mod shared;

use std::sync::Arc;

use async_trait::async_trait;
use clap::Parser;
use smol::{channel, Executor};

use karyon_p2p::{
    endpoint::{Endpoint, Port},
    keypair::{KeyPair, KeyPairType},
    protocol::{Protocol, ProtocolEvent, ProtocolID},
    Backend, Config, Error, Peer, Version,
};

use shared::{read_line_async, run_executor};

#[derive(Parser)]
#[command(author, version, about, long_about = None)]
struct Cli {
    /// Optional list of bootstrap peers to start the seeding process.
    #[arg(short)]
    bootstrap_peers: Vec<Endpoint>,

    /// Optional list of peer endpoints for manual connections.
    #[arg(short)]
    peer_endpoints: Vec<Endpoint>,

    /// Optional endpoint for accepting incoming connections.
    #[arg(short)]
    listen_endpoint: Option<Endpoint>,

    /// Optional TCP/UDP port for the discovery service.
    #[arg(short)]
    discovery_port: Option<Port>,

    /// Username
    #[arg(long)]
    username: String,
}

pub struct ChatProtocol {
    username: String,
    peer: Arc<Peer>,
    executor: Arc<Executor<'static>>,
}

impl ChatProtocol {
    fn new(username: &str, peer: Arc<Peer>, executor: Arc<Executor<'static>>) -> Arc<dyn Protocol> {
        Arc::new(Self {
            peer,
            username: username.to_string(),
            executor,
        })
    }
}

#[async_trait]
impl Protocol for ChatProtocol {
    async fn start(self: Arc<Self>) -> Result<(), Error> {
        let task = self.executor.spawn({
            let this = self.clone();
            async move {
                loop {
                    let input = read_line_async().await.expect("Read line from stdin");
                    let msg = format!("> {}: {}", this.username, input.trim());
                    this.peer.broadcast(&Self::id(), &msg).await;
                }
            }
        });

        loop {
            match self.peer.recv::<Self>().await? {
                ProtocolEvent::Message(msg) => {
                    let msg = String::from_utf8(msg).expect("Convert received bytes to string");
                    println!("{msg}");
                }
                ProtocolEvent::Shutdown => {
                    break;
                }
            }
        }

        task.cancel().await;
        Ok(())
    }

    fn version() -> Result<Version, Error> {
        "0.1.0, 0.1.0".parse()
    }

    fn id() -> ProtocolID {
        "CHAT".into()
    }
}

fn main() {
    env_logger::init();
    let cli = Cli::parse();

    // Create a PeerID based on the username.
    let key_pair = KeyPair::generate(&KeyPairType::Ed25519);

    // Create the configuration for the backend.
    let config = Config {
        listen_endpoint: cli.listen_endpoint,
        peer_endpoints: cli.peer_endpoints,
        bootstrap_peers: cli.bootstrap_peers,
        discovery_port: cli.discovery_port.unwrap_or(0),
        enable_tls: true,
        ..Default::default()
    };

    // Create a new Executor
    let ex = Arc::new(Executor::new());

    // Create a new Backend
    let backend = Backend::new(&key_pair, config, ex.clone().into());

    let (ctrlc_s, ctrlc_r) = channel::unbounded();
    let handle = move || ctrlc_s.try_send(()).expect("Send ctrlc signal");
    ctrlc::set_handler(handle).expect("ctrlc set handler");

    run_executor(
        {
            let ex = ex.clone();
            async {
                let username = cli.username;

                // Attach the ChatProtocol
                let c = move |peer| ChatProtocol::new(&username, peer, ex.clone().into());
                backend
                    .attach_protocol::<ChatProtocol>(c)
                    .await
                    .expect("Attach chat protocol to the p2p backend");

                // Run the backend
                backend.run().await.expect("Run the backend");

                // Wait for ctrlc signal
                ctrlc_r.recv().await.expect("Receive ctrlc signal");

                // Shutdown the backend
                backend.shutdown().await;
            }
        },
        ex,
    );
}