import * as React from 'react'; const AUTO_INTERVAL = 200; const STEP_BUCKETS: [limit: number, stepPtg: number][] = [ [30, 0.05], [70, 0.03], [96, 0.01], ]; export default function usePercent( spinning: boolean, percent?: number | 'auto', ): number | undefined { const [mockPercent, setMockPercent] = React.useState(0); const mockIntervalRef = React.useRef<ReturnType<typeof setInterval>>(); const isAuto = percent === 'auto'; React.useEffect(() => { if (isAuto && spinning) { setMockPercent(0); mockIntervalRef.current = setInterval(() => { setMockPercent((prev) => { const restPTG = 100 - prev; for (let i = 0; i < STEP_BUCKETS.length; i += 1) { const [limit, stepPtg] = STEP_BUCKETS[i]; if (prev <= limit) { return prev + restPTG * stepPtg; } } return prev; }); }, AUTO_INTERVAL); } return () => { clearInterval(mockIntervalRef.current); }; }, [isAuto, spinning]); return isAuto ? mockPercent : percent; }