//! `aura` — the programmatic / CLI face of the engine (the surface the LLM and
//! automation drive: author a node, run a sim/sweep, emit structured metrics).
//!
//! The walking skeleton's closing seam: `aura run` bootstraps a built-in sample
//! signal-quality harness (synthetic source → SMA-cross → Exposure → SimBroker →
//! recording sinks), runs it deterministically (C1), and prints the run's
//! metrics + manifest (#6) as canonical JSON to stdout (the headline C14 move).
//!
//! `aura run --real <SYMBOL> [--from <ms>] [--to <ms>]` feeds that same harness
//! real M1 close bars, streamed lazily from the local data-server archive through
//! the #71 Source seam (`M1FieldSource`) instead of the synthetic stream — the
//! first real-data backtest from the CLI.

mod render;
use render::{ChartData, ChartMode, Series};

use aura_core::{zip_params, Cell, Firing, Scalar, ScalarKind, Timestamp};
use aura_engine::{
    f64_field, join_on_ts, monte_carlo, param_stability, summarize, walk_forward, window_of,
    ColumnarTrace, Composite, Edge, FlatGraph, GraphBuilder, Harness, JoinedRow, McAggregate,
    McFamily, RollMode, RunManifest, RunReport, SourceSpec, SweepFamily, SyntheticSpec, Target,
    VecSource, WalkForwardResult, WindowBounds, WindowRoller, WindowRun,
};
use aura_registry::{
    group_families, mc_member_reports, optimize, rank_by, sweep_member_reports,
    walkforward_member_reports, FamilyKind, Registry, RunTraces, TraceStore, TraceStoreError,
};
use aura_std::{Ema, Exposure, LinComb, LongOnly, Recorder, SimBroker, Sma, Sub};
use std::sync::mpsc::{self, Receiver};
use std::collections::HashSet;

/// The pip size the built-in *synthetic* harnesses run at: a 5-decimal FX major
/// (`EURUSD`-shaped). The synthetic streams carry no instrument, so there is no
/// `instrument_spec` to thread; a single named source keeps the broker's divisor
/// (`sample_harness` / `SimBroker::builder`) and the recorded broker label
/// (`sim_optimal_manifest`) in lockstep, so they cannot silently drift apart.
/// The real path threads the looked-up `spec.pip_size` instead.
const SYNTHETIC_PIP_SIZE: f64 = 0.0001;

/// Real walk-forward roller sizes (Fork D/F). `WindowRoller` takes sizes in the
/// stream's epoch-unit; for real M1 that is nanoseconds. A classic 3-month
/// in-sample / 1-month out-of-sample / 1-month step (contiguous OOS tiling).
const WF_DAY_NS: i64 = 86_400_000_000_000;
const WF_REAL_IS_NS: i64 = 90 * WF_DAY_NS;
const WF_REAL_OOS_NS: i64 = 30 * WF_DAY_NS;
const WF_REAL_STEP_NS: i64 = 30 * WF_DAY_NS;

/// The built-in synthetic price stream: rises through t=4 then reverses, so the
/// demo trace carries one exposure sign flip and a real drawdown (C22 populated
/// trace). Deterministic and fixed (C1).
fn synthetic_prices() -> Vec<(Timestamp, Scalar)> {
    [
        (1_i64, 1.0000_f64),
        (2, 1.0010),
        (3, 1.0030),
        (4, 1.0060),
        (5, 1.0040),
        (6, 1.0010),
        (7, 0.9990),
    ]
    .iter()
    .map(|&(t, p)| (Timestamp(t), Scalar::f64(p)))
    .collect()
}

/// A warm-up-adequate synthetic stream for the enriched sample/sweep: ~18 ticks
/// rising, falling, then rising again so the trend SMA spread and the MACD
/// EMA-of-EMA histogram both warm up and flip sign. It shares the proven warm-up
/// profile of `macd_prices` (the enriched sample embeds the same `macd` composite,
/// so it needs the same warm-up length); the flat `run_sample` keeps the shorter
/// `synthetic_prices`. Deterministic and fixed (C1).
fn showcase_prices() -> Vec<(Timestamp, Scalar)> {
    [
        1.0000_f64, 1.0008, 1.0021, 1.0039, 1.0062, 1.0090, 1.0083, 1.0061, 1.0034,
        1.0012, 0.9998, 1.0006, 1.0024, 1.0047, 1.0069, 1.0086, 1.0097, 1.0092,
    ]
    .iter()
    .enumerate()
    .map(|(i, &p)| (Timestamp(i as i64 + 1), Scalar::f64(p)))
    .collect()
}

/// Bootstrap the sample signal-quality harness with two recording sinks (equity
/// tapped on the SimBroker, exposure tapped on the Exposure node). Rust-authored
/// wiring (C17/C20) over the raw bootstrap API — no builder DSL this cycle. The
/// price taps both SMAs and the broker's price slot (slot 1); exposure feeds the
/// broker's slot 0 (slot order is load-bearing — both are f64).
// The harness-plus-two-drained-sink-receivers tuple has exactly one call site
// (`run_sample`); a named type would be speculative abstraction this cycle.
#[allow(clippy::type_complexity)]
fn sample_harness(pip_size: f64) -> (
    Harness,
    Receiver<(Timestamp, Vec<Scalar>)>,
    Receiver<(Timestamp, Vec<Scalar>)>,
) {
    let (tx_eq, rx_eq) = mpsc::channel();
    let (tx_ex, rx_ex) = mpsc::channel();
    let f64_recorder_sig = || aura_engine::NodeSchema {
        inputs: vec![aura_engine::PortSpec { kind: ScalarKind::F64, firing: Firing::Any, name: "in".into() }],
        output: vec![],
        params: vec![],
    };
    let h = Harness::bootstrap(FlatGraph {
        nodes: vec![
            Box::new(Sma::new(2)),                                          // 0 fast SMA
            Box::new(Sma::new(4)),                                          // 1 slow SMA
            Box::new(Sub::new()),                                           // 2 spread
            Box::new(Exposure::new(0.5)),                                   // 3 exposure
            Box::new(SimBroker::new(pip_size)),                             // 4 sim-optimal broker
            Box::new(Recorder::new(&[ScalarKind::F64], Firing::Any, tx_eq)), // 5 equity sink
            Box::new(Recorder::new(&[ScalarKind::F64], Firing::Any, tx_ex)), // 6 exposure sink
        ],
        signatures: vec![
            Sma::builder().schema().clone(),
            Sma::builder().schema().clone(),
            Sub::builder().schema().clone(),
            Exposure::builder().schema().clone(),
            SimBroker::builder(pip_size).schema().clone(),
            f64_recorder_sig(),
            f64_recorder_sig(),
        ],
        sources: vec![SourceSpec {
            kind: ScalarKind::F64,
            targets: vec![
                Target { node: 0, slot: 0 },
                Target { node: 1, slot: 0 },
                Target { node: 4, slot: 1 }, // price into the broker's price slot
            ],
        }],
        edges: vec![
            Edge { from: 0, to: 2, slot: 0, from_field: 0 },
            Edge { from: 1, to: 2, slot: 1, from_field: 0 },
            Edge { from: 2, to: 3, slot: 0, from_field: 0 },
            Edge { from: 3, to: 4, slot: 0, from_field: 0 }, // exposure into broker slot 0
            Edge { from: 4, to: 5, slot: 0, from_field: 0 }, // equity -> sink 5
            Edge { from: 3, to: 6, slot: 0, from_field: 0 }, // exposure -> sink 6
        ],
    })
    .expect("valid sample signal-quality DAG");
    (h, rx_eq, rx_ex)
}

/// Build the sim-optimal `RunManifest`: the engine-external descriptor fields
/// (commit, seed-free synthetic run, broker label) are constant across the CLI's
/// built-in harnesses — only `params` and `window` vary. Centralizing the broker
/// label keeps it a single source (and a single edit point for per-asset pip
/// work): the `pip_size` it renders is the one its caller ran the broker at.
fn sim_optimal_manifest(
    params: Vec<(String, Scalar)>,
    window: (Timestamp, Timestamp),
    seed: u64,
    pip_size: f64,
) -> RunManifest {
    // Typed params pass straight through: the manifest carries self-describing
    // Scalars, so a length stays `i64` and a scale `f64` in the record.
    RunManifest {
        commit: option_env!("AURA_COMMIT").unwrap_or("unknown").to_string(),
        params,
        window,
        seed,
        broker: format!("sim-optimal(pip_size={pip_size})"),
    }
}

/// Persist a run's drained taps to the on-disk trace store under `runs/traces/<name>/`
/// (beside the run registry's `runs/`). Shared by every run form — all drain the same
/// two f64 taps (equity off the broker, exposure off the strategy) and carry a
/// `RunManifest`. Pure wiring over `ColumnarTrace` + `TraceStore`; the engine is
/// untouched. An I/O failure is a usage-level error (stderr + exit 2), per the spec.
fn persist_traces(
    name: &str,
    manifest: &RunManifest,
    eq_rows: &[(Timestamp, Vec<Scalar>)],
    ex_rows: &[(Timestamp, Vec<Scalar>)],
) {
    let taps = vec![
        ColumnarTrace::from_rows("equity", &[ScalarKind::F64], eq_rows),
        ColumnarTrace::from_rows("exposure", &[ScalarKind::F64], ex_rows),
    ];
    if let Err(e) = TraceStore::open("runs").write(name, manifest, &taps) {
        eprintln!("aura: trace persist failed: {e}");
        std::process::exit(2);
    }
}

/// The maximum length (bytes) of an on-disk member-key path component. Comfortably
/// under the 255-byte POSIX `NAME_MAX` and inside Windows' 260-char `MAX_PATH`
/// once the `runs/traces/<name>/` prefix and `/<tap>.json` suffix are added.
const MAX_KEY: usize = 200;

/// Map any byte outside the portable directory-name charset `[A-Za-z0-9._-]` to
/// `_`. The single source of filesystem-portability for an on-disk path component
/// (valid on Linux / Windows / macOS, also URL-path- and cloud-sync-safe).
fn sanitize_component(s: &str) -> String {
    s.chars()
        .map(|c| if c.is_ascii_alphanumeric() || matches!(c, '.' | '_' | '-') { c } else { '_' })
        .collect()
}

/// Render a scalar value case-lessly: integers/timestamps as decimal digits, bool
/// as `true`/`false`, f64 via Rust's `Display` (decimal, shortest round-trip, NO
/// scientific notation). Case-less rendering is what keeps two members of one
/// family from ever differing only by letter case (case-insensitive-FS safety).
fn render_value(v: &Scalar) -> String {
    match v {
        Scalar::I64(n) => n.to_string(),
        Scalar::F64(x) => x.to_string(),
        Scalar::Bool(b) => b.to_string(),
        Scalar::Timestamp(t) => t.0.to_string(),
    }
}

/// FNV-1a-64 over `bytes` — a fixed, version-stable, non-cryptographic hash used
/// only as the over-cap member-key disambiguator (`std`'s `DefaultHasher` is
/// explicitly unstable across releases, so it cannot name an on-disk artefact).
fn fnv1a64(bytes: &[u8]) -> u64 {
    let mut h: u64 = 0xcbf2_9ce4_8422_2325;
    for &b in bytes {
        h ^= b as u64;
        h = h.wrapping_mul(0x0000_0100_0000_01b3);
    }
    h
}

/// The portable, collision-free member key for a swept grid point: one `name-value`
/// token per *varying* axis (in `named`'s param-space slot order), joined by `_`,
/// every token sanitised to the portable charset. Pinned (singleton) axes carry no
/// information and are omitted. A 1-point grid (no varying axis) keys as `"m"`. A
/// key over `MAX_KEY` degrades to a conformant `h-<16-hex>` FNV fallback so the
/// key is one valid path component for ANY grid (the #105 generalisation).
fn member_key(named: &[(String, Scalar)], varying: &HashSet<String>) -> String {
    let key: String = named
        .iter()
        .filter(|(n, _)| varying.contains(n))
        .map(|(n, v)| format!("{}-{}", sanitize_component(n), sanitize_component(&render_value(v))))
        .collect::<Vec<_>>()
        .join("_");
    let key = if key.is_empty() { "m".to_string() } else { key };
    if key.len() <= MAX_KEY { key } else { format!("h-{:016x}", fnv1a64(key.as_bytes())) }
}

