// cli/graph.rs — graph subcommand handlers
//
// Extracted from main.rs. All graph-related CLI commands:
// link, link-add, link-impact, link-audit, cap-degree,
// normalize-strengths, trace, spectral-*, organize, communities.

use crate::{store, graph};
use crate::store::StoreView;

pub fn cmd_graph() -> Result<(), String> {
    let store = store::Store::load()?;
    let g = store.build_graph();
    println!("Graph: {} nodes, {} edges, {} communities",
        g.nodes().len(), g.edge_count(), g.community_count());
    println!("σ={:.2}  α={:.2}  gini={:.3}  cc={:.4}",
        g.small_world_sigma(), g.degree_power_law_exponent(),
        g.degree_gini(), g.avg_clustering_coefficient());
    Ok(())
}

pub fn cmd_cap_degree(max_deg: usize) -> Result<(), String> {
    let mut store = store::Store::load()?;
    let (hubs, pruned) = store.cap_degree(max_deg)?;
    store.save()?;
    println!("Capped {} hubs, pruned {} weak Auto edges (max_degree={})", hubs, pruned, max_deg);
    Ok(())
}

pub fn cmd_normalize_strengths(apply: bool) -> Result<(), String> {
    if apply { super::check_dry_run(); }
    let result = crate::mcp_server::memory_rpc(
        "graph_normalize_strengths",
        serde_json::json!({"apply": apply}),
    ).map_err(|e| e.to_string())?;
    print!("{}", result);
    Ok(())
}

pub fn cmd_link(key: &[String]) -> Result<(), String> {
    if key.is_empty() {
        return Err("link requires a key".into());
    }
    let key = key.join(" ");
    let result = crate::mcp_server::memory_rpc(
        "memory_links",
        serde_json::json!({"key": key}),
    ).map_err(|e| e.to_string())?;
    print!("{}", result);
    Ok(())
}

pub fn cmd_link_add(source: &str, target: &str, _reason: &[String]) -> Result<(), String> {
    super::check_dry_run();
    let result = crate::mcp_server::memory_rpc(
        "memory_link_add",
        serde_json::json!({"source": source, "target": target}),
    ).map_err(|e| e.to_string())?;
    println!("{}", result);
    Ok(())
}

pub fn cmd_link_set(source: &str, target: &str, strength: f32) -> Result<(), String> {
    super::check_dry_run();
    let result = crate::mcp_server::memory_rpc(
        "memory_link_set",
        serde_json::json!({"source": source, "target": target, "strength": strength}),
    ).map_err(|e| e.to_string())?;
    println!("{}", result);
    Ok(())
}

pub fn cmd_link_impact(source: &str, target: &str) -> Result<(), String> {
    let store = store::Store::load()?;
    let source = store.resolve_key(source)?;
    let target = store.resolve_key(target)?;
    let g = store.build_graph();

    let impact = g.link_impact(&source, &target);

    println!("Link impact: {} → {}", source, target);
    println!("  Source degree: {}  Target degree: {}", impact.source_deg, impact.target_deg);
    println!("  Hub link: {}  Same community: {}", impact.is_hub_link, impact.same_community);
    println!("  ΔCC source: {:+.4}  ΔCC target: {:+.4}", impact.delta_cc_source, impact.delta_cc_target);
    println!("  ΔGini: {:+.6}", impact.delta_gini);
    println!("  Assessment: {}", impact.assessment);
    Ok(())
}

pub fn cmd_trace(key: &[String]) -> Result<(), String> {
    if key.is_empty() {
        return Err("trace requires a key".into());
    }
    let key = key.join(" ");
    let store = store::Store::load()?;
    let resolved = store.resolve_key(&key)?;
    let g = store.build_graph();

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

    // Display the node itself
    println!("=== {} ===", resolved);
    println!("Type: {:?}  Weight: {:.2}",
        node.node_type, node.weight);
    if !node.source_ref.is_empty() {
        println!("Source: {}", node.source_ref);
    }

    // Show content preview
    let preview = crate::util::truncate(&node.content, 200, "...");
    println!("\n{}\n", preview);

    // Walk neighbors, grouped by node type
    let neighbors = g.neighbors(&resolved);
    let mut episodic_session = Vec::new();
    let mut episodic_daily = Vec::new();
    let mut episodic_weekly = Vec::new();
    let mut semantic = Vec::new();

    for (n, strength) in &neighbors {
        if let Some(nnode) = store.nodes.get(n.as_str()) {
            let entry = (n.as_str(), *strength, nnode);
            match nnode.node_type {
                store::NodeType::EpisodicSession =>
                    episodic_session.push(entry),
                store::NodeType::EpisodicDaily =>
                    episodic_daily.push(entry),
                store::NodeType::EpisodicWeekly
                | store::NodeType::EpisodicMonthly =>
                    episodic_weekly.push(entry),
                store::NodeType::Semantic =>
                    semantic.push(entry),
            }
        }
    }

    if !episodic_weekly.is_empty() {
        println!("Weekly digests:");
        for (k, s, n) in &episodic_weekly {
            let preview = crate::util::first_n_chars(n.content.lines().next().unwrap_or(""), 80);
            println!("  [{:.2}] {} — {}", s, k, preview);
        }
    }

    if !episodic_daily.is_empty() {
        println!("Daily digests:");
        for (k, s, n) in &episodic_daily {
            let preview = crate::util::first_n_chars(n.content.lines().next().unwrap_or(""), 80);
            println!("  [{:.2}] {} — {}", s, k, preview);
        }
    }

