//! Git exec channels over the shared SSH library, with host-mediated signing.
use crate::{Result, repo::error};
use gix::bstr::ByteSlice;
use std::io;
fn parse(input: &str) -> io::Result<gix::Url> {
    let url = gix::url::parse(input.as_bytes().as_bstr())
        .map_err(|_| io::Error::other("invalid SSH URL"))?;
    if url.scheme != gix::url::Scheme::Ssh
        || url.host.as_deref().is_none_or(str::is_empty)
        || url.password.is_some()
        || url.path.is_empty()
        || url.path.iter().any(|b| matches!(b, 0 | b'\n' | b'\r'))
    {
        return Err(io::Error::other(
            "use ssh://[user@]host[:port]/path or [user@]host:path without a password",
        ));
    }
    Ok(url)
}
pub fn clean_url(input: &str) -> io::Result<String> {
    if input.starts_with("http://") || input.starts_with("https://") {
        crate::http::clean_url(input).map(|url| url.to_string())
    } else {
        parse(input)?;
        Ok(input.into())
    }
}
pub fn is_ssh(input: &str) -> bool {
    !input.starts_with("http://") && !input.starts_with("https://")
}
pub type Connection =
    gix_transport::client::git::blocking_io::Connection<sausage_ssh::Reader, sausage_ssh::Writer>;
pub fn connection(input: &str, service: gix_transport::Service) -> Result<Connection> {
    let url = parse(input).map_err(|e| error("SSH URL", e))?;
    let host = url.host.as_deref().unwrap();
    let mut session =
        sausage_ssh::identity::connect(host, url.port.unwrap_or(22), url.user.as_deref(), false)
            .map_err(|e| error("SSH", e))?;
    let mut command = service.as_str().as_bytes().to_vec();
    command.extend_from_slice(b" '");
    for byte in url.path.iter() {
        if *byte == b'\'' {
            command.extend_from_slice(b"'\\''");
        } else {
            command.push(*byte);
        }
    }
    command.push(b'\'');
    session
        .open_command(&command)
        .map_err(|e| error("SSH exec", e))?;
    let (read, write) = session.split();
    Ok(Connection::new(
        read,
        write,
        gix_transport::Protocol::V1,
        url.path,
        None::<(&str, Option<u16>)>,
        gix_transport::client::git::ConnectMode::Process,
        false,
    )
    .custom_url(Some(input.into())))
}