/// Build the serve-ready `ChartData` from a run's read-back traces by the spec-§6
/// 3-step union-spine alignment — no tap privileged, no point dropped:
/// (1) xs = the sorted, deduped union of every tap's timestamps;
/// (2) synthesize an empty-payload spine over xs and pass ALL taps (via
///     `ColumnarTrace::to_rows`, which yields uniformly-f64 rows) as symmetric sides
///     of `join_on_ts`, so no side row is dropped and none occupies the privileged
///     `JoinedRow.spine`;
/// (3) flatten each (tap, column) to a `Series` of `Option<f64>` over xs.
fn build_chart_data(traces: RunTraces) -> ChartData {
    let mut xs: Vec<i64> = traces.taps.iter().flat_map(|t| t.ts.iter().copied()).collect();
    xs.sort_unstable();
    xs.dedup();

    let spine: Vec<(Timestamp, Vec<Scalar>)> = xs.iter().map(|&t| (Timestamp(t), Vec::new())).collect();
    let tap_rows: Vec<Vec<(Timestamp, Vec<Scalar>)>> = traces.taps.iter().map(|t| t.to_rows()).collect();
    let sides: Vec<&[(Timestamp, Vec<Scalar>)]> = tap_rows.iter().map(|r| r.as_slice()).collect();
    let joined: Vec<JoinedRow> = join_on_ts(&spine, &sides);

    let mut series: Vec<Series> = Vec::new();
    for (i, tap) in traces.taps.iter().enumerate() {
        for c in 0..tap.columns.len() {
            let name = if tap.columns.len() == 1 { tap.tap.clone() } else { format!("{}[{c}]", tap.tap) };
            let y_scale_id = format!("y_{}", series.len());
            let points: Vec<Option<f64>> =
                joined.iter().map(|r| r.sides[i].as_ref().map(|row| row[c].as_f64())).collect();
            series.push(Series { name, y_scale_id, points });
        }
    }

    ChartData { xs, series }
}

/// `aura chart <name> [--panels]`: read the persisted run's traces, align them, and
/// print the self-contained uPlot page. A missing run is a usage error (stderr +
/// exit 2), per the CLI's convention — never a panic.
fn emit_chart(name: &str, mode: ChartMode) {
    let traces = match TraceStore::open("runs").read(name) {
        Ok(t) => t,
        Err(TraceStoreError::NotFound(n)) => {
            eprintln!("aura: no recorded run '{n}' under runs/traces (run `aura run --trace {n}` first)");
            std::process::exit(2);
        }
        Err(e) => {
            eprintln!("aura: {e}");
            std::process::exit(2);
        }
    };
    print!("{}", render::render_chart_html(&build_chart_data(traces), mode));
}

/// Run the sample harness and fold it into a `RunReport` (drain both sinks →
/// `f64_field` → `summarize` → pair with a `RunManifest`). Pure and deterministic
/// (C1): the same build yields the same report.
fn run_sample(trace: Option<&str>) -> RunReport {
    let (mut h, rx_eq, rx_ex) = sample_harness(SYNTHETIC_PIP_SIZE);
    let sources: Vec<Box<dyn aura_engine::Source>> =
        vec![Box::new(VecSource::new(synthetic_prices()))];
    let window = window_of(&sources).expect("non-empty synthetic stream");
    h.run(sources);

    let eq_rows: Vec<(Timestamp, Vec<Scalar>)> = rx_eq.try_iter().collect();
    let ex_rows: Vec<(Timestamp, Vec<Scalar>)> = rx_ex.try_iter().collect();
    let manifest = sim_optimal_manifest(
        vec![
            ("sma_fast".to_string(), Scalar::i64(2)),
            ("sma_slow".to_string(), Scalar::i64(4)),
            ("exposure_scale".to_string(), Scalar::f64(0.5)),
        ],
        window,
        0,
        SYNTHETIC_PIP_SIZE,
    );
    if let Some(name) = trace {
        persist_traces(name, &manifest, &eq_rows, &ex_rows);
    }
    let metrics = summarize(&f64_field(&eq_rows, 0), &f64_field(&ex_rows, 0));
    RunReport { manifest, metrics }
}

/// `aura run --real <SYMBOL>`: run the built-in sample harness over real M1 close
/// bars streamed lazily from the local data-server archive through the #71 Source
/// seam (`M1FieldSource`, a `Box<dyn Source>`), not the synthetic `VecSource`. Same
/// fold as `run_sample`. The manifest window is read from a *separate* probe source
/// (a Source is single-pass), so the run source streams the window untouched.
/// A no-local-data condition (unknown symbol, or a window overlapping no file / no
/// bars) is a usage error: stderr + exit(2), not a panic.
fn run_sample_real(symbol: &str, from_ms: Option<i64>, to_ms: Option<i64>, trace: Option<&str>) -> RunReport {
    // Per-instrument pip: look up BEFORE any data access, so an un-specced symbol
    // refuses without touching local data. Honest by construction.
    let spec = instrument_spec_or_refuse(symbol);
    let (mut h, rx_eq, rx_ex) = sample_harness(spec.pip_size);
    let server = std::sync::Arc::new(data_server::DataServer::new(data_server::DEFAULT_DATA_PATH));
    if !server.has_symbol(symbol) {
        no_real_data(symbol);
    }

    // Manifest window: drain a separate probe (single-pass Source) for first/last ts.
    let window = probe_window(&server, symbol, from_ms, to_ms);

    let source: Box<dyn aura_engine::Source> =
        match aura_ingest::M1FieldSource::open(&server, symbol, from_ms, to_ms, aura_ingest::M1Field::Close) {
            Some(s) => Box::new(s),
            None => no_real_data(symbol),
        };
    h.run(vec![source]);

    let eq_rows: Vec<(Timestamp, Vec<Scalar>)> = rx_eq.try_iter().collect();
    let ex_rows: Vec<(Timestamp, Vec<Scalar>)> = rx_ex.try_iter().collect();
    let manifest = sim_optimal_manifest(
        vec![
            ("sma_fast".to_string(), Scalar::i64(2)),
            ("sma_slow".to_string(), Scalar::i64(4)),
            ("exposure_scale".to_string(), Scalar::f64(0.5)),
        ],
        window,
        0,
        spec.pip_size,
    );
    if let Some(name) = trace {
        persist_traces(name, &manifest, &eq_rows, &ex_rows);
    }
    let metrics = summarize(&f64_field(&eq_rows, 0), &f64_field(&ex_rows, 0));
    RunReport { manifest, metrics }
}

/// Parse the `run --real` tail: a mandatory `<SYMBOL>` then zero-or-more
/// `--from <ms>` / `--to <ms>` pairs in any order. Pure (no I/O, no exit) so the
/// arg grammar is unit-testable; `main` does the side effects. An unknown token, a
/// flag without its value, a non-`i64` ms, or a repeated flag is an `Err` carrying
/// a short usage message.
#[allow(clippy::type_complexity)]
fn parse_real_args(
    rest: &[&str],
) -> Result<(String, Option<i64>, Option<i64>, Option<String>), String> {
    let usage = || "run --real <SYMBOL> [--from <ms>] [--to <ms>] [--trace <name>]".to_string();
    let (symbol, mut tail) = match rest.split_first() {
        Some((sym, t)) if !sym.is_empty() => (*sym, t),
        _ => return Err(usage()),
    };
    let mut from: Option<i64> = None;
    let mut to: Option<i64> = None;
    let mut trace: Option<String> = None;
    while let Some((flag, t)) = tail.split_first() {
        let (value, t) = t.split_first().ok_or_else(usage)?;
        match *flag {
            "--from" if from.is_none() => from = Some(value.parse().map_err(|_| usage())?),
            "--to" if to.is_none() => to = Some(value.parse().map_err(|_| usage())?),
            "--trace" if trace.is_none() => trace = Some((*value).to_string()),
            _ => return Err(usage()),
        }
        tail = t;
    }
    Ok((symbol.to_string(), from, to, trace))
}

/// The shared `--real <SYMBOL> [--from <ms>] [--to <ms>]` accumulator for the
/// family parsers (`parse_sweep_args` / `parse_walkforward_args`). It holds the
/// one home of the real/window grammar — flag-repeat strictness, the empty-symbol
/// rejection, and the "window flags require `--real`" rule — so the two siblings
/// agree with each other and with `parse_real_args`. Each parser owns its other
/// flags (strategy / name / trace); on a `--real`/`--from`/`--to` token it calls
/// `accept`, and at the end calls `finish` to validate and build the `DataChoice`.
#[derive(Default)]
struct RealWindowGrammar {
    symbol: Option<String>,
    from_ms: Option<i64>,
    to_ms: Option<i64>,
}

impl RealWindowGrammar {
    /// Consume one `--real`/`--from`/`--to` flag and its already-split value.
    /// Returns `Ok(true)` if the flag was a real/window flag (consumed),
    /// `Ok(false)` if it is not ours (the caller handles it), `Err` on a malformed
    /// real/window flag: a repeated flag (mirroring `parse_real_args`'s
    /// `if from.is_none()` strictness) or an empty `--real` symbol.
    fn accept(&mut self, flag: &str, value: &str, usage: &impl Fn() -> String) -> Result<bool, String> {
        match flag {
            "--real" if self.symbol.is_none() && !value.is_empty() => {
                self.symbol = Some(value.to_string());
            }
            "--from" if self.from_ms.is_none() => {
                self.from_ms = Some(value.parse().map_err(|_| usage())?);
            }
            "--to" if self.to_ms.is_none() => {
                self.to_ms = Some(value.parse().map_err(|_| usage())?);
            }
            "--real" | "--from" | "--to" => return Err(usage()), // repeated / empty symbol
            _ => return Ok(false),
        }
        Ok(true)
    }

    /// Validate (window flags require `--real`) and assemble the `DataChoice`.
    fn finish(self, usage: &impl Fn() -> String) -> Result<DataChoice, String> {
        match self.symbol {
            Some(symbol) => Ok(DataChoice::Real { symbol, from_ms: self.from_ms, to_ms: self.to_ms }),
            None if self.from_ms.is_some() || self.to_ms.is_some() => Err(usage()),
            None => Ok(DataChoice::Synthetic),
        }
    }
}

/// What `--real` parsing yields: the synthetic default, or a real symbol + an
/// optional window (parsed, not yet opened). Pure, so the grammar is unit-testable.
#[derive(Debug, Clone, PartialEq)]
enum DataChoice {
    Synthetic,
    Real { symbol: String, from_ms: Option<i64>, to_ms: Option<i64> },
}

/// The source provider threaded into the family builders: synthetic built-in
/// streams, or real M1 close bars from the data-server archive. Replaces the
/// hardcoded `VecSource` so a member's source, pip, window, and roller sizes come
/// from one place (Fork B/D/F).
///
/// `Synthetic` denotes a *consumer-dependent* built-in stream, not one fixed
/// series: the full-window consumers (`full_window` / `run_sources`, used by
/// sweep / MC) draw the 18-bar `showcase_prices()`, while the windowed consumers
/// (`windowed_sources` / `wf_window_sizes`, used by walk-forward) draw the 60-bar
/// `walkforward_prices()` so the `(24,12,12)`-bar roller fits its span. The two
/// faces never reach one consumer (a family is either full-window or windowed), so
/// the split is invisible per call site but real across the type — read both
/// family builders to see it whole.
enum DataSource {
    Synthetic,
    Real {
        server: std::sync::Arc<data_server::DataServer>,
        symbol: String,
        from_ms: Option<i64>,
        to_ms: Option<i64>,
        pip: f64,
    },
}

/// No-local-data refusal — stderr + exit(2), mirroring `run_sample_real`.
fn no_real_data(symbol: &str) -> ! {
    eprintln!("aura: no local data for symbol '{symbol}' at {}", data_server::DEFAULT_DATA_PATH);
    std::process::exit(2)
}

/// Look up the vetted per-instrument pip/spec, or refuse (stderr + exit 2) on an
/// un-specced symbol — the single home of the guessed-pip refusal message, shared
/// by `run_sample_real` and `DataSource::from_choice`. Refusing BEFORE any data
/// access keeps the pip honest by construction (never guessed).
fn instrument_spec_or_refuse(symbol: &str) -> aura_ingest::InstrumentSpec {
    match aura_ingest::instrument_spec(symbol) {
        Some(s) => s,
        None => {
            eprintln!("aura: no vetted pip/instrument spec for symbol '{symbol}' — refusing to run a real instrument with a guessed pip (add it to the instrument table)");
            std::process::exit(2);
        }
    }
}

/// Probe the full data window: open a single-pass probe `M1FieldSource`, drain it
/// for the first/last timestamp, and return `(first, last)`. Refuses (via
/// `no_real_data`) when the symbol/window yields no source or no bars. Shared by
/// `run_sample_real` (which needs the manifest window from a probe separate from
/// the run source) and `DataSource::full_window`.
fn probe_window(
    server: &std::sync::Arc<data_server::DataServer>,
    symbol: &str,
    from_ms: Option<i64>,
    to_ms: Option<i64>,
) -> (Timestamp, Timestamp) {
    let mut probe = aura_ingest::M1FieldSource::open(server, symbol, from_ms, to_ms, aura_ingest::M1Field::Close)
        .unwrap_or_else(|| no_real_data(symbol));
    let first = aura_engine::Source::peek(&probe).unwrap_or_else(|| no_real_data(symbol));
    let mut last = first;
    while let Some((t, _)) = aura_engine::Source::next(&mut probe) {
        last = t;
    }
    (first, last)
}

impl DataSource {
    /// Build a provider from a parsed choice, or refuse (stderr + exit 2) on an
    /// un-vetted symbol / absent data — both BEFORE any member runs (Fork C/G),
    /// via the same `instrument_spec_or_refuse` / `no_real_data` helpers as
    /// `run_sample_real`.
    fn from_choice(choice: DataChoice) -> DataSource {
        match choice {
            DataChoice::Synthetic => DataSource::Synthetic,
            DataChoice::Real { symbol, from_ms, to_ms } => {
                let spec = instrument_spec_or_refuse(&symbol);
                let server = std::sync::Arc::new(data_server::DataServer::new(data_server::DEFAULT_DATA_PATH));
                if !server.has_symbol(&symbol) {
                    no_real_data(&symbol);
                }
                DataSource::Real { server, symbol, from_ms, to_ms, pip: spec.pip_size }
            }
        }
    }

    fn pip_size(&self) -> f64 {
        match self {
            DataSource::Synthetic => SYNTHETIC_PIP_SIZE,
            DataSource::Real { pip, .. } => *pip,
        }
    }

