nemo-relay-cli 0.6.0-rc.2

// SPDX-FileCopyrightText: Copyright (c) 2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
// SPDX-License-Identifier: Apache-2.0

//! Shared coding-agent command parsing, discovery, and process construction.

pub(crate) mod detached;
pub(crate) mod launcher;
mod prepared;
mod types;

pub(crate) use prepared::PreparedAgentLaunch;
pub(crate) use prepared::insert_after_host;
pub(crate) use types::RunOverrides;

use std::ffi::{OsStr, OsString};
use std::path::{Path, PathBuf};
use std::process::Command;

use crate::agents::CodingAgent;

pub(crate) fn shell_quote_arg_for_platform(raw: &str, windows: bool) -> String {
    if windows {
        return cmd_quote_arg(raw);
    }
    posix_quote_arg(raw)
}

fn posix_quote_arg(raw: &str) -> String {
    if raw.is_empty() {
        "''".into()
    } else if raw
        .chars()
        .all(|ch| ch.is_ascii_alphanumeric() || matches!(ch, '/' | ':' | '.' | '_' | '-'))
    {
        raw.to_string()
    } else {
        format!("'{}'", raw.replace('\'', "'\\''"))
    }
}

fn cmd_quote_arg(raw: &str) -> String {
    if raw.is_empty() {
        return "\"\"".into();
    }
    if raw.chars().all(|ch| {
        ch.is_ascii_alphanumeric()
            || matches!(ch, '/' | '\\' | ':' | '.' | '_' | '-' | '=' | '@' | '+')
    }) {
        return raw.to_string();
    }
    let mut escaped = String::new();
    for ch in raw.chars() {
        match ch {
            '%' => escaped.push_str("%%cd:~,%"),
            '"' => escaped.push_str("\"\""),
            _ => escaped.push(ch),
        }
    }
    format!("\"{escaped}\"")
}

#[cfg(windows)]
pub(crate) fn portable_executable_path(path: PathBuf) -> PathBuf {
    use std::ffi::OsString;
    use std::os::windows::ffi::{OsStrExt, OsStringExt};

    let encoded = path.as_os_str().encode_wide().collect::<Vec<_>>();
    strip_windows_verbatim_prefix(&encoded)
        .map(|value| OsString::from_wide(&value))
        .map(PathBuf::from)
        .unwrap_or(path)
}

#[cfg(not(windows))]
pub(crate) fn portable_executable_path(path: PathBuf) -> PathBuf {
    path
}

#[cfg(any(test, windows))]
pub(crate) fn strip_windows_verbatim_prefix(encoded: &[u16]) -> Option<Vec<u16>> {
    const PREFIX: &[u16] = &[b'\\' as u16, b'\\' as u16, b'?' as u16, b'\\' as u16];
    const UNC: &[u16] = &[
        b'\\' as u16,
        b'\\' as u16,
        b'?' as u16,
        b'\\' as u16,
        b'U' as u16,
        b'N' as u16,
        b'C' as u16,
        b'\\' as u16,
    ];
    if let Some(rest) = encoded.strip_prefix(UNC) {
        let mut normalized = vec![b'\\' as u16, b'\\' as u16];
        normalized.extend_from_slice(rest);
        Some(normalized)
    } else {
        encoded.strip_prefix(PREFIX).map(ToOwned::to_owned)
    }
}

/// Parses the intentionally simple command strings accepted by `[agents.*].command`.
///
/// Complex shell expressions belong after `nemo-relay run --`; configuration values are argv
/// prefixes and therefore use whitespace separation consistently in launch and diagnostics.
pub(crate) fn command_argv(command: &str) -> Vec<String> {
    command.split_whitespace().map(ToOwned::to_owned).collect()
}

