Product questions

'use client';

import { useId, useMemo, useState } from 'react';
import { cn, useLocale, useTexts } from '@/lib/kit';
import { Button } from '@/components/ui/button';
import { Icon } from '@/components/ui/icon';
import { Reveal } from '@/components/ui/reveal';
import { Stagger } from '@/components/ui/motion';
import { Eyebrow, Section } from '@/components/ui/section';
import { ShopMotion, Swap, formatNumber } from '@/components/ui/product-image';

/*
 * Questions and answers on a product page: what people asked, answered by
 * the shop or by other customers.
 *
 *   list      search over the questions, answers with votes, the shop answer marked
 *   compact   the five most asked as an accordion, with a link to all
 *   ask       ask a question, with similar questions shown while typing
 *   by-topic  questions sorted into topics, a topic rail on desktop and chips on phones
 */

export type ProductQaVariant = 'list' | 'compact' | 'ask' | 'by-topic';

export interface QaAnswer {
  author: string;
  /** shop: from the shop team, buyer: a verified buyer */
  role?: 'shop' | 'buyer';
  /** e.g. "Product team" */
  title?: string;
  date: string;
  body: string;
  helpful?: number;
}

export interface QaQuestion {
  id: string;
  question: string;
  author?: string;
  date?: string;
  topic?: string;
  answers: QaAnswer[];
  /** How many people asked the same */
  votes?: number;
}

export interface ProductQaProps {
  variant?: ProductQaVariant;
  eyebrow?: string;
  title?: string;
  description?: string;
  questions?: QaQuestion[];
  /** by-topic: the topics in order, with an icon name per topic */
  topics?: { id: string; label: string }[];
  /** ask: the product the question is about */
  product?: { name: string; image?: React.ReactNode };
  /** compact: link to all questions */
  action?: { label: string; href: string };
  /** ask: answer time promise, e.g. "within one business day" */
  answerTime?: string;
  /** ask: text already in the field, e.g. from a search without results */
  defaultQuestion?: string;
  onAsk?: (question: string, email: string) => void;
  /** Where "Ask a question" goes, the ask form on the same page by default: #ask */
  links?: { ask?: string };
  labels?: Partial<Texts>;
  className?: string;
}

const TEXTS = {
  en: {
    search: 'Search questions',
    searchPlaceholder: 'Search questions and answers',
    questions: 'questions',
    question: 'question',
    answers: 'answers',
    answer: 'answer',
    fromShop: 'Answer from the shop',
    buyer: 'Verified buyer',
    helpful: 'Helpful',
    showMore: 'Show more answers',
    showLess: 'Show fewer answers',
    noMatch: 'No question matches yet. Ask it, we answer within a day.',
    ask: 'Ask a question',
    askLabel: 'Your question',
    askPlaceholder: 'e.g. Is it safe in the dishwasher?',
    similar: 'Maybe already answered',
    email: 'Email for the answer',
    emailHint: 'We send the answer here. Your email is never shown.',
    send: 'Send question',
    sending: 'Sending',
    thanks: 'Question sent',
    thanksText: 'We answer',
    askAnother: 'Ask another question',
    sameQuestion: 'Same question',
    allTopics: 'All topics',
    asked: 'asked',
    tooShort: 'Write your question in a few more words.',
    emailError: 'Enter your email so the answer can reach you.',
  },
  de: {
    search: 'Fragen durchsuchen',
    searchPlaceholder: 'Fragen und Antworten durchsuchen',
    questions: 'Fragen',
    question: 'Frage',
    answers: 'Antworten',
    answer: 'Antwort',
    fromShop: 'Antwort vom Shop',
    buyer: 'Verifizierter Kauf',
    helpful: 'Hilfreich',
    showMore: 'Weitere Antworten zeigen',
    showLess: 'Weniger Antworten zeigen',
    noMatch: 'Dazu gibt es noch keine Frage. Stell sie, wir antworten innerhalb eines Tages.',
    ask: 'Frage stellen',
    askLabel: 'Deine Frage',
    askPlaceholder: 'z. B. Darf er in die Spülmaschine?',
    similar: 'Vielleicht schon beantwortet',
    email: 'E-Mail für die Antwort',
    emailHint: 'Wir schicken die Antwort hierhin. Deine E-Mail wird nie gezeigt.',
    send: 'Frage senden',
    sending: 'Wird gesendet',
    thanks: 'Frage gesendet',
    thanksText: 'Wir antworten',
    askAnother: 'Weitere Frage stellen',
    sameQuestion: 'Gleiche Frage',
    allTopics: 'Alle Themen',
    asked: 'gefragt',
    tooShort: 'Schreib deine Frage in ein paar Worten mehr.',
    emailError: 'Gib deine E-Mail ein, damit die Antwort ankommt.',
  },
};

