pitboard-core 0.8.0

//! What an administrator set on this machine for a program, outside every person's home: a
//! file only an administrator writes, such as Codex's `/etc/codex/requirements.toml`, or a
//! managed preference a configuration profile forces on macOS.
//!
//! A tool reads these as well as the person's own settings, and an administrator's beat the
//! person's. So where a tool keeps its login is not always what the person's own file says,
//! and Pitboard reads what the tool reads.
//!
//! The real hosts read none of it in a build for tests ([`READ_BY_REAL_HOSTS`]): what an
//! administrator set on the machine running the tests is no test's business, and a test that
//! needs a setting says it through [`super::memory::MemoryHost`].

use std::path::Path;

/// What one place an administrator sets things in holds.
#[derive(Debug, Clone, PartialEq, Eq)]
pub(crate) enum Administered {
    /// Nothing is set there.
    Unset,
    /// This, as text.
    Set(String),
    /// Something is there that could not be read, and why, in words that follow its name.
    Unreadable(String),
}

/// Whether the real hosts read what an administrator set. Not in a build for tests: a unit
/// test, the command line the integration tests run, or an app built with the fixtures.
pub(crate) const READ_BY_REAL_HOSTS: bool = !cfg!(any(test, feature = "test-support"));

/// The file at `path`, as text. Absent is unset; there and unreadable, or not text, says why.
pub(crate) fn read_text(path: &Path) -> Administered {
    match std::fs::read(path) {
        Ok(bytes) => match String::from_utf8(bytes) {
            Ok(text) => Administered::Set(text),
            Err(_) => Administered::Unreadable("is not UTF-8 text".into()),
        },
        Err(e) if e.kind() == std::io::ErrorKind::NotFound => Administered::Unset,
        Err(e) => Administered::Unreadable(format!("cannot be read: {e}")),
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    fn scratch(name: &str) -> std::path::PathBuf {
        let dir = std::env::temp_dir().join(format!(
            "pitboard-administered-{name}-{}-{:?}",
            std::process::id(),
            std::thread::current().id()
        ));
        let _ = std::fs::remove_dir_all(&dir);
        std::fs::create_dir_all(&dir).expect("a scratch folder");
        dir
    }

    /// A file that is not there sets nothing. One that is there is read whole, and one that
    /// cannot be read, or is not text, says so rather than reading as unset: a tool that
    /// cannot read it does not start, which is not the same as nothing being set.
    #[test]
    fn a_file_is_unset_set_or_unreadable() {
        let dir = scratch("file");
        assert_eq!(read_text(&dir.join("absent.toml")), Administered::Unset);
        std::fs::write(dir.join("set.toml"), "a = 1\n").expect("written");
        assert_eq!(
            read_text(&dir.join("set.toml")),
            Administered::Set("a = 1\n".into())
        );
        std::fs::write(dir.join("bytes.toml"), [0xff, 0xfe, 0x00]).expect("written");
        assert_eq!(
            read_text(&dir.join("bytes.toml")),
            Administered::Unreadable("is not UTF-8 text".into())
        );
        let folder = read_text(&dir);
        assert!(
            matches!(&folder, Administered::Unreadable(why) if why.starts_with("cannot be read")),
            "a folder where the file should be cannot be read as one: {folder:?}"
        );
        let _ = std::fs::remove_dir_all(&dir);
    }

    /// No build for tests reads what this machine's administrator set.
    #[test]
    fn a_build_for_tests_reads_nothing_an_administrator_set() {
        const { assert!(!READ_BY_REAL_HOSTS) };
        let ctx = crate::context::Context::for_unit_test();
        assert_eq!(
            ctx.host()
                .administered_file(Path::new("/etc/codex/requirements.toml")),
            Administered::Unset
        );
        assert_eq!(
            ctx.host()
                .managed_preference("com.openai.codex", "requirements_toml_base64"),
            Administered::Unset
        );
    }
}