use anyhow::Result;
use tun_rs::{AsyncDevice, DeviceBuilder};

use crate::client::ClientCfg;

pub async fn inti_tun_interface(config: &ClientCfg) -> Result<AsyncDevice> {
    println!(
        "Initializing TUN interface with name: {}, IP: {}/{}, MTU: {}",
        config.interface_name,
        config.interface_ip.addr(),
        config.interface_ip.netmask(),
        config.mtu
    );
    let device = match DeviceBuilder::new()
        .name(&config.interface_name)
        .ipv4(config.interface_ip.addr(), config.interface_ip.netmask(), None)
        .mtu(config.mtu)
        .build_async()
    {
        Ok(dev) => dev,
        Err(e) => {
            let msg = format!("Failed to create TUN interface: {:#}", e);
            eprintln!("{}", msg);
            return Err(anyhow::anyhow!(msg));
        }
    };

    Ok(device)
}