type Texts = (typeof TEXTS)['en'];

const FOCUS = 'outline-none focus-visible:outline-solid focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-[var(--ring)]';
const CARD = 'rounded-2xl border border-border bg-card shadow-[var(--highlight),var(--shadow-sm)]';
const FIELD = 'w-full rounded-lg border border-input bg-background px-3.5 text-[15px] text-foreground shadow-[var(--shadow-sm)] outline-none transition-[border-color,box-shadow] placeholder:text-subtle-foreground hover:border-border-strong focus:border-border-strong focus:shadow-[0_0_0_3px_color-mix(in_oklab,var(--ring)_22%,transparent)]';
const ACCENT_TEXT = 'text-[color-mix(in_oklab,var(--primary)_78%,var(--foreground))]';
const MARK = 'rounded-[3px] bg-[color-mix(in_oklab,var(--primary)_24%,transparent)] text-foreground [box-shadow:0_0_0_2px_color-mix(in_oklab,var(--primary)_24%,transparent)]';

function Head({ eyebrow, title, description, aside }: { eyebrow?: string; title?: string; description?: string; aside?: React.ReactNode }) {
  if (!title) return null;
  return (
    <div className="mb-10 flex flex-col gap-6 sm:mb-12 sm:flex-row sm:items-end sm:justify-between">
      <div className="max-w-[40rem]">
        {eyebrow && <Eyebrow>{eyebrow}</Eyebrow>}
        <h2 className="kit-rise text-balance text-h2 font-semibold text-foreground">{title}</h2>
        {description && (
          <p className="kit-rise mt-4 max-w-[34rem] text-pretty text-lead text-muted-foreground" style={{ '--kit-delay': '80ms' } as React.CSSProperties}>
            {description}
          </p>
        )}
      </div>
      {aside}
    </div>
  );
}

function highlight(text: string, q: string, min = 3): React.ReactNode {
  const words = q.trim().split(/[\s?!.,]+/).filter((w) => w.length >= min);
  if (!words.length) return text;
  const re = new RegExp(`(${words.map((w) => w.replace(/[.*+?^${}()|[\]\\]/g, '\\$&')).join('|')})`, 'gi');
  return text.split(re).map((p, i) => (i % 2 ? <mark key={i} className={MARK}>{p}</mark> : p));
}

/** One answer: shop answers get a tinted surface and a badge, a helpful toggle with a count */
function Answer({ a, t, query = '' }: { a: QaAnswer; t: Texts; query?: string }) {
  const locale = useLocale();
  const [on, setOn] = useState(false);
  const shop = a.role === 'shop';
  return (
    <div className={cn('rounded-xl p-4', shop ? 'border border-[color-mix(in_oklab,var(--primary)_25%,var(--border))] bg-[color-mix(in_oklab,var(--primary)_6%,var(--card))]' : 'bg-surface')}>
      <div className="flex flex-wrap items-center gap-x-2 gap-y-1 text-[12.5px]">
        <span className="font-medium text-foreground">{a.author}</span>
        {shop ? (
          <span className={cn('inline-flex items-center gap-1 rounded-full bg-[color-mix(in_oklab,var(--primary)_14%,transparent)] px-2 py-0.5 font-medium', ACCENT_TEXT)}>
            <Icon name="check-circle" size={12} />
            {a.title ?? t.fromShop}
          </span>
        ) : a.role === 'buyer' ? (
          <span className="inline-flex items-center gap-1 text-success-foreground">
            <Icon name="check" size={12} />
            {t.buyer}
          </span>
        ) : null}
        <span className="text-muted-foreground">· {a.date}</span>
      </div>
      <p className="mt-2 text-pretty text-[14.5px] leading-relaxed text-foreground">{highlight(a.body, query)}</p>
      <button
        type="button"
        aria-pressed={on}
        onClick={() => setOn(!on)}
        className={cn('relative mt-3 inline-flex h-9 items-center after:absolute after:-inset-1 after:content-[""] gap-1.5 rounded-md px-2 -ms-2 text-[12.5px] transition-colors', on ? 'text-foreground' : 'text-muted-foreground hover:bg-accent hover:text-foreground', FOCUS)}
      >
        <Icon name="thumbs-up" size={14} className={cn(on && 'animate-[kitshop-pop_0.4s_var(--ease-kit)] text-primary')} />
        {t.helpful}
        {(a.helpful ?? 0) + (on ? 1 : 0) > 0 && (
          <Swap value={(a.helpful ?? 0) + (on ? 1 : 0)}>
            <span className="tabular-nums">({formatNumber(locale, (a.helpful ?? 0) + (on ? 1 : 0))})</span>
          </Swap>
        )}
      </button>
    </div>
  );
}

