use std::{
    alloc::{GlobalAlloc, Layout, System},
    cell::Cell,
};
use temper_core::{Curve, Engine, Settings, Source};

struct CheckedAllocator;
thread_local! {
    static CHECK:Cell<bool>=const {Cell::new(false)};
    static OPERATIONS:Cell<usize>=const {Cell::new(0)};
}
fn record() {
    if CHECK.try_with(Cell::get).unwrap_or(false) {
        let _ = OPERATIONS.try_with(|n| n.set(n.get() + 1));
    }
}
unsafe impl GlobalAlloc for CheckedAllocator {
    unsafe fn alloc(&self, layout: Layout) -> *mut u8 {
        record();
        unsafe { System.alloc(layout) }
    }
    unsafe fn dealloc(&self, pointer: *mut u8, layout: Layout) {
        record();
        unsafe { System.dealloc(pointer, layout) }
    }
    unsafe fn realloc(&self, pointer: *mut u8, layout: Layout, size: usize) -> *mut u8 {
        record();
        unsafe { System.realloc(pointer, layout, size) }
    }
}
#[global_allocator]
static ALLOCATOR: CheckedAllocator = CheckedAllocator;

#[test]
fn processing_notes_settings_and_analysis_do_not_allocate_or_free() {
    let mut engine = Engine::new(48000., 2).unwrap();
    let mut settings = Settings::default();
    engine.set_settings(settings).unwrap();
    CHECK.with(|v| v.set(true));
    for i in 0..96000 {
        if i % 4800 == 0 {
            settings.curve = Curve::ALL[(i / 4800) % 4];
            settings.bright = if i % 9600 == 0 { 8. } else { 0. };
            settings.floor = if i % 9600 == 0 { 0. } else { 0.5 };
            settings.push_gain = ((i / 4800) % 5) as f32 - 2.;
            settings.source = if i > 48000 {
                Source::Midi
            } else {
                Source::Audio
            };
            engine.set_settings(settings).unwrap();
            engine.note_on(30 + (i / 4800 % 12) as u8);
        }
        if i % 4800 == 2400 {
            engine.note_off(30 + (i / 4800 % 12) as u8);
        }
        let t = i as f32 / 48000.;
        let x = if (i / 2400) % 2 == 0 {
            (std::f32::consts::TAU * 55. * t).sin() * 0.5
        } else {
            0.
        };
        std::hint::black_box(engine.process_sample([x, x]));
        if i % 1600 == 0 {
            std::hint::black_box(engine.take_analyzer());
        }
    }
    engine.reset();
    CHECK.with(|v| v.set(false));
    assert_eq!(OPERATIONS.with(Cell::get), 0);
}