tldr_cli/commands/daemon/

daemon.rs

//! Core daemon state machine and runtime
//!
//! This module contains the `TLDRDaemon` struct which manages:
//! - Daemon lifecycle state (Initializing -> Ready -> ShuttingDown)
//! - Salsa-style query cache
//! - Session statistics tracking
//! - Hook activity tracking
//! - Dirty file tracking for incremental re-indexing
//!
//! # Security Mitigations
//!
//! - TIGER-P2-02: Socket cleanup on abnormal exit via signal handlers

use std::collections::hash_map::DefaultHasher;
use std::collections::{HashMap, HashSet};
use std::hash::{Hash, Hasher};
use std::path::PathBuf;
use std::sync::atomic::{AtomicBool, Ordering};
use std::sync::Arc;
use std::time::Instant;

use dashmap::DashMap;
use tokio::sync::{watch, RwLock};

use super::error::{DaemonError, DaemonResult};
use super::ipc::{read_command, send_response, IpcListener, IpcStream};
use super::salsa::{QueryCache, QueryKey};
use super::types::{
    AllSessionsSummary, DaemonCommand, DaemonConfig, DaemonResponse, DaemonStatus, HookStats,
    SalsaCacheStats, SessionStats, HOOK_FLUSH_THRESHOLD,
};

use tldr_core::{
    architecture_analysis, build_project_call_graph, change_impact, collect_all_functions,
    dead_code_analysis, detect_or_parse_language, extract_file, find_importers, get_cfg_context,
    get_code_structure, get_dfg_context, get_file_tree, get_imports, get_relevant_context,
    get_slice, impact_analysis, search as tldr_search, FileTree, Language, NodeType, SliceDirection,
};
#[cfg(feature = "semantic")]
use tldr_core::semantic::{BuildOptions, CacheConfig, IndexSearchOptions, SemanticIndex};
#[cfg(test)]
use super::types::DEFAULT_REINDEX_THRESHOLD;

// =============================================================================
// Helper Functions
// =============================================================================

/// Hash a slice of string arguments into a u64 for cache key generation.
fn hash_str_args(parts: &[&str]) -> u64 {
    let mut hasher = DefaultHasher::new();
    for part in parts {
        part.hash(&mut hasher);
    }
    hasher.finish()
}

/// Count the number of file nodes in a FileTree recursively.
fn count_tree_files(tree: &FileTree) -> usize {
    match tree.node_type {
        NodeType::File => 1,
        NodeType::Dir => tree.children.iter().map(count_tree_files).sum(),
    }
}

// =============================================================================
// TLDRDaemon - Main Daemon Process
// =============================================================================

/// Main daemon process that handles client connections and manages state.
///
/// The daemon runs an event loop that:
/// 1. Accepts incoming IPC connections
/// 2. Reads commands from clients
/// 3. Dispatches commands to handlers
/// 4. Sends responses back to clients
/// 5. Handles shutdown signals gracefully
pub struct TLDRDaemon {
    /// Project root directory
    project: PathBuf,
    /// Daemon configuration
    config: DaemonConfig,
    /// When the daemon was started
    start_time: Instant,
    /// Current daemon status
    status: Arc<RwLock<DaemonStatus>>,
    /// Salsa-style query cache
    cache: QueryCache,
    /// Per-session statistics
    sessions: DashMap<String, SessionStats>,
    /// Per-hook activity statistics
    hooks: DashMap<String, HookStats>,
    /// Set of dirty files awaiting reindex
    dirty_files: Arc<RwLock<HashSet<PathBuf>>>,
    /// Shutdown signal sender
    shutdown_tx: watch::Sender<bool>,
    /// Flag to track if we've been signaled to stop
    stopping: AtomicBool,
    /// Last time a client command was handled (for idle timeout)
    last_activity: Arc<RwLock<Instant>>,
    /// Number of indexed files (for status reporting)
    indexed_files: Arc<RwLock<usize>>,
    /// Persistent semantic index (built lazily on first query, invalidated on Notify)
    #[cfg(feature = "semantic")]
    semantic_index: Arc<RwLock<Option<SemanticIndex>>>,
}

impl TLDRDaemon {
    /// Create a new daemon instance.
    ///
    /// The daemon starts in `Initializing` status and must have `run()` called
    /// to begin accepting connections.
    pub fn new(project: PathBuf, config: DaemonConfig) -> Self {
        let (shutdown_tx, _shutdown_rx) = watch::channel(false);

        Self {
            project,
            config,
            start_time: Instant::now(),
            status: Arc::new(RwLock::new(DaemonStatus::Initializing)),
            cache: QueryCache::with_defaults(),
            sessions: DashMap::new(),
            hooks: DashMap::new(),
            dirty_files: Arc::new(RwLock::new(HashSet::new())),
            shutdown_tx,
            stopping: AtomicBool::new(false),
            last_activity: Arc::new(RwLock::new(Instant::now())),
            indexed_files: Arc::new(RwLock::new(0)),
            #[cfg(feature = "semantic")]
            semantic_index: Arc::new(RwLock::new(None)),
        }
    }

    /// Get the daemon's current status.
    pub async fn status(&self) -> DaemonStatus {
        *self.status.read().await
    }

    /// Get the daemon's uptime in seconds.
    pub fn uptime(&self) -> f64 {
        self.start_time.elapsed().as_secs_f64()
    }

    /// Get the daemon's uptime formatted as a human-readable string.
    pub fn uptime_human(&self) -> String {
        let secs = self.start_time.elapsed().as_secs();
        let hours = secs / 3600;
        let minutes = (secs % 3600) / 60;
        let seconds = secs % 60;
        format!("{}h {}m {}s", hours, minutes, seconds)
    }

    /// Get cache statistics.
    pub fn cache_stats(&self) -> SalsaCacheStats {
        self.cache.stats()
    }

    /// Get the project path.
    pub fn project(&self) -> &PathBuf {
        &self.project
    }

    /// Get the number of indexed files.
    pub async fn indexed_files(&self) -> usize {
        *self.indexed_files.read().await
    }

    /// Get a summary of all sessions.
    pub fn all_sessions_summary(&self) -> AllSessionsSummary {
        let mut summary = AllSessionsSummary {
            active_sessions: self.sessions.len(),
            ..AllSessionsSummary::default()
        };

        for entry in self.sessions.iter() {
            let stats = entry.value();
            summary.total_raw_tokens += stats.raw_tokens;
            summary.total_tldr_tokens += stats.tldr_tokens;
            summary.total_requests += stats.requests;
        }

        summary
    }

    /// Get all hook statistics.
    pub fn hook_stats(&self) -> HashMap<String, HookStats> {
        self.hooks
            .iter()
            .map(|e| (e.key().clone(), e.value().clone()))
            .collect()
    }

    /// Signal the daemon to shut down gracefully.
    pub fn shutdown(&self) {
        self.stopping.store(true, Ordering::SeqCst);
        let _ = self.shutdown_tx.send(true);
    }

    /// Run the daemon main loop.
    ///
    /// This function blocks until the daemon is shut down via:
    /// - A `Shutdown` command from a client
    /// - A SIGTERM/SIGINT signal
    /// - An error in the listener
    pub async fn run(self: Arc<Self>, listener: IpcListener) -> DaemonResult<()> {
        // Set status to Ready
        {
            let mut status = self.status.write().await;
            *status = DaemonStatus::Ready;
        }

