Description list

'use client';

import { useId, useState } from 'react';
import { cn, useInView, useTexts } from '@/lib/kit';
import { Icon, type IconName } from '@/components/ui/icon';
import { CopyButton } from '@/components/ui/copy-button';

/*
 * Terms and their values, as a real <dl>. For detail pages, order and
 * account summaries, product specs and the meta line under a heading.
 * Five looks: stacked rows, two columns, a grid of tiles, an inline meta
 * row and a spec sheet with groups. Values can be copied, linked, marked
 * with a status, and long lists fold away behind "Show all".
 */

const TEXTS = {
  en: { more: 'Show all', less: 'Show fewer', copy: 'Copy' },
  de: { more: 'Alle zeigen', less: 'Weniger zeigen', copy: 'Kopieren' },
};

export type DescriptionTone = 'neutral' | 'success' | 'warning' | 'danger' | 'info';

export interface DescriptionItem {
  term: string;
  value: string;
  /** A second, quieter line under the value */
  description?: string;
  /** A small icon before the term */
  icon?: IconName;
  /** A copy button for the value */
  copy?: boolean;
  /** The value links here */
  href?: string;
  /** Shows the value as a status with a dot */
  tone?: DescriptionTone;
  /** spec: a group heading above this item */
  group?: string;
  /** Any node instead of the plain value, e.g. avatars or a progress bar */
  node?: React.ReactNode;
}

export type DescriptionListVariant = 'stacked' | 'columns' | 'grid' | 'inline' | 'spec';

export interface DescriptionListProps {
  variant?: DescriptionListVariant;
  items: DescriptionItem[];
  /** A heading above the list */
  title?: string;
  /** A line under the heading */
  description?: string;
  /** An edit link or button at the end of the heading row */
  action?: React.ReactNode;
  /** grid: columns on large screens. Default 3. */
  columns?: 2 | 3 | 4;
  /** spec and stacked: rows shown before "Show all" */
  visible?: number;
  labels?: Partial<(typeof TEXTS)['en']>;
  className?: string;
}

const TONE: Record<DescriptionTone, string> = {
  neutral: 'bg-[color-mix(in_oklab,var(--foreground)_45%,transparent)]',
  success: 'bg-success',
  warning: 'bg-warning',
  danger: 'bg-destructive',
  info: 'bg-info',
};

function Value({ item, strong }: { item: DescriptionItem; strong?: boolean }) {
  if (item.node) return <>{item.node}</>;
  const text = item.tone ? (
    <span className="inline-flex items-center gap-2">
      <span aria-hidden className={cn('size-2 shrink-0 rounded-full', TONE[item.tone])} />
      {item.value}
    </span>
  ) : (
    item.value
  );
  return (
    <span className={cn('min-w-0 break-words', strong ? 'font-medium text-foreground' : 'text-foreground')}>
      {item.href ? (
        <a href={item.href} className="rounded-sm underline decoration-[color-mix(in_oklab,var(--foreground)_30%,transparent)] underline-offset-[3px] transition-colors hover:decoration-foreground focus-visible:outline-2 focus-visible:outline-solid focus-visible:outline-offset-2 focus-visible:outline-primary">
          {text}
        </a>
      ) : (
        text
      )}
    </span>
  );
}

function Term({ item, className }: { item: DescriptionItem; className?: string }) {
  return (
    <dt className={cn('flex items-center gap-2 text-[13px] text-muted-foreground', className)}>
      {item.icon && <Icon name={item.icon} size={15} className="shrink-0 text-subtle-foreground" />}
      {item.term}
    </dt>
  );
}

/** Value, its second line and the copy button, in one dd */
function Detail({ item, className, strong }: { item: DescriptionItem; className?: string; strong?: boolean }) {
  return (
    <dd className={cn('flex min-w-0 items-start justify-between gap-3 text-sm', className)}>
      <span className="min-w-0">
        <Value item={item} strong={strong} />
        {item.description && <span className="mt-0.5 block text-[13px] text-muted-foreground">{item.description}</span>}
      </span>
      {item.copy && <CopyButton value={item.value} size="xs" className="-my-1 shrink-0 max-sm:-my-3 max-sm:size-11" />}
    </dd>
  );
}

