use warp::Filter;
use warp::Rejection;
use std::net::SocketAddr;

#[derive(Debug, Clone)]
pub struct RemoteInfo {
    pub remote_addr: Option<SocketAddr>,
    pub user_agent: Option<String>,
}

pub fn with_remote_info() 
-> impl Filter<Extract = (RemoteInfo,), Error = Rejection> + Copy {
    warp::filters::addr::remote()
        .and(warp::header::optional::<String>("user-agent"))
        .map(|addr: Option<SocketAddr>, agent: Option<String>| RemoteInfo { remote_addr: addr, user_agent: agent })
}

let some_route = warp::path!("some"/"route")
        .and(warp::post())
        .and(with_remote_info())
        .and(warp::body::json())
        .and_then(some_route_handler);