        // Set up signal handlers for graceful shutdown
        #[cfg(unix)]
        {
            let daemon = Arc::clone(&self);
            tokio::spawn(async move {
                let mut sigterm =
                    tokio::signal::unix::signal(tokio::signal::unix::SignalKind::terminate())
                        .expect("Failed to register SIGTERM handler");
                let mut sigint =
                    tokio::signal::unix::signal(tokio::signal::unix::SignalKind::interrupt())
                        .expect("Failed to register SIGINT handler");

                tokio::select! {
                    _ = sigterm.recv() => {
                        daemon.shutdown();
                    }
                    _ = sigint.recv() => {
                        daemon.shutdown();
                    }
                }
            });
        }

        // Main event loop
        let idle_timeout = std::time::Duration::from_secs(self.config.idle_timeout_secs);

        loop {
            // Check for shutdown signal
            if self.stopping.load(Ordering::SeqCst) {
                break;
            }

            // Safety net: self-terminate if project directory no longer exists
            if !self.project.exists() {
                eprintln!(
                    "Project directory {} no longer exists, shutting down",
                    self.project.display()
                );
                break;
            }

            // Self-terminate after idle timeout with no client activity
            {
                let last = self.last_activity.read().await;
                if last.elapsed() > idle_timeout {
                    eprintln!(
                        "No client activity for {}s, shutting down",
                        self.config.idle_timeout_secs
                    );
                    break;
                }
            }

            // Accept connection with timeout
            let accept_future = listener.accept();
            let timeout = tokio::time::Duration::from_millis(100);

            match tokio::time::timeout(timeout, accept_future).await {
                Ok(Ok(mut stream)) => {
                    // Update activity timestamp
                    *self.last_activity.write().await = Instant::now();

                    // Handle the connection
                    let daemon = Arc::clone(&self);
                    tokio::spawn(async move {
                        if let Err(e) = daemon.handle_connection(&mut stream).await {
                            eprintln!("Connection error: {}", e);
                        }
                    });
                }
                Ok(Err(e)) => {
                    // Accept error - log and continue
                    eprintln!("Accept error: {}", e);
                }
                Err(_) => {
                    // Timeout - check shutdown and continue
                    continue;
                }
            }
        }

        // Set status to ShuttingDown
        {
            let mut status = self.status.write().await;
            *status = DaemonStatus::ShuttingDown;
        }

        // Persist stats before exit
        self.persist_stats().await?;

        // Set status to Stopped
        {
            let mut status = self.status.write().await;
            *status = DaemonStatus::Stopped;
        }

        Ok(())
    }

    /// Handle a single client connection.
    async fn handle_connection(self: &Arc<Self>, stream: &mut IpcStream) -> DaemonResult<()> {
        // Read command
        let cmd = read_command(stream).await?;

        // Handle command
        let response = self.handle_command(cmd).await;

        // Send response
        send_response(stream, &response).await?;

        Ok(())
    }

    /// Handle a daemon command and return the response.
    pub async fn handle_command(&self, cmd: DaemonCommand) -> DaemonResponse {
        match cmd {
            DaemonCommand::Ping => DaemonResponse::Status {
                status: "ok".to_string(),
                message: Some("pong".to_string()),
            },

            DaemonCommand::Status { session } => self.handle_status(session).await,

            DaemonCommand::Shutdown => {
                self.shutdown();
                DaemonResponse::Status {
                    status: "shutting_down".to_string(),
                    message: Some("Daemon is shutting down".to_string()),
                }
            }

            DaemonCommand::Notify { file } => self.handle_notify(file).await,

            DaemonCommand::Track {
                hook,
                success,
                metrics,
            } => self.handle_track(hook, success, metrics).await,

            DaemonCommand::Warm { language } => {
                let lang = language
                    .as_deref()
                    .and_then(|l| l.parse::<Language>().ok())
                    .unwrap_or(Language::Python);

                let mut warmed = Vec::new();
                let mut errors = Vec::new();

                // 1. Warm call graph
                let calls_key = QueryKey::new(
                    "calls",
                    hash_str_args(&[&self.project.to_string_lossy()]),
                );
                if self.cache.get::<serde_json::Value>(&calls_key).is_some() {
                    warmed.push("call_graph (cached)");
                } else {
                    match build_project_call_graph(&self.project, lang, None, true) {
                        Ok(result) => {
                            let val = serde_json::to_value(&result).unwrap_or_default();
                            self.cache.insert(calls_key, &val, vec![]);
                            warmed.push("call_graph");
                        }
                        Err(e) => errors.push(format!("call_graph: {}", e)),
                    }
                }

                // 2. Warm code structure
                let struct_key = QueryKey::new(
                    "structure",
                    hash_str_args(&[&self.project.to_string_lossy(), ""]),
                );
                if self.cache.get::<serde_json::Value>(&struct_key).is_some() {
                    warmed.push("structure (cached)");
                } else {
                    match get_code_structure(&self.project, lang, 0, None) {
                        Ok(result) => {
                            let val = serde_json::to_value(&result).unwrap_or_default();
                            self.cache.insert(struct_key, &val, vec![]);
                            warmed.push("structure");
                        }
                        Err(e) => errors.push(format!("structure: {}", e)),
                    }
                }

                // 3. Warm file tree
                let tree_key = QueryKey::new(
                    "tree",
                    hash_str_args(&[&self.project.to_string_lossy()]),
                );
                if self.cache.get::<serde_json::Value>(&tree_key).is_some() {
                    warmed.push("file_tree (cached)");
                } else {
                    match get_file_tree(&self.project, None, true, None) {
                        Ok(result) => {
                            let file_count = count_tree_files(&result);
                            let val = serde_json::to_value(&result).unwrap_or_default();
                            self.cache.insert(tree_key, &val, vec![]);
                            *self.indexed_files.write().await = file_count;
                            warmed.push("file_tree");
                        }
                        Err(e) => errors.push(format!("file_tree: {}", e)),
                    }
                }

                // 4. Warm semantic index
                #[cfg(feature = "semantic")]
                {
                    let mut index_guard = self.semantic_index.write().await;
                    if index_guard.is_some() {
                        warmed.push("semantic_index (cached)");
                    } else {
                        let build_opts = BuildOptions {
                            show_progress: false,
                            use_cache: true,
                            ..Default::default()
                        };
                        match SemanticIndex::build(
                            &self.project,
                            build_opts,
                            Some(CacheConfig::default()),
                        ) {
                            Ok(idx) => {
                                *index_guard = Some(idx);
                                warmed.push("semantic_index");
                            }
                            Err(e) => errors.push(format!("semantic_index: {}", e)),
                        }
                    }
                }

                let message = if errors.is_empty() {
                    format!("Warmed: {}", warmed.join(", "))
                } else {
                    format!(
                        "Warmed: {}. Errors: {}",
                        warmed.join(", "),
                        errors.join("; ")
                    )
                };

                DaemonResponse::Status {
                    status: "ok".to_string(),
                    message: Some(message),
                }
            }

            #[cfg(feature = "semantic")]
            DaemonCommand::Semantic { query, top_k } => {
                // Semantic search with persistent index
                let mut index_guard = self.semantic_index.write().await;

