//! `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).

use aura_core::{Firing, Scalar, ScalarKind, Timestamp};
use aura_engine::{
    f64_field, summarize, Edge, Harness, RunManifest, RunReport, SourceSpec, Target,
};
use aura_std::{Exposure, Recorder, SimBroker, Sma, Sub};
use std::sync::mpsc::{self, Receiver};

/// 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()
}

/// 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() -> (
    Harness,
    Receiver<(Timestamp, Vec<Scalar>)>,
    Receiver<(Timestamp, Vec<Scalar>)>,
) {
    let (tx_eq, rx_eq) = mpsc::channel();
    let (tx_ex, rx_ex) = mpsc::channel();
    let h = Harness::bootstrap(
        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(0.0001)),                               // 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
        ],
        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
            ],
        }],
        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)
}

/// 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() -> RunReport {
    let (mut h, rx_eq, rx_ex) = sample_harness();
    let prices = synthetic_prices();
    let window = (
        prices.first().expect("non-empty stream").0,
        prices.last().expect("non-empty stream").0,
    );
    h.run(vec![prices]);

    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 equity = f64_field(&eq_rows, 0);
    let exposure = f64_field(&ex_rows, 0);
    let metrics = summarize(&equity, &exposure);

    RunReport {
        manifest: RunManifest {
            commit: option_env!("AURA_COMMIT").unwrap_or("unknown").to_string(),
            params: vec![
                ("sma_fast".to_string(), 2.0),
                ("sma_slow".to_string(), 4.0),
                ("exposure_scale".to_string(), 0.5),
            ],
            window,
            seed: 0,
            broker: "sim-optimal(pip_size=0.0001)".to_string(),
        },
        metrics,
    }
}

fn main() {
    let mut args = std::env::args().skip(1);
    match args.next().as_deref() {
        Some("run") => println!("{}", run_sample().to_json()),
        _ => {
            eprintln!("aura: usage: aura run");
            std::process::exit(2);
        }
    }
}

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

    #[test]
    fn run_sample_is_deterministic_and_non_trivial() {
        let r1 = run_sample();
        let r2 = run_sample();
        // 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));
        assert_eq!(r1.manifest.commit, "unknown");
    }
}