/**
 * Returns a human-readable relative time string for a given date.
 * Examples: "just now", "5 minutes ago", "2 hours ago", "3 days ago", "2026-01-01"
 */
export function timeAgo(date: Date): string {
  const diffMs = Date.now() - date.getTime();
  const diffSecs = Math.floor(diffMs / 1000);

  if (diffSecs < 60) return "just now";

  const diffMins = Math.floor(diffSecs / 60);
  if (diffMins < 60) return `${diffMins} minute${diffMins === 1 ? "" : "s"} ago`;

  const diffHours = Math.floor(diffMins / 60);
  if (diffHours < 24) return `${diffHours} hour${diffHours === 1 ? "" : "s"} ago`;

  const diffDays = Math.floor(diffHours / 24);
  if (diffDays < 30) return `${diffDays} day${diffDays === 1 ? "" : "s"} ago`;

  return date.toISOString().split("T")[0];
}