hypersteeldb 0.5.2

//! Corpus — the query facade the app (and, later, the C ABI / napi bindings) drives.
//!
//! Any `Projector` (CSV, JSON, text situations, …) is consumed into the roaring inverted index plus a
//! forward row store for display. Queries are IKL over the roaring core; results carry timing and a
//! display sample. This is the DuckDB pattern: many readers, one query engine.

use crate::bitmap::{Postings, RoarPostings};
use crate::index::InfonIndex;
use crate::programs;
use crate::projector::{CorpusKind, Projector};
use crate::projectors::{CsvProjector, JsonProjector, JsonlProjector};
use crate::text::Gazetteer;
use crate::tokenql::evaluate;
use serde::Serialize;
use serde_json::Value;
use std::collections::{HashMap, HashSet};
use std::path::{Path, PathBuf};
use std::sync::OnceLock;
// `std::time::Instant` panics on wasm32-unknown-unknown ("time not implemented on this platform"): the
// target has no monotonic clock. The browser demos call query() directly, so timing is measured only where
// a clock exists and reported as 0.0 elsewhere. Compiling is not the same as running on this target.
#[cfg(not(target_arch = "wasm32"))]
use std::time::Instant;

/// Stop-words excluded from entity-linking content words (query.ts STOPW).
const STOPW: &[&str] = &[
    "the", "a", "an", "of", "to", "in", "on", "for", "and", "or", "is", "are", "was", "were", "be",
    "do", "how", "what", "which", "who", "why", "when", "with", "without", "into", "over", "under",
    "from", "your", "our", "their", "this", "that", "these", "those", "can", "may", "will", "would",
    "should", "could", "not", "you", "use", "used", "using", "best", "common", "about", "across",
    "based", "provide", "provides", "support", "supports", "need", "needs", "want", "wants", "able",
];

#[derive(Serialize, Default, Debug)]
pub struct FolderReport {
    pub situations: u32,
    /// (relative path, situations contributed)
    pub ingested: Vec<(String, usize)>,
    /// (relative path, reason)
    pub skipped: Vec<(String, String)>,
}

/// Recursively collect files under `dir`, skipping hidden entries and common junk dirs.
fn collect_files(dir: &Path) -> Vec<PathBuf> {
    let mut out = Vec::new();
    let mut stack = vec![dir.to_path_buf()];
    while let Some(d) = stack.pop() {
        let rd = match std::fs::read_dir(&d) {
            Ok(r) => r,
            Err(_) => continue,
        };
        for e in rd.flatten() {
            let name = e.file_name().to_string_lossy().to_string();
            if name.starts_with('.') || name == "node_modules" || name == "target" {
                continue;
            }
            let p = e.path();
            if p.is_dir() {
                stack.push(p);
            } else {
                out.push(p);
            }
        }
    }
    out
}

/// Load the multilingual text engine from env (`STEELDB_ML_BUNDLE`, `STEELDB_SPLADE_DIR`) or known
/// defaults; None if the models aren't present.
#[cfg(feature = "onnx")]
fn default_text_engine() -> Option<crate::projectors::TextEngine> {
    // Locations resolve via crate::paths (env override → ~/.steeldb/models → next-to-exe → ./models), so
    // an installed binary finds its bundled models from any CWD. No models present → text files are
    // skipped (reported), not an error.
    let ml = crate::paths::model_dir("step0_bundle_ml", "STEELDB_ML_BUNDLE", "spo.onnx")?;
    let splade = crate::paths::model_dir("splade", "STEELDB_SPLADE_DIR", "splade.onnx");
    crate::projectors::TextEngine::load(&ml, splade.as_deref()).ok()
}

pub struct Corpus {
    ix: InfonIndex<RoarPostings>,
    rows: Vec<Vec<String>>,
    columns: Vec<String>,
    source: String,
    kind: CorpusKind,
    /// high-DF non-discriminative tokens, computed once (registration fix)
    noise: OnceLock<HashSet<String>>,
    /// query-side gazetteer for symmetric high-res entity linking, loaded once
    gaz: OnceLock<Option<Gazetteer>>,
    /// optional growing-gazetteer overlay file merged into the query-side gazetteer (roadmap #4)
    gaz_overlay: Option<PathBuf>,
}

