// cli/node.rs — node subcommand handlers
//
// render, write, used, wrong, not-relevant, not-useful, gap,
// node-delete, node-rename, history, list-keys, list-edges,
// dump-json, lookup-bump, lookups.

use crate::store;

pub fn cmd_used(key: &[String]) -> Result<(), String> {
    if key.is_empty() {
        return Err("used requires a key".into());
    }
    super::check_dry_run();
    let key = key.join(" ");
    let mut store = store::Store::load()?;
    let resolved = store.resolve_key(&key)?;
    store.mark_used(&resolved);

    // Also strengthen edges to this node — conscious-tier delta.
    const DELTA: f32 = 0.01;
    let mut strengthened = 0;
    for rel in &mut store.relations {
        if rel.deleted { continue; }
        if rel.source_key == resolved || rel.target_key == resolved {
            let old = rel.strength;
            rel.strength = (rel.strength + DELTA).clamp(0.05, 0.95);
            if (rel.strength - old).abs() > 0.001 {
                rel.version += 1;
                strengthened += 1;
            }
        }
    }

    store.save()?;
    println!("Marked '{}' as used (strengthened {} edges)", resolved, strengthened);
    Ok(())
}

pub fn cmd_wrong(key: &str, context: &[String]) -> Result<(), String> {
    let ctx = if context.is_empty() { None } else { Some(context.join(" ")) };
    super::check_dry_run();
    let mut store = store::Store::load()?;
    let resolved = store.resolve_key(key)?;
    store.mark_wrong(&resolved, ctx.as_deref());
    store.save()?;
    println!("Marked '{}' as wrong", resolved);
    Ok(())
}

pub fn cmd_not_relevant(key: &str) -> Result<(), String> {
    let mut store = store::Store::load()?;
    let resolved = store.resolve_key(key)?;

    // Weaken all edges to this node — it was routed to incorrectly.
    // Conscious-tier delta: 0.01 per edge.
    const DELTA: f32 = -0.01;
    let mut adjusted = 0;
    for rel in &mut store.relations {
        if rel.deleted { continue; }
        if rel.source_key == resolved || rel.target_key == resolved {
            let old = rel.strength;
            rel.strength = (rel.strength + DELTA).clamp(0.05, 0.95);
            if (rel.strength - old).abs() > 0.001 {
                rel.version += 1;
                adjusted += 1;
            }
        }
    }
    store.save()?;
    println!("Not relevant: '{}' — weakened {} edges by {}", resolved, adjusted, DELTA.abs());
    Ok(())
}

pub fn cmd_not_useful(key: &str) -> Result<(), String> {
    // no args to validate
    super::check_dry_run();
    let mut store = store::Store::load()?;
    let resolved = store.resolve_key(key)?;
    // Same as wrong but with clearer semantics: node content is bad, edges are fine.
    store.mark_wrong(&resolved, Some("not-useful"));
    store.save()?;
    println!("Not useful: '{}' — node weight reduced", resolved);
    Ok(())
}

pub fn cmd_gap(description: &[String]) -> Result<(), String> {
    if description.is_empty() {
        return Err("gap requires a description".into());
    }
    super::check_dry_run();
    let desc = description.join(" ");
    let mut store = store::Store::load()?;
    store.record_gap(&desc);
    store.save()?;
    println!("Recorded gap: {}", desc);
    Ok(())
}

pub fn cmd_list_keys(pattern: Option<&str>) -> Result<(), String> {
    let store = store::Store::load()?;
    let g = store.build_graph();

    if let Some(pat) = pattern {
        let pat_lower = pat.to_lowercase();
        let (prefix, suffix, middle) = if pat_lower.starts_with('*') && pat_lower.ends_with('*') {
            (None, None, Some(pat_lower.trim_matches('*').to_string()))
        } else if pat_lower.starts_with('*') {
            (None, Some(pat_lower.trim_start_matches('*').to_string()), None)
        } else if pat_lower.ends_with('*') {
            (Some(pat_lower.trim_end_matches('*').to_string()), None, None)
        } else {
            (None, None, Some(pat_lower.clone()))
        };
        let mut keys: Vec<_> = store.nodes.keys()
            .filter(|k| {
                let kl = k.to_lowercase();
                if let Some(ref m) = middle { kl.contains(m.as_str()) }
                else if let Some(ref p) = prefix { kl.starts_with(p.as_str()) }
                else if let Some(ref s) = suffix { kl.ends_with(s.as_str()) }
                else { true }
            })
            .cloned()
            .collect();
        keys.sort();
        for k in keys { println!("{}", k); }
        Ok(())
    } else {
        crate::query_parser::run_query(&store, &g, "* | sort key asc")
    }
}

pub fn cmd_list_edges() -> Result<(), String> {
    let store = store::Store::load()?;
    for rel in &store.relations {
        println!("{}\t{}\t{:.2}\t{:?}",
            rel.source_key, rel.target_key, rel.strength, rel.rel_type);
    }
    Ok(())
}

pub fn cmd_dump_json() -> Result<(), String> {
    let store = store::Store::load()?;
    let json = serde_json::to_string_pretty(&store)
        .map_err(|e| format!("serialize: {}", e))?;
    println!("{}", json);
    Ok(())
}

pub fn cmd_node_delete(key: &[String]) -> Result<(), String> {
    if key.is_empty() {
        return Err("node-delete requires a key".into());
    }
    super::check_dry_run();
    let key = key.join(" ");
    let mut store = store::Store::load()?;
    let resolved = store.resolve_key(&key)?;
    store.delete_node(&resolved)?;
    store.save()?;
    println!("Deleted '{}'", resolved);
    Ok(())
}

pub fn cmd_node_rename(old_key: &str, new_key: &str) -> Result<(), String> {
    // args are positional, always valid if present
    super::check_dry_run();
    let mut store = store::Store::load()?;
    let old_resolved = store.resolve_key(old_key)?;
    store.rename_node(&old_resolved, new_key)?;
    store.save()?;
    println!("Renamed '{}' → '{}'", old_resolved, new_key);
    Ok(())
}

pub fn cmd_render(key: &[String]) -> Result<(), String> {
    if key.is_empty() {
        return Err("render requires a key".into());
    }
    let key = key.join(" ");
    let store = store::Store::load()?;
    let bare = store::strip_md_suffix(&key);

    let node = store.nodes.get(&bare)
        .ok_or_else(|| format!("Node not found: {}", bare))?;

    print!("{}", node.content);