/** "Same question" with a count: a vote that the question matters */
function SameVote({ q, t }: { q: QaQuestion; t: Texts }) {
  const locale = useLocale();
  const [on, setOn] = useState(false);
  const n = (q.votes ?? 0) + (on ? 1 : 0);
  return (
    <button
      type="button"
      aria-pressed={on}
      onClick={() => setOn(!on)}
      className={cn('flex w-11 shrink-0 flex-col items-center self-start rounded-xl border py-2 transition-colors sm:w-14', on ? 'border-foreground bg-foreground text-background' : 'border-border-strong text-foreground hover:bg-accent', FOCUS)}
      aria-label={`${t.sameQuestion}, ${formatNumber(locale, n)}`}
    >
      <Icon name="chevron-up" size={16} className={cn('transition-transform duration-300', on && '-translate-y-0.5')} />
      <Swap value={n}>
        <span className="text-[14px] font-semibold tabular-nums">{formatNumber(locale, n)}</span>
      </Swap>
    </button>
  );
}

/* ------------------------------------------------------------------ */
/* list                                                                */
/* ------------------------------------------------------------------ */

function List(p: ProductQaProps & { t: Texts }) {
  const { t } = p;
  const locale = useLocale();
  const [query, setQuery] = useState('');
  const [open, setOpen] = useState<Record<string, boolean>>({});
  const id = useId();
  const q = query.trim().toLowerCase();
  const all = p.questions ?? [];
  const shown = useMemo(() => (q ? all.filter((x) => `${x.question} ${x.answers.map((a) => a.body).join(' ')}`.toLowerCase().includes(q)) : all), [all, q]);
  return (
    <Section className={p.className}>
      <ShopMotion />
      <Head
        eyebrow={p.eyebrow}
        title={p.title}
        description={p.description}
        aside={
          <Button href={p.links?.ask ?? '#ask'} variant="outline" iconLeft="help-circle">
            {t.ask}
          </Button>
        }
      />
      <div className="flex flex-col gap-3 sm:flex-row sm:items-center sm:justify-between">
        <label htmlFor={id} className="relative block sm:w-[26rem]">
          <span className="sr-only">{t.search}</span>
          <Icon name="search" size={16} className="pointer-events-none absolute start-3.5 top-1/2 -translate-y-1/2 text-subtle-foreground" />
          <input id={id} type="search" value={query} onChange={(e) => setQuery(e.target.value)} placeholder={t.searchPlaceholder} className={cn(FIELD, 'h-11 ps-10')} />
        </label>
        <p className="text-[13.5px] text-muted-foreground" aria-live="polite">
          <span className="font-medium tabular-nums text-foreground">{formatNumber(locale, shown.length)}</span> {shown.length === 1 ? t.question : t.questions}
        </p>
      </div>
      {shown.length ? (
        <ul key={q} className="mt-6 divide-y divide-border border-y border-border">
          {shown.map((x, i) => {
            const more = x.answers.length > 1;
            const isOpen = !!open[x.id];
            return (
              <li key={x.id} className="flex gap-4 py-7 animate-[kitshop-in_0.45s_var(--ease-kit)_both] sm:gap-6" style={{ animationDelay: `${Math.min(i, 6) * 60}ms` }}>
                <SameVote q={x} t={t} />
                <div className="min-w-0 flex-1">
                  <h3 className="text-pretty text-[16px] font-semibold leading-snug text-foreground">{highlight(x.question, query)}</h3>
                  {(x.author || x.date) && (
                    <p className="mt-1 text-[12.5px] text-muted-foreground">
                      {[x.author, x.date].filter(Boolean).join(' · ')} · {formatNumber(locale, x.answers.length)} {x.answers.length === 1 ? t.answer : t.answers}
                    </p>
                  )}
                  <div className="mt-4">
                    {x.answers[0] && <Answer a={x.answers[0]} t={t} query={query} />}
                    {more && (
                      <div className={cn('grid transition-[grid-template-rows,opacity,visibility] duration-500 ease-[var(--ease-kit)] motion-reduce:transition-none', isOpen ? 'grid-rows-[1fr] opacity-100' : 'invisible grid-rows-[0fr] opacity-0')}>
                        <div className="space-y-3 overflow-hidden pt-3" inert={!isOpen}>
                          {x.answers.slice(1).map((a, k) => (
                            <Answer key={k} a={a} t={t} query={query} />
                          ))}
                        </div>
                      </div>
                    )}
                  </div>
                  {more && (
                    <button type="button" aria-expanded={isOpen} onClick={() => setOpen((o) => ({ ...o, [x.id]: !isOpen }))} className={cn('mt-1 inline-flex min-h-11 items-center gap-1.5 rounded-md text-[13.5px] font-medium text-foreground', FOCUS)}>
                      {isOpen ? t.showLess : `${t.showMore} (${formatNumber(locale, x.answers.length - 1)})`}
                      <Icon name="chevron-down" size={15} className={cn('transition-transform duration-300', isOpen && 'rotate-180')} />
                    </button>
                  )}
                </div>
              </li>
            );
          })}
        </ul>
      ) : (
        <div className="mt-6 flex flex-col items-center gap-4 rounded-2xl border border-dashed border-border-strong p-10 text-center">
          <p className="max-w-[26rem] text-pretty text-[14px] text-muted-foreground">{t.noMatch}</p>
          <Button href={p.links?.ask ?? '#ask'} variant="outline" iconLeft="help-circle">
            {t.ask}
          </Button>
        </div>
      )}
    </Section>
  );
}

