//! The hive's `meta/` directory: plain state beside the hive's other files
//! (`topology.json`, the swarm limits) that the manager container sees
//! read-only. Agents are built from the swarm's `internal/meta`
//! ([`crate::meta_rev`]), not from anything here.

use anyhow::{Context, Result};

/// Where the manager sees this directory inside its container (RO bind).
pub const CONTAINER_MANAGER_META_MOUNT: &str = "/meta";

/// Delete the permission seed files a hive that predates the swarm's
/// permissions left in the meta directory. Their grants live in the swarm's
/// `agent-permissions` bucket once `workers::permissions_import` has sent
/// them. A file already gone is fine.
///
/// # Errors
///
/// Removing a file fails.
pub fn remove_permission_files() -> Result<()> {
    remove_in(
        &crate::paths::meta_root(),
        crate::workers::permissions_import::META_FILES,
    )
}

fn remove_in(dir: &std::path::Path, files: &[&str]) -> Result<()> {
    for file in files {
        match std::fs::remove_file(dir.join(file)) {
            Ok(()) => {}
            Err(e) if e.kind() == std::io::ErrorKind::NotFound => {}
            Err(e) => return Err(e).with_context(|| format!("removing {file}")),
        }
    }
    Ok(())
}

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

    #[test]
    fn the_listed_files_go_and_nothing_else() {
        let dir = tempfile::tempdir().unwrap();
        for name in ["capabilities.json", "tool-groups.json", "topology.json"] {
            std::fs::write(dir.path().join(name), "{}").unwrap();
        }
        remove_in(dir.path(), &["capabilities.json", "tool-groups.json"]).unwrap();
        assert!(!dir.path().join("capabilities.json").exists());
        assert!(!dir.path().join("tool-groups.json").exists());
        assert!(
            dir.path().join("topology.json").exists(),
            "other state stays"
        );
        // A file already gone is fine.
        remove_in(dir.path(), &["capabilities.json"]).unwrap();
    }

    #[test]
    fn a_file_that_cannot_be_removed_is_an_error_naming_it() {
        let dir = tempfile::tempdir().unwrap();
        // A directory where the file belongs fails with a non-NotFound error.
        std::fs::create_dir(dir.path().join("capabilities.json")).unwrap();
        let err = remove_in(dir.path(), &["capabilities.json"]).unwrap_err();
        assert!(
            format!("{err:#}").contains("removing capabilities.json"),
            "{err:#}"
        );
    }
}