    /// The full run window, probed once. Synthetic: the showcase span. Real:
    /// `probe_window` drains a separate single-pass probe source for first/last ts
    /// (the same helper `run_sample_real` uses for its manifest window).
    fn full_window(&self) -> (Timestamp, Timestamp) {
        match self {
            DataSource::Synthetic => {
                let s: Vec<Box<dyn aura_engine::Source>> = vec![Box::new(VecSource::new(showcase_prices()))];
                window_of(&s).expect("non-empty showcase stream")
            }
            DataSource::Real { server, symbol, from_ms, to_ms, .. } => {
                probe_window(server, symbol, *from_ms, *to_ms)
            }
        }
    }

    /// The full walk-forward span. Synthetic draws the 60-bar `walkforward_prices`
    /// span — NOT `showcase_prices` (which `full_window` uses): walk-forward is a
    /// *windowed* consumer whose roller `(24,12,12)` needs 36 bars, so it uses the
    /// longer built-in stream (byte-unchanged from the pre-`DataSource`
    /// `walkforward_family`, which derived its span the same way). Real: the same
    /// probed `--from..--to` window as `full_window`.
    fn wf_full_span(&self) -> (Timestamp, Timestamp) {
        match self {
            DataSource::Synthetic => {
                let s: Vec<Box<dyn aura_engine::Source>> = vec![Box::new(VecSource::new(walkforward_prices()))];
                window_of(&s).expect("non-empty walkforward stream")
            }
            DataSource::Real { server, symbol, from_ms, to_ms, .. } => {
                probe_window(server, symbol, *from_ms, *to_ms)
            }
        }
    }

    /// A fresh full-window source per member (single-pass). Synthetic: showcase.
    fn run_sources(&self) -> Vec<Box<dyn aura_engine::Source>> {
        match self {
            DataSource::Synthetic => vec![Box::new(VecSource::new(showcase_prices()))],
            DataSource::Real { server, symbol, from_ms, to_ms, .. } => vec![Box::new(
                aura_ingest::M1FieldSource::open(server, symbol, *from_ms, *to_ms, aura_ingest::M1Field::Close)
                    .unwrap_or_else(|| no_real_data(symbol)),
            )],
        }
    }

    /// A fresh windowed source for an IS/OOS sub-window (walk-forward). Synthetic:
    /// `walkforward_window_source`. Real: `open_window` (ns-native `Timestamp`).
    fn windowed_sources(&self, from: Timestamp, to: Timestamp) -> Vec<Box<dyn aura_engine::Source>> {
        match self {
            DataSource::Synthetic => vec![Box::new(walkforward_window_source(from, to))],
            DataSource::Real { server, symbol, .. } => vec![Box::new(
                aura_ingest::M1FieldSource::open_window(server, symbol, Some(from), Some(to), aura_ingest::M1Field::Close)
                    .unwrap_or_else(|| no_real_data(symbol)),
            )],
        }
    }

    /// WindowRoller sizes per data kind (Fork F): bar-index for synthetic (24/12/12
    /// over the 60-bar span), calendar-ns for real.
    fn wf_window_sizes(&self) -> (i64, i64, i64) {
        match self {
            DataSource::Synthetic => (24, 12, 12),
            DataSource::Real { .. } => (WF_REAL_IS_NS, WF_REAL_OOS_NS, WF_REAL_STEP_NS),
        }
    }

    /// The built-in strategy's length grid, **per data kind**. Synthetic keeps the
    /// short lengths that fit the 18/60-bar demo streams (a 200-bar MA would never
    /// warm on a 60-bar stream); real uses realistic M1 lengths so the SMA-cross +
    /// MACD signal is a real trend cross over tens of thousands of bars, not noise.
    /// Returns `(trend_fast grid, trend_slow grid, (macd_fast, macd_slow, macd_signal))`;
    /// only the two trend axes vary (a 2×2 sweep), the MACD lengths are pinned.
    fn strategy_lengths(&self) -> ([i64; 2], [i64; 2], (i64, i64, i64)) {
        match self {
            DataSource::Synthetic => ([2, 3], [4, 5], (2, 4, 3)),
            // 50/200-style intraday crosses on M1 (minutes), standard 12/26/9 MACD.
            DataSource::Real { .. } => ([50, 100], [200, 400], (12, 26, 9)),
        }
    }
}

/// The SMA-cross signal as a named composite (price -> fast/slow SMA -> spread).
/// CLI-local sample builder; the engine ships no sample (the duplication with
/// `blueprint.rs`'s test helper is the dedup tracked in #14). Value-empty: the SMA
/// lengths are injected at compile, not baked here.
fn sma_cross(name: &str) -> Composite {
    let mut g = GraphBuilder::new(name);
    let fast = g.add(Sma::builder().named("fast")); // fast SMA leg
    let slow = g.add(Sma::builder().named("slow")); // slow SMA leg
    let sub = g.add(Sub::builder());
    let price = g.input_role("price");
    g.feed(price, [fast.input("series"), slow.input("series")]);
    g.connect(fast.output("value"), sub.input("lhs"));
    g.connect(slow.output("value"), sub.input("rhs"));
    g.expose(sub.output("value"), "cross");
    g.build().expect("sample sma_cross wiring resolves")
}

/// The blended signal: a trend leg (SMA-cross) and a momentum leg (MACD), combined
/// by a weighted sum. A multiply-nested composite (root → signals → {trend,
/// momentum}); the blend is a multi-param node living inside it, with one weight
/// bound as a structural constant (so it drops out of the sweepable surface).
fn signals(name: &str) -> Composite {
    let mut g = GraphBuilder::new(name);
    let trend = g.add(sma_cross("trend")); // trend leg (one f64 "cross")
    let momentum = g.add(macd("momentum")); // momentum leg (3 outputs)
    // blend: Σ wᵢ·termᵢ over [trend.cross, momentum.histogram, momentum.signal].
    // weights[2] is bound (a fixed signal-line weight) → removed from param_space;
    // weights[0]/[1] stay tunable. `.named("blend")` makes the path signals.blend.*
    // (and renders the `blend:` prefix).
    let blend = g.add(
        LinComb::builder(3)
            .named("blend")
            .bind("weights[2]", Scalar::f64(0.5)),
    );
    let price = g.input_role("price");
    g.feed(price, [trend.input("price"), momentum.input("price")]);
    g.connect(trend.output("cross"), blend.input("term[0]")); // trend.cross        → blend.term[0]
    g.connect(momentum.output("histogram"), blend.input("term[1]")); // momentum.histogram → blend.term[1]
    g.connect(momentum.output("signal"), blend.input("term[2]")); // momentum.signal    → blend.term[2]
    g.expose(blend.output("value"), "signal");
    g.build().expect("sample signals wiring resolves")
}

/// The sample signal-quality blueprint (value-empty) **with its two recording
/// sinks reachable**: returns the equity + exposure receivers a per-point sweep
/// run drains (the eight free params — the trend SMA lengths, the momentum EMA
/// lengths, the two open blend weights, and the exposure scale — are injected at
/// compile via the point vector). The root harness of the sample topology, whose
/// signal is built by the nested `signals` composite; `build_sample` (the `aura
/// graph` entry) is expressed on top of it.
#[allow(clippy::type_complexity)]
fn sample_blueprint_with_sinks(pip_size: f64) -> (
    Composite,
    Receiver<(Timestamp, Vec<Scalar>)>,
    Receiver<(Timestamp, Vec<Scalar>)>,
) {
    let (tx_eq, rx_eq) = mpsc::channel();
    let (tx_ex, rx_ex) = mpsc::channel();
    let mut g = GraphBuilder::new("sample");
    let sig = g.add(signals("signals"));
    let exposure = g.add(Exposure::builder());
    let broker = g.add(SimBroker::builder(pip_size));
    let eq = g.add(Recorder::builder(vec![ScalarKind::F64], Firing::Any, tx_eq));
    let ex = g.add(Recorder::builder(vec![ScalarKind::F64], Firing::Any, tx_ex));
    let price = g.source_role("price", ScalarKind::F64);
    g.feed(price, [sig.input("price"), broker.input("price")]);
    g.connect(sig.output("signal"), exposure.input("signal")); // blended signal -> Exposure
    g.connect(exposure.output("exposure"), broker.input("exposure")); // exposure -> broker slot 0
    g.connect(broker.output("equity"), eq.input("col[0]")); // equity   -> sink
    g.connect(exposure.output("exposure"), ex.input("col[0]")); // exposure -> sink
    let bp = g.build().expect("sample blueprint wiring resolves");
    (bp, rx_eq, rx_ex)
}

/// The sample blueprint without its sink receivers — the `aura graph` render
/// entry, which never runs the graph (so the receivers are dropped).
fn build_sample() -> Composite {
    sample_blueprint_with_sinks(SYNTHETIC_PIP_SIZE).0
}

/// The built-in sample rendered by `aura graph`.
fn sample_blueprint() -> Composite {
    build_sample()
}

/// Run the built-in sample over a small built-in grid (fast ∈ {2,3},
/// slow ∈ {4,5}, scale ∈ {0.5} — 4 points) and render one JSON line per point in
/// enumeration (odometer) order. Pure + deterministic (C1): the same build yields
/// the same report. Each point builds a fresh blueprint (fresh sink channels),
/// bootstraps it under the point vector, runs it, and folds the drained sinks to
/// metrics — the per-point closure the engine `sweep` drives disjointly.
fn sweep_family(trace: Option<&str>, data: &DataSource) -> SweepFamily {
    let pip = data.pip_size();
    let window = data.full_window();
    let bp = sample_blueprint_with_sinks(pip).0;
    let space = bp.param_space();
    let (tf, ts, (mf, ms, msig)) = data.strategy_lengths();
    let binder = bp
        .axis("signals.trend.fast.length", tf)
        .axis("signals.trend.slow.length", ts)
        .axis("signals.momentum.fast.length", [mf])
        .axis("signals.momentum.slow.length", [ms])
        .axis("signals.momentum.signal.length", [msig])
        .axis("signals.blend.weights[0]", [1.0])
        .axis("signals.blend.weights[1]", [1.0])
        .axis("exposure.scale", [0.5]);
    let varying: HashSet<String> = binder.varying_axes().into_iter().collect();
    binder
        .sweep(|point| {
            let (bp, rx_eq, rx_ex) = sample_blueprint_with_sinks(pip);
            let mut h = bp
                .bootstrap_with_cells(point)
                .expect("grid points are kind-checked against param_space");
            let sources = data.run_sources();
            h.run(sources);
            let eq_rows = rx_eq.try_iter().collect::<Vec<_>>();
            let ex_rows = rx_ex.try_iter().collect::<Vec<_>>();
            let named = zip_params(&space, point);
            let key = member_key(&named, &varying);
            let manifest = sim_optimal_manifest(named, window, 0, pip);
            if let Some(name) = trace {
                persist_traces(&format!("{name}/{key}"), &manifest, &eq_rows, &ex_rows);
            }
            let equity = f64_field(&eq_rows, 0);
            let exposure = f64_field(&ex_rows, 0);
            RunReport { manifest, metrics: summarize(&equity, &exposure) }
        })
        .expect("the built-in named grid matches the sample param-space")
}

/// The EMA-distance momentum demo strategy with its two recording sinks reachable.
/// The signal is how far price sits above/below its own EMA (`price - ema`), sized
/// by `Exposure`, then passed through the long-only `LongOnly` gate. Three swept
/// knobs of three kinds — `ema.length` (i64), `exposure.scale` (f64),
/// `longonly.enabled` (bool) — with nothing in common with the SMA-cross demo: the
/// generic-sweep proof. The exposure sink taps the FINAL (gated) exposure so the
/// bool's effect is visible in the trace.
#[allow(clippy::type_complexity)]
fn momentum_blueprint_with_sinks(pip_size: f64) -> (
    Composite,
    Receiver<(Timestamp, Vec<Scalar>)>,
    Receiver<(Timestamp, Vec<Scalar>)>,
) {
    let (tx_eq, rx_eq) = mpsc::channel();
    let (tx_ex, rx_ex) = mpsc::channel();
    let mut g = GraphBuilder::new("momentum");
    // Name the param-bearing nodes explicitly so the swept paths are guaranteed
    // ema.length / exposure.scale / longonly.enabled regardless of default-name
    // derivation (the member-key examples + the param-space test depend on these).
    let ema = g.add(Ema::builder().named("ema")); // ema.length
    let dist = g.add(Sub::builder()); // momentum = price - ema
    let expo = g.add(Exposure::builder().named("exposure")); // exposure.scale
    let gate = g.add(LongOnly::builder().named("longonly")); // longonly.enabled (the bool param)
    let broker = g.add(SimBroker::builder(pip_size));
    let eq = g.add(Recorder::builder(vec![ScalarKind::F64], Firing::Any, tx_eq));
    let ex = g.add(Recorder::builder(vec![ScalarKind::F64], Firing::Any, tx_ex));
    let price = g.source_role("price", ScalarKind::F64);
    g.feed(price, [ema.input("series"), dist.input("lhs"), broker.input("price")]);
    g.connect(ema.output("value"), dist.input("rhs")); // momentum = price - ema
    g.connect(dist.output("value"), expo.input("signal"));
    g.connect(expo.output("exposure"), gate.input("exposure"));
    g.connect(gate.output("exposure"), broker.input("exposure")); // gated exposure -> broker
    g.connect(broker.output("equity"), eq.input("col[0]")); // equity -> sink
    g.connect(gate.output("exposure"), ex.input("col[0]")); // gated exposure -> sink
    let bp = g.build().expect("momentum blueprint wiring resolves");
    (bp, rx_eq, rx_ex)
}

