use std::{net::TcpListener, process};

use axum::{extract::State, routing::get, Router};
use tokio::net::TcpListener as TokioListener;

use log::info;
use prefork::Prefork;
use tower_http::trace::TraceLayer;

async fn hello(State((pid, child_num)): State<(u32, u32)>) -> String {
    format!("Hello from {child_num} with pid {pid}")
}

async fn child(child_num: u32, listener: TcpListener) {
    let pid = process::id();
    tracing_subscriber::fmt()
        .with_max_level(tracing::Level::DEBUG)
        .without_time()
        .init();

    info!("Starting child {child_num}, pid {pid}");

    let router = Router::new()
        .route("/", get(hello))
        .layer(TraceLayer::new_for_http())
        .with_state((pid, child_num));

    let listener = TokioListener::from_std(listener).expect("use tcplistener");
    axum::serve(listener, router).await.expect("start server");
}

fn main() {
    let listener = TcpListener::bind("0.0.0.0:3000").expect("bind to port");
    listener.set_nonblocking(true).expect("set nonblocking");

    let is_parent = Prefork::from_resource(listener)
        .with_num_processes(10)
        .with_tokio(child)
        .fork()
        .expect("fork");
    if is_parent {
        info!("Parent exit");
    }
}