/* ------------------------------------------------------------------ */
/* compact                                                             */
/* ------------------------------------------------------------------ */

function Compact(p: ProductQaProps & { t: Texts }) {
  const { t } = p;
  const [open, setOpen] = useState<string | null>((p.questions ?? [])[0]?.id ?? null);
  const id = useId();
  return (
    <Section className={p.className}>
      <ShopMotion />
      <div className="grid grid-cols-1 gap-8 lg:grid-cols-[minmax(0,20rem)_minmax(0,1fr)] lg:gap-16">
        <div>
          {p.eyebrow && <Eyebrow>{p.eyebrow}</Eyebrow>}
          <h2 className="kit-rise text-balance text-h2 font-semibold text-foreground">{p.title}</h2>
          {p.description && <p className="kit-rise mt-4 text-pretty text-lead text-muted-foreground">{p.description}</p>}
          {p.action && (
            <a href={p.action.href} className={cn('group/all mt-6 inline-flex min-h-11 items-center gap-2 text-[14.5px] font-medium text-foreground max-lg:hidden', FOCUS)}>
              {p.action.label}
              <Icon name="arrow-right" size={15} className="transition-transform duration-300 group-hover/all:translate-x-1" />
            </a>
          )}
        </div>
        <div>
          <Stagger step={60} as="ul" className="divide-y divide-border border-y border-border">
            {(p.questions ?? []).map((x) => {
              const on = open === x.id;
              const a = x.answers[0];
              return (
                <li key={x.id}>
                  <h3>
                    <button
                      type="button"
                      id={`${id}-${x.id}`}
                      aria-expanded={on}
                      aria-controls={`${id}-${x.id}-p`}
                      onClick={() => setOpen(on ? null : x.id)}
                      className={cn('group/q flex w-full items-start gap-4 py-5 text-left', FOCUS)}
                    >
                      <span className={cn('mt-0.5 grid size-7 shrink-0 place-items-center rounded-full text-[12.5px] font-semibold transition-colors duration-300', on ? 'bg-primary text-primary-foreground' : 'bg-muted text-muted-foreground group-hover/q:text-foreground')} aria-hidden>
                        ?
                      </span>
                      <span className="flex-1 text-pretty text-[15.5px] font-medium leading-snug text-foreground">{x.question}</span>
                      <span className="relative mt-1 size-4 shrink-0" aria-hidden>
                        <span className="absolute left-0 top-1/2 h-[1.5px] w-4 -translate-y-1/2 rounded-full bg-foreground" />
                        <span className={cn('absolute left-1/2 top-0 h-4 w-[1.5px] -translate-x-1/2 rounded-full bg-foreground transition-transform duration-300 ease-[var(--ease-kit)]', on && 'scale-y-0')} />
                      </span>
                    </button>
                  </h3>
                  <div id={`${id}-${x.id}-p`} role="region" aria-labelledby={`${id}-${x.id}`} className={cn('grid transition-[grid-template-rows,opacity] duration-500 ease-[var(--ease-kit)] motion-reduce:transition-none', on ? 'grid-rows-[1fr] opacity-100' : 'grid-rows-[0fr] opacity-0')}>
                    <div className="overflow-hidden" inert={!on}>
                      {a && (
                        <div className="pb-5 ps-11">
                          <p className="text-pretty text-[14.5px] leading-relaxed text-muted-foreground">{a.body}</p>
                          <p className="mt-2 text-[12.5px] text-subtle-foreground">
                            {a.author}
                            {a.role === 'shop' && <span className={cn('ms-1.5 font-medium', ACCENT_TEXT)}>· {a.title ?? t.fromShop}</span>}
                          </p>
                        </div>
                      )}
                    </div>
                  </div>
                </li>
              );
            })}
          </Stagger>
          {p.action && (
            <a href={p.action.href} className={cn('group/all mt-5 inline-flex min-h-11 items-center gap-2 text-[14.5px] font-medium text-foreground lg:hidden', FOCUS)}>
              {p.action.label}
              <Icon name="arrow-right" size={15} className="transition-transform duration-300 group-hover/all:translate-x-1" />
            </a>
          )}
        </div>
      </div>
    </Section>
  );
}