    // Show links so the graph is walkable
    let mut neighbors: Vec<(&str, f32)> = Vec::new();
    for r in &store.relations {
        if r.deleted { continue; }
        if r.source_key == bare {
            neighbors.push((&r.target_key, r.strength));
        } else if r.target_key == bare {
            neighbors.push((&r.source_key, r.strength));
        }
    }
    if !neighbors.is_empty() {
        neighbors.sort_by(|a, b| b.1.partial_cmp(&a.1).unwrap_or(std::cmp::Ordering::Equal));
        neighbors.dedup_by(|a, b| a.0 == b.0);
        let total = neighbors.len();
        let shown: Vec<_> = neighbors.iter().take(15)
            .map(|(k, s)| format!("({:.2})  `poc-memory render {}`", s, k))
            .collect();
        print!("\n\n---\nLinks:");
        for link in &shown {
            println!("\n  {}", link);
        }
        if total > 15 {
            println!("  ... and {} more (`poc-memory graph link {}`)", total - 15, bare);
        }
    }
    Ok(())
}

pub fn cmd_history(key: &[String], full: bool) -> Result<(), String> {
    if key.is_empty() {
        return Err("history requires a key".into());
    }
    let raw_key = key.join(" ");

    let store = store::Store::load()?;
    let key = store.resolve_key(&raw_key).unwrap_or(raw_key);
    drop(store);

    let path = 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);

    let mut versions: Vec<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 = store::Node::from_capnp_migrate(node_reader)?;
            if node.key == key {
                versions.push(node);
            }
        }
    }

    if versions.is_empty() {
        return Err(format!("No history found for '{}'", key));
    }

    eprintln!("{} versions of '{}':\n", versions.len(), key);
    for node in &versions {
        let ts = if node.timestamp > 0 && node.timestamp < 4_000_000_000 {
            store::format_datetime(node.timestamp)
        } else {
            format!("(raw:{})", node.timestamp)
        };
        let deleted_marker = if node.deleted { " DELETED" } else { "" };
        let content_len = node.content.len();
        if full {
            eprintln!("=== v{} {} {}{} w={:.3} {}b ===",
                node.version, ts, node.provenance, deleted_marker, node.weight, content_len);
            eprintln!("{}", node.content);
        } else {
            let preview = crate::util::first_n_chars(&node.content, 120);
            let preview = preview.replace('\n', "\\n");
            eprintln!("  v{:<3} {}  {:24} w={:.3}  {}b{}",
                node.version, ts, node.provenance, node.weight, content_len, deleted_marker);
            eprintln!("       {}", preview);
        }
    }

    if !full {
        if let Some(latest) = versions.last() {
            eprintln!("\n--- Latest content (v{}, {}) ---",
                latest.version, latest.provenance);
            print!("{}", latest.content);
        }
    }

    Ok(())
}

pub fn cmd_write(key: &[String]) -> Result<(), String> {
    if key.is_empty() {
        return Err("write requires a key (reads content from stdin)".into());
    }
    let raw_key = key.join(" ");
    let mut content = String::new();
    std::io::Read::read_to_string(&mut std::io::stdin(), &mut content)
        .map_err(|e| format!("read stdin: {}", e))?;

    if content.trim().is_empty() {
        return Err("No content on stdin".into());
    }
    super::check_dry_run();

    let mut store = store::Store::load()?;
    let key = store.resolve_key(&raw_key).unwrap_or(raw_key);
    let result = store.upsert(&key, &content)?;
    match result {
        "unchanged" => println!("No change: '{}'", key),
        "updated" => println!("Updated '{}' (v{})", key, store.nodes[&key].version),
        _ => println!("Created '{}'", key),
    }
    if result != "unchanged" {
        store.save()?;
    }
    Ok(())
}

pub fn cmd_lookup_bump(keys: &[String]) -> Result<(), String> {
    if keys.is_empty() {
        return Err("lookup-bump requires at least one key".into());
    }
    let keys: Vec<&str> = keys.iter().map(|s| s.as_str()).collect();
    crate::lookups::bump_many(&keys)
}

pub fn cmd_lookups(date: Option<&str>) -> Result<(), String> {
    let date = date.map(|d| d.to_string())
        .unwrap_or_else(|| chrono::Local::now().format("%Y-%m-%d").to_string());

    let store = store::Store::load()?;
    let keys: Vec<String> = store.nodes.values().map(|n| n.key.clone()).collect();
    let resolved = crate::lookups::dump_resolved(&date, &keys)?;

    if resolved.is_empty() {
        println!("No lookups for {}", date);
        return Ok(());
    }

    println!("Lookups for {}:", date);
    for (key, count) in &resolved {
        println!("  {:4}  {}", count, key);
    }
    println!("\n{} distinct keys, {} total lookups",
        resolved.len(),
        resolved.iter().map(|(_, c)| *c as u64).sum::<u64>());
    Ok(())
}