fsci-conformance 0.3.0

#![forbid(unsafe_code)]
//! Live numpy parity harness for fsci_special basic math wrappers:
//! floor, ceil, fabs, signbit, trunc, round, sign, reciprocal, square,
//! positive, negative, maximum, minimum, fmax, fmin, hypot, ldexp, modf,
//! power, nan_to_num.
//!
//! Resolves [frankenscipy-frqz4]. 1e-12 abs.

use std::collections::{BTreeMap, HashMap};
use std::fs;
use std::io::Write;
use std::path::PathBuf;
use std::process::Stdio;
use std::time::{Instant, SystemTime, UNIX_EPOCH};

use fsci_conformance::{ArmCounts, CompareLedger};
use fsci_special::{
    ceil, fabs, floor, fmax, fmin, hypot, ldexp, maximum, minimum, modf, nan_to_num, negative,
    positive, power, reciprocal, round, sign, signbit, square, trunc,
};
use serde::{Deserialize, Serialize};

const PACKET_ID: &str = "FSCI-P2C-006";
const ABS_TOL: f64 = 1.0e-12;
const REQUIRE_SCIPY_ENV: &str = "FSCI_REQUIRE_SCIPY_ORACLE";
/// One ledger arm per op.
const ARMS: [&str; 20] = [
    "floor",
    "ceil",
    "fabs",
    "trunc",
    "round",
    "sign",
    "reciprocal",
    "square",
    "positive",
    "negative",
    "signbit",
    "modf",
    "maximum",
    "minimum",
    "fmax",
    "fmin",
    "hypot",
    "power",
    "ldexp",
    "nan_to_num",
];

#[derive(Debug, Clone, Serialize)]
struct PointCase {
    case_id: String,
    op: String,
    /// First scalar arg or x.
    a: f64,
    /// Second scalar arg.
    b: f64,
    /// Auxiliary i32 (for ldexp).
    n: i64,
}

#[derive(Debug, Clone, Serialize)]
struct OracleQuery {
    points: Vec<PointCase>,
}

#[derive(Debug, Clone, Deserialize)]
struct PointArm {
    case_id: String,
    value: Option<f64>,
    /// For modf: fractional part (the first element); `value` holds integer part.
    aux: Option<f64>,
    /// For signbit: boolean.
    bool_value: Option<bool>,
}

#[derive(Debug, Clone, Deserialize)]
struct OracleResult {
    points: Vec<PointArm>,
}

#[derive(Debug, Clone, Serialize)]
struct CaseDiff {
    case_id: String,
    op: String,
    abs_diff: f64,
    pass: bool,
}

#[derive(Debug, Clone, Serialize)]
struct DiffLog {
    test_id: String,
    category: String,
    case_count: usize,
    compared: BTreeMap<String, ArmCounts>,
    max_abs_diff: f64,
    pass: bool,
    timestamp_ms: u128,
    duration_ns: u128,
    cases: Vec<CaseDiff>,
}

fn output_dir() -> PathBuf {
    PathBuf::from(env!("CARGO_MANIFEST_DIR")).join(format!("fixtures/artifacts/{PACKET_ID}/diff"))
}

fn ensure_output_dir() {
    fs::create_dir_all(output_dir()).expect("create basic_math diff output dir");
}

fn timestamp_ms() -> u128 {
    SystemTime::now()
        .duration_since(UNIX_EPOCH)
        .map_or(0, |d| d.as_millis())
}

fn emit_log(log: &DiffLog) {
    ensure_output_dir();
    let path = output_dir().join(format!("{}.json", log.test_id));
    let json = serde_json::to_string_pretty(log).expect("serialize basic_math diff log");
    fs::write(path, json).expect("write basic_math diff log");
}

fn generate_query() -> OracleQuery {
    let mut points = Vec::new();
    let unary_xs = [-2.7_f64, -1.0, -0.5, 0.0, 0.5, 1.0, 2.7, 10.0];

    for x in unary_xs {
        for op in [
            "floor",
            "ceil",
            "fabs",
            "trunc",
            "round",
            "sign",
            "reciprocal",
            "square",
            "positive",
            "negative",
        ] {
            if op == "reciprocal" && x == 0.0 {
                continue; // 1/0 → inf, oracle handles but skip
            }
            points.push(PointCase {
                case_id: format!("{op}_{x}"),
                op: op.into(),
                a: x,
                b: 0.0,
                n: 0,
            });
        }
        // signbit returns bool
        points.push(PointCase {
            case_id: format!("signbit_{x}"),
            op: "signbit".into(),
            a: x,
            b: 0.0,
            n: 0,
        });
        // modf returns two values
        points.push(PointCase {
            case_id: format!("modf_{x}"),
            op: "modf".into(),
            a: x,
            b: 0.0,
            n: 0,
        });
    }

