whycodes-index 0.6.31

//! whycodes-index — fast, gitignore-aware workspace file index.
//!
//! One background scan of the project roots feeds every consumer:
//!
//! * **TUI file picker** — fuzzy path queries (`@file`, Ctrl+Space) served by
//!   a resident [`nucleo`] engine; keystroke queries never touch the disk.
//! * **File tools** — `glob` / `list` / `grep` enumerate the in-memory store
//!   instead of re-walking the tree on every tool call. Grep also consults
//!   a resident content-trigram overlay so regex confirm only opens files
//!   that could contain a required literal.
//!
//! The walk honours `.gitignore` / `.ignore` (via the [`ignore`] crate, the
//! same engine ripgrep uses) plus the shared pruning [`policy`]. After the
//! initial scan a `notify` watcher streams debounced deltas so the index
//! stays warm as files are created, edited and deleted during a session.
//!
//! ```no_run
//! let index = whycodes_index::WorkspaceIndex::start(vec![".".into()]);
//! let hits = index.query("main.rs", 20);
//! ```

mod content;
mod fuzzy;
pub mod policy;
mod store;
pub mod walk;
mod watch;

use std::path::{Path, PathBuf};
use std::sync::atomic::{AtomicBool, AtomicU8, AtomicUsize, Ordering};
use std::sync::mpsc::{self, Receiver, Sender};
use std::sync::{Arc, Mutex, MutexGuard, RwLock, RwLockReadGuard, RwLockWriteGuard};
use std::thread::JoinHandle;
use std::time::{Duration, Instant};

pub use content::{
    ContentIndex, MAX_INDEX_BYTES, TRIGRAM_LEN, extract_trigrams, pack_trigram, required_trigrams,
};
pub use fuzzy::FileMatch;
use fuzzy::FuzzyEngine;
pub use store::{Entry, IndexStore};
pub use walk::{WalkEntry, WalkStats, walk_root, walk_root_limited};
use watch::{Change, ChangeKind, Command};

/// Project-local WhyCodes dir: `.whycodes`.
/// Duplicated from `whycodes-core::paths` because `index` is a leaf crate
/// and must not depend on `core`.
fn project_meta_dir(working_dir: &Path) -> PathBuf {
    working_dir.join(".whycodes")
}

/// Default cap on indexed entries per root.
pub const DEFAULT_MAX_ENTRIES: usize = 200_000;

/// Debounce window for watcher events (save storms, builds, checkouts).
const WATCH_DEBOUNCE: Duration = Duration::from_millis(250);

const STATE_SCANNING: u8 = 0;
const STATE_READY: u8 = 1;

/// Scan progress reported by [`WorkspaceIndex::status`].
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum ScanStatus {
    /// Initial walk still running; fuzzy queries already return partial hits.
    Scanning {
        /// Entries discovered so far (all roots).
        scanned: usize,
    },
    /// Index warm; tools may skip their own walks.
    Ready {
        /// Total indexed entries.
        total: usize,
        /// True when the entry cap stopped the scan early.
        truncated: bool,
    },
}

/// Options for [`WorkspaceIndex::start_with`].
#[derive(Debug, Clone)]
pub struct IndexOptions {
    /// Keep the index fresh with a filesystem watcher (default true).
    pub watch: bool,
    /// Hard cap on indexed entries per root (default 200k).
    pub max_entries: usize,
    /// Walk threads per root; 0 = auto (min(8, cores)), 1 = serial.
    pub threads: usize,
}

impl Default for IndexOptions {
    fn default() -> Self {
        Self {
            watch: true,
            max_entries: DEFAULT_MAX_ENTRIES,
            threads: 0,
        }
    }
}

/// Per-root state: the store (tools/browse) and the fuzzy engine (picker).
struct RootState {
    store: RwLock<IndexStore>,
    fuzzy: Mutex<FuzzyEngine>,
    content: RwLock<ContentIndex>,
}

