// cli/journal.rs — journal subcommand handlers

use crate::store;
use crate::store::StoreView;

pub fn cmd_tail(n: usize, full: bool) -> Result<(), String> {
    let path = crate::store::nodes_path();
    if !path.exists() {
        return Err("No node log found".into());
    }

    use std::io::BufReader;
    let file = std::fs::File::open(&path)
        .map_err(|e| format!("open {}: {}", path.display(), e))?;
    let mut reader = BufReader::new(file);

    // Read all entries, keep last N
    let mut entries: Vec<crate::store::Node> = Vec::new();
    while let Ok(msg) = capnp::serialize::read_message(&mut reader, capnp::message::ReaderOptions::new()) {
        let log = msg.get_root::<crate::memory_capnp::node_log::Reader>()
            .map_err(|e| format!("read log: {}", e))?;
        for node_reader in log.get_nodes()
            .map_err(|e| format!("get nodes: {}", e))? {
            let node = crate::store::Node::from_capnp_migrate(node_reader)?;
            entries.push(node);
        }
    }

    let start = entries.len().saturating_sub(n);
    for node in &entries[start..] {
        let ts = if node.timestamp > 0 && node.timestamp < 4_000_000_000 {
            crate::store::format_datetime(node.timestamp)
        } else {
            format!("(raw:{})", node.timestamp)
        };
        let del = if node.deleted { " [DELETED]" } else { "" };
        if full {
            eprintln!("--- {} (v{}) {} via {} w={:.3}{} ---",
                node.key, node.version, ts, node.provenance, node.weight, del);
            eprintln!("{}\n", node.content);
        } else {
            let preview = crate::util::first_n_chars(&node.content, 100).replace('\n', "\\n");
            eprintln!("  {}  v{}  w={:.2}{}",
                ts, node.version, node.weight, del);
            eprintln!("  {}  via {}", node.key, node.provenance);
            if !preview.is_empty() {
                eprintln!("  {}", preview);
            }
            eprintln!();
        }
    }

    Ok(())
}