/// Run the momentum strategy over its built-in grid — `ema.length ∈ {5,10}` ×
/// `exposure.scale ∈ {0.5,1.0}` × `longonly.enabled ∈ {true,false}` = 8 points,
/// all three axes varying. Mirrors `sweep_family`: capture the binder's varying
/// axes, key each member via the generic portable `member_key`. With `--trace`,
/// persist each member under `runs/traces/<name>/<member_key>/`.
fn momentum_sweep_family(trace: Option<&str>, data: &DataSource) -> SweepFamily {
    let pip = data.pip_size();
    let window = data.full_window();
    let bp = momentum_blueprint_with_sinks(pip).0;
    let space = bp.param_space();
    let binder = bp
        .axis("ema.length", [5, 10])
        .axis("exposure.scale", [0.5, 1.0])
        .axis("longonly.enabled", [true, false]);
    let varying: HashSet<String> = binder.varying_axes().into_iter().collect();
    binder
        .sweep(|point| {
            let (bp, rx_eq, rx_ex) = momentum_blueprint_with_sinks(pip);
            let mut h = bp
                .bootstrap_with_cells(point)
                .expect("grid points are kind-checked against param_space");
            let sources = data.run_sources();
            h.run(sources);
            let eq_rows = rx_eq.try_iter().collect::<Vec<_>>();
            let ex_rows = rx_ex.try_iter().collect::<Vec<_>>();
            let named = zip_params(&space, point);
            let key = member_key(&named, &varying);
            let manifest = sim_optimal_manifest(named, window, 0, pip);
            if let Some(name) = trace {
                persist_traces(&format!("{name}/{key}"), &manifest, &eq_rows, &ex_rows);
            }
            let equity = f64_field(&eq_rows, 0);
            let exposure = f64_field(&ex_rows, 0);
            RunReport { manifest, metrics: summarize(&equity, &exposure) }
        })
        .expect("the momentum named grid matches the momentum param-space")
}

/// Render a sweep family as one `RunReport` JSON line per point. Test helper:
/// production (`run_sweep`) renders *and* persists per point.
#[cfg(test)]
fn sweep_report() -> String {
    let mut out = String::new();
    for pt in &sweep_family(None, &DataSource::Synthetic).points {
        out.push_str(&pt.report.to_json());
        out.push('\n');
    }
    out
}

/// The default run registry: an append-only JSONL store under the current
/// working directory. (A project-configured runs-dir via `Aura.toml` is a later
/// refinement.)
fn default_registry() -> Registry {
    Registry::open("runs/runs.jsonl")
}

/// Which built-in strategy `aura sweep` runs. Default (today's behaviour) is the
/// SMA-cross sample; `momentum` is the bool-param demo.
#[derive(Clone, Copy, PartialEq, Debug)]
enum Strategy {
    SmaCross,
    Momentum,
}

/// Parse the `sweep` tail:
/// `[--strategy <sma|momentum>] [--real <SYMBOL> [--from <ms>] [--to <ms>]] [--name <n> | --trace <n>]`.
/// Defaults: SMA-cross, synthetic, name "sweep", no persist (today's bare `aura
/// sweep`). `--name` and `--trace` are mutually exclusive; `--from`/`--to` (ms,
/// `i64`) require `--real` (there is no synthetic window knob). Pure (no I/O /
/// exit) so the grammar is unit-testable; `main` does the side effects. An unknown
/// token, a flag without its value, an unknown strategy, both name flags, or a
/// window flag without `--real` rejects.
fn parse_sweep_args(rest: &[&str]) -> Result<(Strategy, String, bool, DataChoice), String> {
    let usage = || "sweep [--strategy <sma|momentum>] [--real <SYMBOL> [--from <ms>] [--to <ms>]] [--name <n> | --trace <n>]".to_string();
    let mut strategy = Strategy::SmaCross;
    let mut name: Option<(String, bool)> = None; // (name, persist)
    let mut real = RealWindowGrammar::default();
    let mut tail = rest;
    while let Some((flag, t)) = tail.split_first() {
        let (value, t) = t.split_first().ok_or_else(usage)?;
        if real.accept(flag, value, &usage)? {
            tail = t;
            continue;
        }
        match *flag {
            "--strategy" => {
                strategy = match *value {
                    "sma" => Strategy::SmaCross,
                    "momentum" => Strategy::Momentum,
                    _ => return Err(usage()),
                };
            }
            "--name" if name.is_none() => name = Some(((*value).to_string(), false)),
            "--trace" if name.is_none() => name = Some(((*value).to_string(), true)),
            _ => return Err(usage()),
        }
        tail = t;
    }
    let (name, persist) = name.unwrap_or_else(|| ("sweep".to_string(), false));
    Ok((strategy, name, persist, real.finish(&usage)?))
}

/// Parse the `walkforward` tail: `[--real <SYMBOL> [--from <ms>] [--to <ms>]] [--name <n> | --trace <n>]`.
/// Defaults: synthetic, name "walkforward", no persist. `--name`/`--trace` are
/// mutually exclusive; `--from`/`--to` require `--real`. Pure (no I/O / exit).
fn parse_walkforward_args(rest: &[&str]) -> Result<(String, bool, DataChoice), String> {
    let usage = || "walkforward [--real <SYMBOL> [--from <ms>] [--to <ms>]] [--name <n> | --trace <n>]".to_string();
    let mut name: Option<(String, bool)> = None; // (name, persist)
    let mut real = RealWindowGrammar::default();
    let mut tail = rest;
    while let Some((flag, t)) = tail.split_first() {
        let (value, t) = t.split_first().ok_or_else(usage)?;
        if real.accept(flag, value, &usage)? {
            tail = t;
            continue;
        }
        match *flag {
            "--name" if name.is_none() => name = Some(((*value).to_string(), false)),
            "--trace" if name.is_none() => name = Some(((*value).to_string(), true)),
            _ => return Err(usage()),
        }
        tail = t;
    }
    let (name, persist) = name.unwrap_or_else(|| ("walkforward".to_string(), false));
    Ok((name, persist, real.finish(&usage)?))
}

/// Render a family-member stdout line: the assigned `family_id` plus the embedded
/// `RunReport`. The report is emitted in its own declaration key order (manifest
/// leads with `commit`, C18) so the line is byte-identical to the stored
/// `families.jsonl`. `serde_json::json!` would route the report through a
/// `serde_json::Value` and re-alphabetize the manifest keys (broker-first),
/// diverging from the store — hence the report is spliced in pre-serialized (#99).
fn family_member_line(id: &str, report: &RunReport) -> String {
    format!(
        r#"{{"family_id":{},"report":{}}}"#,
        serde_json::to_string(id).expect("a string id always serializes"),
        report.to_json()
    )
}

/// Monte-Carlo variant of [`family_member_line`]: the per-draw line also carries the
/// realization `seed` (between `family_id` and `report`), matching `run_mc`'s shape.
fn mc_member_line(id: &str, seed: u64, report: &RunReport) -> String {
    format!(
        r#"{{"family_id":{},"seed":{},"report":{}}}"#,
        serde_json::to_string(id).expect("a string id always serializes"),
        seed,
        report.to_json()
    )
}

/// `aura sweep [--strategy <sma|momentum>] [--name <n>|--trace <n>]`: run the
/// selected built-in sweep, persist it as a *family* (related records sharing one
/// `family_id`, C18/C21) via `append_family`, and print each point's record line
/// carrying the assigned id. With `--trace`, also persist each member's streams
/// under `runs/traces/<n>/<member_key>/` (opt-in).
fn run_sweep(strategy: Strategy, name: &str, persist: bool, data: DataSource) {
    let reg = default_registry();
    let family = match strategy {
        Strategy::SmaCross => sweep_family(persist.then_some(name), &data),
        Strategy::Momentum => momentum_sweep_family(persist.then_some(name), &data),
    };
    let id = match reg.append_family(name, FamilyKind::Sweep, &sweep_member_reports(&family)) {
        Ok(id) => id,
        Err(e) => {
            eprintln!("aura: {e}");
            std::process::exit(2);
        }
    };
    for pt in &family.points {
        println!("{}", family_member_line(&id, &pt.report));
    }
}

/// `aura walkforward [--name <n>|--trace <n>]`: run a built-in rolling walk-forward
/// over the sample blueprint + a synthetic windowed source. Per window: sweep the
/// built-in grid on the in-sample slice, optimize by total_pips (axis 2 inside axis 3,
/// where aura-cli bridges engine + registry), run the chosen params out-of-sample.
/// Persist the per-window OOS reports as a *family* (C18/C21) via `append_family`,
/// print each carrying the assigned id, then the stitched summary line. With
/// `--trace`, also persist each OOS member's streams under
/// `runs/traces/<n>/oos<ns>/` (opt-in). Deterministic (C1).
fn run_walkforward(name: &str, persist: bool, data: DataSource) {
    let reg = default_registry();
    let result = walkforward_family(persist.then_some(name), &data);
    let id =
        match reg.append_family(name, FamilyKind::WalkForward, &walkforward_member_reports(&result))
        {
            Ok(id) => id,
            Err(e) => {
                eprintln!("aura: {e}");
                std::process::exit(2);
            }
        };
    for w in &result.windows {
        println!("{}", family_member_line(&id, &w.run.oos_report));
    }
    println!("{}", walkforward_summary_json(&result));
}

/// The built-in rolling walk-forward: 24-bar in-sample, 12-bar out-of-sample,
/// stepping 12 (contiguous OOS tiling), over the 60-bar synthetic span -> 3
/// windows. Each window sweeps the built-in grid in-sample, optimizes by
/// total_pips (axis 2), and runs the chosen params out-of-sample.
fn walkforward_family(trace: Option<&str>, data: &DataSource) -> WalkForwardResult {
    let span = data.wf_full_span();
    let (is_len, oos_len, step) = data.wf_window_sizes();
    let roller = match WindowRoller::new(span, is_len, oos_len, step, RollMode::Rolling) {
        Ok(r) => r,
        Err(e) => {
            eprintln!("aura: walk-forward window too short for one IS+OOS span: {e:?}");
            std::process::exit(2);
        }
    };
    let space = sample_blueprint_with_sinks(data.pip_size()).0.param_space();
    walk_forward(roller, space, |w: WindowBounds| {
        let is_family = sweep_over(w.is.0, w.is.1, data);
        let best = optimize(&is_family, "total_pips").expect("total_pips is a known metric");
        let (oos_equity, oos_report) = run_oos(&best.params, w.oos.0, w.oos.1, trace, data);
        WindowRun {
            // The tag-free sweep winner is the chosen point; its kinds live on
            // WalkForwardResult.space (computed once above from the same blueprint).
            chosen_params: best.params,
            oos_equity,
            oos_report,
        }
    })
}

/// Sweep the built-in named grid over an in-sample window, sourcing the in-memory
/// windowed stream. Mirrors `sweep_family`, but windowed by `[from, to]`.
fn sweep_over(from: Timestamp, to: Timestamp, data: &DataSource) -> SweepFamily {
    let pip = data.pip_size();
    let bp = sample_blueprint_with_sinks(pip).0;
    let space = bp.param_space();
    let (tf, ts, (mf, ms, msig)) = data.strategy_lengths();
    bp.axis("signals.trend.fast.length", tf)
        .axis("signals.trend.slow.length", ts)
        .axis("signals.momentum.fast.length", [mf])
        .axis("signals.momentum.slow.length", [ms])
        .axis("signals.momentum.signal.length", [msig])
        .axis("signals.blend.weights[0]", [1.0])
        .axis("signals.blend.weights[1]", [1.0])
        .axis("exposure.scale", [0.5])
        .sweep(|point| {
            let (bp, rx_eq, rx_ex) = sample_blueprint_with_sinks(pip);
            let mut h = bp
                .bootstrap_with_cells(point)
                .expect("grid points are kind-checked against param_space");
            let sources = data.windowed_sources(from, to);
            let window = window_of(&sources).expect("non-empty in-sample window");
            h.run(sources);
            let equity = f64_field(&rx_eq.try_iter().collect::<Vec<_>>(), 0);
            let exposure = f64_field(&rx_ex.try_iter().collect::<Vec<_>>(), 0);
            RunReport {
                manifest: sim_optimal_manifest(zip_params(&space, point), window, 0, pip),
                metrics: summarize(&equity, &exposure),
            }
        })
        .expect("the built-in named grid matches the sample param-space")
}

