//! Shared helpers for the integration tests: v2 client sessions against a
//! live server, and raw frame construction.

use omnivox::{Cereal, CodecError, Session, encrypt_with_nonce, frame_nonce, handshake::perform};
use tokio::net::TcpStream;
use tokio::net::tcp::{OwnedReadHalf, OwnedWriteHalf};

#[derive(Debug, Default)]
pub struct Msg(pub Vec<u8>);

impl Cereal for Msg {
    fn encode(&self, out: &mut Vec<u8>) {
        omnivox::write_byte_vec(out, &self.0);
    }
    fn decode(bytes: &[u8]) -> Result<Self, CodecError> {
        Ok(Self(omnivox::Reader::new(bytes).byte_vec()?))
    }
}

pub const TEST_PSK: [u8; 32] = [42u8; 32];

/// Builds one framed message with the given sequence number.
pub fn frame(key: &[u8; 32], counter: u64, msg: &[u8]) -> Vec<u8> {
    let mut plain = Vec::new();
    Msg(msg.to_vec()).encode(&mut plain);
    let pkt = encrypt_with_nonce(key, &frame_nonce(counter), &plain);
    let mut bytes = Vec::new();
    pkt.encode(&mut bytes);
    let mut out = Vec::new();
    out.extend_from_slice(&(bytes.len() as u32).to_le_bytes());
    out.extend_from_slice(&bytes);
    out
}

/// Connects and completes the v2 handshake as the client role, returning
/// the raw halves plus the session keys for manual framing.
pub async fn client_session(port: u16, psk: &[u8; 32]) -> (OwnedReadHalf, OwnedWriteHalf, Session) {
    let stream = TcpStream::connect(("127.0.0.1", port)).await.unwrap();
    let (mut r, mut w) = stream.into_split();
    let session = perform(&mut r, &mut w, psk, false).await.unwrap();
    (r, w, session)
}