/// State shared between the public handle and the scanner thread.
struct Shared {
    roots: Vec<PathBuf>,
    states: Vec<RootState>,
    scanned: AtomicUsize,
    state: AtomicU8,
    truncated: AtomicBool,
    cancel: AtomicBool,
    cmd_tx: Sender<Command>,
    /// Flipped by nucleo worker threads (via the notify callback) whenever
    /// fresh fuzzy results are ready; the UI polls with [`take_results_dirty`].
    results_dirty: Arc<AtomicBool>,
    threads: usize,
    max_entries: usize,
    watch: bool,
}

fn lock<T>(m: &Mutex<T>) -> MutexGuard<'_, T> {
    m.lock().unwrap_or_else(|e| e.into_inner())
}
fn read<T>(l: &RwLock<T>) -> RwLockReadGuard<'_, T> {
    l.read().unwrap_or_else(|e| e.into_inner())
}
fn write<T>(l: &RwLock<T>) -> RwLockWriteGuard<'_, T> {
    l.write().unwrap_or_else(|e| e.into_inner())
}

/// Resident workspace file index. Clone-handle via `Arc`.
///
/// The background scanner thread is owned by this handle: dropping the last
/// handle cancels the walk and joins the thread (bounded — the walk checks
/// the cancel flag per entry and the command loop wakes every 250 ms).
pub struct WorkspaceIndex {
    shared: Arc<Shared>,
    scanner: Option<JoinHandle<()>>,
}

impl WorkspaceIndex {
    /// Start scanning `roots` in the background with default options.
    pub fn start(roots: Vec<PathBuf>) -> Arc<Self> {
        Self::start_with(roots, IndexOptions::default())
    }

    /// Like [`start`](Self::start) with explicit options.
    ///
    /// Roots are canonicalized; missing/non-dir roots and roots nested inside
    /// an earlier root are dropped (they would duplicate entries).
    pub fn start_with(roots: Vec<PathBuf>, opts: IndexOptions) -> Arc<Self> {
        let roots = sanitize_roots(roots);
        let results_dirty = Arc::new(AtomicBool::new(false));
        let states = (0..roots.len())
            .map(|_| RootState {
                store: RwLock::new(IndexStore::new()),
                fuzzy: Mutex::new(FuzzyEngine::new(results_dirty.clone())),
                content: RwLock::new(ContentIndex::new()),
            })
            .collect();
        let (cmd_tx, cmd_rx) = mpsc::channel();
        let threads = if opts.threads == 0 {
            std::thread::available_parallelism()
                .map(|n| n.get().min(8))
                .unwrap_or(1)
        } else {
            opts.threads
        };
        let shared = Arc::new(Shared {
            roots,
            states,
            scanned: AtomicUsize::new(0),
            state: AtomicU8::new(STATE_SCANNING),
            truncated: AtomicBool::new(false),
            cancel: AtomicBool::new(false),
            cmd_tx,
            results_dirty,
            threads,
            max_entries: opts.max_entries,
            watch: opts.watch,
        });
        let thread_shared = shared.clone();
        let scanner = std::thread::Builder::new()
            .name("whycodes-index".into())
            .spawn(move || scanner_main(thread_shared, cmd_rx))
            .ok();
        Arc::new(Self { shared, scanner })
    }

    /// Roots of the index: `[working_dir]` plus every directory listed in
    /// `.whycodes/external_dirs_allowed`.
    pub fn project_roots(working_dir: &Path) -> Vec<PathBuf> {
        let mut roots = vec![working_dir.to_path_buf()];
        let allow = project_meta_dir(working_dir).join("external_dirs_allowed");
        if let Ok(content) = std::fs::read_to_string(&allow) {
            for line in content.lines() {
                let line = line.trim();
                if line.is_empty() || line.starts_with('#') {
                    continue;
                }
                roots.push(PathBuf::from(line));
            }
        }
        roots
    }

    /// The canonicalized roots being indexed.
    pub fn roots(&self) -> &[PathBuf] {
        &self.shared.roots
    }

    /// The primary root (working directory). `None` if no roots were indexed.
    pub fn primary_root(&self) -> Option<&Path> {
        self.shared.roots.first().map(PathBuf::as_path)
    }

    /// Current scan progress.
    pub fn status(&self) -> ScanStatus {
        if self.shared.state.load(Ordering::Acquire) == STATE_READY {
            ScanStatus::Ready {
                total: self.len(),
                truncated: self.shared.truncated.load(Ordering::Relaxed),
            }
        } else {
            ScanStatus::Scanning {
                scanned: self.shared.scanned.load(Ordering::Relaxed),
            }
        }
    }

    /// True once the initial walk has finished.
    pub fn is_ready(&self) -> bool {
        self.shared.state.load(Ordering::Acquire) == STATE_READY
    }