/// Run the chosen params over an out-of-sample window; return the recorded
/// pip-equity segment (for stitching) and the OOS RunReport (the C18 record).
fn run_oos(
    params: &[Cell],
    from: Timestamp,
    to: Timestamp,
    trace: Option<&str>,
    data: &DataSource,
) -> (Vec<(Timestamp, f64)>, RunReport) {
    let pip = data.pip_size();
    let (bp, rx_eq, rx_ex) = sample_blueprint_with_sinks(pip);
    let space = bp.param_space();
    let mut h = bp
        .bootstrap_with_cells(params)
        .expect("chosen params pre-validated by the in-sample GridSpace::new");
    let sources = data.windowed_sources(from, to);
    let window = window_of(&sources).expect("non-empty out-of-sample window");
    h.run(sources);
    let eq_rows = rx_eq.try_iter().collect::<Vec<_>>();
    let ex_rows = rx_ex.try_iter().collect::<Vec<_>>();
    let manifest = sim_optimal_manifest(zip_params(&space, params), window, 0, pip);
    if let Some(name) = trace {
        persist_traces(&format!("{name}/oos{}", from.0), &manifest, &eq_rows, &ex_rows);
    }
    let equity = f64_field(&eq_rows, 0);
    let exposure = f64_field(&ex_rows, 0);
    let report = RunReport { manifest, metrics: summarize(&equity, &exposure) };
    (equity, report)
}

/// The walk-forward summary line: window count, stitched OOS total pips (the last
/// stitched-curve value), and the on-demand per-param stability. Canonical JSON
/// (C14).
fn walkforward_summary_json(result: &WalkForwardResult) -> String {
    let total = result.stitched_oos_equity.last().map(|&(_, v)| v).unwrap_or(0.0);
    serde_json::json!({
        "walkforward": {
            "windows": result.windows.len(),
            "stitched_total_pips": total,
            "param_stability": param_stability(result),
        }
    })
    .to_string()
}

/// A longer deterministic stream than `showcase_prices` — enough for several
/// IS/OOS windows with SMA warm-up. Seed-determined via `SyntheticSpec` (C1).
fn walkforward_prices() -> Vec<(Timestamp, Scalar)> {
    let spec = SyntheticSpec { start: 1.0, len: 60, step: 1 };
    let mut src = spec.source(7);
    let mut out = Vec::new();
    while let Some(item) = aura_engine::Source::next(&mut src) {
        out.push(item);
    }
    out
}

/// The in-memory windowed source the built-in demo uses (the firewall mapping to
/// `DataServer::stream_m1_windowed` is the real-data path; the demo stays in-memory,
/// mirroring `run_sweep`'s `showcase_prices`). Inclusive `[from, to]`.
fn walkforward_window_source(from: Timestamp, to: Timestamp) -> VecSource {
    VecSource::new(
        walkforward_prices()
            .into_iter()
            .filter(|&(t, _)| t >= from && t <= to)
            .collect(),
    )
}

/// Render the built-in walk-forward as the per-window OOS RunReport lines plus the
/// summary line — the `run_walkforward` shape minus registry persistence. Test
/// helper (mirrors `sweep_report`).
#[cfg(test)]
fn walkforward_report() -> String {
    let result = walkforward_family(None, &DataSource::Synthetic);
    let mut out = String::new();
    for w in &result.windows {
        out.push_str(&w.run.oos_report.to_json());
        out.push('\n');
    }
    out.push_str(&walkforward_summary_json(&result));
    out.push('\n');
    out
}

/// The built-in Monte-Carlo family: the sample harness over a fixed (empty) base
/// point, re-seeded across a built-in seed set — each seed a disjoint C1
/// realization of a synthetic price walk (C12 axis 4). Mirrors `sweep_family`,
/// varying the *seed* rather than a tuning param. The seed -> `Source`
/// construction lives inside the per-draw closure (eager-agnostic, #71).
fn mc_family(trace: Option<&str>) -> McFamily {
    let base_point: Vec<Scalar> = Vec::new();
    monte_carlo(&base_point, &[1, 2, 3], |seed, _base| {
        let (mut h, rx_eq, rx_ex) = sample_harness(SYNTHETIC_PIP_SIZE);
        let spec = SyntheticSpec { start: 1.0, len: 32, step: 1 };
        let sources: Vec<Box<dyn aura_engine::Source>> = vec![Box::new(spec.source(seed))];
        let window = window_of(&sources).expect("non-empty synthetic stream");
        h.run(sources);
        let eq_rows = rx_eq.try_iter().collect::<Vec<_>>();
        let ex_rows = rx_ex.try_iter().collect::<Vec<_>>();
        let manifest = sim_optimal_manifest(
            vec![
                ("sma_fast".to_string(), Scalar::i64(2)),
                ("sma_slow".to_string(), Scalar::i64(4)),
                ("exposure_scale".to_string(), Scalar::f64(0.5)),
            ],
            window,
            seed,
            SYNTHETIC_PIP_SIZE,
        );
        if let Some(name) = trace {
            persist_traces(&format!("{name}/seed{seed}"), &manifest, &eq_rows, &ex_rows);
        }
        let equity = f64_field(&eq_rows, 0);
        let exposure = f64_field(&ex_rows, 0);
        RunReport { manifest, metrics: summarize(&equity, &exposure) }
    })
}

/// Render an `McAggregate` as one canonical JSON line. `McAggregate` itself is not
/// `Serialize` (only its `MetricStats` fields are), so the line is built from the
/// three per-metric stat blocks.
fn mc_aggregate_json(agg: &McAggregate) -> String {
    serde_json::json!({
        "mc_aggregate": {
            "total_pips": agg.total_pips,
            "max_drawdown": agg.max_drawdown,
            "exposure_sign_flips": agg.exposure_sign_flips,
        }
    })
    .to_string()
}

/// `aura mc [--name <n>|--trace <n>]`: run the built-in Monte-Carlo family, persist
/// it to the family store via `append_family` (C18/C21), print each draw's record
/// line (carrying the assigned `family_id`) plus the aggregate line. With `--trace`,
/// also persist each draw's streams under `runs/traces/<n>/seed<seed>/` (opt-in).
fn run_mc(name: &str, persist: bool) {
    let reg = default_registry();
    let family = mc_family(persist.then_some(name));
    let id = match reg.append_family(name, FamilyKind::MonteCarlo, &mc_member_reports(&family)) {
        Ok(id) => id,
        Err(e) => {
            eprintln!("aura: {e}");
            std::process::exit(2);
        }
    };
    for draw in &family.draws {
        println!("{}", mc_member_line(&id, draw.seed, &draw.report));
    }
    println!("{}", mc_aggregate_json(&family.aggregate));
}

/// Render the built-in Monte-Carlo family as the per-draw `RunReport` lines plus
/// the aggregate line — the `run_mc` shape minus registry persistence (no
/// `family_id`, which is store-assigned). Test helper, mirroring `sweep_report` /
/// `walkforward_report`: it carries the C1-determinism test of the family
/// computation, separate from the store-dependent id.
#[cfg(test)]
fn mc_report() -> String {
    let family = mc_family(None);
    let mut out = String::new();
    for draw in &family.draws {
        out.push_str(&draw.report.to_json());
        out.push('\n');
    }
    out.push_str(&mc_aggregate_json(&family.aggregate));
    out.push('\n');
    out
}

/// `aura runs families`: one header line per stored family (id, kind, member
/// count), in first-seen store order.
fn runs_families() {
    let reg = default_registry();
    let members = match reg.load_family_members() {
        Ok(m) => m,
        Err(e) => {
            eprintln!("aura: {e}");
            std::process::exit(2);
        }
    };
    for fam in group_families(members) {
        println!(
            "{}",
            serde_json::json!({ "family_id": fam.id, "kind": fam.kind, "members": fam.members.len() })
        );
    }
}

/// `aura runs family <id> [rank <metric>]`: list one family's member reports in
/// ordinal order, or best-first by `metric`. An unknown id is an empty family
/// (prints nothing, exit 0); an unknown metric is a usage error (stderr + exit 2).
fn runs_family(id: &str, rank: Option<&str>) {
    let reg = default_registry();
    let members = match reg.load_family_members() {
        Ok(m) => m,
        Err(e) => {
            eprintln!("aura: {e}");
            std::process::exit(2);
        }
    };
    let Some(family) = group_families(members).into_iter().find(|f| f.id == id) else {
        return; // unknown family id: empty, exit 0
    };
    let reports: Vec<RunReport> = family.members.iter().map(|m| m.report.clone()).collect();
    let ordered = match rank {
        Some(metric) => match rank_by(reports, metric) {
            Ok(r) => r,
            Err(e) => {
                eprintln!("aura: {e}");
                std::process::exit(2);
            }
        },
        None => reports,
    };
    for report in &ordered {
        println!("{}", report.to_json());
    }
}

// --- MACD proof-of-concept (a richer, nested indicator + strategy) -----------

/// The MACD signal as a named composite: price → fast/slow `Ema` → the MACD line
/// (their spread) → a signal `Ema` of that line → the histogram (line − signal).
/// The composite exposes all **three MACD lines** as a named output record
/// (`macd`, `signal`, `histogram`); the strategy trades the histogram by reading
/// `from_field: 2`. A richer fixture than `sma_cross`: a nested EMA-of-EMA chain
/// with interior fan-out (the MACD line feeds *both* the signal EMA and the
/// histogram). Three `length` knobs (fast, slow, signal) are injected at compile
/// in node order; value-empty here.
fn macd(name: &str) -> Composite {
    let mut g = GraphBuilder::new(name);
    let fast = g.add(Ema::builder().named("fast")); // fast EMA
    let slow = g.add(Ema::builder().named("slow")); // slow EMA
    let line = g.add(Sub::builder()); // MACD line = fast − slow
    let signal = g.add(Ema::builder().named("signal")); // signal EMA of the MACD line
    let hist = g.add(Sub::builder()); // histogram = MACD line − signal
    let price = g.input_role("price");
    g.feed(price, [fast.input("series"), slow.input("series")]);
    g.connect(fast.output("value"), line.input("lhs")); // fast   → line
    g.connect(slow.output("value"), line.input("rhs")); // slow   → line
    g.connect(line.output("value"), signal.input("series")); // line → signal EMA
    g.connect(line.output("value"), hist.input("lhs")); // line → histogram
    g.connect(signal.output("value"), hist.input("rhs")); // signal → histogram
    g.expose(line.output("value"), "macd"); // the MACD line
    g.expose(signal.output("value"), "signal"); // the signal line
    g.expose(hist.output("value"), "histogram"); // the histogram
    g.build().expect("sample macd wiring resolves")
}

/// The MACD strategy blueprint (value-empty): the `macd` histogram → `Exposure` →
/// `SimBroker` → recording sinks. Channels are threaded so a run can drain the
/// sinks; `macd_blueprint` drops the receivers for the structural render.
fn macd_strategy_blueprint(
    tx_eq: mpsc::Sender<(Timestamp, Vec<Scalar>)>,
    tx_ex: mpsc::Sender<(Timestamp, Vec<Scalar>)>,
) -> Composite {
    let mut g = GraphBuilder::new("macd_strategy");
    let macd_node = g.add(macd("macd"));
    let exposure = g.add(Exposure::builder());
    let broker = g.add(SimBroker::builder(SYNTHETIC_PIP_SIZE));
    let eq = g.add(Recorder::builder(vec![ScalarKind::F64], Firing::Any, tx_eq));
    let ex = g.add(Recorder::builder(vec![ScalarKind::F64], Firing::Any, tx_ex));
    let price = g.source_role("price", ScalarKind::F64);
    g.feed(price, [macd_node.input("price"), broker.input("price")]);
    g.connect(macd_node.output("histogram"), exposure.input("signal")); // histogram → Exposure
    g.connect(exposure.output("exposure"), broker.input("exposure")); // exposure  → broker slot 0
    g.connect(broker.output("equity"), eq.input("col[0]")); // equity    → sink
    g.connect(exposure.output("exposure"), ex.input("col[0]")); // exposure  → sink
    g.build().expect("macd_strategy wiring resolves")
}

/// The MACD strategy blueprint as a param-space fixture (receivers dropped, since
/// `param_space()` reads structure only, never runs the graph).
#[cfg(test)]
fn macd_blueprint() -> Composite {
    let (tx_eq, _rx_eq) = mpsc::channel();
    let (tx_ex, _rx_ex) = mpsc::channel();
    macd_strategy_blueprint(tx_eq, tx_ex)
}

/// The point vector for the MACD strategy, in `param_space()` slot order:
/// `[fast EMA length, slow EMA length, signal EMA length, exposure scale]`. Short
/// windows so the 7-tick synthetic stream still produces a non-trivial trace
/// (conventional MACD is 12/26/9, meaningless on 7 points).
fn macd_point() -> Vec<Scalar> {
    vec![Scalar::i64(2), Scalar::i64(4), Scalar::i64(3), Scalar::f64(0.5)]
}

