import clsx from 'clsx';

// Skeleton loading previews. The base block uses Tailwind's animate-pulse and
// the light-gray surface tokens so placeholders match real card/table styling.
// Composites below mirror the layouts they stand in for (event cards, admin
// tables, FAQ accordions, article bodies) to avoid layout shift when data lands.

interface SkeletonProps {
  className?: string;
}

export function Skeleton({
  className,
  tone = 'default',
}: SkeletonProps & {
  /** `on-dark` lightens the surface for placeholders over a dark hero. */
  tone?: 'default' | 'on-dark';
}) {
  return (
    <div
      aria-hidden="true"
      className={clsx(
        'animate-pulse motion-reduce:animate-none rounded-lg',
        tone === 'on-dark' ? 'bg-white/20' : 'bg-secondary-light-gray/70',
        className
      )}
    />
  );
}

// Screen-reader announcement wrapper for a group of skeleton blocks.
export function SkeletonGroup({ className, children }: SkeletonProps & { children: React.ReactNode }) {
  return (
    <div role="status" aria-busy="true" className={className}>
      <span className="sr-only">Loading…</span>
      {children}
    </div>
  );
}

// Paragraph-style stack of text lines with a shorter last line.
export function SkeletonText({ lines = 3, className }: SkeletonProps & { lines?: number }) {
  return (
    <div className={clsx('space-y-2.5', className)} aria-hidden="true">
      {Array.from({ length: lines }).map((_, i) => (
        <Skeleton key={i} className={clsx('h-4', i === lines - 1 ? 'w-2/3' : 'w-full')} />
      ))}
    </div>
  );
}

// Mirrors the event card in EventsClient: banner, title, meta rows, price + button.
export function EventCardSkeleton() {
  return (
    <div className="bg-white rounded-card overflow-hidden shadow-card h-full" aria-hidden="true">
      <Skeleton className="h-40 w-full rounded-none" />
      <div className="p-6">
        <Skeleton className="h-6 w-3/4" />
        <div className="mt-4 space-y-2">
          <Skeleton className="h-4 w-2/3" />
          <Skeleton className="h-4 w-1/2" />
          <Skeleton className="h-4 w-2/5" />
        </div>
        <div className="mt-6 flex items-center justify-between">
          <Skeleton className="h-7 w-24" />
          <Skeleton className="h-9 w-24 rounded-btn" />
        </div>
      </div>
    </div>
  );
}

export function EventGridSkeleton({ count = 6 }: { count?: number }) {
  return (
    <SkeletonGroup className="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">
      {Array.from({ length: count }).map((_, i) => (
        <EventCardSkeleton key={i} />
      ))}
    </SkeletonGroup>
  );
}

// Mirrors the featured "next event" hero card on the homepage: side banner + info column.
export function FeaturedEventSkeleton() {
  return (
    <SkeletonGroup>
      <div className="bg-gray-50 border border-gray-200 rounded-2xl overflow-hidden shadow-lg">
        <div className="flex flex-col md:flex-row">
          <Skeleton className="w-full md:w-2/5 flex-shrink-0 h-48 md:h-auto md:min-h-[280px] rounded-none" />
          <div className="flex-1 p-5 md:p-8">
            <Skeleton className="h-7 w-2/3" />
            <Skeleton className="mt-3 h-4 w-full" />
            <Skeleton className="mt-2 h-4 w-5/6" />
            <div className="mt-4 md:mt-5 space-y-2.5">
              <Skeleton className="h-4 w-48" />
              <Skeleton className="h-4 w-32" />
              <Skeleton className="h-4 w-56" />
            </div>
            <div className="mt-5 md:mt-6 flex items-center justify-between gap-4">
              <Skeleton className="h-9 w-28" />
              <Skeleton className="h-10 w-28 rounded-xl" />
            </div>
          </div>
        </div>
      </div>
    </SkeletonGroup>
  );
}

// Accordion-style rows for FAQ lists. `compact` matches the homepage variant
// (rounded-btn, px-5); the default matches the /faq page cards (px-6, more spacing).
export function FaqListSkeleton({ count = 5, compact = false }: { count?: number; compact?: boolean }) {
  return (
    <SkeletonGroup className={compact ? 'space-y-3' : 'space-y-4'}>
      {Array.from({ length: count }).map((_, i) => (
        <div
          key={i}
          className={clsx(
            'bg-white border border-gray-200 flex items-center justify-between',
            compact ? 'rounded-btn px-5 py-4' : 'rounded-card px-6 py-4 shadow-card border-0'
          )}
          aria-hidden="true"
        >
          <Skeleton className={clsx('h-5', i % 2 === 0 ? 'w-3/5' : 'w-2/5')} />
          <Skeleton className="h-5 w-5 rounded-full flex-shrink-0" />
        </div>
      ))}
    </SkeletonGroup>
  );
}

