#[derive(Debug)]
struct PingError;

async fn restart_wg() -> Result<(), Box<dyn std::error::Error>> {
    tokio::process::Command::new("systemctl")
        .args(["restart", "wg-quick@wg0"])
        .spawn()?
        .wait()
        .await?;

    Ok(())
}

async fn ping() -> Result<(), Box<dyn std::error::Error>> {
    let pinger = surge_ping::Pinger::new("192.168.5.1".parse()?)?;

    let mut any_success = false;
    for i in 0..3 {
        any_success |= pinger.ping(i).await.is_ok();
    }

    if !any_success {
        return Err(PingError.into());
    }

    Ok(())
}

#[tokio::main(flavor = "current_thread")]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut ticker = tokio::time::interval(std::time::Duration::from_secs(15));
    loop {
        ticker.tick().await;

        match ping().await {
            Ok(_) => {
                println!("online");
            }
            Err(e) => {
                if e.is::<PingError>() {
                    println!("restarting");
                    if let Err(e) = restart_wg().await {
                        eprintln!("Failed to restart tunnel: {}", e);
                    }
                }
            }
        }
    }
}

impl std::fmt::Display for PingError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "All ping attempts failed")
    }
}

impl std::error::Error for PingError {}