#[derive(Serialize)]
pub struct Hit {
    pub sid: u32,
    pub cells: Vec<String>,
}

#[derive(Serialize)]
pub struct QueryOut {
    pub count: usize,
    pub micros: f64,
    pub columns: Vec<String>,
    pub hits: Vec<Hit>,
}

#[derive(Serialize)]
pub struct Stats {
    pub source: String,
    pub kind: CorpusKind,
    pub situations: u32,
    pub vocab: usize,
    pub columns: Vec<String>,
    /// top facets (first path segment) by number of distinct tokens, for schema browsing
    pub facets: Vec<(String, usize)>,
    /// numeric fields available for `(num field op value)` range predicates
    pub numeric_fields: Vec<String>,
}

impl Corpus {
    /// Build the index + forward store by draining any projector's Situation stream.
    pub fn from_projector(p: Box<dyn Projector>) -> std::io::Result<Corpus> {
        let columns = p.columns();
        let kind = p.kind();
        let source = p.source();
        let mut by_token: HashMap<String, Vec<u32>> = HashMap::new();
        let mut rows: Vec<Vec<String>> = Vec::new();
        let mut numbers_raw: Vec<(u32, String, f64)> = Vec::new();
        let mut sid: u32 = 0;
        p.project(&mut |s| {
            for tok in s.tokens {
                by_token.entry(tok).or_default().push(sid);
            }
            for (f, v) in s.numbers {
                numbers_raw.push((sid, f, v));
            }
            rows.push(s.display);
            sid += 1;
        })?;
        // sids are appended in ascending order, so each posting list is already sorted.
        let mut ix = InfonIndex::from_postings(by_token, sid);
        for (sid, f, v) in numbers_raw {
            ix.add_number(sid, &f, v);
        }
        Ok(Corpus { ix, rows, columns, source, kind, noise: OnceLock::new(), gaz: OnceLock::new(), gaz_overlay: None })
    }

    pub fn from_csv(path: &Path) -> std::io::Result<Corpus> {
        Corpus::from_projector(Box::new(CsvProjector::open(path)?))
    }
    pub fn from_json(path: &Path) -> std::io::Result<Corpus> {
        Corpus::from_projector(Box::new(JsonProjector::open(path)))
    }
    pub fn from_jsonl(path: &Path, max_lines: Option<usize>) -> std::io::Result<Corpus> {
        Corpus::from_projector(Box::new(JsonlProjector::open(path, max_lines)))
    }

    /// Ingest a whole folder into ONE corpus — the "ask over a folder" path. Each file is auto-routed
    /// to a projector by extension (csv/tsv, json/ndjson/jsonl, and — with the `onnx` feature + models
    /// present — txt/md). Every situation is tagged with a `src/<file>` token and its file is shown, so
    /// the agent can slice by source. Unsupported files are skipped and counted.
    pub fn from_folder(dir: &Path) -> std::io::Result<(Corpus, FolderReport)> {
        let mut files = collect_files(dir);
        files.sort();
        let mut by_token: HashMap<String, Vec<u32>> = HashMap::new();
        let mut rows: Vec<Vec<String>> = Vec::new();
        let mut numbers_raw: Vec<(u32, String, f64)> = Vec::new();
        let mut sid: u32 = 0;
        let mut report = FolderReport::default();

        // one text engine reused across every text file (models load once)
        #[cfg(feature = "onnx")]
        let mut text_engine = default_text_engine();

        for path in &files {
            let rel = path.strip_prefix(dir).unwrap_or(path).to_string_lossy().to_string();
            let src_tok = format!("src/{}", crate::projector::slug(&rel));
            let ext = path.extension().and_then(|e| e.to_str()).unwrap_or("").to_lowercase();

            let push = |s: crate::projector::Situation, by_token: &mut HashMap<String, Vec<u32>>, rows: &mut Vec<Vec<String>>, numbers_raw: &mut Vec<(u32, String, f64)>, sid: &mut u32| {
                for t in s.tokens {
                    by_token.entry(t).or_default().push(*sid);
                }
                for (f, v) in s.numbers {
                    numbers_raw.push((*sid, f, v));
                }
                by_token.entry(src_tok.clone()).or_default().push(*sid);
                rows.push(vec![rel.clone(), s.display.join(" · ")]);
                *sid += 1;
            };