    /// Total indexed entries across roots.
    pub fn len(&self) -> usize {
        self.shared
            .states
            .iter()
            .map(|s| read(&s.store).len())
            .sum()
    }

    /// True when no entries are indexed (yet).
    pub fn is_empty(&self) -> bool {
        self.len() == 0
    }

    /// Block until the index is ready or `timeout` elapses. For tests and
    /// one-shot CLI paths; the TUI should poll [`status`](Self::status).
    pub fn wait_ready(&self, timeout: Duration) -> bool {
        let deadline = Instant::now() + timeout;
        while !self.is_ready() && Instant::now() < deadline {
            std::thread::sleep(Duration::from_millis(2));
        }
        self.is_ready()
    }

    /// Non-blocking picker query: point every engine at `pattern` and read
    /// the matches currently available. Never waits on a rematch — fresh
    /// results are announced via [`take_results_dirty`] and picked up with
    /// [`read_matches`](Self::read_matches).
    ///
    /// Special forms: an empty pattern browses the top level of the primary
    /// root; a pattern ending in `/` browses that directory (store-backed,
    /// always synchronous).
    pub fn query_now(&self, pattern: &str, limit: usize) -> Vec<FileMatch> {
        let pattern = pattern.trim();
        if pattern.is_empty() {
            return self.browse(0, "");
        }
        if let Some(dir) = pattern.strip_suffix('/') {
            return self.browse(0, dir);
        }
        for state in &self.shared.states {
            lock(&state.fuzzy).set_query(pattern);
        }
        self.read_fuzzy(limit).0
    }

    /// Non-blocking re-read of current matches (call when
    /// [`take_results_dirty`](Self::take_results_dirty) returns true).
    pub fn read_matches(&self, limit: usize) -> Vec<FileMatch> {
        self.read_fuzzy(limit).0
    }

    /// One-shot check for freshly published matcher results.
    pub fn take_results_dirty(&self) -> bool {
        self.shared.results_dirty.swap(false, Ordering::Acquire)
    }

    /// Re-issue the last fuzzy query so workers publish a snapshot.
    ///
    /// Needed when a `tick(0)` missed notify and the picker is idle on an
    /// empty list. See `FuzzyEngine::rearm`.
    pub fn rearm_fuzzy(&self) {
        for state in &self.shared.states {
            lock(&state.fuzzy).rearm();
        }
    }

    /// True while any engine is still matching or ingesting (walk running).
    /// UIs should keep polling on a short cadence while this holds.
    pub fn matching(&self) -> bool {
        self.shared.states.iter().any(|s| lock(&s.fuzzy).nudge())
    }

    /// Merge current fuzzy results across roots, best-first, capped.
    fn read_fuzzy(&self, limit: usize) -> (Vec<FileMatch>, bool) {
        let mut all = Vec::new();
        let mut running = false;
        for (i, state) in self.shared.states.iter().enumerate() {
            let (mut hits, r) = lock(&state.fuzzy).read(limit);
            running |= r;
            for h in &mut hits {
                h.root = i as u16;
            }
            all.extend(hits);
        }
        all.sort_by(|a, b| {
            b.score
                .cmp(&a.score)
                .then_with(|| a.rel.len().cmp(&b.rel.len()))
        });
        all.truncate(limit);
        (all, running)
    }

    /// Blocking fuzzy query (tests / one-shot callers). UIs should use
    /// [`query_now`](Self::query_now) + the dirty flag instead.
    pub fn query(&self, pattern: &str, limit: usize) -> Vec<FileMatch> {
        let pattern = pattern.trim();
        if pattern.is_empty() {
            return self.browse(0, "");
        }
        if let Some(dir) = pattern.strip_suffix('/') {
            return self.browse(0, dir);
        }
        let mut all = Vec::new();
        for (i, state) in self.shared.states.iter().enumerate() {
            let mut hits = lock(&state.fuzzy).query_blocking(pattern, limit);
            for h in &mut hits {
                h.root = i as u16;
            }
            all.extend(hits);
        }
        all.sort_by(|a, b| {
            b.score
                .cmp(&a.score)
                .then_with(|| a.rel.len().cmp(&b.rel.len()))
        });
        all.truncate(limit);
        all
    }