/**
 * Terms and values for detail pages, summaries, specs and meta lines.
 *   <DescriptionList title="Account" items={[{ term: 'Plan', value: 'Studio' }]} />
 *   <DescriptionList variant="columns" items={…} />
 *   <DescriptionList variant="grid" columns={4} items={…} />
 *   <DescriptionList variant="inline" items={…} />
 *   <DescriptionList variant="spec" visible={6} items={…} />
 */
export function DescriptionList({ variant = 'stacked', items, title, description, action, columns = 3, visible, labels, className }: DescriptionListProps) {
  const t = useTexts(TEXTS, labels);
  const [ref, inView] = useInView<HTMLDivElement>();
  const [all, setAll] = useState(false);
  const listId = useId();
  const foldable = (variant === 'spec' || variant === 'stacked' || variant === 'columns') && visible !== undefined && items.length > visible;
  const head = (title || action) && (
    <div className={cn('flex items-start justify-between gap-4', variant === 'grid' || variant === 'inline' ? 'mb-4' : 'mb-2')}>
      <div className="min-w-0">
        {title && <h3 className="text-[15px] font-semibold text-foreground">{title}</h3>}
        {description && <p className="mt-0.5 text-[13px] text-muted-foreground">{description}</p>}
      </div>
      {action && <div className="shrink-0">{action}</div>}
    </div>
  );
  // Rows rise one after another once the list scrolls into view
  const rise = (i: number) => ({
    className: cn('transition-[opacity,translate] duration-500 ease-[var(--ease-kit)] motion-reduce:transition-none', !inView && 'translate-y-2 opacity-0'),
    style: { transitionDelay: inView ? `${Math.min(i, 10) * 45}ms` : '0ms' } as React.CSSProperties,
  });
  const folded = (i: number) => foldable && !all && i >= (visible ?? 0);
  const more = foldable && (
    <button
      type="button"
      aria-expanded={all}
      aria-controls={listId}
      onClick={() => setAll(!all)}
      className={cn(variant === 'spec' ? 'ms-1.5' : '-ms-1.5', 'mt-2 inline-flex min-h-11 items-center gap-1 rounded-md px-1.5 text-[13px] font-medium text-foreground outline-none hover:underline focus-visible:shadow-[0_0_0_2px_color-mix(in_oklab,var(--primary)_55%,transparent)] sm:min-h-8')}
    >
      {all ? t.less : `${t.more} (${items.length})`}
      <Icon name="chevron-down" size={14} className={cn('transition-[rotate] duration-300 ease-[var(--ease-kit)]', all && 'rotate-180')} />
    </button>
  );

  /* ---------- inline: the meta line under a heading ---------- */
  if (variant === 'inline') {
    return (
      <div ref={ref} className={cn('w-full', className)}>
        {head}
        <dl className="grid grid-cols-2 gap-x-6 gap-y-4 sm:flex sm:flex-wrap sm:items-stretch sm:gap-0">
          {items.map((item, i) => (
            <div key={i} {...rise(i)} className={cn(rise(i).className, 'min-w-0 sm:px-6 sm:first:ps-0 sm:[&+&]:border-s sm:[&+&]:border-border')}>
              <Term item={item} className="text-[12px]" />
              <dd className="mt-1 flex items-center gap-1.5 text-sm">
                <Value item={item} strong />
                {item.copy && <CopyButton value={item.value} size="xs" className="-my-1 max-sm:-my-3 max-sm:size-11" />}
              </dd>
            </div>
          ))}
        </dl>
      </div>
    );
  }