    if !episodic_session.is_empty() {
        println!("Session entries:");
        for (k, s, n) in &episodic_session {
            let preview = crate::util::first_n_chars(
                n.content.lines()
                    .find(|l| !l.is_empty() && !l.starts_with("<!--"))
                    .unwrap_or(""),
                80);
            println!("  [{:.2}] {}", s, k);
            if !n.source_ref.is_empty() {
                println!("         ↳ source: {}", n.source_ref);
            }
            println!("         {}", preview);
        }
    }

    if !semantic.is_empty() {
        println!("Semantic links:");
        for (k, s, _) in &semantic {
            println!("  [{:.2}] {}", s, k);
        }
    }

    println!("\nLinks: {} session, {} daily, {} weekly, {} semantic",
        episodic_session.len(), episodic_daily.len(),
        episodic_weekly.len(), semantic.len());

    Ok(())
}

pub fn cmd_organize(term: &str, key_only: bool, create_anchor: bool) -> Result<(), String> {
    let mut store = store::Store::load()?;

    // Step 1: find all non-deleted nodes matching the term
    let term_lower = term.to_lowercase();
    let mut topic_nodes: Vec<(String, String)> = Vec::new(); // (key, content)

    let skip_prefixes = ["_", "deep-index#", "facts-", "irc-history#"];

    for (key, node) in &store.nodes {
        if node.deleted { continue; }
        // Skip episodic/digest nodes — use NodeType, not key prefix
        if node.node_type != crate::store::NodeType::Semantic { continue; }
        let key_matches = key.to_lowercase().contains(&term_lower);
        let content_matches = !key_only && node.content.to_lowercase().contains(&term_lower);
        if !key_matches && !content_matches { continue; }
        if skip_prefixes.iter().any(|p| key.starts_with(p)) { continue; }
        topic_nodes.push((key.clone(), node.content.clone()));
    }

    if topic_nodes.is_empty() {
        println!("No topic nodes found matching '{}'", term);
        return Ok(());
    }

    topic_nodes.sort_by(|a, b| a.0.cmp(&b.0));

    println!("=== Organize: '{}' ===", term);
    println!("Found {} topic nodes:\n", topic_nodes.len());
    for (key, content) in &topic_nodes {
        let lines = content.lines().count();
        let words = content.split_whitespace().count();
        println!("  {:60} {:>4} lines  {:>5} words", key, lines, words);
    }

    // Step 2: check connectivity within cluster
    let g = store.build_graph();
    println!("=== Connectivity ===\n");

    // Pick hub by intra-cluster connectivity, not overall degree
    let cluster_keys: std::collections::HashSet<&str> = topic_nodes.iter()
        .filter(|(k,_)| store.nodes.contains_key(k.as_str()))
        .map(|(k,_)| k.as_str())
        .collect();

    let mut best_hub: Option<(&str, usize)> = None;
    for key in &cluster_keys {
        let intra_degree = g.neighbor_keys(key).iter()
            .filter(|n| cluster_keys.contains(*n))
            .count();
        if best_hub.is_none() || intra_degree > best_hub.unwrap().1 {
            best_hub = Some((key, intra_degree));
        }
    }

    if let Some((hub, deg)) = best_hub {
        println!("  Hub: {} (degree {})", hub, deg);
        let hub_nbrs = g.neighbor_keys(hub);

        let mut unlinked = Vec::new();
        for (key, _) in &topic_nodes {
            if key == hub { continue; }
            if store.nodes.get(key.as_str()).is_none() { continue; }
            if !hub_nbrs.contains(key.as_str()) {
                unlinked.push(key.clone());
            }
        }

        if unlinked.is_empty() {
            println!("  All cluster nodes connected to hub ✓");
        } else {
            println!("  NOT linked to hub:");
            for key in &unlinked {
                println!("    {} → needs link to {}", key, hub);
            }
        }
    }

    // Step 4: anchor node
    if create_anchor {
        println!("\n=== Anchor node ===\n");
        if store.nodes.contains_key(term) && !store.nodes[term].deleted {
            println!("  Anchor '{}' already exists ✓", term);
        } else {
            let desc = format!("Anchor node for '{}' search term", term);
            store.upsert(term, &desc)?;
            let anchor_uuid = store.nodes.get(term).unwrap().uuid;
            for (key, _) in &topic_nodes {
                if store.nodes.get(key.as_str()).is_none() { continue; }
                let target_uuid = store.nodes[key.as_str()].uuid;
                let rel = store::new_relation(
                    anchor_uuid, target_uuid,
                    store::RelationType::Link, 0.8,
                    term, key,
                );
                store.add_relation(rel)?;
            }
            println!("  Created anchor '{}' with {} links", term, topic_nodes.len());
        }
    }

    store.save()?;
    Ok(())
}

/// Show communities sorted by isolation (most isolated first).
/// Useful for finding poorly-integrated knowledge clusters that need
/// organize agents aimed at them.
pub fn cmd_communities(top_n: usize, min_size: usize) -> Result<(), String> {
    let result = crate::mcp_server::memory_rpc(
        "graph_communities",
        serde_json::json!({"top_n": top_n, "min_size": min_size}),
    ).map_err(|e| e.to_string())?;
    print!("{}", result);
    Ok(())
}