                // Build index lazily on first query
                if index_guard.is_none() {
                    let build_opts = BuildOptions {
                        show_progress: false,
                        use_cache: true,
                        ..Default::default()
                    };
                    let cache_config = Some(CacheConfig::default());

                    match SemanticIndex::build(&self.project, build_opts, cache_config) {
                        Ok(idx) => {
                            *index_guard = Some(idx);
                        }
                        Err(e) => {
                            return DaemonResponse::Error {
                                status: "error".to_string(),
                                error: format!("Failed to build semantic index: {}", e),
                            };
                        }
                    }
                }

                // Search the index
                let index = index_guard.as_mut().unwrap();
                let search_opts = IndexSearchOptions {
                    top_k,
                    threshold: 0.5,
                    include_snippet: true,
                    snippet_lines: 5,
                };

                match index.search(&query, &search_opts) {
                    Ok(report) => match serde_json::to_value(&report) {
                        Ok(value) => DaemonResponse::Result(value),
                        Err(e) => DaemonResponse::Error {
                            status: "error".to_string(),
                            error: format!("Serialization error: {}", e),
                        },
                    },
                    Err(e) => DaemonResponse::Error {
                        status: "error".to_string(),
                        error: format!("Semantic search failed: {}", e),
                    },
                }
            }

            #[cfg(not(feature = "semantic"))]
            DaemonCommand::Semantic { .. } => DaemonResponse::Error {
                status: "error".to_string(),
                error: "Semantic search requires the 'semantic' feature".to_string(),
            },

            // Pass-through analysis commands with Salsa cache integration
            DaemonCommand::Search {
                pattern,
                max_results,
            } => {
                let max = max_results.unwrap_or(100);
                let key = QueryKey::new(
                    "search",
                    hash_str_args(&[&pattern, &max.to_string()]),
                );
                if let Some(cached) = self.cache.get::<serde_json::Value>(&key) {
                    return DaemonResponse::Result(cached);
                }
                match tldr_search(
                    &pattern,
                    &self.project,
                    None,
                    2,
                    max,
                    1000,
                    None,
                ) {
                    Ok(result) => {
                        let val = serde_json::to_value(&result).unwrap_or_default();
                        self.cache.insert(key, &val, vec![]);
                        DaemonResponse::Result(val)
                    }
                    Err(e) => DaemonResponse::Error {
                        status: "error".to_string(),
                        error: e.to_string(),
                    },
                }
            }

            DaemonCommand::Extract { file, session: _ } => {
                let file_str = file.to_string_lossy().to_string();
                let key = QueryKey::new("extract", hash_str_args(&[&file_str]));
                if let Some(cached) = self.cache.get::<serde_json::Value>(&key) {
                    return DaemonResponse::Result(cached);
                }
                let file_hash = super::salsa::hash_path(&file);
                match extract_file(&file, Some(&self.project)) {
                    Ok(result) => {
                        let val = serde_json::to_value(&result).unwrap_or_default();
                        self.cache.insert(key, &val, vec![file_hash]);
                        DaemonResponse::Result(val)
                    }
                    Err(e) => DaemonResponse::Error {
                        status: "error".to_string(),
                        error: e.to_string(),
                    },
                }
            }

            DaemonCommand::Tree { path } => {
                let root = path.unwrap_or_else(|| self.project.clone());
                let root_str = root.to_string_lossy().to_string();
                let key = QueryKey::new("tree", hash_str_args(&[&root_str]));
                if let Some(cached) = self.cache.get::<serde_json::Value>(&key) {
                    return DaemonResponse::Result(cached);
                }
                match get_file_tree(&root, None, true, None) {
                    Ok(result) => {
                        let val = serde_json::to_value(&result).unwrap_or_default();
                        self.cache.insert(key, &val, vec![]);
                        DaemonResponse::Result(val)
                    }
                    Err(e) => DaemonResponse::Error {
                        status: "error".to_string(),
                        error: e.to_string(),
                    },
                }
            }

            DaemonCommand::Structure { path, lang } => {
                let path_str = path.to_string_lossy().to_string();
                let lang_str = lang.as_deref().unwrap_or("");
                let key = QueryKey::new(
                    "structure",
                    hash_str_args(&[&path_str, lang_str]),
                );
                if let Some(cached) = self.cache.get::<serde_json::Value>(&key) {
                    return DaemonResponse::Result(cached);
                }
                let language = match detect_or_parse_language(lang.as_deref(), &path) {
                    Ok(l) => l,
                    Err(e) => {
                        return DaemonResponse::Error {
                            status: "error".to_string(),
                            error: e.to_string(),
                        }
                    }
                };
                match get_code_structure(&path, language, 0, None) {
                    Ok(result) => {
                        let val = serde_json::to_value(&result).unwrap_or_default();
                        self.cache.insert(key, &val, vec![]);
                        DaemonResponse::Result(val)
                    }
                    Err(e) => DaemonResponse::Error {
                        status: "error".to_string(),
                        error: e.to_string(),
                    },
                }
            }

            DaemonCommand::Context { entry, depth } => {
                let d = depth.unwrap_or(2);
                let key = QueryKey::new(
                    "context",
                    hash_str_args(&[&entry, &d.to_string()]),
                );
                if let Some(cached) = self.cache.get::<serde_json::Value>(&key) {
                    return DaemonResponse::Result(cached);
                }
                match get_relevant_context(
                    &self.project,
                    &entry,
                    d,
                    Language::Python,
                    true,
                    None,
                ) {
                    Ok(result) => {
                        let val = serde_json::to_value(&result).unwrap_or_default();
                        self.cache.insert(key, &val, vec![]);
                        DaemonResponse::Result(val)
                    }
                    Err(e) => DaemonResponse::Error {
                        status: "error".to_string(),
                        error: e.to_string(),
                    },
                }
            }

            DaemonCommand::Cfg { file, function } => {
                let file_str = file.to_string_lossy().to_string();
                let key = QueryKey::new(
                    "cfg",
                    hash_str_args(&[&file_str, &function]),
                );
                if let Some(cached) = self.cache.get::<serde_json::Value>(&key) {
                    return DaemonResponse::Result(cached);
                }
                let language = match detect_or_parse_language(None, &file) {
                    Ok(l) => l,
                    Err(e) => {
                        return DaemonResponse::Error {
                            status: "error".to_string(),
                            error: e.to_string(),
                        }
                    }
                };
                let file_hash = super::salsa::hash_path(&file);
                match get_cfg_context(&file_str, &function, language) {
                    Ok(result) => {
                        let val = serde_json::to_value(&result).unwrap_or_default();
                        self.cache.insert(key, &val, vec![file_hash]);
                        DaemonResponse::Result(val)
                    }
                    Err(e) => DaemonResponse::Error {
                        status: "error".to_string(),
                        error: e.to_string(),
                    },
                }
            }

            DaemonCommand::Dfg { file, function } => {
                let file_str = file.to_string_lossy().to_string();
                let key = QueryKey::new(
                    "dfg",
                    hash_str_args(&[&file_str, &function]),
                );
                if let Some(cached) = self.cache.get::<serde_json::Value>(&key) {
                    return DaemonResponse::Result(cached);
                }
                let language = match detect_or_parse_language(None, &file) {
                    Ok(l) => l,
                    Err(e) => {
                        return DaemonResponse::Error {
                            status: "error".to_string(),
                            error: e.to_string(),
                        }
                    }
                };
                let file_hash = super::salsa::hash_path(&file);
                match get_dfg_context(&file_str, &function, language) {
                    Ok(result) => {
                        let val = serde_json::to_value(&result).unwrap_or_default();
                        self.cache.insert(key, &val, vec![file_hash]);
                        DaemonResponse::Result(val)
                    }
                    Err(e) => DaemonResponse::Error {
                        status: "error".to_string(),
                        error: e.to_string(),
                    },
                }
            }

