//! RSA and chacha20 key exchange methods
use super::*;
/*
use tokio::prelude::*;

pub async fn write_cckey<W: AsyncWrite + Unpin>(mut to: W, rsa: &crypt::RsaPublicKey, key: &crypt::Key, iv: &crypt::IV) -> std::io::Result<()>
{
    let key = {
	let mut buf = Vec::with_capacity(chacha20stream::key::KEY_SIZE);
	crypt::rsa_encrypt(rsa, &mut buf, key.as_ref())?;
	buf
    };

    to.write_all(&key[..]).await?; //TODO: Find size of `key` here.
    to.write_all(iv.as_ref()).await?;
    
    Ok(())
}
 */

/// A future that writes an RSA encrypted chacha20 key to a stream when awaited
//TODO: Find size of RSA ecnrypted chacha `Key`.
#[pin_project]
struct CCKeyWrite<'a, W: AsyncWrite>{
    /// The bytes of an **already encrypted** chacha20 key.
    enc_key: Vec<u8>,
    /// A non-encrypted chacha20 IV.
    iv: [u8; chacha20stream::key::IV_SIZE],

    /// Stream to write the data to when this future is awaited.
    #[pin] stream: &'a mut W,
}

//TODO: impl `Future` for CCKeyWrite should `write_all` both `enc_key` and `iv` to `stream` when `.await`ed.
impl<'a, W: AsyncWrite> Future for CCKeyWrite<'a, S>
{
    type Output = io::Result<()>;

    //todo: how to we `write_all` in `poll`? implement it outselves with looping `poll_write` and `futures::ready!()`?
}