#![no_std]
#![no_main]

use lancer_user::io::write_bytes;
use lancer_user::net;
use lancer_user::syscall;

#[unsafe(no_mangle)]
pub extern "C" fn lancer_main() -> ! {
    let (rx, tx) = match net::init() {
        Some(pair) => pair,
        None => {
            lancer_user::show!(net, error, "netsock init failed");
            syscall::exit();
        }
    };

    if !net::has_relay() {
        write_bytes(b"networking not available (use SSH)\n");
        syscall::exit();
    }

    let mut args_buf = [0u8; 128];
    let args_len = net::recv_args(&rx, &mut args_buf);
    let args = &args_buf[..args_len];

    let (_cmd_tok, rest) = net::next_token(args);
    let (hostname_tok, _) = net::next_token(rest);

    if hostname_tok.is_empty() {
        write_bytes(b"usage: resolve <hostname>\n");
        syscall::exit();
    }

    let mut msg = [0u8; 62];
    let len = hostname_tok.len().min(61);
    msg[1..1 + len].copy_from_slice(&hostname_tok[..len]);

    let mut any = false;
    let mut resp_buf = [0u8; 64];

    msg[0] = net::MSG_DNS_QUERY;
    net::send_request(&tx, &msg[..1 + len]);

    let n = net::recv_response_blocking(&rx, &mut resp_buf);
    if n >= 6 && resp_buf[0] == net::MSG_DNS_RESULT && resp_buf[1] == 0 {
        let mut out = [0u8; 20];
        let pos = net::write_ip_decimal(&mut out, &resp_buf[2..6]);
        write_bytes(&out[..pos]);
        write_bytes(b"\n");
        any = true;
    }

    msg[0] = net::MSG_DNS_QUERY6;
    net::send_request(&tx, &msg[..1 + len]);

    let n = net::recv_response_blocking(&rx, &mut resp_buf);
    if n >= 18 && resp_buf[0] == net::MSG_DNS_RESULT6 && resp_buf[1] == 0 {
        let mut out = [0u8; 48];
        let pos = net::write_ipv6(&mut out, &resp_buf[2..18]);
        write_bytes(&out[..pos]);
        write_bytes(b"\n");
        any = true;
    }

    if !any {
        write_bytes(b"DNS lookup failed\n");
    }

    syscall::exit()
}