  /* ---------- grid: tiles on a hairline grid ---------- */
  if (variant === 'grid') {
    const cols = { 2: 'sm:grid-cols-2', 3: 'sm:grid-cols-2 lg:grid-cols-3', 4: 'sm:grid-cols-2 lg:grid-cols-4' }[columns];
    // Fill the last row with empty tiles, so the hairlines meet the edge everywhere and no grey block shows
    const fillSm = (2 - (items.length % 2)) % 2;
    const fillLg = (columns - (items.length % columns)) % columns;
    const fillers = Array.from({ length: Math.max(fillSm, fillLg) }, (_, k) => cn('hidden bg-card', k < fillSm && 'sm:block', columns > 2 && (k < fillLg ? 'lg:block' : 'lg:hidden')));
    return (
      <div ref={ref} className={cn('w-full', className)}>
        {head}
        <dl className={cn('grid grid-cols-[minmax(0,1fr)] gap-px overflow-hidden rounded-xl border border-border bg-border', cols)}>
          {items.map((item, i) => (
            <div key={i} className="group/tile relative min-w-0 bg-card p-4 transition-colors duration-200 hover:bg-[color-mix(in_oklab,var(--foreground)_2.5%,var(--card))] sm:p-5">
              <div {...rise(i)}>
                <Term item={item} />
                <Detail item={item} strong className="mt-1.5 text-[15px]" />
              </div>
            </div>
          ))}
          {fillers.map((c, k) => (
            <div key={`f${k}`} aria-hidden className={c} />
          ))}
        </dl>
      </div>
    );
  }

  /* ---------- spec: groups with zebra rows ---------- */
  if (variant === 'spec') {
    // One dl per group: a heading inside a dl is not allowed, so it sits above its own list
    const groups: { name?: string; rows: { item: DescriptionItem; i: number }[] }[] = [];
    items.forEach((item, i) => {
      const last = groups[groups.length - 1];
      if (!last || (item.group && item.group !== last.name)) groups.push({ name: item.group ?? last?.name, rows: [{ item, i }] });
      else last.rows.push({ item, i });
    });
    return (
      <div ref={ref} id={listId} className={cn('w-full', className)}>
        {head}
        {groups.map((g, gi) => {
          const rows = g.rows.filter((r) => !folded(r.i));
          if (!rows.length) return null;
          return (
            <div key={gi}>
              {g.name && <p className={cn('px-3 pb-2 text-[11px] font-medium uppercase tracking-[0.09em] text-subtle-foreground', gi > 0 ? 'pt-6' : 'pt-1')}>{g.name}</p>}
              <dl className="grid grid-cols-[minmax(0,1fr)]">
                {/* Zebra counts within its group, so every group starts on a light row */}
                {rows.map(({ item, i }, k) => (
                  <div
                    key={i}
                    {...rise(i)}
                    className={cn(
                      rise(i).className,
                      'grid grid-cols-[minmax(0,1fr)] items-start gap-0.5 rounded-md px-3 py-2.5 sm:grid-cols-[minmax(0,2fr)_minmax(0,3fr)] sm:gap-4 starting:opacity-0',
                      k % 2 === 1 && 'bg-[color-mix(in_oklab,var(--foreground)_3.5%,transparent)]',
                    )}
                  >
                    <Term item={item} />
                    <Detail item={item} />
                  </div>
                ))}
              </dl>
            </div>
          );
        })}
        {more}
      </div>
    );
  }

  /* ---------- columns: term left, value right ---------- */
  if (variant === 'columns') {
    return (
      <div ref={ref} className={cn('w-full', className)}>
        {head}
        <dl id={listId} className="grid grid-cols-[minmax(0,1fr)] border-t border-border">
          {items.map((item, i) =>
            folded(i) ? null : (
              <div
                key={i}
                {...rise(i)}
                className={cn(rise(i).className, 'grid gap-1 border-b border-border py-3.5 sm:grid-cols-[minmax(0,1fr)_minmax(0,2fr)] sm:gap-6 sm:py-4 starting:opacity-0')}
              >
                <Term item={item} className="sm:pt-px" />
                <Detail item={item} />
              </div>
            ),
          )}
        </dl>
        {more}
      </div>
    );
  }

  /* ---------- stacked: term above value ---------- */
  return (
    <div ref={ref} className={cn('w-full', className)}>
      {head}
      <dl id={listId} className="grid grid-cols-[minmax(0,1fr)] divide-y divide-border">
        {items.map((item, i) =>
          folded(i) ? null : (
            <div key={i} {...rise(i)} className={cn(rise(i).className, 'py-3.5 starting:opacity-0')}>
              <Term item={item} />
              <Detail item={item} className="mt-1" strong />
            </div>
          ),
        )}
      </dl>
      {more}
    </div>
  );
}