codingest 0.1.1

//! codingest Cypher query/traversal benchmark + query-parity harness.
//!
//! KGLite deleted its in-tree `code_tree` builder on 2026-07-16, so the old
//! cross-builder comparison (in-tree vs standalone) is gone. This harness now
//! builds the SAME target directory TWICE with `codingest::builder::run_with_options`
//! (two independent builds A and B), then runs an identical Cypher workload
//! against BOTH through kglite's canonical read path
//! (`kglite::api::session::{execute_read, ExecuteOptions}` — the exact pipeline
//! an MCP / CLI user hits).
//!
//! For each query we alternate timed iterations A/B/A/B… (warm cache) and report
//! median + min per side. Before timing, each query's result is compared across
//! the two builds (row count + a canonicalized, order-insensitive value digest);
//! a MISMATCH is reported and that query is NOT timed. Because the builder is
//! deterministic, two independent builds must return identical results — so a
//! MISMATCH is a query-result determinism regression, and the A/B delta is
//! run-to-run timing variance. (`make gate` fails on any MISMATCH.)
//!
//! Usage:
//!   cargo run -p codingest --bin codingest_bench --release -- <path>
//!   cargo run -p codingest --bin codingest_bench --release -- <path> --json

use kglite::api::session::{execute_read, ExecuteOptions, ExecuteOutcome};
use kglite::api::{DirGraph, GraphRead, Value};
use std::collections::hash_map::DefaultHasher;
use std::collections::HashMap;
use std::hash::{Hash, Hasher};
use std::path::Path;
use std::time::Instant;

const WARMUP: usize = 3;
const ITERS: usize = 20;

struct Query {
    name: &'static str,
    cypher: String,
}

/// Run one read-only query through the canonical session path.
fn run_query(graph: &DirGraph, query: &str) -> ExecuteOutcome {
    let params: HashMap<String, Value> = HashMap::new();
    let opts = ExecuteOptions::eager(&params);
    execute_read(graph, query, &opts)
        .unwrap_or_else(|e| panic!("query failed:\n  {query}\n  error: {e:?}"))
}

/// (row_count, order-insensitive value digest) for parity comparison.
/// Rows are canonicalized (`{:?}` per cell — stable for `Value`), sorted, and
/// hashed with the fixed-key `DefaultHasher`, so ordering nondeterminism between
/// the two graphs cannot produce a false MISMATCH — only a genuine difference in
/// the row multiset can.
fn digest(outcome: &ExecuteOutcome) -> (usize, u64) {
    let r = &outcome.result;
    let mut rows: Vec<String> = r
        .rows
        .iter()
        .map(|row| {
            row.iter()
                .map(|v| format!("{v:?}"))
                .collect::<Vec<_>>()
                .join("\u{1}")
        })
        .collect();
    rows.sort();
    let mut h = DefaultHasher::new();
    rows.len().hash(&mut h);
    for s in &rows {
        s.hash(&mut h);
    }
    (r.rows.len(), h.finish())
}

/// Extract the string in the first cell of the first row, if any.
fn first_string(outcome: &ExecuteOutcome) -> Option<String> {
    outcome
        .result
        .rows
        .first()
        .and_then(|row| row.first())
        .and_then(|v| match v {
            Value::String(s) => Some(s.clone()),
            _ => None,
        })
}

fn median(mut v: Vec<f64>) -> f64 {
    v.sort_by(|a, b| a.partial_cmp(b).unwrap());
    v[v.len() / 2]
}

fn min(v: &[f64]) -> f64 {
    v.iter().cloned().fold(f64::INFINITY, f64::min)
}

struct QueryResult {
    name: String,
    rows: usize,
    parity: bool,
    a_median_ms: f64,
    a_min_ms: f64,
    b_median_ms: f64,
    b_min_ms: f64,
    delta_pct: f64,
}

fn main() {
    let mut args = std::env::args().skip(1);
    let path = match args.next() {
        Some(p) => p,
        None => {
            eprintln!("usage: code_tree_bench <path> [--json]");
            std::process::exit(2);
        }
    };
    let rest: Vec<String> = args.collect();
    let json = rest.iter().any(|a| a == "--json");
    let target = Path::new(&path);

