//! Run with
//!
//! ```not_rust
//! cargo run -p example-hello-world
//! ```

use axum::{response::Html, routing::get, Router};
use listenfd::ListenFd;
use tokio::net::TcpListener;

#[tokio::main]
async fn main() {
    // build our application with a route
    let app = Router::new().route("/", get(handler));

    let mut listenfd = ListenFd::from_env();
    let listener = match listenfd.take_tcp_listener(0).unwrap() {
        // if we are given a tcp listener on listen fd 0, we use that one
        Some(listener) => TcpListener::from_std(listener).unwrap(),
        // otherwise fall back to local listening
        None => TcpListener::bind("127.0.0.1:3000").await.unwrap(),
    };

    // run it
    println!("listening on {}", listener.local_addr().unwrap());
    axum::serve(listener, app).await.unwrap();
}

async fn handler() -> Html<&'static str> {
    Html("<h1>Hello, World!</h1>")
}