/* ------------------------------------------------------------------ */
/* ask                                                                 */
/* ------------------------------------------------------------------ */

function Ask(p: ProductQaProps & { t: Texts }) {
  const { t } = p;
  const [text, setText] = useState(p.defaultQuestion ?? '');
  const [email, setEmail] = useState('');
  const [state, setState] = useState<'idle' | 'sending' | 'done'>('idle');
  const [tried, setTried] = useState(false);
  const [peek, setPeek] = useState<string | null>(null);
  const id = useId();
  // Only longer words count, so "does" or "with" never make a question look similar
  const words = text.toLowerCase().split(/[\s?!.,]+/).filter((w) => w.length >= 5);
  const similar = (p.questions ?? [])
    .map((x) => ({ x, score: words.filter((w) => x.question.toLowerCase().includes(w)).length }))
    .filter((s) => s.score > 0)
    .sort((a, b) => b.score - a.score)
    .slice(0, 3)
    .map((s) => s.x);
  const shortText = text.trim().length < 12;
  const badEmail = !/^\S+@\S+\.\S+$/.test(email);
  const submit = (e: React.FormEvent) => {
    e.preventDefault();
    setTried(true);
    if (shortText || badEmail) {
      document.getElementById(shortText ? `${id}-q` : `${id}-e`)?.focus();
      return;
    }
    setState('sending');
    p.onAsk?.(text, email);
    window.setTimeout(() => setState('done'), 800);
  };
  return (
    <Section className={p.className}>
      <ShopMotion />
      <div id="ask" className="mx-auto max-w-[44rem]">
        <Head eyebrow={p.eyebrow} title={p.title} description={p.description} />
        {state === 'done' ? (
          <div className={cn(CARD, 'animate-[kitshop-zoom_0.45s_var(--ease-kit)] p-6 text-center sm:p-8')} role="status">
            <span className="mx-auto grid size-14 animate-[kitshop-pop_0.5s_var(--ease-kit)] place-items-center rounded-full bg-[color-mix(in_oklab,var(--success)_16%,transparent)] text-success-foreground">
              <Icon name="send" size={22} />
            </span>
            <h3 className="mt-5 text-[20px] font-semibold text-foreground">{t.thanks}</h3>
            <p className="mx-auto mt-2 max-w-[28rem] text-pretty text-[14.5px] leading-relaxed text-muted-foreground">
              {t.thanksText} {p.answerTime}. „{text.trim()}“
            </p>
            <Button variant="outline" className="mt-6" onClick={() => { setState('idle'); setText(''); setTried(false); }}>
              {t.askAnother}
            </Button>
          </div>
        ) : (
          <form noValidate onSubmit={submit} className={cn(CARD, 'p-5 sm:p-7')}>
            {p.product && (
              <div className="mb-6 flex items-center gap-3 border-b border-border pb-5">
                {p.product.image && <span className="size-12 shrink-0 overflow-hidden rounded-lg bg-surface-2 [&>*]:size-full">{p.product.image}</span>}
                <p className="text-[15px] font-medium text-foreground">{p.product.name}</p>
              </div>
            )}
            <label htmlFor={`${id}-q`} className="mb-2 block text-[14px] font-medium text-foreground">
              {t.askLabel}
            </label>
            <textarea
              id={`${id}-q`}
              value={text}
              onChange={(e) => setText(e.target.value.slice(0, 300))}
              rows={3}