    // Two independent codingest builds with identical arguments:
    // verbose=false, include_tests=false, save_to=None, max_loc=None, docs=true.
    let t = Instant::now();
    let graph_a = codingest::builder::run_with_options(target, false, false, None, None, true)
        .unwrap_or_else(|e| {
            eprintln!("build A failed: {e}");
            std::process::exit(1);
        });
    let build_a_secs = t.elapsed().as_secs_f64();

    let t = Instant::now();
    let graph_b = codingest::builder::run_with_options(target, false, false, None, None, true)
        .unwrap_or_else(|e| {
            eprintln!("build B failed: {e}");
            std::process::exit(1);
        });
    let build_b_secs = t.elapsed().as_secs_f64();

    let a: &DirGraph = &graph_a;
    let b: &DirGraph = &graph_b;

    let nodes = a.graph.node_count();
    let edges = a.graph.edge_count();

    // Anchors discovered at runtime on graph A (graph B is equivalent, so the
    // same node exists there): the CALLS in-degree and out-degree hubs.
    let hot_in = first_string(&run_query(
        a,
        "MATCH (:Function)-[:CALLS]->(f:Function) \
         RETURN f.qualified_name AS q, count(*) AS c ORDER BY c DESC, q ASC LIMIT 1",
    ))
    .unwrap_or_default();
    let hot_out = first_string(&run_query(
        a,
        "MATCH (f:Function)-[:CALLS]->(:Function) \
         RETURN f.qualified_name AS q, count(*) AS c ORDER BY c DESC, q ASC LIMIT 1",
    ))
    .unwrap_or_default();

    let queries = vec![
        Query {
            name: "count_functions (full-label scan + count)",
            cypher: "MATCH (f:Function) RETURN count(f)".to_string(),
        },
        Query {
            name: "eq_filter_pub (equality property filter)",
            cypher: "MATCH (f:Function) WHERE f.visibility = 'pub' RETURN count(f)".to_string(),
        },
        Query {
            name: "contains_new (CONTAINS string filter)",
            cypher: "MATCH (f:Function) WHERE f.qualified_name CONTAINS 'new' RETURN count(f)"
                .to_string(),
        },
        Query {
            name: "top20_by_branch_count (ORDER BY + LIMIT)",
            cypher: "MATCH (f:Function) RETURN f.qualified_name, f.branch_count \
                     ORDER BY f.branch_count DESC, f.qualified_name ASC LIMIT 20"
                .to_string(),
        },
        Query {
            name: "defs_per_file (grouped aggregation)",
            cypher: "MATCH (file:File)-[:DEFINES]->(f:Function) \
                     RETURN file.path, count(f) AS c ORDER BY c DESC, file.path ASC LIMIT 20"
                .to_string(),
        },
        Query {
            name: "calls_edge_scan (1-hop edge scan + count)",
            cypher: "MATCH (:Function)-[:CALLS]->(:Function) RETURN count(*)".to_string(),
        },
        Query {
            name: "anchored_callers (anchored 1-hop, in-hub)",
            cypher: format!(
                "MATCH (caller:Function)-[:CALLS]->(f:Function {{qualified_name: '{hot_in}'}}) \
                 RETURN caller.qualified_name ORDER BY caller.qualified_name ASC"
            ),
        },
        Query {
            name: "two_hop_into_hot (2-hop traversal + count)",
            cypher: format!(
                "MATCH (a:Function)-[:CALLS]->(b:Function)-[:CALLS]->\
                 (f:Function {{qualified_name: '{hot_in}'}}) RETURN count(*)"
            ),
        },
        Query {
            name: "varlen_callers_1_3 ([:CALLS*1..3] + count DISTINCT)",
            cypher: format!(
                "MATCH (f:Function {{qualified_name: '{hot_in}'}})<-[:CALLS*1..3]-(caller:Function) \
                 RETURN count(DISTINCT caller)"
            ),
        },
        Query {
            name: "reverse_callees_of_hub (reverse-direction 1-hop)",
            cypher: format!(
                "MATCH (callee:Function)<-[:CALLS]-(f:Function {{qualified_name: '{hot_out}'}}) \
                 RETURN callee.qualified_name ORDER BY callee.qualified_name ASC"
            ),
        },
        Query {
            name: "method_calls_mix (Struct-HAS_METHOD->Fn-CALLS->Fn)",
            cypher: "MATCH (s:Struct)-[:HAS_METHOD]->(m:Function)-[:CALLS]->(f:Function) \
                     RETURN count(*)"
                .to_string(),
        },
    ];

    let mut results: Vec<QueryResult> = Vec::new();

    for q in &queries {
        // Parity first: run once on each graph, compare row-count + digest.
        let out_a = run_query(a, &q.cypher);
        let out_b = run_query(b, &q.cypher);
        let (rows_a, dig_a) = digest(&out_a);
        let (rows_b, dig_b) = digest(&out_b);
        let parity = rows_a == rows_b && dig_a == dig_b;

        if !parity {
            eprintln!(
                "MISMATCH on `{}`: build A rows={rows_a} digest={dig_a:016x} | \
                 build B rows={rows_b} digest={dig_b:016x}\n  query: {}",
                q.name, q.cypher
            );
            results.push(QueryResult {
                name: q.name.to_string(),
                rows: rows_a,
                parity: false,
                a_median_ms: f64::NAN,
                a_min_ms: f64::NAN,
                b_median_ms: f64::NAN,
                b_min_ms: f64::NAN,
                delta_pct: f64::NAN,
            });
            continue;
        }

