Hi, I'm Hendra Febri — Crafting Clean Code & Immersive Soundscapes.

1// Project 90 days of cash flow from recurring invoices
2export async function forecastCashFlow(orgId: string, days = 90) {
3  const invoices = await db.invoice.findMany({
4    where: { orgId, status: "recurring" },
5  });
6 
7  const timeline = new Map<string, number>();
8 
9  for (const invoice of invoices) {
10    for (const date of nextOccurrences(invoice.schedule, days)) {
11      const key = date.toISOString().slice(0, 10);
12      timeline.set(key, (timeline.get(key) ?? 0) + invoice.amount);
13    }
14  }
15 
16  return [...timeline.entries()].sort(([a], [b]) => a.localeCompare(b));
17}

1// Drift-free metronome using the audio clock, not setInterval
2export function useMetronome(bpm: number) {
3  const [beat, setBeat] = useState(0);
4  const nextTick = useRef(0);
5 
6  useEffect(() => {
7    const interval = 60 / bpm;
8    nextTick.current = audio.currentTime + 0.05;
9 
10    const id = setInterval(() => {
11      while (nextTick.current < audio.currentTime + 0.1) {
12        scheduleClick(nextTick.current);
13        nextTick.current += interval;
14        setBeat((b) => (b + 1) % 4);
15      }
16    }, 25);
17 
18    return () => clearInterval(id);
19  }, [bpm]);
20 
21  return beat;
22}

1// Synthesized kick: a sine with a fast pitch drop
2export function kick(ctx: AudioContext, time: number) {
3  const osc = ctx.createOscillator();
4  const gain = ctx.createGain();
5 
6  osc.frequency.setValueAtTime(150, time);
7  osc.frequency.exponentialRampToValueAtTime(42, time + 0.12);
8  gain.gain.setValueAtTime(0.95, time);
9  gain.gain.exponentialRampToValueAtTime(0.001, time + 0.45);
10 
11  osc.connect(gain).connect(ctx.destination);
12  osc.start(time);
13  osc.stop(time + 0.5);
14}