/// Builds the host version probe while preserving a configured wrapper prefix.
///
/// The last recognizable host token wins so package selectors such as
/// `npm exec --package @openai/codex -- codex` do not truncate the probe at the package name.
/// Opaque wrappers must expose the selected host's version when passed `--version`.
pub(crate) fn version_probe_argv(agent: CodingAgent, argv: &[String]) -> Vec<String> {
    let mut probe = argv
        .iter()
        .rposition(|argument| CodingAgent::infer(argument) == Some(agent))
        .map_or_else(|| argv.to_vec(), |index| argv[..=index].to_vec());
    if probe.is_empty() {
        probe.push(agent.executable().into());
    }
    probe.push("--version".into());
    probe
}

/// Resolves a command using the current platform's executable conventions.
pub(crate) fn resolve_executable(command: &str) -> Option<PathBuf> {
    resolve_executable_for_platform(
        command,
        std::env::var_os("PATH").as_deref(),
        std::env::var_os("PATHEXT").as_deref(),
        cfg!(windows),
    )
}

/// Resolves a command against an explicit PATH. This keeps setup detection deterministic in tests.
pub(crate) fn resolve_executable_in_path(command: &str, path: Option<&OsStr>) -> Option<PathBuf> {
    resolve_executable_for_platform(
        command,
        path,
        std::env::var_os("PATHEXT").as_deref(),
        cfg!(windows),
    )
}

pub(crate) fn resolve_executable_for_platform(
    command: &str,
    path: Option<&OsStr>,
    path_ext: Option<&OsStr>,
    windows: bool,
) -> Option<PathBuf> {
    if command.is_empty() {
        return None;
    }
    let command_path = Path::new(command);
    let extensions = executable_extensions(command_path, path_ext, windows);
    if command_path.is_absolute() || command_path.components().count() > 1 {
        return resolve_candidate(command_path, &extensions);
    }
    path.into_iter()
        .flat_map(std::env::split_paths)
        .find_map(|directory| resolve_candidate(&directory.join(command), &extensions))
}

fn executable_extensions(command: &Path, path_ext: Option<&OsStr>, windows: bool) -> Vec<OsString> {
    if !windows || command.extension().is_some() {
        return vec![OsString::new()];
    }
    path_ext
        .and_then(OsStr::to_str)
        .filter(|value| !value.is_empty())
        .unwrap_or(".EXE;.CMD;.BAT;.COM")
        .split(';')
        .filter(|extension| !extension.is_empty())
        .map(OsString::from)
        .collect()
}

fn resolve_candidate(base: &Path, extensions: &[OsString]) -> Option<PathBuf> {
    extensions.iter().find_map(|extension| {
        let candidate = if extension.is_empty() {
            base.to_path_buf()
        } else {
            let mut value = base.as_os_str().to_os_string();
            value.push(extension);
            PathBuf::from(value)
        };
        candidate.is_file().then_some(candidate)
    })
}

/// Creates a synchronous command.
///
/// Rust's Windows process implementation recognizes `.cmd` and `.bat` programs and applies its
/// hardened batch-file argument encoder. Keeping process construction here argv-based avoids
/// reinterpreting host arguments through a second, hand-built shell command line.
pub(crate) fn std_command(argv: &[String]) -> Command {
    debug_assert!(!argv.is_empty());
    let program = resolve_executable(&argv[0]).unwrap_or_else(|| PathBuf::from(&argv[0]));
    let mut command = Command::new(program);
    command.args(&argv[1..]);
    command
}

/// Creates an asynchronous command with the same argv behavior as [`std_command`].
pub(crate) fn tokio_command(argv: &[String]) -> tokio::process::Command {
    debug_assert!(!argv.is_empty());
    let program = resolve_executable(&argv[0]).unwrap_or_else(|| PathBuf::from(&argv[0]));
    let mut command = tokio::process::Command::new(program);
    command.args(&argv[1..]);
    command
}

mod supervision;
pub(crate) use supervision::SupervisedChild;

#[cfg(test)]
#[path = "../../tests/coverage/shared/agent_process_tests.rs"]
mod tests;