export function formatTime(totalSeconds: number): string {
  const hours = Math.floor(totalSeconds / 3600);
  const minutes = Math.floor((totalSeconds % 3600) / 60);
  const seconds = Math.floor(totalSeconds % 60);
  const millis = Math.round((totalSeconds % 1) * 1000);

  const mm = String(minutes).padStart(2, '0');
  const ss = String(seconds).padStart(2, '0');
  const ms = String(millis).padStart(3, '0');

  if (hours > 0) {
    return `${hours}:${mm}:${ss}.${ms}`;
  }
  return `${mm}:${ss}.${ms}`;
}

export function formatTimeParts(totalSeconds: number): { main: string; ms: string } {
  const hours = Math.floor(totalSeconds / 3600);
  const minutes = Math.floor((totalSeconds % 3600) / 60);
  const seconds = Math.floor(totalSeconds % 60);
  const millis = Math.round((totalSeconds % 1) * 1000);

  const mm = String(minutes).padStart(2, '0');
  const ss = String(seconds).padStart(2, '0');
  const ms = String(millis).padStart(3, '0');

  const main = hours > 0 ? `${hours}:${mm}:${ss}` : `${mm}:${ss}`;
  return { main, ms: `.${ms}` };
}

export function parseTime(str: string): number | null {
  const hmsMatch = str.match(/^(\d+):(\d{2}):(\d{2})(?:\.(\d{1,3}))?$/);
  if (hmsMatch) {
    const h = parseInt(hmsMatch[1], 10);
    const m = parseInt(hmsMatch[2], 10);
    const s = parseInt(hmsMatch[3], 10);
    const ms = hmsMatch[4] ? parseInt(hmsMatch[4].padEnd(3, '0'), 10) : 0;
    return h * 3600 + m * 60 + s + ms / 1000;
  }

  const msMatch = str.match(/^(\d{2}):(\d{2})(?:\.(\d{1,3}))?$/);
  if (msMatch) {
    const m = parseInt(msMatch[1], 10);
    const s = parseInt(msMatch[2], 10);
    const ms = msMatch[3] ? parseInt(msMatch[3].padEnd(3, '0'), 10) : 0;
    return m * 60 + s + ms / 1000;
  }

  return null;
}