//! Bytes kept beside the ledger, named by their BLAKE3 (spec §7.2): tool
//! call arguments and results in full, so the audit is never truncated;
//! retention drops old bodies and keeps the hashes (spec §22.1).

use anyhow::Result;
use std::path::Path;

/// Store `bytes` under `<data>/attachments/` and return their hash (hex).
pub fn put(data: &Path, bytes: &[u8]) -> Result<String> {
    let hash = blake3::hash(bytes).to_hex().to_string();
    let dir = data.join("attachments").join(&hash[..2]);
    let path = dir.join(&hash);
    if !path.exists() {
        std::fs::create_dir_all(&dir)?;
        crate::durable::write_atomic(&path, bytes)?;
    }
    Ok(hash)
}

/// The bytes stored under `hash`, if they are still kept.
pub fn get(data: &Path, hash: &str) -> Option<Vec<u8>> {
    if hash.len() < 3 || !hash.bytes().all(|b| b.is_ascii_hexdigit()) {
        return None;
    }
    std::fs::read(data.join("attachments").join(&hash[..2]).join(hash)).ok()
}