            DaemonCommand::Slice {
                file,
                function,
                line,
            } => {
                let file_str = file.to_string_lossy().to_string();
                let key = QueryKey::new(
                    "slice",
                    hash_str_args(&[&file_str, &function, &line.to_string()]),
                );
                if let Some(cached) = self.cache.get::<serde_json::Value>(&key) {
                    return DaemonResponse::Result(cached);
                }
                let language = match detect_or_parse_language(None, &file) {
                    Ok(l) => l,
                    Err(e) => {
                        return DaemonResponse::Error {
                            status: "error".to_string(),
                            error: e.to_string(),
                        }
                    }
                };
                let file_hash = super::salsa::hash_path(&file);
                match get_slice(
                    &file_str,
                    &function,
                    line as u32,
                    SliceDirection::Backward,
                    None,
                    language,
                ) {
                    Ok(result) => {
                        let val = serde_json::to_value(&result).unwrap_or_default();
                        self.cache.insert(key, &val, vec![file_hash]);
                        DaemonResponse::Result(val)
                    }
                    Err(e) => DaemonResponse::Error {
                        status: "error".to_string(),
                        error: e.to_string(),
                    },
                }
            }

            DaemonCommand::Calls { path } => {
                let root = path.unwrap_or_else(|| self.project.clone());
                let root_str = root.to_string_lossy().to_string();
                let key = QueryKey::new("calls", hash_str_args(&[&root_str]));
                if let Some(cached) = self.cache.get::<serde_json::Value>(&key) {
                    return DaemonResponse::Result(cached);
                }
                match build_project_call_graph(&root, Language::Python, None, true) {
                    Ok(result) => {
                        let val = serde_json::to_value(&result).unwrap_or_default();
                        self.cache.insert(key, &val, vec![]);
                        DaemonResponse::Result(val)
                    }
                    Err(e) => DaemonResponse::Error {
                        status: "error".to_string(),
                        error: e.to_string(),
                    },
                }
            }

            DaemonCommand::Impact { func, depth } => {
                let d = depth.unwrap_or(3);
                let key = QueryKey::new(
                    "impact",
                    hash_str_args(&[&func, &d.to_string()]),
                );
                if let Some(cached) = self.cache.get::<serde_json::Value>(&key) {
                    return DaemonResponse::Result(cached);
                }
                let graph =
                    match build_project_call_graph(&self.project, Language::Python, None, true) {
                        Ok(g) => g,
                        Err(e) => {
                            return DaemonResponse::Error {
                                status: "error".to_string(),
                                error: e.to_string(),
                            }
                        }
                    };
                match impact_analysis(&graph, &func, d, None) {
                    Ok(result) => {
                        let val = serde_json::to_value(&result).unwrap_or_default();
                        self.cache.insert(key, &val, vec![]);
                        DaemonResponse::Result(val)
                    }
                    Err(e) => DaemonResponse::Error {
                        status: "error".to_string(),
                        error: e.to_string(),
                    },
                }
            }

            DaemonCommand::Dead { path, entry } => {
                let root = path.unwrap_or_else(|| self.project.clone());
                let root_str = root.to_string_lossy().to_string();
                let entry_str = entry
                    .as_ref()
                    .map(|v| v.join(","))
                    .unwrap_or_default();
                let key = QueryKey::new(
                    "dead",
                    hash_str_args(&[&root_str, &entry_str]),
                );
                if let Some(cached) = self.cache.get::<serde_json::Value>(&key) {
                    return DaemonResponse::Result(cached);
                }
                let graph =
                    match build_project_call_graph(&root, Language::Python, None, true) {
                        Ok(g) => g,
                        Err(e) => {
                            return DaemonResponse::Error {
                                status: "error".to_string(),
                                error: e.to_string(),
                            }
                        }
                    };
                // Collect all functions from the project by extracting each file
                let extensions: HashSet<String> =
                    Language::Python.extensions().iter().map(|s| s.to_string()).collect();
                let file_tree = match get_file_tree(&root, Some(&extensions), true, None) {
                    Ok(t) => t,
                    Err(e) => {
                        return DaemonResponse::Error {
                            status: "error".to_string(),
                            error: e.to_string(),
                        }
                    }
                };
                let files = tldr_core::fs::tree::collect_files(&file_tree, &root);
                let mut module_infos = Vec::new();
                for file_path in files {
                    if let Ok(info) = extract_file(&file_path, Some(&root)) {
                        module_infos.push((file_path, info));
                    }
                }
                let all_functions = collect_all_functions(&module_infos);
                let entry_strings: Option<Vec<String>> = entry;
                let entry_refs: Option<&[String]> = entry_strings.as_deref();
                match dead_code_analysis(&graph, &all_functions, entry_refs) {
                    Ok(result) => {
                        let val = serde_json::to_value(&result).unwrap_or_default();
                        self.cache.insert(key, &val, vec![]);
                        DaemonResponse::Result(val)
                    }
                    Err(e) => DaemonResponse::Error {
                        status: "error".to_string(),
                        error: e.to_string(),
                    },
                }
            }

            DaemonCommand::Arch { path } => {
                let root = path.unwrap_or_else(|| self.project.clone());
                let root_str = root.to_string_lossy().to_string();
                let key = QueryKey::new("arch", hash_str_args(&[&root_str]));
                if let Some(cached) = self.cache.get::<serde_json::Value>(&key) {
                    return DaemonResponse::Result(cached);
                }
                let graph =
                    match build_project_call_graph(&root, Language::Python, None, true) {
                        Ok(g) => g,
                        Err(e) => {
                            return DaemonResponse::Error {
                                status: "error".to_string(),
                                error: e.to_string(),
                            }
                        }
                    };
                match architecture_analysis(&graph) {
                    Ok(result) => {
                        let val = serde_json::to_value(&result).unwrap_or_default();
                        self.cache.insert(key, &val, vec![]);
                        DaemonResponse::Result(val)
                    }
                    Err(e) => DaemonResponse::Error {
                        status: "error".to_string(),
                        error: e.to_string(),
                    },
                }
            }

            DaemonCommand::Imports { file } => {
                let file_str = file.to_string_lossy().to_string();
                let key = QueryKey::new("imports", hash_str_args(&[&file_str]));
                if let Some(cached) = self.cache.get::<serde_json::Value>(&key) {
                    return DaemonResponse::Result(cached);
                }
                let language = match detect_or_parse_language(None, &file) {
                    Ok(l) => l,
                    Err(e) => {
                        return DaemonResponse::Error {
                            status: "error".to_string(),
                            error: e.to_string(),
                        }
                    }
                };
                let file_hash = super::salsa::hash_path(&file);
                match get_imports(&file, language) {
                    Ok(result) => {
                        let val = serde_json::to_value(&result).unwrap_or_default();
                        self.cache.insert(key, &val, vec![file_hash]);
                        DaemonResponse::Result(val)
                    }
                    Err(e) => DaemonResponse::Error {
                        status: "error".to_string(),
                        error: e.to_string(),
                    },
                }
            }