/// A longer synthetic stream than the SMA sample's 7 ticks: MACD's EMAs each warm
/// up over their `length`, so the stream rises, falls, then rises again to give the
/// histogram room to flip sign more than once *after* warm-up. Deterministic (C1).
fn macd_prices() -> Vec<(Timestamp, Scalar)> {
    [
        1.0000_f64, 1.0008, 1.0021, 1.0039, 1.0062, 1.0090, 1.0083, 1.0061, 1.0034,
        1.0012, 0.9998, 1.0006, 1.0024, 1.0047, 1.0069, 1.0086, 1.0097, 1.0092,
    ]
    .iter()
    .enumerate()
    .map(|(i, &p)| (Timestamp(i as i64 + 1), Scalar::f64(p)))
    .collect()
}

/// Run the MACD strategy: compile the nested composite blueprint to a flat harness
/// (the same bootstrap path the SMA sample's compiled view uses), drive it on the
/// synthetic stream, and fold both sinks into a `RunReport`. Pure and
/// deterministic (C1).
fn run_macd(trace: Option<&str>) -> RunReport {
    let (tx_eq, rx_eq) = mpsc::channel();
    let (tx_ex, rx_ex) = mpsc::channel();
    let flat = macd_strategy_blueprint(tx_eq, tx_ex)
        .compile_with_params(&macd_point())
        .expect("valid macd blueprint");
    let mut h = Harness::bootstrap(flat).expect("valid macd harness");

    let sources: Vec<Box<dyn aura_engine::Source>> =
        vec![Box::new(VecSource::new(macd_prices()))];
    let window = window_of(&sources).expect("non-empty macd stream");
    h.run(sources);

    let eq_rows: Vec<(Timestamp, Vec<Scalar>)> = rx_eq.try_iter().collect();
    let ex_rows: Vec<(Timestamp, Vec<Scalar>)> = rx_ex.try_iter().collect();
    let manifest = sim_optimal_manifest(
        vec![
            ("ema_fast".to_string(), Scalar::i64(2)),
            ("ema_slow".to_string(), Scalar::i64(4)),
            ("ema_signal".to_string(), Scalar::i64(3)),
            ("exposure_scale".to_string(), Scalar::f64(0.5)),
        ],
        window,
        0,
        SYNTHETIC_PIP_SIZE,
    );
    if let Some(name) = trace {
        persist_traces(name, &manifest, &eq_rows, &ex_rows);
    }
    let metrics = summarize(&f64_field(&eq_rows, 0), &f64_field(&ex_rows, 0));
    RunReport { manifest, metrics }
}

const USAGE: &str =
    "usage: aura run [--macd] [--trace <name>] | aura run --real <SYMBOL> [--from <ms>] [--to <ms>] [--trace <name>] | aura chart <name> [--panels] | aura graph | aura sweep [--strategy <sma|momentum>] [--real <SYMBOL> [--from <ms>] [--to <ms>]] [--name <n>|--trace <n>] | aura mc [--name <n>|--trace <n>] | aura walkforward [--real <SYMBOL> [--from <ms>] [--to <ms>]] [--name <n>|--trace <n>] | aura runs families | aura runs family <id> [rank <metric>]";

fn main() {
    // Collect argv and match the whole vector: every accepted form is exhaustive,
    // so an unexpected trailing token falls through to the usage-error path rather
    // than masquerading as a successful run (#16 strict reading).
    let args: Vec<String> = std::env::args().skip(1).collect();
    match args.iter().map(String::as_str).collect::<Vec<_>>().as_slice() {
        ["run"] => println!("{}", run_sample(None).to_json()),
        ["run", "--macd"] => println!("{}", run_macd(None).to_json()),
        ["run", "--trace", name] => println!("{}", run_sample(Some(name)).to_json()),
        ["run", "--macd", "--trace", name] => println!("{}", run_macd(Some(name)).to_json()),
        ["run", "--real", rest @ ..] => match parse_real_args(rest) {
            Ok((sym, from, to, trace)) => {
                println!("{}", run_sample_real(&sym, from, to, trace.as_deref()).to_json())
            }
            Err(msg) => {
                eprintln!("aura: {msg}");
                std::process::exit(2);
            }
        },
        ["chart", name] => emit_chart(name, ChartMode::Overlay),
        ["chart", name, "--panels"] => emit_chart(name, ChartMode::Panels),
        ["graph"] => print!("{}", render::render_html(&sample_blueprint())),
        ["sweep", rest @ ..] => match parse_sweep_args(rest) {
            Ok((strategy, name, persist, choice)) => {
                run_sweep(strategy, &name, persist, DataSource::from_choice(choice))
            }
            Err(msg) => {
                eprintln!("aura: {msg}");
                std::process::exit(2);
            }
        },
        ["walkforward", rest @ ..] => match parse_walkforward_args(rest) {
            Ok((name, persist, choice)) => {
                run_walkforward(&name, persist, DataSource::from_choice(choice))
            }
            Err(msg) => {
                eprintln!("aura: {msg}");
                std::process::exit(2);
            }
        },
        ["mc"] => run_mc("mc", false),
        ["mc", "--name", n] => run_mc(n, false),
        ["mc", "--trace", n] => run_mc(n, true),
        ["runs", "families"] => runs_families(),
        ["runs", "family", id] => runs_family(id, None),
        ["runs", "family", id, "rank", metric] => runs_family(id, Some(metric)),
        ["--help"] | ["-h"] => println!("{USAGE}"),
        _ => {
            eprintln!("aura: {USAGE}");
            std::process::exit(2);
        }
    }
}

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

    /// #99: a sweep/walk-forward family-member stdout line embeds the `RunReport` in
    /// its own declaration key order (manifest leads with `commit`), byte-matching the
    /// stored `families.jsonl` — never `serde_json::Value`'s alphabetical order (which
    /// would lead the manifest with `broker`).
    #[test]
    fn family_member_line_keeps_report_in_store_key_order() {
        let report = RunReport {
            manifest: sim_optimal_manifest(vec![], (Timestamp(0), Timestamp(0)), 0, 1.0),
            metrics: summarize(&[], &[]),
        };
        let line = family_member_line("demo-1", &report);
        assert!(
            line.starts_with(r#"{"family_id":"demo-1","report":{"manifest":{"commit":"#),
            "got: {line}"
        );
        assert!(
            !line.contains(r#""manifest":{"broker":"#),
            "manifest re-alphabetized (broker-first), should be commit-first: {line}"
        );
    }

    /// #99: the Monte-Carlo per-draw line carries the `seed` between `family_id` and
    /// `report`, and the embedded report stays in store (commit-first) key order.
    #[test]
    fn mc_member_line_keeps_report_in_store_key_order_with_seed() {
        let report = RunReport {
            manifest: sim_optimal_manifest(vec![], (Timestamp(0), Timestamp(0)), 7, 1.0),
            metrics: summarize(&[], &[]),
        };
        let line = mc_member_line("mc-1", 7, &report);
        assert!(
            line.starts_with(r#"{"family_id":"mc-1","seed":7,"report":{"manifest":{"commit":"#),
            "got: {line}"
        );
        assert!(
            !line.contains(r#""manifest":{"broker":"#),
            "manifest re-alphabetized (broker-first), should be commit-first: {line}"
        );
    }

    // The vetted GER40 real-data window: the whole of September 2024 (UTC,
    // inclusive), the same calendar month the gated ingest `ger40_breakout_real`
    // test drives. Expressed in Unix-ms (`run_sample_real`'s window currency):
    // `[2024-09-01T00:00:00Z, 2024-10-01T00:00:00Z - 1ms]`. Both gated GER40
    // tests bound their runs to this window so the C1-determinism check stays
    // fast — an unbounded `None, None` run drains the full archive every call.
    const GER40_SEP2024_FROM_MS: i64 = 1_725_148_800_000;
    const GER40_SEP2024_TO_MS: i64 = 1_727_740_799_999;

    #[test]
    fn data_source_synthetic_pip_and_window_match_the_built_ins() {
        let d = DataSource::Synthetic;
        assert_eq!(d.pip_size(), SYNTHETIC_PIP_SIZE);
        assert!(!d.run_sources().is_empty());
        assert_eq!(d.wf_window_sizes(), (24, 12, 12));
        // full_window equals window_of over the showcase stream (byte-unchanged source)
        let s: Vec<Box<dyn aura_engine::Source>> = vec![Box::new(VecSource::new(showcase_prices()))];
        assert_eq!(d.full_window(), window_of(&s).unwrap());
    }

    #[test]
    fn wf_real_roller_sizes_are_90_30_30_days_in_ns() {
        // Independent expected value: a day reconstructed from its time units
        // (24 h * 60 min * 60 s * 1e9 ns), not the constant's own `86_400_000_000_000`
        // literal — so the test fails if either the literal or the day-count is wrong.
        let day_ns: i64 = 24 * 60 * 60 * 1_000_000_000;
        assert_eq!(WF_REAL_IS_NS, 90 * day_ns);
        assert_eq!(WF_REAL_OOS_NS, 30 * day_ns);
        assert_eq!(WF_REAL_STEP_NS, 30 * day_ns);
    }

    #[test]
    fn strategy_lengths_are_short_for_synthetic_realistic_for_real() {
        // Synthetic keeps the demo-stream lengths (byte-unchanged: the 18/60-bar
        // built-in streams cannot warm a long MA).
        assert_eq!(DataSource::Synthetic.strategy_lengths(), ([2, 3], [4, 5], (2, 4, 3)));
        // Real uses realistic M1 lengths — no 2-5-bar noise over tens of thousands
        // of bars. Constructing Real needs a server, but strategy_lengths matches on
        // the variant only (no data access).
        let real = DataSource::Real {
            server: std::sync::Arc::new(data_server::DataServer::new(data_server::DEFAULT_DATA_PATH)),
            symbol: "EURUSD".into(),
            from_ms: None,
            to_ms: None,
            pip: 0.0001,
        };
        let (tf, ts, macd) = real.strategy_lengths();
        assert_eq!((tf, ts, macd), ([50, 100], [200, 400], (12, 26, 9)));
        // every trend-fast < every trend-slow (a valid SMA cross, both variants).
        assert!(tf.iter().max().unwrap() < ts.iter().min().unwrap());
        let (stf, sts, _) = DataSource::Synthetic.strategy_lengths();
        assert!(stf.iter().max().unwrap() < sts.iter().min().unwrap());
    }

    #[test]
    fn walkforward_report_is_deterministic() {
        // The built-in WFO render is byte-identical across two
        // calls (C1).
        assert_eq!(walkforward_report(), walkforward_report());
    }

    #[test]
    fn walkforward_report_has_one_oos_line_per_window_plus_summary() {
        // N per-window OOS RunReport lines + one summary line.
        let out = walkforward_report();
        let lines: Vec<&str> = out.lines().collect();
        assert_eq!(lines.len(), 4); // built-in roll = 3 windows + 1 summary
        assert!(lines[3].contains(r#""walkforward""#), "summary line: {}", lines[3]);
        for line in &lines[..3] {
            assert!(
                line.contains(r#""manifest""#) && line.contains(r#""metrics""#),
                "expected an OOS RunReport line, got: {line}",
            );
        }
    }

    /// The drained sink trace of a seeded run — the recorded rows of the equity
    /// and exposure sinks. Compared row-for-row so the C1 seed-determinism
    /// property is tested at the trace level (strictly stronger than the folded
    /// 3-field metrics). `PartialEq` not `Eq`: `Scalar` carries `f64`.
    #[derive(Debug, PartialEq)]
    struct SeededTrace {
        equity: Vec<(Timestamp, Vec<Scalar>)>,
        exposure: Vec<(Timestamp, Vec<Scalar>)>,
    }

    /// A seeded run of the sample harness: the synthetic stream is generated
    /// from `seed`, that same seed is recorded into the manifest, and the
    /// drained sink trace is returned alongside the report. Every byte of both
    /// is a function of `seed`.
    fn run_sample_seeded(seed: u64) -> (RunReport, SeededTrace) {
        let (mut h, rx_eq, rx_ex) = sample_harness(SYNTHETIC_PIP_SIZE);
        let spec = SyntheticSpec { start: 1.0, len: 64, step: 1 };
        let window = (Timestamp(1), Timestamp((spec.len as i64 - 1) * spec.step + 1));
        h.run(vec![Box::new(spec.source(seed))]);
        let eq_rows: Vec<(Timestamp, Vec<Scalar>)> = rx_eq.try_iter().collect();
        let ex_rows: Vec<(Timestamp, Vec<Scalar>)> = rx_ex.try_iter().collect();
        let metrics = summarize(&f64_field(&eq_rows, 0), &f64_field(&ex_rows, 0));
        let report = RunReport {
            manifest: sim_optimal_manifest(
                vec![
                    ("sma_fast".to_string(), Scalar::i64(2)),
                    ("sma_slow".to_string(), Scalar::i64(4)),
                    ("exposure_scale".to_string(), Scalar::f64(0.5)),
                ],
                window,
                seed,
                SYNTHETIC_PIP_SIZE,
            ),
            metrics,
        };
        (report, SeededTrace { equity: eq_rows, exposure: ex_rows })
    }

    #[test]
    fn same_seed_bit_identical_trace() {
        // Bit-identical sink trace for a fixed seed (acceptance bullet 1, C1).
        let (_, trace_a) = run_sample_seeded(42);
        let (_, trace_b) = run_sample_seeded(42);
        assert_eq!(trace_a, trace_b);
    }

