use std::str::FromStr;

use anyhow::{bail, Result};
use trust_dns_client::client::{Client, SyncClient};
use trust_dns_client::rr::{DNSClass, Name, RData, RecordType};
use trust_dns_client::udp::UdpClientConnection;

fn main() -> Result<()> {
    let (port, host) = resolve_dns("daeken.dev")?;

    dbg!(port);
    dbg!(host);

    Ok(())
}

fn resolve_dns(server: &str) -> Result<(u16, String)> {
    let name = Name::from_str(&format!("_hypercosm._tls.{}", server))?;

    let resp = make_dns_client()?.query(&name, DNSClass::IN, RecordType::SRV)?;

    // TODO: Ensure exactly 1 result: I think.
    let ans = resp.answers()[0].rdata();

    if let RData::SRV(srv) = ans {
        // TODO: Handle priority and weight.

        let port = srv.port();

        // TODO: Should this be ascii or utf8
        let name = srv.target().to_ascii();

        Ok((port, name))
    } else {
        bail!("Invalid DNS responce");
    }
}

fn make_dns_client() -> Result<impl Client> {
    // TODO: Make this use TLS

    let addr = "1.1.1.1:53".parse()?;
    let conn = UdpClientConnection::new(addr)?;

    let client = SyncClient::new(conn);

    Ok(client)
}