use std::future::Future;
use std::net::{IpAddr, Ipv6Addr};
use futures::future::{self};
use futures::StreamExt;
use tarpc::{
    server::{Channel},
    tokio_serde::formats::Json,
};
use tarpc::server::incoming::Incoming;
use tarpc::server::BaseChannel;
use realm_server::server::RealmChatServer;
use realm_server::types::RealmChat;

async fn spawn(fut: impl Future<Output = ()> + Send + 'static) {
    tokio::spawn(fut);
}

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let server_addr = (IpAddr::V6(Ipv6Addr::LOCALHOST), 5051);

    // JSON transport is provided by the json_transport tarpc module. It makes it easy
    // to start up a serde-powered json serialization strategy over TCP.
    let mut listener = tarpc::serde_transport::tcp::listen(&server_addr, Json::default).await?;
    tracing::info!("Listening on port {}", listener.local_addr().port());
    listener.config_mut().max_frame_length(usize::MAX);
    listener
        // Ignore accept errors.
        .filter_map(|r| future::ready(r.ok()))
        .map(BaseChannel::with_defaults)
        // Limit channels to 1 per IP.
        .max_channels_per_key(1, |t| t.transport().peer_addr().unwrap().ip())
        // serve is generated by the service attribute. It takes as input any type implementing
        // the generated World trait.
        .map(|channel| {
            let server = RealmChatServer(channel.transport().peer_addr().unwrap());
            channel.execute(server.serve()).for_each(spawn)
        })
        // Max 10 channels.
        .buffer_unordered(10)
        .for_each(|_| async {})
        .await;

    Ok(())
}