    #[test]
    fn different_seed_different_trace() {
        // Different seeds perturb the trace (acceptance bullet 2).
        let (a, _) = run_sample_seeded(1);
        let (b, _) = run_sample_seeded(2);
        assert_ne!(a.metrics, b.metrics);
    }

    #[test]
    fn seed_recorded_in_manifest() {
        // The seed that drove the run is recorded (acceptance bullet 3).
        let (report, _) = run_sample_seeded(7);
        assert_eq!(report.manifest.seed, 7);
    }

    #[test]
    fn sample_blueprint_with_sinks_bootstraps_runs_and_drains() {
        // the factory returns the two Recorder receivers (build_sample drops them),
        // so a caller can bootstrap one point, run it, and drain both sinks.
        let (bp, rx_eq, rx_ex) = sample_blueprint_with_sinks(SYNTHETIC_PIP_SIZE);
        let mut h = bp
            .with("signals.trend.fast.length", 2)
            .with("signals.trend.slow.length", 4)
            .with("signals.momentum.fast.length", 2)
            .with("signals.momentum.slow.length", 4)
            .with("signals.momentum.signal.length", 3)
            .with("signals.blend.weights[0]", 1.0)
            .with("signals.blend.weights[1]", 1.0)
            .with("exposure.scale", 0.5)
            .bootstrap()
            .expect("sample blueprint compiles under a valid point");
        h.run(vec![Box::new(VecSource::new(showcase_prices()))]);
        assert!(!rx_eq.try_iter().collect::<Vec<_>>().is_empty(), "equity sink drained empty");
        assert!(!rx_ex.try_iter().collect::<Vec<_>>().is_empty(), "exposure sink drained empty");
    }

    #[test]
    fn sweep_report_renders_four_points_in_odometer_order() {
        let out = sweep_report();
        let lines: Vec<&str> = out.lines().collect();
        assert_eq!(lines.len(), 4, "one JSON line per grid point; got: {out:?}");
        // each line is a full RunReport; the commit is the real git HEAD
        // (volatile), so pin the per-point manifest params (odometer order, last
        // axis fastest) + the metric keys, not the commit value.
        for line in &lines {
            assert!(line.starts_with(r#"{"manifest":{"commit":""#), "not a RunReport: {line}");
        }
        assert!(lines[0].contains(r#""params":[["signals.trend.fast.length",{"I64":2}],["signals.trend.slow.length",{"I64":4}],["signals.momentum.fast.length",{"I64":2}],["signals.momentum.slow.length",{"I64":4}],["signals.momentum.signal.length",{"I64":3}],["signals.blend.weights[0]",{"F64":1.0}],["signals.blend.weights[1]",{"F64":1.0}],["exposure.scale",{"F64":0.5}]]"#), "line0: {}", lines[0]);
        assert!(lines[1].contains(r#""params":[["signals.trend.fast.length",{"I64":2}],["signals.trend.slow.length",{"I64":5}],["signals.momentum.fast.length",{"I64":2}],["signals.momentum.slow.length",{"I64":4}],["signals.momentum.signal.length",{"I64":3}],["signals.blend.weights[0]",{"F64":1.0}],["signals.blend.weights[1]",{"F64":1.0}],["exposure.scale",{"F64":0.5}]]"#), "line1: {}", lines[1]);
        assert!(lines[2].contains(r#""params":[["signals.trend.fast.length",{"I64":3}],["signals.trend.slow.length",{"I64":4}],["signals.momentum.fast.length",{"I64":2}],["signals.momentum.slow.length",{"I64":4}],["signals.momentum.signal.length",{"I64":3}],["signals.blend.weights[0]",{"F64":1.0}],["signals.blend.weights[1]",{"F64":1.0}],["exposure.scale",{"F64":0.5}]]"#), "line2: {}", lines[2]);
        assert!(lines[3].contains(r#""params":[["signals.trend.fast.length",{"I64":3}],["signals.trend.slow.length",{"I64":5}],["signals.momentum.fast.length",{"I64":2}],["signals.momentum.slow.length",{"I64":4}],["signals.momentum.signal.length",{"I64":3}],["signals.blend.weights[0]",{"F64":1.0}],["signals.blend.weights[1]",{"F64":1.0}],["exposure.scale",{"F64":0.5}]]"#), "line3: {}", lines[3]);
        for line in &lines {
            assert!(line.contains(r#""total_pips":"#), "missing total_pips: {line}");
            assert!(line.contains(r#""max_drawdown":"#), "missing max_drawdown: {line}");
            assert!(line.contains(r#""exposure_sign_flips":"#), "missing flips: {line}");
            assert!(line.ends_with('}'), "line not closed: {line}");
        }
    }

    #[test]
    fn sweep_report_is_deterministic() {
        // C1 at the CLI edge: the same build yields a bit-identical report.
        assert_eq!(sweep_report(), sweep_report());
    }

    #[test]
    fn mc_report_is_deterministic_and_one_line_per_seed() {
        // C1 at the CLI edge: the family computation renders bit-identically.
        assert_eq!(mc_report(), mc_report());
        let out = mc_report();
        let lines: Vec<&str> = out.lines().collect();
        // three seeds -> three member lines + one aggregate line
        assert_eq!(lines.len(), 4, "expected 3 members + 1 aggregate: {out}");
        for line in &lines[..3] {
            assert!(line.contains(r#""total_pips":"#), "member line missing metrics: {line}");
        }
        assert!(lines[3].contains(r#""mc_aggregate":"#), "missing aggregate line: {}", lines[3]);
    }

    #[test]
    fn cli_families_persist_and_round_trip_per_kind() {
        use aura_registry::{
            group_families, mc_member_reports, sweep_member_reports, walkforward_member_reports,
            FamilyKind, Registry,
        };
        let dir = std::env::temp_dir().join(format!("aura-cli-fam-{}", std::process::id()));
        let _ = std::fs::remove_dir_all(&dir);
        std::fs::create_dir_all(&dir).expect("temp dir");
        let reg = Registry::open(dir.join("runs.jsonl"));

        // the exact persist chain `run_sweep`/`run_mc`/`run_walkforward` use, against
        // a fresh temp store (the run_* fns themselves bind `default_registry()`):
        // engine family -> per-kind extractor -> append_family.
        let sid = reg
            .append_family(
                "sweep",
                FamilyKind::Sweep,
                &sweep_member_reports(&sweep_family(None, &DataSource::Synthetic)),
            )
            .expect("sweep family");
        let mid = reg
            .append_family("mc", FamilyKind::MonteCarlo, &mc_member_reports(&mc_family(None)))
            .expect("mc family");
        let wid = reg
            .append_family(
                "walkforward",
                FamilyKind::WalkForward,
                &walkforward_member_reports(&walkforward_family(None, &DataSource::Synthetic)),
            )
            .expect("walkforward family");
        assert_eq!((sid.as_str(), mid.as_str(), wid.as_str()), ("sweep-0", "mc-0", "walkforward-0"));

        let families = group_families(reg.load_family_members().expect("load"));
        assert_eq!(families.len(), 3);
        let by_id = |id: &str| families.iter().find(|f| f.id == id).expect("family present");
        assert_eq!(by_id("sweep-0").kind, FamilyKind::Sweep);
        assert_eq!(by_id("mc-0").kind, FamilyKind::MonteCarlo);
        assert_eq!(by_id("mc-0").members.len(), 3); // 3 seeds
        assert_eq!(by_id("walkforward-0").kind, FamilyKind::WalkForward);
        assert_eq!(by_id("walkforward-0").members.len(), 3); // 3 windows
        let _ = std::fs::remove_dir_all(&dir);
    }

    #[test]
    fn run_macd_compiles_from_nested_composite_and_is_deterministic() {
        // the MACD strategy authors a nested EMA-of-EMA composite, compiles it to a
        // flat runnable harness (the call not panicking proves the compile+bootstrap
        // path), and runs it. C1 determinism: two runs are bit-identical.
        let r1 = run_macd(None);
        let r2 = run_macd(None);
        assert_eq!(r1.metrics, r2.metrics);
        assert_eq!(r1.to_json(), r2.to_json());

        // the synthetic stream is carried end-to-end and the trace is well-formed.
        let (from, to) = r1.manifest.window;
        assert_eq!((from.0, to.0), (1, 18));
        assert!(r1.metrics.total_pips.is_finite(), "macd pips must be finite: {:?}", r1.metrics);
        assert!(r1.metrics.max_drawdown >= 0.0, "drawdown is non-negative: {:?}", r1.metrics);
        // after warm-up the EMA-of-EMA histogram crosses zero, so the strategy
        // reverses exposure at least once — a genuinely non-trivial trace.
        assert!(
            r1.metrics.exposure_sign_flips >= 1,
            "macd trace should flip exposure: {:?}",
            r1.metrics
        );
    }

    /// E2E acceptance (#41, the worked example): the real MACD strategy
    /// blueprint's swept param surface qualifies the three otherwise-indistinguishable
    /// EMA `length` slots by node name to `macd.fast.length` / `macd.slow.length` /
    /// `macd.signal.length` — the named composite boundary visible end-to-end through
    /// `param_space()`, with the slot count and order unchanged (C23 — node names are
    /// non-load-bearing: every interior slot stays sweepable, the `exposure.scale`
    /// knob is unaffected).
    #[test]
    fn macd_param_space_surfaces_the_three_named_legs() {
        let names: Vec<String> =
            macd_blueprint().param_space().into_iter().map(|p| p.name).collect();
        // three named composite-interior slots, in declared (fast, slow, signal)
        // order, then the strategy-level Exposure `scale` (a root-level leaf).
        assert_eq!(
            names,
            vec![
                "macd.fast.length".to_string(),
                "macd.slow.length".to_string(),
                "macd.signal.length".to_string(),
                "exposure.scale".to_string(),
            ],
            "MACD param surface must expose the three named EMA lengths + scale",
        );
    }

    /// `aura run --real <SYMBOL>` dogfoods the #71 streaming Source seam: the same
    /// built-in sample signal-quality harness, but fed real M1 **close** bars
    /// streamed lazily through `aura_ingest::M1FieldSource` (a `Box<dyn Source>`),
    /// not synthetic `VecSource` prices. The property: over the verified bounded
    /// Sept-2024 GER40 window, `run_sample_real` yields a `RunReport` whose
    /// `total_pips` is finite and is C1-deterministic — two runs of the same
    /// window are bit-identical JSON. Bounding the window (vs the full unbounded
    /// archive) keeps the determinism check fast.
    ///
    /// Gated like the ingest `streaming_seam` test: skip (early return) when the
    /// local Pepperstone archive is absent, so the test never fails on a machine
    /// without the data. Uses `GER40` — a *vetted* symbol (pip 1.0): the
    /// per-instrument-pip refusal makes `run_sample_real` reject an un-specced
    /// symbol before any data access (`std::process::exit(2)`), so this CLI-level
    /// test must drive a symbol in the instrument table. The bounded-window AAPL.US
    /// streaming property still lives in the ingest `streaming_seam` test, which
    /// builds its source literally without the spec lookup.
    #[test]
    fn run_sample_real_streams_real_close_bars_deterministically() {
        // GER40 is in the vetted instrument table (index pip 1.0); the un-specced
        // AAPL.US would now refuse at the spec lookup before any data access.
        const SYMBOL: &str = "GER40";

        // Mirror skip_if_no_data: never fail where the local archive is absent.
        let server = std::sync::Arc::new(data_server::DataServer::new(
            data_server::DEFAULT_DATA_PATH,
        ));
        if !server.has_symbol(SYMBOL) {
            eprintln!(
                "skip: no local data at {} (symbol {SYMBOL} absent)",
                data_server::DEFAULT_DATA_PATH
            );
            return;
        }

        // The headline: a real-data run over the bounded Sept-2024 window yields
        // a finite, C1-deterministic RunReport.
        let r1 = run_sample_real(SYMBOL, Some(GER40_SEP2024_FROM_MS), Some(GER40_SEP2024_TO_MS), None);
        let r2 = run_sample_real(SYMBOL, Some(GER40_SEP2024_FROM_MS), Some(GER40_SEP2024_TO_MS), None);

        assert!(
            r1.metrics.total_pips.is_finite(),
            "real-data run must yield finite pips: {:?}",
            r1.metrics
        );
        // C1 at the CLI edge: the same real window streamed twice is bit-identical.
        assert_eq!(
            r1.to_json(),
            r2.to_json(),
            "two real-data runs of the same window must be bit-identical (C1)"
        );
    }

    #[test]
    fn sim_optimal_manifest_renders_per_instrument_pip() {
        let m = sim_optimal_manifest(vec![], (Timestamp(1), Timestamp(2)), 0, 1.0);
        assert_eq!(m.broker, "sim-optimal(pip_size=1)");
        let m2 = sim_optimal_manifest(vec![], (Timestamp(1), Timestamp(2)), 0, 0.0001);
        assert_eq!(m2.broker, "sim-optimal(pip_size=0.0001)");
    }