            DaemonCommand::Importers { module, path } => {
                let root = path.unwrap_or_else(|| self.project.clone());
                let root_str = root.to_string_lossy().to_string();
                let key = QueryKey::new(
                    "importers",
                    hash_str_args(&[&module, &root_str]),
                );
                if let Some(cached) = self.cache.get::<serde_json::Value>(&key) {
                    return DaemonResponse::Result(cached);
                }
                match find_importers(&root, &module, Language::Python) {
                    Ok(result) => {
                        let val = serde_json::to_value(&result).unwrap_or_default();
                        self.cache.insert(key, &val, vec![]);
                        DaemonResponse::Result(val)
                    }
                    Err(e) => DaemonResponse::Error {
                        status: "error".to_string(),
                        error: e.to_string(),
                    },
                }
            }

            DaemonCommand::Diagnostics { path, project: _ } => {
                DaemonResponse::Error {
                    status: "error".to_string(),
                    error: format!(
                        "Diagnostics requires external tool orchestration; \
                         use CLI directly: tldr diagnostics {}",
                        path.display()
                    ),
                }
            }

            DaemonCommand::ChangeImpact {
                files,
                session: _,
                git: _,
            } => {
                let files_str = files
                    .as_ref()
                    .map(|v| {
                        v.iter()
                            .map(|p| p.to_string_lossy().to_string())
                            .collect::<Vec<_>>()
                            .join(",")
                    })
                    .unwrap_or_default();
                let key = QueryKey::new(
                    "change_impact",
                    hash_str_args(&[&files_str]),
                );
                if let Some(cached) = self.cache.get::<serde_json::Value>(&key) {
                    return DaemonResponse::Result(cached);
                }
                let changed: Option<Vec<PathBuf>> = files;
                match change_impact(
                    &self.project,
                    changed.as_deref(),
                    Language::Python,
                ) {
                    Ok(result) => {
                        let val = serde_json::to_value(&result).unwrap_or_default();
                        self.cache.insert(key, &val, vec![]);
                        DaemonResponse::Result(val)
                    }
                    Err(e) => DaemonResponse::Error {
                        status: "error".to_string(),
                        error: e.to_string(),
                    },
                }
            }
        }
    }

    /// Handle the Status command.
    async fn handle_status(&self, session: Option<String>) -> DaemonResponse {
        let status = self.status().await;
        let uptime = self.uptime();
        let files = self.indexed_files().await;
        let salsa_stats = self.cache_stats();
        let all_sessions = Some(self.all_sessions_summary());
        let hook_stats = Some(self.hook_stats());

        // Get session-specific stats if requested
        let session_stats =
            session.and_then(|id| self.sessions.get(&id).map(|entry| entry.value().clone()));

        DaemonResponse::FullStatus {
            status,
            uptime,
            files,
            project: self.project.clone(),
            salsa_stats,
            dedup_stats: None,
            session_stats,
            all_sessions,
            hook_stats,
        }
    }

    /// Handle the Notify command (file change notification).
    async fn handle_notify(&self, file: PathBuf) -> DaemonResponse {
        // Add file to dirty set
        let dirty_count = {
            let mut dirty = self.dirty_files.write().await;
            dirty.insert(file.clone());
            dirty.len()
        };

        // Invalidate cache entries for this file
        let file_hash = super::salsa::hash_path(&file);
        self.cache.invalidate_by_input(file_hash);

        // Invalidate semantic index so it rebuilds on next query
        #[cfg(feature = "semantic")]
        {
            let mut idx = self.semantic_index.write().await;
            *idx = None;
        }

        let threshold = self.config.auto_reindex_threshold;
        let reindex_triggered = dirty_count >= threshold;

        // Trigger reindex if threshold reached
        if reindex_triggered {
            // Clear dirty set
            let mut dirty = self.dirty_files.write().await;
            dirty.clear();

            // In full implementation, would spawn background reindex task
            // For now, just clear the dirty set
        }

        DaemonResponse::NotifyResponse {
            status: "ok".to_string(),
            dirty_count,
            threshold,
            reindex_triggered,
        }
    }

    /// Handle the Track command (hook activity tracking).
    async fn handle_track(
        &self,
        hook: String,
        success: bool,
        metrics: HashMap<String, f64>,
    ) -> DaemonResponse {
        // Get or create hook stats
        let mut entry = self
            .hooks
            .entry(hook.clone())
            .or_insert_with(|| HookStats::new(hook.clone()));

        // Record invocation
        let metrics_opt = if metrics.is_empty() {
            None
        } else {
            Some(metrics)
        };
        entry.record_invocation(success, metrics_opt);

        let total_invocations = entry.invocations;
        let flushed = total_invocations.is_multiple_of(HOOK_FLUSH_THRESHOLD as u64);

        // Flush stats periodically
        if flushed {
            // In full implementation, would persist stats to disk
            // For now, just mark as flushed
        }

        DaemonResponse::TrackResponse {
            status: "ok".to_string(),
            hook,
            total_invocations,
            flushed,
        }
    }

    /// Persist statistics to disk.
    async fn persist_stats(&self) -> DaemonResult<()> {
        // Create cache directory if it doesn't exist
        let cache_dir = self.project.join(".tldr/cache");
        if !cache_dir.exists() {
            std::fs::create_dir_all(&cache_dir)?;
        }

        // Save Salsa cache stats
        let salsa_stats_path = cache_dir.join("salsa_stats.json");
        let stats = self.cache_stats();
        let json = serde_json::to_string_pretty(&stats)?;
        std::fs::write(salsa_stats_path, json)?;

        // Save full query cache
        let cache_path = cache_dir.join("query_cache.bin");
        self.cache.save_to_file(&cache_path)?;

        Ok(())
    }
}

// =============================================================================
// Daemon Control Functions
// =============================================================================

/// Start a daemon in the background for the given project.
///
/// Returns the PID of the daemon process.
pub async fn start_daemon_background(project: &std::path::Path) -> DaemonResult<u32> {
    use std::process::Command;

    // Get the current executable path
    let exe_path = std::env::current_exe().map_err(DaemonError::Io)?;

    // Spawn the daemon process
    #[cfg(unix)]
    {
        use std::os::unix::process::CommandExt;

        let child = unsafe {
            Command::new(&exe_path)
                .args(["daemon", "start", "--project"])
                .arg(project.as_os_str())
                .arg("--foreground")
                .stdin(std::process::Stdio::null())
                .stdout(std::process::Stdio::null())
                .stderr(std::process::Stdio::null())
                .pre_exec(|| {
                    // Create new session (detach from terminal)
                    libc::setsid();
                    Ok(())
                })
                .spawn()
                .map_err(DaemonError::Io)?
        };

        Ok(child.id())
    }

    #[cfg(windows)]
    {
        use std::os::windows::process::CommandExt;
        const DETACHED_PROCESS: u32 = 0x00000008;
        const CREATE_NO_WINDOW: u32 = 0x08000000;

        let child = Command::new(&exe_path)
            .args(["daemon", "start", "--project"])
            .arg(project.as_os_str())
            .arg("--foreground")
            .stdin(std::process::Stdio::null())
            .stdout(std::process::Stdio::null())
            .stderr(std::process::Stdio::null())
            .creation_flags(DETACHED_PROCESS | CREATE_NO_WINDOW)
            .spawn()
            .map_err(DaemonError::Io)?;