            // ANY-DOC BRIDGE: pdf/docx/pptx/html/md/txt → extract text → text projection (same engine).
            #[cfg(feature = "docs")]
            if crate::docs::is_doc_ext(&ext) {
                if let Some(eng) = text_engine.as_mut() {
                    match crate::docs::extract_text(path) {
                        Ok(Some(text)) => {
                            let before = sid;
                            eng.project_text(&text, &mut |s| push(s, &mut by_token, &mut rows, &mut numbers_raw, &mut sid));
                            report.ingested.push((rel.clone(), (sid - before) as usize));
                        }
                        Ok(None) => {}
                        Err(e) => report.skipped.push((rel.clone(), format!("extract failed: {e}"))),
                    }
                } else {
                    report.skipped.push((rel.clone(), "text models unavailable".into()));
                }
                continue;
            }

            let projector: Option<Box<dyn Projector>> = match ext.as_str() {
                "csv" | "tsv" => CsvProjector::open(path).ok().map(|p| Box::new(p) as Box<dyn Projector>),
                "json" | "ndjson" | "jsonl" => Some(Box::new(JsonProjector::open(path))),
                "txt" | "md" | "text" => {
                    #[cfg(feature = "onnx")]
                    {
                        if let Some(eng) = text_engine.as_mut() {
                            if let Ok(text) = std::fs::read_to_string(path) {
                                let before = sid;
                                eng.project_text(&text, &mut |s| push(s, &mut by_token, &mut rows, &mut numbers_raw, &mut sid));
                                report.ingested.push((rel.clone(), (sid - before) as usize));
                            }
                        } else {
                            report.skipped.push((rel.clone(), "text models unavailable".into()));
                        }
                        None
                    }
                    #[cfg(not(feature = "onnx"))]
                    {
                        report.skipped.push((rel.clone(), "built without onnx feature".into()));
                        None
                    }
                }
                other if other.is_empty() => None,
                other => {
                    report.skipped.push((rel.clone(), format!("no projector for .{other}")));
                    None
                }
            };

            if let Some(p) = projector {
                let before = sid;
                let _ = p.project(&mut |s| push(s, &mut by_token, &mut rows, &mut numbers_raw, &mut sid));
                report.ingested.push((rel.clone(), (sid - before) as usize));
            }
        }

        let mut ix = InfonIndex::from_postings(by_token, sid);
        for (sid, f, v) in numbers_raw {
            ix.add_number(sid, &f, v);
        }
        report.situations = sid;
        Ok((
            Corpus {
                ix,
                rows,
                columns: vec!["file".into(), "record".into()],
                source: dir.display().to_string(),
                kind: CorpusKind::Csv,
                noise: OnceLock::new(),
                gaz: OnceLock::new(), gaz_overlay: None,
            },
            report,
        ))
    }