              placeholder={t.askPlaceholder}
              aria-invalid={(tried && shortText) || undefined}
              className={cn(FIELD, 'resize-none py-3 leading-relaxed', tried && shortText && 'border-destructive')}
            />
            {tried && shortText && (
              <p role="alert" className="mt-1.5 text-[13px] text-destructive">
                {t.tooShort}
              </p>
            )}
            {similar.length > 0 && (
              <div className="mt-4 animate-[kitshop-in_0.35s_var(--ease-kit)] rounded-xl border border-border bg-surface p-3" aria-live="polite">
                <p className="flex items-center gap-1.5 px-1 text-[12.5px] font-medium text-muted-foreground">
                  <Icon name="lightbulb" size={14} />
                  {t.similar}
                </p>
                <ul className="mt-2 space-y-1">
                  {similar.map((x) => {
                    const on = peek === x.id;
                    return (
                      <li key={x.id}>
                        <button type="button" aria-expanded={on} onClick={() => setPeek(on ? null : x.id)} className={cn('flex min-h-11 w-full items-center justify-between gap-3 rounded-lg px-2 py-2 text-left text-[14px] text-foreground transition-colors hover:bg-accent', FOCUS)}>
                          <span>{highlight(x.question, text, 5)}</span>
                          <Icon name="chevron-down" size={15} className={cn('shrink-0 text-muted-foreground transition-transform duration-300', on && 'rotate-180')} />
                        </button>
                        {on && x.answers[0] && <p className="animate-[kitshop-in_0.3s_var(--ease-kit)] px-2 pb-2 text-pretty text-[13.5px] leading-relaxed text-muted-foreground">{x.answers[0].body}</p>}
                      </li>
                    );
                  })}
                </ul>
              </div>
            )}
            <label htmlFor={`${id}-e`} className="mb-2 mt-5 block text-[14px] font-medium text-foreground">
              {t.email}
            </label>
            <input
              id={`${id}-e`}
              type="email"
              value={email}
              onChange={(e) => setEmail(e.target.value)}
              autoComplete="email"
              aria-invalid={(tried && badEmail) || undefined}
              aria-describedby={`${id}-eh`}
              className={cn(FIELD, 'h-11', tried && badEmail && 'border-destructive')}
            />
            <p id={`${id}-eh`} className={cn('mt-1.5 text-[12.5px]', tried && badEmail ? 'text-destructive' : 'text-muted-foreground')}>
              {tried && badEmail ? t.emailError : t.emailHint}
            </p>
            <div className="mt-6 flex flex-col gap-3 sm:flex-row sm:items-center sm:justify-between">
              {p.answerTime && (
                <p className="flex items-center gap-1.5 text-[13px] text-muted-foreground">
                  <Icon name="clock" size={14} />
                  {t.thanksText} {p.answerTime}
                </p>
              )}
              <Button type="submit" iconLeft={state === 'sending' ? 'loader' : 'send'} disabled={state === 'sending'}>
                <Swap value={state === 'sending'}>{state === 'sending' ? t.sending : t.send}</Swap>
              </Button>
            </div>
          </form>
        )}
      </div>
    </Section>
  );
}