        Ok(child.id())
    }
}

/// Wait for a daemon to become ready by polling the socket.
///
/// Returns `Ok(())` if the daemon becomes available within the timeout.
pub async fn wait_for_daemon(project: &std::path::Path, timeout_secs: u64) -> DaemonResult<()> {
    let start = Instant::now();
    let timeout = std::time::Duration::from_secs(timeout_secs);

    while start.elapsed() < timeout {
        // Try to connect
        if super::ipc::check_socket_alive(project).await {
            return Ok(());
        }

        // Wait a bit before retrying
        tokio::time::sleep(std::time::Duration::from_millis(100)).await;
    }

    Err(DaemonError::ConnectionTimeout { timeout_secs })
}

// =============================================================================
// Tests
// =============================================================================

#[cfg(test)]
mod tests {
    use super::*;
    use tempfile::TempDir;

    #[test]
    fn test_daemon_new() {
        let temp = TempDir::new().unwrap();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        assert_eq!(daemon.project(), temp.path());
        assert!(daemon.uptime() < 1.0);
    }

    #[tokio::test]
    async fn test_daemon_status_initial() {
        let temp = TempDir::new().unwrap();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        assert_eq!(daemon.status().await, DaemonStatus::Initializing);
    }

    #[tokio::test]
    async fn test_daemon_uptime_human() {
        let temp = TempDir::new().unwrap();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let uptime = daemon.uptime_human();
        assert!(uptime.contains("h"));
        assert!(uptime.contains("m"));
        assert!(uptime.contains("s"));
    }

    #[tokio::test]
    async fn test_daemon_handle_ping() {
        let temp = TempDir::new().unwrap();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon.handle_command(DaemonCommand::Ping).await;

        match response {
            DaemonResponse::Status { status, message } => {
                assert_eq!(status, "ok");
                assert_eq!(message, Some("pong".to_string()));
            }
            _ => panic!("Expected Status response"),
        }
    }

    #[tokio::test]
    async fn test_daemon_handle_shutdown() {
        let temp = TempDir::new().unwrap();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon.handle_command(DaemonCommand::Shutdown).await;

        match response {
            DaemonResponse::Status { status, .. } => {
                assert_eq!(status, "shutting_down");
            }
            _ => panic!("Expected Status response"),
        }

        // Verify daemon is stopping
        assert!(daemon.stopping.load(Ordering::SeqCst));
    }

    #[tokio::test]
    async fn test_daemon_handle_notify() {
        let temp = TempDir::new().unwrap();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let file = temp.path().join("test.rs");
        let response = daemon.handle_command(DaemonCommand::Notify { file }).await;

        match response {
            DaemonResponse::NotifyResponse {
                dirty_count,
                threshold,
                reindex_triggered,
                ..
            } => {
                assert_eq!(dirty_count, 1);
                assert_eq!(threshold, DEFAULT_REINDEX_THRESHOLD);
                assert!(!reindex_triggered);
            }
            _ => panic!("Expected NotifyResponse"),
        }
    }

    #[tokio::test]
    async fn test_daemon_handle_notify_threshold() {
        let temp = TempDir::new().unwrap();
        let config = DaemonConfig {
            auto_reindex_threshold: 3, // Lower threshold for testing
            ..DaemonConfig::default()
        };
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        // Add files up to threshold
        for i in 0..3 {
            let file = temp.path().join(format!("test{}.rs", i));
            daemon.handle_command(DaemonCommand::Notify { file }).await;
        }

        // The third notification should trigger reindex
        let file = temp.path().join("test3.rs");
        let response = daemon.handle_command(DaemonCommand::Notify { file }).await;

        match response {
            DaemonResponse::NotifyResponse {
                reindex_triggered: _, ..
            } => {
                // After threshold is hit, dirty set is cleared
                // So reindex_triggered would have been true, but dirty_count is now 1
            }
            _ => panic!("Expected NotifyResponse"),
        }
    }

    #[tokio::test]
    async fn test_daemon_handle_track() {
        let temp = TempDir::new().unwrap();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon
            .handle_command(DaemonCommand::Track {
                hook: "test-hook".to_string(),
                success: true,
                metrics: HashMap::new(),
            })
            .await;

        match response {
            DaemonResponse::TrackResponse {
                hook,
                total_invocations,
                ..
            } => {
                assert_eq!(hook, "test-hook");
                assert_eq!(total_invocations, 1);
            }
            _ => panic!("Expected TrackResponse"),
        }
    }

    #[tokio::test]
    async fn test_daemon_all_sessions_summary() {
        let temp = TempDir::new().unwrap();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        // Add a session
        daemon.sessions.insert(
            "test-session".to_string(),
            SessionStats {
                session_id: "test-session".to_string(),
                raw_tokens: 1000,
                tldr_tokens: 100,
                requests: 10,
                started_at: None,
            },
        );

        let summary = daemon.all_sessions_summary();
        assert_eq!(summary.active_sessions, 1);
        assert_eq!(summary.total_raw_tokens, 1000);
        assert_eq!(summary.total_tldr_tokens, 100);
        assert_eq!(summary.total_requests, 10);
    }

    // =========================================================================
    // Pass-through handler tests
    // =========================================================================

    /// Helper to create a temp dir with a Python file for testing
    fn create_test_project() -> TempDir {
        let temp = TempDir::new().unwrap();
        let py_file = temp.path().join("main.py");
        std::fs::write(
            &py_file,
            "def hello():\n    \"\"\"Say hello.\"\"\"\n    return 'hello'\n\ndef main():\n    hello()\n",
        )
        .unwrap();
        temp
    }

    #[test]
    fn test_hash_str_args_deterministic() {
        let h1 = hash_str_args(&["search", "pattern", "100"]);
        let h2 = hash_str_args(&["search", "pattern", "100"]);
        assert_eq!(h1, h2);
    }

    #[test]
    fn test_hash_str_args_different_inputs() {
        let h1 = hash_str_args(&["search", "pattern_a"]);
        let h2 = hash_str_args(&["search", "pattern_b"]);
        assert_ne!(h1, h2);
    }

    #[tokio::test]
    async fn test_daemon_search_returns_result() {
        let temp = create_test_project();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon
            .handle_command(DaemonCommand::Search {
                pattern: "def hello".to_string(),
                max_results: Some(10),
            })
            .await;

        match response {
            DaemonResponse::Result(val) => {
                assert!(val.is_array(), "Search should return an array of matches");
                let arr = val.as_array().unwrap();
                assert!(!arr.is_empty(), "Should find at least one match for 'def hello'");
            }
            DaemonResponse::Error { error, .. } => {
                panic!("Search returned error: {}", error);
            }
            other => panic!("Expected Result response, got {:?}", other),
        }
    }

    #[tokio::test]
    async fn test_daemon_search_caches_result() {
        let temp = create_test_project();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        // First call populates cache
        let _r1 = daemon
            .handle_command(DaemonCommand::Search {
                pattern: "def hello".to_string(),
                max_results: Some(10),
            })
            .await;

        // Second call should hit cache
        let _r2 = daemon
            .handle_command(DaemonCommand::Search {
                pattern: "def hello".to_string(),
                max_results: Some(10),
            })
            .await;

        let stats = daemon.cache_stats();
        assert!(stats.hits >= 1, "Second call should hit cache");
    }

    #[tokio::test]
    async fn test_daemon_extract_returns_result() {
        let temp = create_test_project();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon
            .handle_command(DaemonCommand::Extract {
                file: temp.path().join("main.py"),
                session: None,
            })
            .await;

        match response {
            DaemonResponse::Result(val) => {
                assert!(val.is_object(), "Extract should return a module info object");
                // Should contain functions field
                assert!(val.get("functions").is_some(), "Should have 'functions' field");
            }
            DaemonResponse::Error { error, .. } => {
                panic!("Extract returned error: {}", error);
            }
            other => panic!("Expected Result response, got {:?}", other),
        }
    }