        // Warmup both sides.
        for _ in 0..WARMUP {
            let _ = run_query(a, &q.cypher);
            let _ = run_query(b, &q.cypher);
        }
        // Timed, alternating A/B.
        let mut ta = Vec::with_capacity(ITERS);
        let mut tb = Vec::with_capacity(ITERS);
        for _ in 0..ITERS {
            let s = Instant::now();
            let _ = run_query(a, &q.cypher);
            ta.push(s.elapsed().as_secs_f64() * 1000.0);
            let s = Instant::now();
            let _ = run_query(b, &q.cypher);
            tb.push(s.elapsed().as_secs_f64() * 1000.0);
        }
        let a_min_ms = min(&ta);
        let b_min_ms = min(&tb);
        let a_median_ms = median(ta);
        let b_median_ms = median(tb);
        let delta_pct = if a_median_ms > 0.0 {
            (b_median_ms - a_median_ms) / a_median_ms * 100.0
        } else {
            0.0
        };

        results.push(QueryResult {
            name: q.name.to_string(),
            rows: rows_a,
            parity: true,
            a_median_ms,
            a_min_ms,
            b_median_ms,
            b_min_ms,
            delta_pct,
        });
    }

    if json {
        let out = serde_json::json!({
            "path": path,
            "nodes": nodes,
            "edges": edges,
            "build_a_secs": (build_a_secs * 1000.0).round() / 1000.0,
            "build_b_secs": (build_b_secs * 1000.0).round() / 1000.0,
            "anchor_hot_in": hot_in,
            "anchor_hot_out": hot_out,
            "warmup": WARMUP,
            "iters": ITERS,
            "queries": results.iter().map(|r| serde_json::json!({
                "name": r.name,
                "rows": r.rows,
                "parity": r.parity,
                "a_median_ms": (r.a_median_ms * 1000.0).round() / 1000.0,
                "a_min_ms": (r.a_min_ms * 1000.0).round() / 1000.0,
                "b_median_ms": (r.b_median_ms * 1000.0).round() / 1000.0,
                "b_min_ms": (r.b_min_ms * 1000.0).round() / 1000.0,
                "delta_pct": (r.delta_pct * 100.0).round() / 100.0,
            })).collect::<Vec<_>>(),
        });
        println!("{}", serde_json::to_string_pretty(&out).unwrap());
        return;
    }

    println!("codingest Cypher benchmark — query-parity across two independent builds");
    println!("target : {path}");
    println!("graph  : {nodes} nodes / {edges} edges  (identical across both builds)");
    println!("build  : A {build_a_secs:.3}s | B {build_b_secs:.3}s  (one-off, context)");
    println!("anchor : in-hub  = {hot_in}");
    println!("         out-hub = {hot_out}");
    println!("timing : {WARMUP} warmup + {ITERS} timed iters, alternating A/B, warm cache\n");

    println!(
        "{:<52} {:>7} {:>12} {:>12} {:>9}  parity",
        "query", "rows", "build A(ms)", "build B(ms)", "delta"
    );
    println!("{}", "-".repeat(110));
    for r in &results {
        if r.parity {
            println!(
                "{:<52} {:>7} {:>12} {:>12} {:>8.1}%  OK",
                r.name,
                r.rows,
                format!("{:.3} (min {:.3})", r.a_median_ms, r.a_min_ms),
                format!("{:.3} (min {:.3})", r.b_median_ms, r.b_min_ms),
                r.delta_pct,
            );
        } else {
            println!(
                "{:<52} {:>7} {:>12} {:>12} {:>9}  MISMATCH",
                r.name, r.rows, "-", "-", "-",
            );
        }
    }
    let mismatches = results.iter().filter(|r| !r.parity).count();
    println!(
        "\n{} queries, {} OK, {} MISMATCH",
        results.len(),
        results.len() - mismatches,
        mismatches
    );
}