/* ------------------------------------------------------------------ */
/* by-topic                                                            */
/* ------------------------------------------------------------------ */

function ByTopic(p: ProductQaProps & { t: Texts }) {
  const { t } = p;
  const locale = useLocale();
  const topics = p.topics ?? [];
  const [topic, setTopic] = useState<string | null>(null);
  const all = p.questions ?? [];
  const shown = topic ? all.filter((x) => x.topic === topic) : all;
  const count = (id: string | null) => (id ? all.filter((x) => x.topic === id).length : all.length);
  const items = [{ id: null as string | null, label: t.allTopics }, ...topics.map((x) => ({ id: x.id as string | null, label: x.label }))];
  return (
    <Section className={p.className}>
      <ShopMotion />
      <Head eyebrow={p.eyebrow} title={p.title} description={p.description} />
      <div className="grid grid-cols-1 gap-6 lg:grid-cols-[14rem_minmax(0,1fr)] lg:gap-12">
        <nav aria-label={t.allTopics} className="lg:sticky lg:top-8 lg:self-start">
          <ul className="kit-no-scrollbar kit-fade-end -mx-6 flex gap-2 overflow-x-auto px-6 py-1 lg:mx-0 lg:flex-col lg:gap-0.5 lg:overflow-visible lg:px-0 lg:[mask-image:none]">
            {items.map((x) => {
              const on = topic === x.id;
              return (
                <li key={x.id ?? 'all'} className="shrink-0">
                  <button
                    type="button"
                    aria-pressed={on}
                    onClick={() => setTopic(x.id)}
                    className={cn(
                      'flex h-11 w-full items-center justify-between gap-3 whitespace-nowrap rounded-full border px-4 text-[14px] font-medium transition-colors lg:rounded-lg lg:border-0 lg:px-3',
                      on ? 'border-foreground bg-foreground text-background lg:bg-muted lg:text-foreground' : 'border-border-strong text-muted-foreground hover:text-foreground lg:hover:bg-surface',
                      FOCUS,
                    )}
                  >
                    {x.label}
                    <span className={cn('text-[12.5px] tabular-nums', on ? 'opacity-70 lg:opacity-100 lg:text-muted-foreground' : 'text-subtle-foreground')}>{formatNumber(locale, count(x.id))}</span>
                  </button>
                </li>
              );
            })}
          </ul>
        </nav>
        <ul key={topic ?? 'all'} className="grid grid-cols-1 gap-4 sm:grid-cols-2">
          {shown.map((x, i) => {
            const a = x.answers[0];
            return (
              <li key={x.id} className="animate-[kitshop-in_0.45s_var(--ease-kit)_both]" style={{ animationDelay: `${Math.min(i, 6) * 60}ms` }}>
                <article className={cn(CARD, 'flex h-full flex-col p-5 sm:p-6')}>
                  {!topic && x.topic && <p className="text-[12px] font-medium text-subtle-foreground">{topics.find((tp) => tp.id === x.topic)?.label}</p>}
                  <h3 className="mt-1 text-pretty text-[16px] font-semibold leading-snug text-foreground">{x.question}</h3>
                  {a && <p className="mt-3 text-pretty text-[14px] leading-relaxed text-muted-foreground">{a.body}</p>}
                  {a && (
                    <p className="mt-auto flex flex-wrap items-center gap-x-2 pt-4 text-[12.5px] text-muted-foreground">
                      <span className="font-medium text-foreground">{a.author}</span>
                      {a.role === 'shop' && <span className={ACCENT_TEXT}>· {a.title ?? t.fromShop}</span>}
                      {x.votes !== undefined && (
                        <span className="ms-auto inline-flex items-center gap-1 tabular-nums">
                          <Icon name="users" size={13} />
                          {formatNumber(locale, x.votes)} {t.asked}
                        </span>
                      )}
                    </p>
                  )}
                </article>
              </li>
            );
          })}
        </ul>
      </div>
    </Section>
  );
}

/* ------------------------------------------------------------------ */
/* The block                                                           */
/* ------------------------------------------------------------------ */

/**
 * Product questions in four layouts. list: search, answers and votes.
 * compact: the most asked as an accordion. ask: the question form with
 * similar questions. by-topic: questions sorted into topics.
 */
export function ProductQa(props: ProductQaProps) {
  const { variant = 'list' } = props;
  const t = useTexts(TEXTS, props.labels);
  if (variant === 'compact') return <Compact {...props} t={t} />;
  if (variant === 'ask') return <Ask {...props} t={t} />;
  if (variant === 'by-topic') return <ByTopic {...props} t={t} />;
  return <List {...props} t={t} />;
}