/**
 * PublicCardPage — /card/:npub
 *
 * A read-only view of a skater's Rider Card, shareable and scannable. The QR on
 * the card opens /verify so anyone can confirm the card is genuine.
 */
import { useState } from 'react';
import { useParams, Link } from 'react-router-dom';
import { nip19 } from 'nostr-tools';
import { useSeoMeta } from '@unhead/react';
import { ArrowLeft, Sparkles, RefreshCw } from 'lucide-react';

import { useRiderCard, useRiderBadges, useRiderRoles, useCardProfile } from '@/hooks/useRiderCard';
import { useUserCrews } from '@/hooks/useCrews';
import { useUserSkaterProfile } from '@/hooks/useSkaters';
import { useCurrentUser } from '@/hooks/useCurrentUser';
import { useTranslation } from '@/contexts/language';
import { genUserName } from '@/lib/genUserName';
import { Button } from '@/components/ui/button';
import { CardPreview, type CardData, type BadgeAward } from '@/components/RiderCard';
import { RIDER_CARD_KIND, RIDER_CARD_D, DEFAULT_RIDER_CARD, cardVerifyUrl } from '@/lib/riderCard';
import { SKATER_STYLES, SKATER_LEVELS } from '@/lib/types';

function decodePubkey(value: string): string | null {
  if (/^[0-9a-f]{64}$/i.test(value)) return value.toLowerCase();
  try {
    const d = nip19.decode(value);
    return d.type === 'npub' ? d.data : null;
  } catch {
    return null;
  }
}

export default function PublicCardPage() {
  const { t } = useTranslation();
  const { npub = '' } = useParams<{ npub: string }>();
  const pubkey = decodePubkey(npub);
  const { user } = useCurrentUser();

  const cardProfile = useCardProfile(pubkey ?? undefined);
  const metadata = cardProfile.data;
  const displayName = metadata?.name ?? (pubkey ? genUserName(pubkey) : '');
  const { data: savedCard } = useRiderCard(pubkey ?? undefined);
  const { data: badges = [] } = useRiderBadges(pubkey ?? undefined);
  const { data: roles = [] } = useRiderRoles(pubkey ?? undefined);
  const { memberships } = useUserCrews(pubkey ?? undefined);
  const { data: skaterProfile } = useUserSkaterProfile(pubkey ?? undefined);

  const derivedStyle = (skaterProfile?.styles ?? []).map((s) => SKATER_STYLES[s]?.label ?? s).join(' · ');
  const derivedLevel = skaterProfile?.level
    ? (SKATER_LEVELS[skaterProfile.level]?.label ?? '')
    : (skaterProfile?.customLevel ?? '');

  const [side, setSide] = useState<'front' | 'back'>('front');

  useSeoMeta({
    title: `${displayName || 'Rider'} card — SkateSpots`,
    description: `A SkateSpots Rider Card${displayName ? ` for ${displayName}` : ''}.`,
  });

  if (!pubkey) {
    return (
      <div className="max-w-lg mx-auto px-4 py-20 text-center">
        <p className="text-gray-400">{t('cardUi.public.invalid')}</p>
        <Button asChild variant="outline" className="mt-6"><Link to="/card">{t('cardUi.public.createYourOwn')}</Link></Button>
      </div>
    );
  }

  const config = savedCard?.config ?? DEFAULT_RIDER_CARD;
  const receivedBadges: BadgeAward[] = badges.map(b => ({
    skill: b.skill,
    witnessName: genUserName(b.witnessPubkey),
    witnessPubkey: b.witnessPubkey,
    spotName: b.spotName,
    timestamp: b.timestamp,
  }));

  const cardData: CardData = {
    type: 'rider',
    theme: config.theme as CardData['theme'],
    holographic: config.holographic ?? true,
    name: displayName,
    nip05: metadata?.nip05,
    avatar: metadata?.picture,
    pubkey,
    npub: nip19.npubEncode(pubkey),
    style: derivedStyle,
    level: derivedLevel || undefined,
    sponsors: config.sponsors,
    ridesFor: config.ridesFor,
    showCrews: config.showCrews,
    showLocal: config.showLocal,
    showRoles: config.showRoles,
    receivedBadges,
    verifyUrl: cardVerifyUrl(RIDER_CARD_KIND, pubkey, RIDER_CARD_D),
    accent: config.accent || undefined,
    logo: config.logo || undefined,
    side,
    crews: memberships.map(m => ({ name: m.crew.name, image: m.crew.image })),
    local: skaterProfile?.location || skaterProfile?.homeSpot || undefined,
    roles,
    issuerName: '',
    recipientName: '',
    accessLevel: '',
    validThru: '',
  };

  const isMe = user?.pubkey === pubkey;

  return (
    <div className="max-w-2xl mx-auto px-4 pb-16">
      <div className="pt-8 pb-6">
        <Link to={isMe ? '/card' : '/'} className="inline-flex items-center gap-1.5 text-xs text-gray-500 hover:text-gray-300 uppercase tracking-widest">
          <ArrowLeft className="h-3.5 w-3.5" /> {isMe ? t('cardUi.public.backToEditor') : t('cardUi.public.backHome')}
        </Link>
      </div>

      <div
        className="w-full rounded-2xl flex items-center justify-center py-8 relative overflow-hidden"
        style={{ background: 'radial-gradient(ellipse at 50% 60%, rgba(255,0,64,0.08) 0%, rgba(0,0,0,0) 70%), #0a0a0a', border: '1px solid rgba(255,255,255,0.06)' }}
      >
        <CardPreview d={cardData} zoomable />
      </div>

      {config.back && (
        <div className="mt-3 flex justify-center">
          <button
            type="button"
            onClick={() => setSide(s => (s === 'front' ? 'back' : 'front'))}
            className="inline-flex items-center gap-1.5 rounded-full border border-white/10 bg-white/5 px-3 py-1 text-[10px] font-black uppercase tracking-widest text-gray-300 hover:bg-white/10"
          >
            <RefreshCw className="h-3 w-3" />
            {side === 'front' ? t('cardUi.back.showBack') : t('cardUi.back.showFront')}
          </button>
        </div>
      )}

      {!savedCard?.config && (
        <p className="text-center text-xs text-gray-600 mt-4">{t('cardUi.public.notCustomised')}</p>
      )}

      <div className="mt-6 flex flex-col gap-2">
        <Button asChild className="h-12 bg-gradient-to-r from-[#ff0040] to-[#ff6600] font-black uppercase gap-2">
          <Link to={isMe ? '/card' : '/card'}>
            <Sparkles className="h-4 w-4" />
            {isMe ? t('cardUi.public.editYourCard') : t('cardUi.public.createYourOwn')}
          </Link>
        </Button>
        <p className="text-[11px] text-gray-600 text-center">{t('cardUi.public.verifyNote')}</p>
      </div>
    </div>
  );
}