    /// Depth-1 listing of `rel_dir` inside `root` (dirs first, alpha).
    /// `""` lists the top level. Filesystem-free — reads the store.
    pub fn browse(&self, root: u16, rel_dir: &str) -> Vec<FileMatch> {
        let Some(state) = self.shared.states.get(root as usize) else {
            return Vec::new();
        };
        read(&state.store)
            .browse(root, rel_dir)
            .into_iter()
            .map(|e| FileMatch {
                rel: e.rel.to_string(),
                is_dir: e.is_dir,
                score: 0,
                indices: Vec::new(),
                root,
            })
            .collect()
    }

    /// Visit every primary-root entry without cloning (tools hot path).
    /// Return `false` from `f` to stop early.
    pub fn visit(&self, f: &mut dyn FnMut(&Entry) -> bool) {
        if let Some(state) = self.shared.states.first() {
            for e in read(&state.store).entries() {
                if !f(e) {
                    return;
                }
            }
        }
    }

    /// Visit primary-root files under `search_root` that the content overlay
    /// cannot rule out for `pattern`. `None` means "do not prune" (regex /
    /// too short / Unicode case-fold / overlay not complete / path outside
    /// the primary root) — the caller should fall back to [`visit`].
    ///
    /// `f` receives `(abs, rel, size)` with `rel` scoped to `search_root`,
    /// matching [`visit`] + tools `visit_index`. Return `false` to stop.
    pub fn visit_content_candidates(
        &self,
        search_root: &Path,
        pattern: &str,
        case_insensitive: bool,
        f: &mut dyn FnMut(&Path, &str, u64) -> bool,
    ) -> Option<()> {
        let required = required_trigrams(pattern, case_insensitive)?;
        let state = self.shared.states.first()?;
        // Lock order: store → content (never reversed; see apply_changes).
        let store = read(&state.store);
        let content = read(&state.content);
        if !content.is_complete() {
            return None;
        }
        let root = self.shared.roots.first()?;
        let prefix = content_search_prefix(root, search_root)?;
        for e in store.entries() {
            if e.is_dir || !content_entry_in_scope(&prefix, &e.rel) {
                continue;
            }
            if !content.may_match(&e.rel, &required) {
                continue;
            }
            let rel = content_scoped_rel(&prefix, &e.rel);
            if !f(&root.join(&*e.rel), &rel, e.size) {
                break;
            }
        }
        Some(())
    }

    /// Clone of all primary-root entries (tools that need owned data).
    pub fn entries(&self) -> Vec<Entry> {
        self.shared
            .states
            .first()
            .map(|s| read(&s.store).entries().to_vec())
            .unwrap_or_default()
    }

    /// Absolute path for a match.
    pub fn resolve(&self, m: &FileMatch) -> PathBuf {
        self.shared.roots[m.root as usize].join(&m.rel)
    }

    /// Trigger a full background rescan (e.g. after branch switches).
    pub fn rescan(&self) {
        let _ = self.shared.cmd_tx.send(Command::Rescan);
    }
}

impl Drop for WorkspaceIndex {
    fn drop(&mut self) {
        self.shared.cancel.store(true, Ordering::Relaxed);
        let _ = self.shared.cmd_tx.send(Command::Shutdown);
        if let Some(h) = self.scanner.take() {
            // Windows ReadDirectoryChangesW watcher Drop can block; never
            // stall process exit on the scanner thread.
            let _ = h.join();
        }
    }
}

impl std::fmt::Debug for WorkspaceIndex {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("WorkspaceIndex")
            .field("roots", &self.shared.roots)
            .field("status", &self.status())
            .finish()
    }
}

fn content_search_prefix(primary: &Path, search_root: &Path) -> Option<String> {
    let search = std::fs::canonicalize(search_root).unwrap_or_else(|_| search_root.to_path_buf());
    let rel = search.strip_prefix(primary).ok()?;
    let prefix = rel.to_string_lossy().replace('\\', "/");
    Some(prefix.trim_matches('/').to_string())
}

fn content_entry_in_scope(prefix: &str, rel: &str) -> bool {
    prefix.is_empty()
        || (rel.len() > prefix.len()
            && rel.starts_with(prefix)
            && rel.as_bytes().get(prefix.len()) == Some(&b'/'))
}

fn content_scoped_rel(prefix: &str, rel: &str) -> String {
    if prefix.is_empty() {
        rel.to_string()
    } else {
        rel[prefix.len() + 1..].to_string()
    }
}