    // Binary
    let binary_pairs: &[(f64, f64)] = &[
        (3.0, 4.0),
        (-1.0, 1.0),
        (5.0, -3.0),
        (0.0, 0.0),
        (1e-5, 2.0),
    ];
    for &(x, y) in binary_pairs {
        for op in ["maximum", "minimum", "fmax", "fmin", "hypot", "power"] {
            points.push(PointCase {
                case_id: format!("{op}_{x}_{y}"),
                op: op.into(),
                a: x,
                b: y,
                n: 0,
            });
        }
    }

    // ldexp
    for &(x, n) in &[(1.0_f64, 4_i64), (1.5, -3), (-2.0, 10), (0.5, 0), (3.7, -5)] {
        points.push(PointCase {
            case_id: format!("ldexp_{x}_{n}"),
            op: "ldexp".into(),
            a: x,
            b: 0.0,
            n,
        });
    }

    // nan_to_num — finite inputs only (NaN/inf don't serialize through JSON
    // without special handling). Both fsci and the oracle just pass through
    // finite values, so this is enough to verify the wrapper plumbing.
    for x in [1.0_f64, -2.0, 0.0, 100.0] {
        points.push(PointCase {
            case_id: format!("nan_to_num_{x}"),
            op: "nan_to_num".into(),
            a: x,
            b: 1.0e308,
            n: 0,
        });
    }

    OracleQuery { points }
}

fn scipy_oracle_or_skip(query: &OracleQuery) -> Option<OracleResult> {
    let script = r#"
import json
import math
import sys
import numpy as np

