const units = ["B", "KB", "MB", "GB", "TB"];

export const statusLabels = {
  queued: "Queued",
  downloading: "Downloading",
  paused: "Paused",
  extracting: "Extracting",
  ready: "Ready",
  moving: "Moving",
  completed: "Completed",
  failed: "Failed",
  cancelled: "Cancelled",
};

export function formatBytes(bytes) {
  let value = Math.max(0, bytes || 0);
  let unitIndex = 0;
  while (value >= 1024 && unitIndex < units.length - 1) {
    value /= 1024;
    unitIndex += 1;
  }
  return `${value.toFixed(unitIndex === 0 ? 0 : 1)} ${units[unitIndex]}`;
}

function roundTo(value, step) {
  return Math.max(step, Math.round(value / step) * step);
}

export function formatRemaining(seconds) {
  if (!Number.isFinite(seconds) || seconds <= 0) return "almost done";
  if (seconds < 60) return `${roundTo(seconds, 5)}s`;
  if (seconds < 600) {
    const rounded = roundTo(seconds, 15);
    const minutes = Math.floor(rounded / 60);
    const remainingSeconds = rounded % 60;
    return remainingSeconds === 0 ? `${minutes}m` : `${minutes}m ${remainingSeconds}s`;
  }
  if (seconds < 3600) return `${roundTo(seconds / 60, 1)}m`;
  const totalMinutes = roundTo(seconds / 60, 5);
  const hours = Math.floor(totalMinutes / 60);
  const minutes = totalMinutes % 60;
  return minutes === 0 ? `${hours}h` : `${hours}h ${minutes}m`;
}

export function formatDate(value) {
  const date = new Date(value);
  return Number.isNaN(date.getTime()) ? "" : date.toLocaleString();
}

export function percentOf(done, total) {
  if (!total || total <= 0) return null;
  return Math.min(100, (done / total) * 100);
}