/// Canonicalize roots, drop missing/non-dirs, dedup exact and nested roots.
fn sanitize_roots(roots: Vec<PathBuf>) -> Vec<PathBuf> {
    let mut out: Vec<PathBuf> = Vec::new();
    for root in roots {
        let Ok(canon) = std::fs::canonicalize(&root) else {
            continue;
        };
        if !canon.is_dir() {
            continue;
        }
        // A root equal to or nested inside an earlier one duplicates entries.
        if out.iter().any(|r| canon.starts_with(r)) {
            continue;
        }
        out.push(canon);
    }
    out
}

#[cfg(test)]
pub(crate) fn recv_should_stop(e: mpsc::RecvTimeoutError) -> bool {
    matches!(e, mpsc::RecvTimeoutError::Disconnected)
}

#[derive(Debug)]
pub(crate) enum RecvAct {
    Stop,
    Idle,
    Rescan,
    Batch(Vec<Change>),
}

pub(crate) fn classify_recv(r: Result<Command, mpsc::RecvTimeoutError>) -> RecvAct {
    match r {
        Ok(Command::Shutdown) => RecvAct::Stop,
        Ok(Command::Rescan) => RecvAct::Rescan,
        Ok(Command::Batch(cs)) => RecvAct::Batch(cs),
        Err(mpsc::RecvTimeoutError::Disconnected) => RecvAct::Stop,
        Err(mpsc::RecvTimeoutError::Timeout) => RecvAct::Idle,
    }
}

/// Scanner thread body: initial scan, then watcher-fed delta loop.
fn scanner_main(shared: Arc<Shared>, cmd_rx: Receiver<Command>) {
    full_scan(&shared);
    if shared.cancel.load(Ordering::Relaxed) {
        return;
    }

    // Arm notify *before* flipping Ready. `wait_ready` is the test/TUI
    // signal that creates will be seen — if Ready precedes `watch()`, a
    // write in that window is lost (CI: `watcher_picks_up_changes`).
    let watcher = if shared.watch {
        watch::spawn(&shared.roots, shared.cmd_tx.clone())
    } else {
        None
    };
    shared.state.store(STATE_READY, Ordering::Release);

    let mut pending: Vec<Change> = Vec::new();
    loop {
        if shared.cancel.load(Ordering::Relaxed) {
            break;
        }
        match classify_recv(cmd_rx.recv_timeout(WATCH_DEBOUNCE)) {
            RecvAct::Stop => break,
            RecvAct::Idle => {}
            RecvAct::Rescan => {
                pending.clear();
                full_scan(&shared);
                if !shared.cancel.load(Ordering::Relaxed) {
                    shared.state.store(STATE_READY, Ordering::Release);
                }
            }
            RecvAct::Batch(cs) => pending.extend(cs),
        }
        if !pending.is_empty() {
            apply_changes(&shared, std::mem::take(&mut pending));
        }
    }
    // Drop the watcher off this thread: Windows ReadDirectoryChangesW
    // teardown can block, and Drop of WorkspaceIndex joins us.
    if let Some(watcher) = watcher {
        detach_watcher(watcher);
    }
}

/// Spawn a thread whose only job is `drop(watcher)`. Failure to spawn is
/// logged; the watcher then drops on this thread (join may stall on Windows).
fn detach_watcher(watcher: notify::RecommendedWatcher) {
    log_unwatch_spawn(
        std::thread::Builder::new()
            .name("whycodes-index-unwatch".into())
            .spawn(move || drop(watcher)),
    );
}

pub(crate) fn log_unwatch_spawn(result: std::io::Result<std::thread::JoinHandle<()>>) {
    if let Err(e) = result {
        tracing::debug!(error = %e, "index unwatch thread spawn failed");
    }
}

/// Full (re)scan of every root: streams entries into the fuzzy engines
/// (queries stay live during the scan) and fills the stores.
fn full_scan(shared: &Arc<Shared>) {
    shared.scanned.store(0, Ordering::Relaxed);
    shared.truncated.store(false, Ordering::Relaxed);
    shared.state.store(STATE_SCANNING, Ordering::Release);

