//! Active-workload performance evidence (TRAFFIC-15).
//!
//! Deterministic ACTIVE workload — steering, braking, traffic, rule
//! transitions, score updates — over the worst validated scenario, plus
//! structural budget asserts (entity/event caps) that hold in ANY profile.
//! Wall-clock numbers are REPORTED, never asserted: debug, idle, CPU-only,
//! or no-GPU timings are diagnostic, never a release pass. Release budgets
//! (§6) pass only from `cargo ... --release` runs on declared hardware
//! with actual rendering/GPU; see `docs/PERF_BASELINE.md`.
//!
//! ```sh
//! cargo test --locked -p nigig-traffic --test perf_release -- --test-threads=1 --nocapture
//! ```

use nigig_traffic::traffic::{TrafficWorld, TICK_DT};
use std::time::Instant;

fn percentile(mut v: Vec<u128>, p: f64) -> u128 {
    v.sort_unstable();
    v[((p * v.len() as f64) as usize).min(v.len().saturating_sub(1))]
}

#[test]
fn active_workload_reports_and_structural_budgets_hold() {
    // Worst validated scenario: most entities + a moving hazard.
    let scenarios = TrafficWorld::all_scenarios();
    let mut worst = 0usize;
    let mut worst_ents = 0usize;
    for (i, _) in scenarios.iter().enumerate() {
        let mut w = TrafficWorld::new();
        w.load_scenario(i);
        let n = w.sim.world.entities.len();
        if n > worst_ents {
            worst_ents = n;
            worst = i;
        }
    }
    println!(
        "worst-content scenario: {} ({worst_ents} entities)",
        scenarios[worst].id
    );
    // Structural budgets (§6) hold in every profile.
    assert!(worst_ents <= 256, "entity budget: {worst_ents}");
    const { assert!(TICK_DT > 0.0) };

    // Active workload: 60 s of scripted driving with steering reversals,
    // braking zones, and full-lock turns (rule transitions + score path).
    let mut w = TrafficWorld::new();
    w.load_scenario(worst);
    // Skip intro for a pure Active measurement.
    for _ in 0..60 {
        w.tick(&makepad_game_blocks::DriveInput::default());
    }
    let mut samples = Vec::with_capacity(3600);
    let mut inputs = 0u64;
    for i in 0..3600u64 {
        let phase = (i / 600) % 4;
        let input = makepad_game_blocks::DriveInput {
            steer: match phase {
                0 => 0.6,
                1 => -0.6,
                2 => 1.0,
                _ => -1.0,
            },
            throttle: if i % 900 < 700 { 0.8 } else { 0.0 },
            brake: if i % 900 >= 700 { 0.8 } else { 0.0 },
            ..makepad_game_blocks::DriveInput::default()
        };
        let t0 = Instant::now();
        w.tick(&input);
        samples.push(t0.elapsed().as_nanos());
        inputs += 1;
    }
    assert_eq!(inputs, 3600);
    // The sim really ran: ticks advanced and the verdict histogram is live.
    assert_eq!(w.run.tick, 3660);
    let counts = w.verdict_counts();
    assert!(counts.iter().sum::<u64>() > 0);
    let p50 = percentile(samples.clone(), 0.50);
    let p95 = percentile(samples.clone(), 0.95);
    let p99 = percentile(samples, 0.99);
    println!(
        "active tick ns p50={p50} p95={p95} p99={p99} (n=3600, profile-dependent, diagnostic only)"
    );
    println!("verdict histogram: {counts:?}");
    println!(
        "score: {}/{}",
        w.run.score.total_points, w.run.score.max_points
    );
}