use criterion::{black_box, criterion_group, criterion_main, Criterion};
use euler::System;
use sbp::operators::{SbpOperator2d, Upwind4, UpwindOperator2d, SBP4};
use sbp::Float;

fn advance_system<SBP: SbpOperator2d>(universe: &mut System<SBP>, n: usize) {
    for _ in 0..n {
        universe.advance(1.0 / 40.0 * 0.2);
    }
}

fn advance_system_upwind<UO: UpwindOperator2d>(universe: &mut System<UO>, n: usize) {
    for _ in 0..n {
        universe.advance_upwind(1.0 / 40.0 * 0.2);
    }
}

fn advance_embedded<UO: UpwindOperator2d>(universe: &mut System<UO>, embedded: bool) {
    let dt = 0.2 / std::cmp::max(universe.nx(), universe.ny()) as Float;
    let t = 1.0;
    if embedded {
        let mut dt = dt;
        universe.advance_adaptive(t, &mut dt, 1e-2);
    } else {
        for _ in 0..(t / dt).round() as isize {
            universe.advance_upwind(dt);
        }
    }
}

fn performance_benchmark(c: &mut Criterion) {
    let mut group = c.benchmark_group("EulerSystem");
    group.sample_size(25);

    let w = 40;
    let h = 26;
    let x = ndarray::Array1::linspace(-10.0, 10.0, w);
    let x = x.broadcast((h, w)).unwrap();
    let y = ndarray::Array1::linspace(-10.0, 10.0, h);
    let y = y.broadcast((w, h)).unwrap().reversed_axes();

    let mut universe = System::new(x.into_owned(), y.into_owned(), Upwind4);
    group.bench_function("advance", |b| {
        b.iter(|| {
            universe.init_with_vortex(0.0, 0.0);
            advance_system(&mut universe, black_box(20))
        })
    });

    let mut universe = System::new(x.into_owned(), y.into_owned(), Upwind4);
    group.bench_function("advance_upwind", |b| {
        b.iter(|| {
            universe.init_with_vortex(0.0, 0.0);
            advance_system_upwind(&mut universe, black_box(20))
        })
    });

    let mut universe = System::new(x.into_owned(), y.into_owned(), SBP4);
    group.bench_function("advance_trad4", |b| {
        b.iter(|| {
            universe.init_with_vortex(0.0, 0.0);
            advance_system(&mut universe, black_box(20))
        })
    });
    group.finish();

    let mut group = c.benchmark_group("adaptive integration");
    group.sample_size(10);
    let mut universe = System::new(x.into_owned(), y.into_owned(), Upwind4);
    group.bench_function("static dt", |b| {
        b.iter(|| {
            universe.init_with_vortex(0.0, 0.0);
            advance_embedded(&mut universe, false);
        })
    });
    group.bench_function("adaptive dt", |b| {
        b.iter(|| {
            universe.init_with_vortex(0.0, 0.0);
            advance_embedded(&mut universe, true);
        })
    });
    group.finish();
}

criterion_group!(benches, performance_benchmark);
criterion_main!(benches);