import { afterEach, describe, expect, it } from 'vitest';
import { attachMusicPulse, readMusicPulse, setMusicPulseAudible } from '@/audio/music-pulse';

const fakeAnalyser = (level: number) => ({
  frequencyBinCount: 8,
  getByteFrequencyData(target: Uint8Array) { target.fill(level); },
}) as unknown as AnalyserNode;

afterEach(() => {
  attachMusicPulse(null);
  setMusicPulseAudible(false);
});

describe('music pulse', () => {
  it('reads zero without an analyser', () => {
    setMusicPulseAudible(true);
    expect(readMusicPulse()).toBe(0);
  });
  it('reads zero while the soundtrack is not audible', () => {
    attachMusicPulse(fakeAnalyser(255));
    expect(readMusicPulse()).toBe(0);
  });
  it('normalizes the low-band level when audible', () => {
    attachMusicPulse(fakeAnalyser(51));
    setMusicPulseAudible(true);
    expect(readMusicPulse()).toBeCloseTo(0.2);
  });
});