    /// Single document (pdf/docx/pptx/html/md/txt) → extract text → text-projected corpus. Uses the
    /// env/default text engine; errors if the models or extractable text are absent.
    #[cfg(feature = "docs")]
    pub fn from_document(path: &Path) -> std::io::Result<Corpus> {
        let text = crate::docs::extract_text(path)?
            .ok_or_else(|| std::io::Error::new(std::io::ErrorKind::InvalidData, "no extractable text"))?;
        let mut eng = default_text_engine()
            .ok_or_else(|| std::io::Error::new(std::io::ErrorKind::Other, "text models unavailable (set STEELDB_ML_BUNDLE)"))?;
        let mut by_token: HashMap<String, Vec<u32>> = HashMap::new();
        let mut rows: Vec<Vec<String>> = Vec::new();
        let mut numbers_raw: Vec<(u32, String, f64)> = Vec::new();
        let mut sid: u32 = 0;
        eng.project_text(&text, &mut |s| {
            for t in s.tokens {
                by_token.entry(t).or_default().push(sid);
            }
            for (f, v) in s.numbers {
                numbers_raw.push((sid, f, v));
            }
            rows.push(s.display);
            sid += 1;
        });
        let mut ix = InfonIndex::from_postings(by_token, sid);
        for (sid, f, v) in numbers_raw {
            ix.add_number(sid, &f, v);
        }
        Ok(Corpus {
            ix,
            rows,
            columns: vec!["sentence".into()],
            source: path.display().to_string(),
            kind: CorpusKind::Text,
            noise: OnceLock::new(),
            gaz: OnceLock::new(), gaz_overlay: None,
        })
    }

    /// Native text projection (SPO tagger + optional English SPLADE) → queryable corpus.
    #[cfg(feature = "onnx")]
    pub fn from_text(
        path: &Path,
        ml_bundle: &Path,
        splade_dir: Option<&Path>,
    ) -> Result<Corpus, Box<dyn std::error::Error + Send + Sync>> {
        let p = crate::projectors::TextProjector::open(path, ml_bundle, splade_dir)?;
        Ok(Corpus::from_projector(Box::new(p))?)
    }

    /// An empty corpus to grow incrementally (realtime/hot-model ingest): `add_situation` appends as
    /// documents are projected, and the query/agent layer sees each addition immediately.
    pub fn new_incremental(source: impl Into<String>, columns: Vec<String>, kind: CorpusKind) -> Corpus {
        Corpus {
            ix: InfonIndex::from_postings(HashMap::new(), 0),
            rows: Vec::new(),
            columns,
            source: source.into(),
            kind,
            noise: OnceLock::new(),
            gaz: OnceLock::new(), gaz_overlay: None,
        }
    }

    /// Point the query-side gazetteer at a growing-gazetteer overlay file (entities learned at ingest).
    /// Must be called before the first query so the lazily-loaded gazetteer picks it up.
    pub fn set_gazetteer_overlay(&mut self, path: impl Into<PathBuf>) {
        self.gaz_overlay = Some(path.into());
    }

    /// Append one projected situation. Invalidates the high-DF noise cache (the corpus size changed),
    /// so registration recomputes on the next analytics call. Returns the new sid.
    pub fn add_situation(&mut self, tokens: Vec<String>, display: Vec<String>) -> u32 {
        self.add_situation_num(tokens, display, Vec::new())
    }

    /// Append one situation with numeric fields (realtime ingest of CSV/text carrying quantities).
    pub fn add_situation_num(&mut self, tokens: Vec<String>, display: Vec<String>, numbers: Vec<(String, f64)>) -> u32 {
        self.add_situation_polar(tokens, display, numbers, Vec::new())
    }

    /// Append a situation carrying **infon polarity** for some of its tokens (paper §1.2, §4): each
    /// `(token, i)` records that assertion's belief level, so Dempster-Shafer `Bel`/`Pl` and signed mass
    /// are computable over the bitmap. Tokens absent from `beliefs` default to `+1` (asserted).
    pub fn add_situation_polar(
        &mut self,
        mut tokens: Vec<String>,
        display: Vec<String>,
        numbers: Vec<(String, f64)>,
        beliefs: Vec<(String, f32)>,
    ) -> u32 {
        tokens.sort();
        tokens.dedup();
        let sid = self.ix.add(&tokens);
        for (tok, level) in &beliefs {
            self.ix.add_infon_polar(sid, tok, *level);
        }
        for (f, v) in numbers {
            self.ix.add_number(sid, &f, v);
        }
        self.rows.push(display);
        self.noise.take(); // situation count changed → recompute registration lazily
        sid
    }