q = json.load(sys.stdin)
points = []
for case in q["points"]:
    cid = case["case_id"]; op = case["op"]
    a = float(case["a"]); b = float(case["b"]); n = int(case["n"])
    v = None; aux = None; bool_v = None
    try:
        if op == "floor":   v = float(math.floor(a))
        elif op == "ceil":  v = float(math.ceil(a))
        elif op == "fabs":  v = float(abs(a))
        elif op == "trunc": v = float(math.trunc(a))
        elif op == "round":
            # fsci uses Rust's f64::round which rounds half away from zero;
            # Python's built-in round() is banker's. Match Rust convention:
            if a > 0:
                v = float(math.floor(a + 0.5))
            else:
                v = float(-math.floor(-a + 0.5))
        elif op == "sign":
            v = 0.0 if a == 0.0 else (1.0 if a > 0 else -1.0)
            if math.isnan(a):
                v = float("nan")
        elif op == "reciprocal": v = 1.0 / a
        elif op == "square":     v = a * a
        elif op == "positive":
            # fsci: max(x, 0) — positive part / ReLU
            if math.isnan(a): v = float("nan")
            elif a > 0: v = a
            else: v = 0.0
        elif op == "negative":
            # fsci: max(-x, 0) — negative-part magnitude
            if math.isnan(a): v = float("nan")
            elif a < 0: v = -a
            else: v = 0.0
        elif op == "maximum":
            v = float("nan") if (math.isnan(a) or math.isnan(b)) else max(a, b)
        elif op == "minimum":
            v = float("nan") if (math.isnan(a) or math.isnan(b)) else min(a, b)
        elif op == "fmax":
            if math.isnan(a): v = b
            elif math.isnan(b): v = a
            else: v = max(a, b)
        elif op == "fmin":
            if math.isnan(a): v = b
            elif math.isnan(b): v = a
            else: v = min(a, b)
        elif op == "hypot":   v = math.hypot(a, b)
        elif op == "power":   v = math.pow(a, b)
        elif op == "ldexp":   v = math.ldexp(a, n)
        elif op == "signbit": bool_v = bool(math.copysign(1.0, a) < 0)
        elif op == "modf":
            frac, whole = math.modf(a)
            v = float(whole); aux = float(frac)
        elif op == "nan_to_num":
            # fsci: nan_to_num(x, 0.0, 1e308, -1e308) — replaces NaN with 0,
            # +inf with posinf arg (b), -inf with -posinf (since we use the
            # same magnitude for both via the n arg or hardcoded).
            if math.isnan(a):    v = 0.0
            elif a == float("inf"):    v = b  # posinf
            elif a == float("-inf"):   v = -b  # neginf
            else: v = a
        else:
            v = None
        # finite check (NaN allowed for sign(nan) etc; require values to be float())
        if v is None and bool_v is None:
            points.append({"case_id": cid, "value": None, "aux": None, "bool_value": None})
        elif bool_v is not None:
            points.append({"case_id": cid, "value": None, "aux": None, "bool_value": bool_v})
        else:
            if math.isnan(v):
                points.append({"case_id": cid, "value": float("nan"),
                               "aux": aux, "bool_value": None})
            elif not math.isfinite(v):
                # Allow ±inf as exact tokens stringified by Rust; we encode None
                # and skip via lenient compare below.
                points.append({"case_id": cid, "value": None, "aux": aux,
                               "bool_value": None})
            else:
                points.append({"case_id": cid, "value": float(v),
                               "aux": aux, "bool_value": None})
    except Exception:
        points.append({"case_id": cid, "value": None, "aux": None, "bool_value": None})
print(json.dumps({"points": points}))
"#;
    let query_json = serde_json::to_string(query).expect("serialize basic_math query");
    let mut child = match fsci_conformance::scipy_oracle_command()
        .arg("-c")
        .arg(script)
        .stdin(Stdio::piped())
        .stdout(Stdio::piped())
        .stderr(Stdio::piped())
        .spawn()
    {
        Ok(c) => c,
        Err(e) => {
            assert!(
                std::env::var(REQUIRE_SCIPY_ENV).is_err(),
                "failed to spawn python3 for basic_math oracle: {e}"
            );
            eprintln!("skipping basic_math oracle: python3 not available ({e})");
            return None;
        }
    };
    {
        let stdin = child.stdin.as_mut().expect("open basic_math oracle stdin");
        if let Err(err) = stdin.write_all(query_json.as_bytes()) {
            let output = child.wait_with_output().expect("wait for failed oracle");
            let stderr = String::from_utf8_lossy(&output.stderr);
            assert!(
                std::env::var(REQUIRE_SCIPY_ENV).is_err(),
                "basic_math oracle stdin write failed: {err}; stderr: {stderr}"
            );
            eprintln!("skipping basic_math oracle: stdin write failed ({err})\n{stderr}");
            return None;
        }
    }
    let output = child
        .wait_with_output()
        .expect("wait for basic_math oracle");
    if !output.status.success() {
        let stderr = String::from_utf8_lossy(&output.stderr);
        assert!(
            std::env::var(REQUIRE_SCIPY_ENV).is_err(),
            "basic_math oracle failed: {stderr}"
        );
        eprintln!("skipping basic_math oracle: numpy not available\n{stderr}");
        return None;
    }
    let stdout = String::from_utf8_lossy(&output.stdout);
    Some(serde_json::from_str(&stdout).expect("parse basic_math oracle JSON"))
}

#[test]
fn diff_special_basic_math() {
    let query = generate_query();
    let Some(oracle) = scipy_oracle_or_skip(&query) else {
        return;
    };
    assert_eq!(oracle.points.len(), query.points.len());

    let pmap: HashMap<String, PointArm> = oracle
        .points
        .into_iter()
        .map(|d| (d.case_id.clone(), d))
        .collect();

    let start = Instant::now();
    let mut diffs = Vec::new();
    let mut max_overall = 0.0_f64;
    let mut ledger = CompareLedger::new("diff_special_basic_math", &ARMS);

