use std::process::ExitCode;

use lazaret_host_coordinator::client_bootstrap::ensure_domain_nofile_limit;
use lazaret_runtime_supervisor::sandbox::DOMAIN_OPEN_FILE_LIMIT;
use rustix::process::{Resource, Rlimit, getrlimit, setrlimit};

fn main() -> ExitCode {
    match verify_low_inherited_soft_limit() {
        Ok(()) => ExitCode::SUCCESS,
        Err(error) => {
            eprintln!("NOFILE fixture failed: {error}");
            ExitCode::FAILURE
        }
    }
}

fn verify_low_inherited_soft_limit() -> Result<(), Box<dyn std::error::Error>> {
    let inherited = getrlimit(Resource::Nofile);
    if let Some(maximum) = inherited.maximum
        && maximum < DOMAIN_OPEN_FILE_LIMIT
    {
        return Err(
            format!("test host hard limit {maximum} is below {DOMAIN_OPEN_FILE_LIMIT}").into(),
        );
    }
    setrlimit(
        Resource::Nofile,
        Rlimit {
            current: Some(1_024),
            maximum: inherited.maximum,
        },
    )?;
    ensure_domain_nofile_limit()?;
    let observed = getrlimit(Resource::Nofile);
    if observed.current != Some(DOMAIN_OPEN_FILE_LIMIT) || observed.maximum != inherited.maximum {
        return Err(format!("unexpected raised limit: {observed:?}").into());
    }
    Ok(())
}