    /// The underlying inverted index, for callers that need the lower-level set algebra or the topology
    /// programs directly.
    pub fn index(&self) -> &InfonIndex<RoarPostings> {
        &self.ix
    }

    pub fn query(&self, ikl: &str, limit: usize) -> QueryOut {
        #[cfg(not(target_arch = "wasm32"))]
        let t = Instant::now();
        let result = evaluate(&self.ix, ikl);
        #[cfg(not(target_arch = "wasm32"))]
        let micros = t.elapsed().as_secs_f64() * 1e6;
        #[cfg(target_arch = "wasm32")]
        let micros = 0.0;
        let sids = result.to_sorted();
        let hits = sids
            .iter()
            .take(limit)
            .map(|&sid| Hit {
                sid,
                cells: self.rows.get(sid as usize).cloned().unwrap_or_default(),
            })
            .collect();
        QueryOut { count: sids.len(), micros, columns: self.columns.clone(), hits }
    }

    /// Top tokens under a facet (for agent vocabulary discovery).
    pub fn facet_tokens(&self, facet: &str, limit: usize) -> Vec<(String, usize)> {
        self.ix.tokens_in_facet(facet, limit)
    }

    /// Distinct facet names (token prefixes) present in the corpus — the real schema, for validating
    /// DSL/tool arguments against what was actually extracted.
    pub fn facet_names(&self) -> Vec<String> {
        let mut set: HashSet<&str> = HashSet::new();
        for t in self.ix.tokens() {
            set.insert(t.split('/').next().unwrap_or(t));
        }
        let mut v: Vec<String> = set.into_iter().map(String::from).collect();
        v.sort();
        v
    }

    /// True if `token` (a `facet/value`) exists in the index.
    pub fn has_token(&self, token: &str) -> bool {
        self.ix.post_len(token) > 0
    }

    /// Dempster-Shafer belief interval `[Bel, Pl]` for a token over the whole corpus (paper §4.1).
    pub fn belief_interval(&self, token: &str) -> (f64, f64) {
        let universe = crate::tokenql::TokenStore::universe(&self.ix);
        self.ix.belief_interval(token, &universe)
    }

    /// Net signed infon mass for a token over the whole corpus.
    pub fn signed_mass(&self, token: &str) -> f64 {
        let universe = crate::tokenql::TokenStore::universe(&self.ix);
        self.ix.signed_mass(token, &universe)
    }

    /// A linter over this corpus's vocabulary — validates IKL atoms, suggests corrections, repairs
    /// syntax (paper §2, the compile-time boundary).
    pub fn linter(&self) -> crate::linter::Linter {
        crate::linter::Linter::from_tokens(self.ix.tokens().cloned())
            .with_numeric_fields(self.ix.numeric_fields().cloned())
    }

    /// Distinct leaf values of the most-supported tokens — candidate terms for ontology discovery over
    /// the corpus's own vocabulary.
    pub fn top_token_leaves(&self, limit: usize) -> Vec<String> {
        let mut v: Vec<(&String, usize)> = self.ix.tokens().map(|t| (t, self.ix.post_len(t))).collect();
        v.sort_by(|a, b| b.1.cmp(&a.1));
        let mut seen = HashSet::new();
        let mut out = Vec::new();
        for (t, _) in v {
            let leaf = t.split('/').nth(1).unwrap_or(t).to_string();
            if leaf.len() >= 3 && seen.insert(leaf.clone()) {
                out.push(leaf);
                if out.len() >= limit {
                    break;
                }
            }
        }
        out
    }

    /// REGISTRATION — non-discriminative tokens present in > ~12% of situations: the coarse fragments
    /// (developers, reference…) that co-occur with everything and drown the analytics. Concept facets
    /// only; contextual facets (time/geo/qty/dur) and the specific gazetteer/entity values survive.
    /// Ported from `query.ts` `registration()` (`71e1714`). Computed once, then cached.
    pub fn noise_tokens(&self) -> &HashSet<String> {
        self.noise.get_or_init(|| {
            let thresh = 0.12 * self.ix.situations() as f64;
            self.ix
                .tokens()
                .filter(|t| {
                    let f = t.split('/').next().unwrap_or("");
                    !matches!(f, "time" | "geo" | "qty" | "dur") && self.ix.post_len(t) as f64 > thresh
                })
                .cloned()
                .collect()
        })
    }