    #[test]
    fn run_real_ger40_uses_index_pip() {
        // Gated: needs local GER40 data. Mirrors the existing real-path test's skip.
        let server = data_server::DataServer::new(data_server::DEFAULT_DATA_PATH);
        if !server.has_symbol("GER40") {
            eprintln!("skip: no local GER40 data at {}", data_server::DEFAULT_DATA_PATH);
            return;
        }
        // Bounded to the vetted Sept-2024 window so the pip-label + determinism
        // checks run fast (not the full unbounded archive).
        let report =
            run_sample_real("GER40", Some(GER40_SEP2024_FROM_MS), Some(GER40_SEP2024_TO_MS), None);
        // The looked-up index pip (1.0) reaches the manifest — not the FX 0.0001.
        assert_eq!(report.manifest.broker, "sim-optimal(pip_size=1)");
        // Deterministic (C1): a second run yields the same report.
        let again =
            run_sample_real("GER40", Some(GER40_SEP2024_FROM_MS), Some(GER40_SEP2024_TO_MS), None);
        assert_eq!(report.manifest.broker, again.manifest.broker);
        assert_eq!(report.metrics.total_pips, again.metrics.total_pips);
    }

    /// `parse_real_args` accepts a bare symbol (no window) and a full
    /// symbol + `--from`/`--to` pair in any order, and rejects a flag missing its
    /// value — the pure arg grammar `main` relies on for `run --real`.
    #[test]
    fn parse_real_args_accepts_symbol_and_optional_window() {
        assert_eq!(parse_real_args(&["EURUSD"]), Ok(("EURUSD".to_string(), None, None, None)));
        assert_eq!(
            parse_real_args(&["EURUSD", "--from", "100", "--to", "200"]),
            Ok(("EURUSD".to_string(), Some(100), Some(200), None))
        );
        // flags in any order
        assert_eq!(
            parse_real_args(&["EURUSD", "--to", "200", "--from", "100"]),
            Ok(("EURUSD".to_string(), Some(100), Some(200), None))
        );
        // the --trace tail flag carries a string name, parsed alongside the window
        assert_eq!(
            parse_real_args(&["EURUSD", "--from", "100", "--trace", "demo"]),
            Ok(("EURUSD".to_string(), Some(100), None, Some("demo".to_string())))
        );
        // a flag without its value, an empty symbol, and a non-numeric ms all reject
        assert!(parse_real_args(&["EURUSD", "--from"]).is_err());
        assert!(parse_real_args(&[]).is_err());
        assert!(parse_real_args(&["EURUSD", "--from", "notanumber"]).is_err());
    }

    #[test]
    fn run_sample_is_deterministic_and_non_trivial() {
        let r1 = run_sample(None);
        let r2 = run_sample(None);
        // C1 determinism: two runs are bit-identical (metrics + rendered JSON).
        assert_eq!(r1.metrics, r2.metrics);
        assert_eq!(r1.to_json(), r2.to_json());

        let m = &r1.metrics;
        // exactly one exposure sign flip in the demo trace (rises then reverses).
        assert_eq!(m.exposure_sign_flips, 1);
        // a non-trivial, populated trace: a real drawdown.
        assert!(m.max_drawdown > 0.0);
        // hand-computed magnitudes for the chosen stream (float tolerance; the
        // computation's dust is ~1e-15).
        assert!(
            (m.max_drawdown - 0.17).abs() < 1e-9,
            "max_drawdown = {}",
            m.max_drawdown
        );
        assert!(
            (m.total_pips - (-0.13)).abs() < 1e-9,
            "total_pips = {}",
            m.total_pips
        );

        // manifest carries the sample's known configuration.
        let (from, to) = r1.manifest.window;
        assert_eq!((from.0, to.0), (1, 7));
        // commit is the build's git identity (or the no-git "unknown" fallback);
        // either way it is non-empty and fixed at compile time, so it is stable
        // across runs of the same build (C1 determinism, already asserted above
        // via `to_json()`).
        assert!(!r1.manifest.commit.is_empty());
        assert_eq!(r1.manifest.commit, r2.manifest.commit);
    }

    fn pair(name: &str, v: Scalar) -> (String, Scalar) {
        (name.to_string(), v)
    }

    #[test]
    fn member_key_renders_varying_axes_portably() {
        let named = vec![
            pair("ema.length", Scalar::i64(5)),
            pair("exposure.scale", Scalar::f64(0.5)),
            pair("longonly.enabled", Scalar::bool(true)),
        ];
        let varying: std::collections::HashSet<String> =
            named.iter().map(|(n, _)| n.clone()).collect();
        let key = member_key(&named, &varying);
        assert_eq!(key, "ema.length-5_exposure.scale-0.5_longonly.enabled-true");
        assert!(key.chars().all(|c| c.is_ascii_alphanumeric() || matches!(c, '.' | '_' | '-')));
    }

    #[test]
    fn member_key_omits_pinned_axes() {
        let named = vec![
            pair("ema.length", Scalar::i64(5)),
            pair("exposure.scale", Scalar::f64(0.5)),
            pair("longonly.enabled", Scalar::bool(false)),
        ];
        let mut varying = std::collections::HashSet::new();
        varying.insert("longonly.enabled".to_string());
        assert_eq!(member_key(&named, &varying), "longonly.enabled-false");
    }

    #[test]
    fn member_key_handles_negative_float_and_sanitises_names() {
        let named = vec![pair("exposure.scale", Scalar::f64(-0.5))];
        let varying: std::collections::HashSet<String> =
            ["exposure.scale".to_string()].into_iter().collect();
        assert_eq!(member_key(&named, &varying), "exposure.scale--0.5");

        let named2 = vec![pair("weird key!", Scalar::f64(1.0))];
        let varying2: std::collections::HashSet<String> =
            ["weird key!".to_string()].into_iter().collect();
        assert_eq!(member_key(&named2, &varying2), "weird_key_-1");
    }

    #[test]
    fn member_key_is_m_when_no_axis_varies() {
        let named = vec![pair("exposure.scale", Scalar::f64(0.5))];
        let varying = std::collections::HashSet::new();
        assert_eq!(member_key(&named, &varying), "m");
    }

    #[test]
    fn member_key_caps_length_with_conformant_hash_fallback() {
        let named: Vec<(String, Scalar)> = (0..40)
            .map(|i| pair(&format!("some.long.axis.path.number.{i}"), Scalar::i64(i)))
            .collect();
        let varying: std::collections::HashSet<String> =
            named.iter().map(|(n, _)| n.clone()).collect();
        let key = member_key(&named, &varying);
        assert!(key.len() <= MAX_KEY, "over-cap key not bounded: {} bytes", key.len());
        assert!(key.chars().all(|c| c.is_ascii_alphanumeric() || matches!(c, '.' | '_' | '-')));
        let mut named2 = named.clone();
        named2[0].1 = Scalar::i64(999);
        assert_ne!(key, member_key(&named2, &varying), "distinct over-cap inputs must differ");
    }

    #[test]
    fn member_key_collision_free_over_a_non_trend_axis_set() {
        // #105 regression: vary exposure.scale + a bool (NOT the old hardcoded
        // trend.fast/slow). Distinct points -> distinct keys; the old f…s… key
        // would have collapsed them all to one dir.
        let varying: std::collections::HashSet<String> =
            ["exposure.scale".to_string(), "longonly.enabled".to_string()].into_iter().collect();
        let p = |s: f64, b: bool| {
            vec![
                pair("ema.length", Scalar::i64(5)), // pinned -> omitted from key
                pair("exposure.scale", Scalar::f64(s)),
                pair("longonly.enabled", Scalar::bool(b)),
            ]
        };
        let keys: Vec<String> = [(0.5, true), (0.5, false), (1.0, true), (1.0, false)]
            .iter()
            .map(|&(s, b)| member_key(&p(s, b), &varying))
            .collect();
        let unique: std::collections::HashSet<&String> = keys.iter().collect();
        assert_eq!(unique.len(), 4, "distinct points must yield distinct keys: {keys:?}");
    }

    #[test]
    fn momentum_param_space_is_ema_exposure_longonly() {
        // pins the default node-name path segments (ema / exposure / longonly) and
        // the param order/kinds the member key + sweep depend on.
        let names: Vec<String> =
            momentum_blueprint_with_sinks(SYNTHETIC_PIP_SIZE).0.param_space().into_iter().map(|p| p.name).collect();
        assert_eq!(
            names,
            vec![
                "ema.length".to_string(),
                "exposure.scale".to_string(),
                "longonly.enabled".to_string(),
            ],
        );
    }

    #[test]
    fn momentum_sweep_is_deterministic_and_has_eight_points() {
        let a = momentum_sweep_family(None, &DataSource::Synthetic);
        let b = momentum_sweep_family(None, &DataSource::Synthetic);
        assert_eq!(a.points.len(), 8, "2x2x2 grid = 8 points");
        assert_eq!(a, b, "C1: the momentum family is a pure function of the build");
    }

    #[test]
    fn parse_sweep_args_defaults_selects_and_rejects() {
        assert_eq!(
            parse_sweep_args(&[]),
            Ok((Strategy::SmaCross, "sweep".to_string(), false, DataChoice::Synthetic))
        );
        assert_eq!(
            parse_sweep_args(&["--trace", "swp"]),
            Ok((Strategy::SmaCross, "swp".to_string(), true, DataChoice::Synthetic))
        );
        assert_eq!(
            parse_sweep_args(&["--name", "s"]),
            Ok((Strategy::SmaCross, "s".to_string(), false, DataChoice::Synthetic))
        );
        assert_eq!(
            parse_sweep_args(&["--strategy", "momentum", "--trace", "mom"]),
            Ok((Strategy::Momentum, "mom".to_string(), true, DataChoice::Synthetic))
        );
        assert!(parse_sweep_args(&["--strategy", "bogus"]).is_err());
        assert!(parse_sweep_args(&["--name", "a", "--trace", "b"]).is_err()); // mutually exclusive
        assert!(parse_sweep_args(&["--trace"]).is_err()); // flag missing its value
    }

    /// `parse_sweep_args` admits a real symbol with an optional `--from`/`--to`
    /// window (yielding `DataChoice::Real`), still honouring `--strategy`/`--trace`;
    /// a `--real` without its symbol, or a window flag without `--real`, is rejected.
    #[test]
    fn parse_sweep_args_accepts_real_symbol_and_window() {
        assert_eq!(
            parse_sweep_args(&["--real", "EURUSD", "--from", "100", "--to", "200", "--trace", "s"]),
            Ok((Strategy::SmaCross, "s".to_string(), true,
                DataChoice::Real { symbol: "EURUSD".to_string(), from_ms: Some(100), to_ms: Some(200) }))
        );
        assert!(parse_sweep_args(&["--real"]).is_err());          // --real needs a symbol
        assert!(parse_sweep_args(&["--from", "100"]).is_err());   // --from without --real
    }

    /// `parse_sweep_args` mirrors `parse_real_args`'s real/window strictness: an
    /// empty `--real` symbol and a repeated `--real`/`--from`/`--to` are usage
    /// errors (not last-write-wins, not a downstream refusal) — so sibling commands
    /// reject the same malformed real-grammar the same way.
    #[test]
    fn parse_sweep_args_rejects_empty_symbol_and_repeated_real_window() {
        assert!(parse_sweep_args(&["--real", ""]).is_err()); // empty symbol
        assert!(parse_sweep_args(&["--real", "EURUSD", "--real", "GBPUSD"]).is_err()); // repeated --real
        assert!(parse_sweep_args(&["--real", "EURUSD", "--from", "1", "--from", "2"]).is_err()); // repeated --from
        assert!(parse_sweep_args(&["--real", "EURUSD", "--to", "1", "--to", "2"]).is_err()); // repeated --to
    }

    /// `parse_walkforward_args` defaults to synthetic / name "walkforward" / no
    /// persist, admits `--real <SYMBOL>` (window-less here) yielding `DataChoice::Real`,
    /// and rejects two name flags or a `--real` missing its symbol.
    #[test]
    fn parse_walkforward_args_defaults_and_accepts_real() {
        assert_eq!(parse_walkforward_args(&[]), Ok(("walkforward".to_string(), false, DataChoice::Synthetic)));
        assert_eq!(
            parse_walkforward_args(&["--real", "EURUSD", "--trace", "w"]),
            Ok(("w".to_string(), true, DataChoice::Real { symbol: "EURUSD".to_string(), from_ms: None, to_ms: None }))
        );
        assert!(parse_walkforward_args(&["--name", "a", "--trace", "b"]).is_err());
        assert!(parse_walkforward_args(&["--real"]).is_err());
    }

    /// `parse_walkforward_args` mirrors `parse_real_args`'s real/window strictness:
    /// an empty `--real` symbol and a repeated `--real`/`--from`/`--to` are usage
    /// errors — the same real-grammar rejection its sibling `parse_sweep_args` gives.
    #[test]
    fn parse_walkforward_args_rejects_empty_symbol_and_repeated_real_window() {
        assert!(parse_walkforward_args(&["--real", ""]).is_err()); // empty symbol
        assert!(parse_walkforward_args(&["--real", "EURUSD", "--real", "GBPUSD"]).is_err());
        assert!(parse_walkforward_args(&["--real", "EURUSD", "--from", "1", "--from", "2"]).is_err());
        assert!(parse_walkforward_args(&["--real", "EURUSD", "--to", "1", "--to", "2"]).is_err());
    }
}