// Long-form content: heading, meta line, then paragraph blocks.
export function ArticleSkeleton({ withBanner = false }: { withBanner?: boolean }) {
  return (
    <SkeletonGroup>
      {withBanner && <Skeleton className="h-56 md:h-80 w-full rounded-card mb-8" />}
      <Skeleton className="h-9 w-3/4 md:w-1/2" />
      <Skeleton className="mt-3 h-4 w-40" />
      <div className="mt-8 space-y-6">
        <SkeletonText lines={4} />
        <SkeletonText lines={3} />
        <Skeleton className="h-6 w-1/3" />
        <SkeletonText lines={4} />
      </div>
    </SkeletonGroup>
  );
}

// Stacked list of card rows (dashboard tickets/payments, contact lists).
export function CardListSkeleton({ count = 3 }: { count?: number }) {
  return (
    <SkeletonGroup className="space-y-4">
      {Array.from({ length: count }).map((_, i) => (
        <div key={i} className="bg-white rounded-card shadow-card p-5" aria-hidden="true">
          <div className="flex items-start justify-between gap-4">
            <div className="flex-1">
              <Skeleton className="h-5 w-1/3" />
              <Skeleton className="mt-2.5 h-4 w-1/2" />
              <Skeleton className="mt-2 h-4 w-2/5" />
            </div>
            <Skeleton className="h-6 w-20 rounded-full" />
          </div>
        </div>
      ))}
    </SkeletonGroup>
  );
}

// Admin data tables: desktop table inside a Card, mobile stacked cards —
// mirrors the two-breakpoint layout every admin list page renders.
export function TableSkeleton({ rows = 6, cols = 5 }: { rows?: number; cols?: number }) {
  return (
    <SkeletonGroup>
      {/* Desktop: table */}
      <div className="bg-white rounded-card overflow-hidden shadow-card hidden md:block" aria-hidden="true">
        <div className="bg-secondary-gray px-4 py-3 flex gap-4">
          {Array.from({ length: cols }).map((_, i) => (
            <Skeleton key={i} className="h-3.5 flex-1 bg-secondary-light-gray" />
          ))}
        </div>
        <div className="divide-y divide-secondary-light-gray">
          {Array.from({ length: rows }).map((_, r) => (
            <div key={r} className="px-4 py-3.5 flex items-center gap-4">
              <div className="flex items-center gap-3 flex-1">
                <Skeleton className="w-10 h-10 rounded-lg flex-shrink-0" />
                <Skeleton className="h-4 w-2/3" />
              </div>
              {Array.from({ length: cols - 1 }).map((_, c) => (
                <Skeleton key={c} className={clsx('h-4 flex-1', c === cols - 2 && 'max-w-[80px]')} />
              ))}
            </div>
          ))}
        </div>
      </div>
      {/* Mobile: card list */}
      <div className="md:hidden space-y-3" aria-hidden="true">
        {Array.from({ length: Math.min(rows, 4) }).map((_, i) => (
          <div key={i} className="bg-white rounded-card shadow-card p-4">
            <div className="flex items-center gap-3">
              <Skeleton className="w-12 h-12 rounded-lg flex-shrink-0" />
              <div className="flex-1">
                <Skeleton className="h-4 w-3/4" />
                <Skeleton className="mt-2 h-3.5 w-1/2" />
              </div>
              <Skeleton className="h-6 w-16 rounded-full" />
            </div>
          </div>
        ))}
      </div>
    </SkeletonGroup>
  );
}

// Full admin page placeholder: title bar + table. Used by the `if (loading)`
// gates that replace the entire page, so it includes the header row.
export function AdminPageSkeleton({ rows = 6, cols = 5 }: { rows?: number; cols?: number }) {
  return (
    <div>
      <div className="flex items-center justify-between mb-6">
        <Skeleton className="h-8 w-48" />
        <Skeleton className="h-10 w-36 rounded-btn hidden md:block" />
      </div>
      <TableSkeleton rows={rows} cols={cols} />
    </div>
  );
}

// Thumbnail grid (admin gallery/media pages).
export function ImageGridSkeleton({ count = 12 }: { count?: number }) {
  return (
    <SkeletonGroup className="grid grid-cols-2 sm:grid-cols-3 lg:grid-cols-4 gap-4">
      {Array.from({ length: count }).map((_, i) => (
        <Skeleton key={i} className="aspect-square w-full rounded-card" />
      ))}
    </SkeletonGroup>
  );
}