    /// Retrieve situations matching ANY of `tokens`, ranked by coverage (how many of the query tokens
    /// each situation contains) then sid. This makes free-text search return the most-relevant passages
    /// first instead of document order. Returns (sid, coverage, cells).
    pub fn search_ranked(&self, tokens: &[String], limit: usize) -> Vec<(u32, usize, Vec<String>)> {
        if tokens.is_empty() {
            return Vec::new();
        }
        let posts: Vec<RoarPostings> = tokens.iter().map(|t| self.ix.post(t)).collect();
        let mut union = RoarPostings::empty();
        for p in &posts {
            union.or_inplace(p);
        }
        let mut scored: Vec<(u32, usize)> = union
            .to_sorted()
            .into_iter()
            .map(|sid| (sid, posts.iter().filter(|p| p.contains(sid)).count()))
            .collect();
        scored.sort_by(|a, b| b.1.cmp(&a.1).then(a.0.cmp(&b.0)));
        scored.truncate(limit);
        scored
            .into_iter()
            .map(|(sid, cov)| (sid, cov, self.rows.get(sid as usize).cloned().unwrap_or_default()))
            .collect()
    }

    /// Query-side gazetteer, loaded once from `STEELDB_GAZETTEER` or `models/splade/gazetteer.json`.
    fn gazetteer(&self) -> Option<&Gazetteer> {
        self.gaz
            .get_or_init(|| {
                let p = std::env::var("STEELDB_GAZETTEER")
                    .map(PathBuf::from)
                    .ok()
                    .filter(|p| p.exists())
                    .or_else(|| {
                        crate::paths::model_dir("splade", "STEELDB_SPLADE_DIR", "gazetteer.json")
                            .map(|d| d.join("gazetteer.json"))
                    });
                let mut g = p.and_then(|p| Gazetteer::load(&p).ok());
                // Merge the growing-gazetteer overlay (entities learned during ingest) so question
                // mentions resolve to the same high-res tokens the corpus carries.
                if let Some(ov) = &self.gaz_overlay {
                    if ov.exists() {
                        let mut base = g.take().unwrap_or_else(Gazetteer::empty);
                        base.merge_overlay(ov);
                        g = Some(base);
                    }
                }
                g
            })
            .as_ref()
    }

    /// Entity-linking: resolve a question's mentions (acronyms, content words, prefixes, bigrams) plus
    /// any gazetteer surfaces to the store's PRECISE existing tokens — the tokens docs are actually
    /// indexed under, which the coarse SPLADE projection of a short question misses. Pure set-algebra
    /// linking (no lexical text search). Noise tokens are excluded. Ported from `query.ts` (`17d6490`).
    pub fn entity_link(&self, question: &str) -> Vec<String> {
        let noise = self.noise_tokens();
        let vocab: HashSet<&str> = self.ix.tokens().map(|s| s.as_str()).collect();

        // leaf index: leaf and its hyphen/slash parts → the precise tokens that contain them (cap 5)
        let mut leaf_idx: HashMap<String, Vec<String>> = HashMap::new();
        let put = |k: &str, t: &str, idx: &mut HashMap<String, Vec<String>>| {
            if k.len() >= 3 {
                let e = idx.entry(k.to_string()).or_default();
                if !e.iter().any(|x| x == t) {
                    e.push(t.to_string());
                }
            }
        };
        for t in self.ix.tokens() {
            let leaf = match t.find('/') {
                Some(i) => &t[i + 1..],
                None => t.as_str(),
            };
            put(leaf, t, &mut leaf_idx);
            for part in leaf.split(['-', '/']) {
                put(part, t, &mut leaf_idx);
            }
        }

        let mut out: Vec<String> = Vec::new();
        let mut seen: HashSet<String> = HashSet::new();
        let add = |key: &str, out: &mut Vec<String>, seen: &mut HashSet<String>| {
            if let Some(hits) = leaf_idx.get(key) {
                for t in hits.iter().take(5) {
                    if !noise.contains(t) && seen.insert(t.clone()) {
                        out.push(t.clone());
                    }
                }
            }
        };