    #[tokio::test]
    async fn test_daemon_extract_nonexistent_file() {
        let temp = TempDir::new().unwrap();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon
            .handle_command(DaemonCommand::Extract {
                file: temp.path().join("nonexistent.py"),
                session: None,
            })
            .await;

        match response {
            DaemonResponse::Error { error, .. } => {
                assert!(
                    !error.is_empty(),
                    "Should return an error for nonexistent file"
                );
            }
            _ => panic!("Expected Error response for nonexistent file"),
        }
    }

    #[tokio::test]
    async fn test_daemon_tree_returns_result() {
        let temp = create_test_project();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon
            .handle_command(DaemonCommand::Tree { path: None })
            .await;

        match response {
            DaemonResponse::Result(val) => {
                assert!(val.is_object(), "Tree should return a FileTree object");
            }
            DaemonResponse::Error { error, .. } => {
                panic!("Tree returned error: {}", error);
            }
            other => panic!("Expected Result response, got {:?}", other),
        }
    }

    #[tokio::test]
    async fn test_daemon_structure_returns_result() {
        let temp = create_test_project();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon
            .handle_command(DaemonCommand::Structure {
                path: temp.path().to_path_buf(),
                lang: Some("python".to_string()),
            })
            .await;

        match response {
            DaemonResponse::Result(val) => {
                assert!(val.is_object(), "Structure should return a CodeStructure object");
            }
            DaemonResponse::Error { error, .. } => {
                panic!("Structure returned error: {}", error);
            }
            other => panic!("Expected Result response, got {:?}", other),
        }
    }

    #[tokio::test]
    async fn test_daemon_imports_returns_result() {
        let temp = create_test_project();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon
            .handle_command(DaemonCommand::Imports {
                file: temp.path().join("main.py"),
            })
            .await;

        match response {
            DaemonResponse::Result(val) => {
                assert!(val.is_array(), "Imports should return an array");
            }
            DaemonResponse::Error { error, .. } => {
                panic!("Imports returned error: {}", error);
            }
            other => panic!("Expected Result response, got {:?}", other),
        }
    }

    #[tokio::test]
    async fn test_daemon_cfg_returns_result() {
        let temp = create_test_project();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let file = temp.path().join("main.py");
        let response = daemon
            .handle_command(DaemonCommand::Cfg {
                file,
                function: "hello".to_string(),
            })
            .await;

        match response {
            DaemonResponse::Result(val) => {
                assert!(val.is_object(), "Cfg should return a CfgInfo object");
                assert!(val.get("function").is_some(), "Should have 'function' field");
            }
            DaemonResponse::Error { error, .. } => {
                panic!("Cfg returned error: {}", error);
            }
            other => panic!("Expected Result response, got {:?}", other),
        }
    }

    #[tokio::test]
    async fn test_daemon_dfg_returns_result() {
        let temp = create_test_project();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let file = temp.path().join("main.py");
        let response = daemon
            .handle_command(DaemonCommand::Dfg {
                file,
                function: "hello".to_string(),
            })
            .await;

        match response {
            DaemonResponse::Result(val) => {
                assert!(val.is_object(), "Dfg should return a DfgInfo object");
                assert!(val.get("function").is_some(), "Should have 'function' field");
            }
            DaemonResponse::Error { error, .. } => {
                panic!("Dfg returned error: {}", error);
            }
            other => panic!("Expected Result response, got {:?}", other),
        }
    }

    #[tokio::test]
    async fn test_daemon_calls_returns_result() {
        let temp = create_test_project();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon
            .handle_command(DaemonCommand::Calls { path: None })
            .await;

        match response {
            DaemonResponse::Result(val) => {
                assert!(val.is_object(), "Calls should return a ProjectCallGraph object");
            }
            DaemonResponse::Error { error, .. } => {
                panic!("Calls returned error: {}", error);
            }
            other => panic!("Expected Result response, got {:?}", other),
        }
    }

    #[tokio::test]
    async fn test_daemon_arch_returns_result() {
        let temp = create_test_project();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon
            .handle_command(DaemonCommand::Arch { path: None })
            .await;

        match response {
            DaemonResponse::Result(val) => {
                assert!(val.is_object(), "Arch should return an ArchitectureReport object");
            }
            DaemonResponse::Error { error, .. } => {
                panic!("Arch returned error: {}", error);
            }
            other => panic!("Expected Result response, got {:?}", other),
        }
    }

    #[tokio::test]
    async fn test_daemon_diagnostics_returns_error_with_guidance() {
        let temp = TempDir::new().unwrap();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let path = temp.path().join("src");
        let response = daemon
            .handle_command(DaemonCommand::Diagnostics {
                path: path.clone(),
                project: None,
            })
            .await;

        match response {
            DaemonResponse::Error { error, .. } => {
                assert!(
                    error.contains("Diagnostics requires external tool orchestration"),
                    "Error should explain that diagnostics needs CLI: {}",
                    error
                );
                assert!(
                    error.contains("tldr diagnostics"),
                    "Error should suggest CLI usage"
                );
            }
            other => panic!("Expected Error response, got {:?}", other),
        }
    }

    #[tokio::test]
    async fn test_daemon_importers_returns_result() {
        let temp = create_test_project();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon
            .handle_command(DaemonCommand::Importers {
                module: "os".to_string(),
                path: None,
            })
            .await;

        match response {
            DaemonResponse::Result(val) => {
                assert!(val.is_object(), "Importers should return an ImportersReport object");
            }
            DaemonResponse::Error { error, .. } => {
                panic!("Importers returned error: {}", error);
            }
            other => panic!("Expected Result response, got {:?}", other),
        }
    }

    #[tokio::test]
    async fn test_daemon_dead_returns_result() {
        let temp = create_test_project();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon
            .handle_command(DaemonCommand::Dead {
                path: None,
                entry: None,
            })
            .await;

        match response {
            DaemonResponse::Result(val) => {
                assert!(val.is_object(), "Dead should return a DeadCodeReport object");
            }
            DaemonResponse::Error { error, .. } => {
                panic!("Dead returned error: {}", error);
            }
            other => panic!("Expected Result response, got {:?}", other),
        }
    }

    #[tokio::test]
    async fn test_daemon_change_impact_returns_result() {
        let temp = create_test_project();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon
            .handle_command(DaemonCommand::ChangeImpact {
                files: Some(vec![temp.path().join("main.py")]),
                session: None,
                git: None,
            })
            .await;

        match response {
            DaemonResponse::Result(val) => {
                assert!(
                    val.is_object(),
                    "ChangeImpact should return a ChangeImpactReport object"
                );
            }
            DaemonResponse::Error { error, .. } => {
                panic!("ChangeImpact returned error: {}", error);
            }
            other => panic!("Expected Result response, got {:?}", other),
        }
    }

    #[tokio::test]
    async fn test_daemon_extract_cache_invalidation() {
        let temp = create_test_project();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let file = temp.path().join("main.py");

        // First extract populates cache
        let r1 = daemon
            .handle_command(DaemonCommand::Extract {
                file: file.clone(),
                session: None,
            })
            .await;
        assert!(matches!(r1, DaemonResponse::Result(_)));

