export function formatDuration(ms: number | null | undefined): string {
  if (!ms || ms <= 0) return "--:--";
  const total = Math.floor(ms / 1000);
  const m = Math.floor(total / 60);
  const s = total % 60;
  return `${m}:${s.toString().padStart(2, "0")}`;
}

export function formatTime(seconds: number): string {
  if (!Number.isFinite(seconds) || seconds < 0) seconds = 0;
  const total = Math.floor(seconds);
  const m = Math.floor(total / 60);
  const s = total % 60;
  return `${m}:${s.toString().padStart(2, "0")}`;
}

export function formatDate(value: string | null | undefined): string {
  if (!value) return "";
  const d = new Date(value);
  if (Number.isNaN(d.getTime())) return value;
  return d.toLocaleDateString("ru-RU", { year: "numeric", month: "long", day: "numeric" });
}

export function initials(name: string | null | undefined): string {
  if (!name) return "?";
  return name
    .split(/\s+/)
    .slice(0, 2)
    .map((p) => p[0]?.toUpperCase() ?? "")
    .join("");
}

export function cx(...parts: (string | false | null | undefined)[]): string {
  return parts.filter(Boolean).join(" ");
}