/** Join conditional class names. */
export function cn(...parts: Array<string | false | null | undefined>): string {
  return parts.filter(Boolean).join(' ');
}

export function formatCurrency(amount: number, currency = 'USD'): string {
  return new Intl.NumberFormat('en-US', { style: 'currency', currency }).format(amount);
}

export function formatDate(value: Date | string): string {
  const d = typeof value === 'string' ? new Date(value) : value;
  return new Intl.DateTimeFormat('en-US', { dateStyle: 'medium' }).format(d);
}

export function slugify(value: string): string {
  return value
    .toLowerCase()
    .trim()
    .replace(/[^a-z0-9]+/g, '-')
    .replace(/^-+|-+$/g, '');
}