mod cfg;
mod macros;
mod math;
mod measure;
mod sysfs;

use std::{env, thread::sleep};

use sysfs::NetdevError;

use crate::{cfg::Config, measure::LinkSpeed};

fn main() -> eyre::Result<()> {
    let config = Config::from_file()?;

    let arg_netdev = env::args().nth(1);

    // prefer given argument over the config file
    #[allow(clippy::match_same_arms)]
    let netdev_name = match (config.netdev, arg_netdev) {
        (Some(_), Some(na)) => na,
        (Some(nc), None) => nc,
        (None, Some(na)) => na,
        (None, None) => {
            eyre::bail!(
                "No network device specified. Please provide a network device name as an argument or in the config file.\n\n{}",
                NetdevError::available_netdevs_msg()
            );
        }
    };

    let link_speed = LinkSpeed::new(&netdev_name)?;

    link_speed.for_each(|measurement| {
        println!(
            "RX: {:.0} MBit/s, TX: {:.0} MBit/s",
            mbit!(measurement.rx),
            mbit!(measurement.tx)
        );

        sleep(config.interval);
    });

    Ok(())
}