        // acronyms: EKS → acronym/eks (any 2-6 uppercase run)
        for w in question.split(|c: char| !c.is_alphanumeric()) {
            if (2..=6).contains(&w.chars().count()) && w.chars().all(|c| c.is_ascii_uppercase()) {
                add(&w.to_lowercase(), &mut out, &mut seen);
            }
        }
        let words: Vec<String> = question
            .to_lowercase()
            .split(|c: char| !c.is_alphanumeric())
            .filter(|w| w.len() >= 3 && !STOPW.contains(w))
            .map(|w| w.to_string())
            .collect();
        for w in &words {
            add(w, &mut out, &mut seen);
            // prefix: redshift → aws-service/reds… (leaf is a prefix of a longer question word)
            if w.len() >= 5 {
                let mut prefix_hits: Vec<String> = Vec::new();
                for (leaf, toks) in &leaf_idx {
                    if leaf.len() >= 4 && w.starts_with(leaf.as_str()) {
                        for t in toks.iter().take(3) {
                            prefix_hits.push(t.clone());
                        }
                    }
                }
                for t in prefix_hits {
                    if !noise.contains(&t) && seen.insert(t.clone()) {
                        out.push(t);
                    }
                }
            }
        }
        // bigrams: "amazon eks" → amazon-eks
        for pair in words.windows(2) {
            add(&format!("{}-{}", pair[0], pair[1]), &mut out, &mut seen);
        }
        // gazetteer: project the question through the SAME high-res vocabulary (symmetric linking)
        if let Some(gaz) = self.gazetteer() {
            for h in gaz.extract(question) {
                if vocab.contains(h.token.as_str()) && !noise.contains(&h.token) && seen.insert(h.token.clone()) {
                    out.push(h.token);
                }
            }
        }
        out.truncate(50);
        out
    }

    // ── bitmap-program analytics (fd46262) — deterministic templates beyond bare retrieve ──
    pub fn breakdown(&self, anchor: &str, facet: &str, k: usize) -> Value {
        programs::breakdown(&self.ix, anchor, facet, k)
    }
    pub fn crosstab(&self, anchor: &str, facet_a: &str, facet_b: &str, k: usize) -> Value {
        programs::crosstab(&self.ix, anchor, facet_a, facet_b, k)
    }
    pub fn rank(&self, facet: &str, k: usize) -> Value {
        programs::rank(&self.ix, facet, k, self.noise_tokens())
    }
    pub fn cooccurs(&self, token: &str, k: usize) -> Value {
        programs::cooccurs(&self.ix, token, k, self.noise_tokens())
    }
    pub fn s_path(&self, a: &str, b: &str, s: usize) -> Value {
        programs::s_path(&self.ix, a, b, s, self.noise_tokens())
    }
    pub fn s_clusters(&self, s: usize, k: usize) -> Value {
        programs::s_clusters(&self.ix, s, k, self.noise_tokens())
    }
    pub fn narrow(&self, scope: &[String], filters: &[String]) -> Value {
        programs::narrow(&self.ix, scope, filters)
    }

    pub fn stats(&self) -> Stats {
        let mut facet_tokens: HashMap<String, usize> = HashMap::new();
        for tok in self.ix.tokens() {
            let facet = tok.split('/').next().unwrap_or(tok).to_string();
            *facet_tokens.entry(facet).or_default() += 1;
        }
        let mut facets: Vec<(String, usize)> = facet_tokens.into_iter().collect();
        facets.sort_by(|a, b| b.1.cmp(&a.1).then(a.0.cmp(&b.0)));
        let mut numeric_fields: Vec<String> = self.ix.numeric_fields().cloned().collect();
        numeric_fields.sort();
        Stats {
            source: self.source.clone(),
            kind: self.kind,
            situations: self.ix.situations(),
            vocab: self.ix.vocab_size(),
            columns: self.columns.clone(),
            facets,
            numeric_fields,
        }
    }
}