    for (i, state) in shared.states.iter().enumerate() {
        if shared.cancel.load(Ordering::Relaxed) {
            return;
        }
        write(&state.store).clear();
        write(&state.content).clear();
        let injector = {
            let mut fz = lock(&state.fuzzy);
            fz.restart();
            fz.injector()
        };
        let remaining = shared
            .max_entries
            .saturating_sub(shared.scanned.load(Ordering::Relaxed));
        if remaining == 0 {
            shared.truncated.store(true, Ordering::Relaxed);
            break;
        }
        // Walk threads push straight into nucleo (streaming matches) and
        // queue entries for a bulk store insert afterwards.
        let queue = Mutex::new(Vec::new());
        let stats = walk::walk_root(
            &shared.roots[i],
            shared.threads,
            remaining,
            &shared.scanned,
            &shared.cancel,
            &|e: WalkEntry| {
                FuzzyEngine::push(&injector, &e.rel, e.is_dir);
                lock(&queue).push(e);
            },
        );
        // A cancel inside stops the fill; the next root's check returns.
        fill_root(shared, i, std::mem::take(&mut *lock(&queue)));
        if stats.truncated {
            shared.truncated.store(true, Ordering::Relaxed);
            break;
        }
    }
}

/// Bulk-insert one root's walked entries into its stores. Reading every
/// file for the content index is the slow part: on a huge tree (a home
/// directory hits `max_entries`) it ran for minutes, and the drop at exit
/// joined it, so the process never quit. On a network mount (a WSL share)
/// each read costs milliseconds, so files are read with no lock held:
/// holding the store lock across them froze every `entries()` caller,
/// including the TUI's first frame.
fn fill_root(shared: &Shared, i: usize, entries: Vec<WalkEntry>) {
    let state = &shared.states[i];
    let mut files = Vec::new();
    {
        let mut store = write(&state.store);
        for e in entries {
            if !e.is_dir {
                files.push((e.rel.clone(), e.size));
            }
            store.insert(i as u16, e.rel, e.is_dir, e.size);
        }
    }
    for (rel, size) in files {
        if shared.cancel.load(Ordering::Relaxed) {
            return;
        }
        let posting = ContentIndex::load(&shared.roots[i], &rel, size);
        write(&state.content).insert(&rel, posting);
    }
    write(&state.content).mark_complete();
}

/// Apply one debounced watcher batch: upserts push into nucleo; removals
/// rebuild that root's engine from the store (nucleo has no item removal).
pub(crate) fn apply_changes(shared: &Arc<Shared>, changes: Vec<Change>) {
    // Group by root so each engine is touched at most once per batch.
    let mut by_root: rustc_hash::FxHashMap<u16, Vec<Change>> = Default::default();
    for c in changes {
        by_root.entry(c.root).or_default().push(c);
    }
    for (root_idx, cs) in by_root {
        let Some(state) = shared.states.get(root_idx as usize) else {
            continue;
        };
        let root = &shared.roots[root_idx as usize];
        let mut saw_removal = false;
        let mut upserts: Vec<(Box<str>, bool)> = Vec::new();
        {
            let mut store = write(&state.store);
            let mut content = write(&state.content);
            for c in cs {
                match c.kind {
                    ChangeKind::Remove => {
                        store.remove_tree(root_idx, &c.rel);
                        content.remove_tree(&c.rel);
                        saw_removal = true;
                    }
                    ChangeKind::Upsert => {
                        // Re-stat; a create+delete inside one debounce window
                        // collapses to a remove.
                        match std::fs::symlink_metadata(root.join(&c.rel)) {
                            Ok(md) => {
                                let is_dir = md.is_dir();
                                let size = if is_dir { 0 } else { md.len() };
                                upserts.push((c.rel.clone().into_boxed_str(), is_dir));
                                if is_dir {
                                    content.remove(&c.rel);
                                } else {
                                    content.upsert(root, &c.rel, size);
                                }
                                store.insert(root_idx, c.rel.into_boxed_str(), is_dir, size);
                            }
                            Err(_) => {
                                store.remove_tree(root_idx, &c.rel);
                                content.remove_tree(&c.rel);
                                saw_removal = true;
                            }
                        }
                    }
                }
            }
        }
        // Lock order is store → content, then (after drop) fuzzy → store.
        // Never reverse either pair.
        let mut fz = lock(&state.fuzzy);
        if saw_removal {
            fz.restart();
            let inj = fz.injector();
            for e in read(&state.store).iter_root(root_idx) {
                FuzzyEngine::push(&inj, &e.rel, e.is_dir);
            }
        } else {
            let inj = fz.injector();
            for (rel, is_dir) in upserts {
                FuzzyEngine::push(&inj, &rel, is_dir);
            }
        }
    }
}

#[cfg(test)]
#[path = "lib_tests.rs"]
mod tests;