task::block_on(async move {
        loop {
            let event = swarm.next().await;
            if let KademliaEvent::QueryResult {
                result: QueryResult::GetClosestPeers(result),
                ..
            } = event {
                match result {
                    Ok(ok) =>
                        if !ok.peers.is_empty() {
                            println!("Query finished with closest peers: {:#?}", ok.peers)
                        } else {
                            // The example is considered failed as there
                            // should always be at least 1 reachable peer.
                            println!("Query finished with no closest peers.")
                        }
                    Err(GetClosestPeersError::Timeout { peers, .. }) =>
                        if !peers.is_empty() {
                            println!("Query timed out with closest peers: {:#?}", peers)
                        } else {
                            // The example is considered failed as there
                            // should always be at least 1 reachable peer.
                            println!("Query timed out with no closest peers.");
                        }
                };

                break;
            }
        }

        Ok(())
    })
}