export function formatNaturalExpiry(expiresAt: string | Date): string {
  const expDate = new Date(expiresAt);
  const now = new Date();
  const diffMs = expDate.getTime() - now.getTime();

  const timeStr = expDate.toLocaleTimeString([], {
    hour: "numeric",
    minute: "2-digit",
  });
  const fullISO = expDate.toISOString();

  let dateStr = "";
  const isToday = expDate.getDate() === now.getDate() &&
    expDate.getMonth() === now.getMonth() &&
    expDate.getFullYear() === now.getFullYear();

  const tomorrow = new Date(now);
  tomorrow.setDate(tomorrow.getDate() + 1);
  const isTomorrow = expDate.getDate() === tomorrow.getDate() &&
    expDate.getMonth() === tomorrow.getMonth() &&
    expDate.getFullYear() === tomorrow.getFullYear();

  if (isToday) {
    dateStr = "Today";
  } else if (isTomorrow) {
    dateStr = "Tomorrow";
  } else if (expDate.getFullYear() === now.getFullYear()) {
    dateStr = expDate.toLocaleDateString([], {
      month: "short",
      day: "numeric",
    });
  } else {
    dateStr = expDate.toLocaleDateString([], {
      month: "short",
      day: "numeric",
      year: "numeric",
    });
  }

  let badge = "";

  if (diffMs <= 0) {
    badge = '<span class="status-badge-red" title="' + fullISO +
      '">Expired</span>';
  } else {
    const totalMins = Math.floor(diffMs / 60000);
    const hours = totalMins / 60;
    const days = hours / 24;
    const months = days / 30;
    const years = days / 365;

    let timeRemainingStr = "";
    let badgeClass = "status-badge-green";

    if (hours < 1) {
      timeRemainingStr = totalMins + "m left";
      badgeClass = "status-badge-amber";
    } else if (hours < 24) {
      const h = Math.floor(hours);
      const m = totalMins % 60;
      timeRemainingStr = h + "h " + m + "m left";
      badgeClass = "status-badge-amber";
    } else if (days <= 60) {
      timeRemainingStr = Math.floor(days) + "d left";
    } else if (months <= 12) {
      timeRemainingStr = months.toFixed(1) + " mos left";
    } else {
      timeRemainingStr = years.toFixed(1) + " yrs left";
    }

    badge = '<span class="' + badgeClass + '" title="' + fullISO + '">' +
      timeRemainingStr + "</span>";
  }

  return dateStr + " &middot; " + timeStr + " &middot; " + badge;
}

export function formatNaturalJoinTime(
  createdAt: string | Date,
  isActive: boolean = true,
): string {
  const createdDate = new Date(createdAt);
  const now = new Date();

  const diffMs = now.getTime() - createdDate.getTime();
  const diffMins = Math.floor(diffMs / 60000);

  const timeStr = createdDate.toLocaleTimeString([], {
    hour: "numeric",
    minute: "2-digit",
  });
  const isToday = createdDate.getDate() === now.getDate() &&
    createdDate.getMonth() === now.getMonth() &&
    createdDate.getFullYear() === now.getFullYear();
  const dateStr = isToday
    ? "Today"
    : createdDate.toLocaleDateString([], { month: "short", day: "numeric" });

  let durationStr = "";
  if (diffMins < 60) {
    durationStr = diffMins + "m";
  } else {
    const h = Math.floor(diffMins / 60);
    const m = diffMins % 60;
    durationStr = h + "h " + m + "m";
  }

  const badgeStyle = isActive
    ? "background:rgba(34,197,94,0.15);color:#16a34a;padding:2px 6px;border-radius:4px;font-size:0.75rem;font-weight:600;"
    : "background:rgba(234,179,8,0.15);color:#ca8a04;padding:2px 6px;border-radius:4px;font-size:0.75rem;font-weight:600;";
  const badgeText = isActive ? "Active " + durationStr : "Paused";

  const activeBadge = '<span style="' + badgeStyle + '">' + badgeText +
    "</span>";

  return "Joined " + dateStr + " &middot; " + timeStr + " &middot; " +
    activeBadge;
}