import { expect, test } from '../helpers/serve-dist';

// Issue 2 (cold-GPU first frame): the build links the world's programs with
// renderer.compileAsync() against the composer's target, and frame 0 draws
// everything once as a safety net. After frame 0 no program may be created:
// each later one is a 70-280 ms hitch inside the opening shot. Test builds
// dispatch portfolio-program-count whenever renderer.info.programs changes.

interface ProgramCountEvent {
  generation: number;
  frame: number;
  programs: number;
  warmup: { outcome: 'ready' | 'timeout' | 'failed'; waited: number; parallel: boolean; programs: number };
}

test('compiles every scene program before the first frame and none after it', async ({ page, distUrl }) => {
  await page.addInitScript(() => {
    const events: unknown[] = [];
    (window as unknown as { __programCounts: unknown[] }).__programCounts = events;
    window.addEventListener('portfolio-program-count', (event) => {
      events.push(structuredClone((event as CustomEvent).detail));
    });
  });
  await page.goto(distUrl, { waitUntil: 'domcontentloaded' });
  await expect(page.locator('canvas.journey-canvas')).toHaveAttribute('data-lit', '', { timeout: 20_000 });

  // The ignition hold, then the pull-away and the first chapters.
  await page.waitForTimeout(3_500);
  await page.mouse.move(200, 300);
  for (let step = 0; step < 12; step += 1) {
    await page.mouse.wheel(0, 400);
    await page.waitForTimeout(120);
  }
  await page.waitForTimeout(500);

  const events = await page.evaluate(
    () => (window as unknown as { __programCounts: ProgramCountEvent[] }).__programCounts,
  );
  expect(events.length).toBeGreaterThan(0);
  for (const generation of new Set(events.map((event) => event.generation))) {
    const own = events.filter((event) => event.generation === generation);
    const first = own[0]!;
    // The first report comes right after frame 0.
    expect(first.frame).toBe(1);
    // The warm-up compiled the scene before frame 0 (or gave up on a slow driver).
    expect(['ready', 'timeout']).toContain(first.warmup.outcome);
    expect(first.warmup.programs).toBeGreaterThan(0);
    expect(first.programs).toBeGreaterThanOrEqual(first.warmup.programs);
    // Frame 0 adds only the post passes (9 on desktop). A warm-up keyed for
    // the wrong target or light count would add the whole scene again (~60).
    expect(first.programs - first.warmup.programs).toBeLessThanOrEqual(12);
    // No growth afterwards.
    expect(own.slice(1)).toEqual([]);
  }
});