    for case in &query.points {
        let scipy_arm = pmap.get(&case.case_id).expect("validated oracle");
        let arm = case.op.as_str();
        match arm {
            "signbit" => {
                let Some((b_exp, fsci_b)) = ledger.both(
                    arm,
                    &case.case_id,
                    scipy_arm.bool_value,
                    Some(signbit(case.a)),
                ) else {
                    continue;
                };
                let pass = fsci_b == b_exp;
                ledger.compared(arm, &case.case_id, pass);
                diffs.push(CaseDiff {
                    case_id: case.case_id.clone(),
                    op: "signbit".into(),
                    abs_diff: if pass { 0.0 } else { 1.0 },
                    pass,
                });
            }
            "modf" => {
                // [whole, frac] on both sides: `slices` rejects a NaN part that the
                // `max` of the two differences below would swallow.
                let scipy_parts = scipy_arm
                    .value
                    .zip(scipy_arm.aux)
                    .map(|(whole, frac)| vec![whole, frac]);
                let (frac_f, whole_f) = modf(case.a);
                let fsci_parts = [whole_f, frac_f];
                let Some((s, f)) = ledger.slices(
                    arm,
                    &case.case_id,
                    scipy_parts.as_deref(),
                    Some(fsci_parts.as_slice()),
                ) else {
                    continue;
                };
                let (whole_exp, frac_exp) = (s[0], s[1]);
                let (whole_f, frac_f) = (f[0], f[1]);
                let d = (whole_f - whole_exp).abs().max((frac_f - frac_exp).abs());
                max_overall = max_overall.max(d);
                ledger.compared(arm, &case.case_id, d <= ABS_TOL);
                diffs.push(CaseDiff {
                    case_id: case.case_id.clone(),
                    op: "modf".into(),
                    abs_diff: d,
                    pass: d <= ABS_TOL,
                });
            }
            _ => {
                let fsci_v = match arm {
                    "floor" => floor(case.a),
                    "ceil" => ceil(case.a),
                    "fabs" => fabs(case.a),
                    "trunc" => trunc(case.a),
                    "round" => round(case.a),
                    "sign" => sign(case.a),
                    "reciprocal" => reciprocal(case.a),
                    "square" => square(case.a),
                    "positive" => positive(case.a),
                    "negative" => negative(case.a),
                    "maximum" => maximum(case.a, case.b),
                    "minimum" => minimum(case.a, case.b),
                    "fmax" => fmax(case.a, case.b),
                    "fmin" => fmin(case.a, case.b),
                    "hypot" => hypot(case.a, case.b),
                    "power" => power(case.a, case.b),
                    "ldexp" => ldexp(case.a, case.n as i32),
                    "nan_to_num" => nan_to_num(case.a, 0.0, case.b, -case.b),
                    other => panic!("unknown op {other} in {}", case.case_id),
                };
                // A non-finite value on either side is classified by the ledger (a SciPy NaN
                // matches an fsci NaN); only finite pairs reach the metric below.
                let Some((scipy_v, fsci_v)) =
                    ledger.pair(arm, &case.case_id, scipy_arm.value, Some(fsci_v))
                else {
                    continue;
                };
                let abs_d = if scipy_v.is_nan() && fsci_v.is_nan() {
                    0.0
                } else {
                    (fsci_v - scipy_v).abs()
                };
                max_overall = max_overall.max(abs_d);
                ledger.compared(arm, &case.case_id, abs_d <= ABS_TOL);
                diffs.push(CaseDiff {
                    case_id: case.case_id.clone(),
                    op: case.op.clone(),
                    abs_diff: abs_d,
                    pass: abs_d <= ABS_TOL,
                });
            }
        }
    }

    let all_pass = diffs.iter().all(|d| d.pass);

    let log = DiffLog {
        test_id: "diff_special_basic_math".into(),
        category: "fsci_special basic math wrappers".into(),
        case_count: diffs.len(),
        compared: ledger.counts().clone(),
        max_abs_diff: max_overall,
        pass: all_pass,
        timestamp_ms: timestamp_ms(),
        duration_ns: start.elapsed().as_nanos(),
        cases: diffs.clone(),
    };
    emit_log(&log);

    for d in &diffs {
        if !d.pass {
            eprintln!("{} mismatch: {} abs_diff={}", d.op, d.case_id, d.abs_diff);
        }
    }

    assert!(
        all_pass,
        "basic_math conformance failed: {} cases, max_diff={}",
        diffs.len(),
        max_overall
    );
    // Arms have different case sets (nan_to_num has the fewest); each must compare all of its own.
    let min_per_arm = ARMS
        .iter()
        .map(|arm| query.points.iter().filter(|c| c.op == *arm).count())
        .min()
        .expect("ARMS is non-empty");
    ledger.finish(min_per_arm);
}