// Node-side test of the cymbal2 track-render instrument: executes the
// actual MATLAB model through numbl on the CPU path (no browser, no
// worker, no GPU) and checks the audio. The request's params override
// shrinks the render (low rate, short tail) so the full time integration
// stays test-sized; the GPU path has its own harness in
// webapp/scripts/gpu-selftest.ts. Run with: npx tsx test.ts
import { readdirSync, readFileSync } from 'node:fs';
import { join, dirname } from 'node:path';
import { fileURLToPath } from 'node:url';
import { renderRequest, type RenderEnv } from './core.ts';
import type { NoteSpec, TrackRenderRequest } from './types.ts';

const matlabDir = join(dirname(fileURLToPath(import.meta.url)), '..', 'matlab');
const mfiles = readdirSync(matlabDir)
  .filter((f) => f.endsWith('.m'))
  .sort()
  .map((f) => ({ name: f, source: readFileSync(join(matlabDir, f), 'utf8') }));

const env: RenderEnv = {
  mfiles,
  shipped: mfiles,
  post: () => {},
  checkCancel: () => {},
  yieldToHost: async () => {},
};

let failures = 0;
function check(label: string, ok: boolean, detail = ''): void {
  console.log(`${ok ? 'ok  ' : 'FAIL'} ${label}${detail ? ` (${detail})` : ''}`);
  if (!ok) failures++;
}

function stats(y: Float32Array) {
  let peak = 0;
  let finite = true;
  for (let i = 0; i < y.length; i++) {
    if (!Number.isFinite(y[i])) finite = false;
    peak = Math.max(peak, Math.abs(y[i]));
  }
  return { peak, finite };
}

// The explicit nonlinearity needs the full simulation rate: dropping the
// sample rate raises the time step and the integration diverges. Shrink
// the render by shortening the tail instead.
const SR = 44100;

function req(notes: NoteSpec[], overrides: Partial<TrackRenderRequest> = {}): TrackRenderRequest {
  const end = notes.reduce((m, n) => Math.max(m, n.timeSec + n.durationSec), 0);
  return {
    notes,
    sampleRate: SR,
    lengthSamples: Math.ceil((end + 0.4) * SR),
    quality: 'preview',
    settings: {},
    params: { tail_s: 0.25 }, // test-sized ring; the physics is the same
    ...overrides,
  };
}

const note = (timeSec: number, pitch: number, velocity: number): NoteSpec =>
  ({ timeSec, durationSec: 0.1, pitch, velocity });

const t0 = performance.now();

// One stroke: finite and audible. (The renders are cached by note key, so
// an identical repeat returns the same buffer; determinism of the model
// itself is pinned in matlab/cymbal2_validate.m.)
const a = await renderRequest('cymbal2', req([note(0, 60, 0.4)]), env);
{
  const s = stats(a.audio);
  check('single stroke is finite', s.finite);
  check('single stroke is audible', s.peak > 1e-6, `peak ${s.peak.toExponential(2)}`);
}

// The note cache.
{
  const t = performance.now();
  await renderRequest('cymbal2', req([note(0, 60, 0.4)]), env);
  const ms = performance.now() - t;
  check('repeat render hits the note cache', ms < 500, `${ms.toFixed(0)} ms`);
}

// Velocity changes the sound (normalize is off, so amplitude scales).
const soft = await renderRequest('cymbal2', req([note(0, 60, 0.15)]), env);
{
  const pa = stats(a.audio).peak;
  const ps = stats(soft.audio).peak;
  check('velocity changes the sound', ps < pa, `soft ${ps.toExponential(2)} < hard ${pa.toExponential(2)}`);
}

// A pattern: both strokes come from the cache and land at their onsets.
const tr = await renderRequest('cymbal2', req([note(0, 60, 0.4), note(0.5, 60, 0.4), note(1.0, 60, 0.15)]), env);
{
  const s = stats(tr.audio);
  check('track render is finite', s.finite);
  const at = (sec: number) => stats(tr.audio.slice(Math.floor(sec * SR), Math.floor((sec + 0.25) * SR))).peak;
  check('energy at first onset', at(0.0) > 1e-6);
  check('energy at second onset', at(0.5) > 1e-6);
  check('energy at third onset', at(1.0) > 1e-6);
}

console.log(`total time: ${((performance.now() - t0) / 1000).toFixed(1)} s`);
if (failures > 0) { console.error(`${failures} check(s) failed`); process.exit(1); }