        // Notify file change - should invalidate the cache entry
        daemon
            .handle_command(DaemonCommand::Notify { file: file.clone() })
            .await;

        // After invalidation, next extract should be a cache miss
        let _r2 = daemon
            .handle_command(DaemonCommand::Extract {
                file,
                session: None,
            })
            .await;

        let stats = daemon.cache_stats();
        // Should have: 1 miss (first), 1 invalidation, 1 miss (after invalidation)
        assert!(
            stats.invalidations >= 1,
            "File notify should have caused invalidation"
        );
    }

    #[tokio::test]
    async fn test_daemon_slice_returns_result() {
        let temp = create_test_project();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let file = temp.path().join("main.py");
        let response = daemon
            .handle_command(DaemonCommand::Slice {
                file,
                function: "hello".to_string(),
                line: 3,
            })
            .await;

        match response {
            DaemonResponse::Result(val) => {
                assert!(val.is_array(), "Slice should return an array of line numbers");
            }
            DaemonResponse::Error { error, .. } => {
                panic!("Slice returned error: {}", error);
            }
            other => panic!("Expected Result response, got {:?}", other),
        }
    }

    #[tokio::test]
    async fn test_daemon_context_returns_result_or_error() {
        let temp = create_test_project();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon
            .handle_command(DaemonCommand::Context {
                entry: "main".to_string(),
                depth: Some(1),
            })
            .await;

        // Context may return Result or Error depending on whether 'main' is found
        // in the call graph. Both are valid outcomes for this test.
        match response {
            DaemonResponse::Result(val) => {
                assert!(val.is_object(), "Context should return a RelevantContext object");
            }
            DaemonResponse::Error { .. } => {
                // Function not found in call graph is acceptable
            }
            other => panic!("Expected Result or Error response, got {:?}", other),
        }
    }

    #[tokio::test]
    async fn test_daemon_impact_returns_result_or_error() {
        let temp = create_test_project();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon
            .handle_command(DaemonCommand::Impact {
                func: "hello".to_string(),
                depth: Some(2),
            })
            .await;

        // Impact may return Result or Error depending on call graph contents
        match response {
            DaemonResponse::Result(val) => {
                assert!(val.is_object(), "Impact should return an ImpactReport object");
            }
            DaemonResponse::Error { .. } => {
                // Function not found in call graph is acceptable for small test projects
            }
            other => panic!("Expected Result or Error response, got {:?}", other),
        }
    }

    #[cfg(feature = "semantic")]
    #[tokio::test]
    async fn test_semantic_search_builds_index() {
        // Create a temp dir with a simple Python file
        let temp = tempfile::tempdir().unwrap();
        let py_file = temp.path().join("hello.py");
        std::fs::write(
            &py_file,
            "def greet(name):\n    return f'Hello, {name}!'\n\ndef farewell(name):\n    return f'Goodbye, {name}!'\n",
        )
        .unwrap();

        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon
            .handle_command(DaemonCommand::Semantic {
                query: "greeting function".to_string(),
                top_k: 5,
            })
            .await;

        // Should return a Result with search results, not an error
        match &response {
            DaemonResponse::Result(value) => {
                assert!(value.get("query").is_some());
                assert!(value.get("results").is_some());
            }
            DaemonResponse::Error { error, .. } => {
                // May fail in CI without ONNX model - that's acceptable
                // but it should NOT say "not yet implemented"
                assert!(
                    !error.contains("not yet implemented"),
                    "Semantic search should be wired, got: {}",
                    error
                );
            }
            other => panic!("Unexpected response: {:?}", other),
        }
    }

    #[cfg(feature = "semantic")]
    #[tokio::test]
    async fn test_semantic_index_invalidated_on_notify() {
        let temp = tempfile::tempdir().unwrap();
        let py_file = temp.path().join("example.py");
        std::fs::write(&py_file, "def compute(x):\n    return x * 2\n").unwrap();

        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        // First semantic search - builds index
        let _ = daemon
            .handle_command(DaemonCommand::Semantic {
                query: "computation".to_string(),
                top_k: 5,
            })
            .await;

        // Verify index is populated
        {
            let idx = daemon.semantic_index.read().await;
            // Index may be Some (if ONNX model available) or None (if build failed)
            // We just verify the field exists and is accessible
            let _ = idx.is_some();
        }

        // Notify a file change - should invalidate the index
        let _ = daemon
            .handle_command(DaemonCommand::Notify {
                file: py_file.clone(),
            })
            .await;

        // Verify index was cleared
        {
            let idx = daemon.semantic_index.read().await;
            assert!(
                idx.is_none(),
                "Semantic index should be invalidated after Notify"
            );
        }
    }

    #[tokio::test]
    async fn test_daemon_warm_wires_caches() {
        let temp = tempfile::tempdir().unwrap();
        let py_file = temp.path().join("example.py");
        std::fs::write(
            &py_file,
            "def add(a, b):\n    return a + b\n\ndef multiply(x, y):\n    return x * y\n",
        )
        .unwrap();

        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon
            .handle_command(DaemonCommand::Warm { language: None })
            .await;

        match &response {
            DaemonResponse::Status { status, message } => {
                assert_eq!(status, "ok");
                let msg = message.as_deref().unwrap_or("");
                // Should mention what was warmed, not just "Warm completed"
                assert!(
                    msg.contains("Warmed"),
                    "Expected warm details, got: {}",
                    msg
                );
            }
            other => panic!("Expected Status response, got {:?}", other),
        }
    }

    #[tokio::test]
    async fn test_daemon_warm_with_language() {
        let temp = tempfile::tempdir().unwrap();
        let rs_file = temp.path().join("lib.rs");
        std::fs::write(
            &rs_file,
            "pub fn hello() -> String {\n    \"hello\".to_string()\n}\n",
        )
        .unwrap();

        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        let response = daemon
            .handle_command(DaemonCommand::Warm {
                language: Some("rust".to_string()),
            })
            .await;

        match &response {
            DaemonResponse::Status { status, .. } => {
                assert_eq!(status, "ok");
            }
            other => panic!("Expected Status response, got {:?}", other),
        }
    }

    #[tokio::test]
    async fn test_daemon_last_activity_updated_on_command() {
        let temp = tempfile::tempdir().unwrap();
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(temp.path().to_path_buf(), config);

        // Record initial activity time
        let before = *daemon.last_activity.read().await;

        // Small delay to ensure time difference
        tokio::time::sleep(tokio::time::Duration::from_millis(10)).await;

        // Any command should NOT update last_activity (only connections do),
        // but handle_command is what we can test. Verify the field exists and is accessible.
        let _ = daemon
            .handle_command(DaemonCommand::Ping)
            .await;

        // last_activity is set at connection accept, not command handling,
        // so it should still be the initial value
        let after = *daemon.last_activity.read().await;
        assert_eq!(before, after);
    }

    #[tokio::test]
    async fn test_daemon_created_with_nonexistent_project() {
        // Daemon should be constructable with any path — the exists() check
        // happens in the run loop, not in new()
        let fake_path = PathBuf::from("/tmp/nonexistent-project-dir-12345");
        let config = DaemonConfig::default();
        let daemon = TLDRDaemon::new(fake_path.clone(), config);

        assert_eq!(daemon.project(), &fake_path);
        // The project doesn't exist, but daemon construction succeeds.
        // The run() loop would detect this and self-terminate.
        assert!(!fake_path.exists());
    }
}