import { useMemo, useState } from 'react';
import { useSeoMeta } from '@unhead/react';
import { Link } from 'react-router-dom';
import { nip19 } from 'nostr-tools';
import { LazyMount } from '@/components/LazyMount';
import { Card, CardContent } from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { Input } from '@/components/ui/input';
import { Skeleton } from '@/components/ui/skeleton';
import { Avatar, AvatarImage, AvatarFallback } from '@/components/ui/avatar';
import { useSkaters, useUserSkaterProfile } from '@/hooks/useSkaters';
import { useSkaterVerifications } from '@/hooks/useSkaterVerifications';
import { useCurrentUser } from '@/hooks/useCurrentUser';
import { useAuthor } from '@/hooks/useAuthor';
import { genUserName } from '@/lib/genUserName';
import { useTranslation } from '@/contexts/language';
import {
  SKATER_STYLES,
  SKATER_STANCES,
  SKATER_LEVELS,
  type Skater,
  type SkaterStyle,
} from '@/lib/types';
import { cn } from '@/lib/utils';
import { PersonStanding, Search, MapPin, Check, Sparkles, Users, ShieldCheck, X } from 'lucide-react';

// ─── Skater card ────────────────────────────────────────────────────────────
function SkaterCard({ skater, verified }: { skater: Skater; verified?: boolean }) {
  const { t } = useTranslation();
  const author = useAuthor(skater.pubkey);
  const metadata = author.data?.metadata;
  const name = metadata?.name ?? skater.title ?? genUserName(skater.pubkey);
  const avatar = metadata?.picture ?? skater.image;
  const npub = nip19.npubEncode(skater.pubkey);
  const level = skater.level ? SKATER_LEVELS[skater.level] : undefined;

  return (
    <Link
      to={`/${npub}`}
      className="group relative rounded-2xl border-2 border-white/10 bg-black/60 overflow-hidden hover:border-[#ff0040]/50 transition-all hover:-translate-y-0.5"
    >
      {/* accent glow */}
      <div className="absolute -top-16 -right-16 w-40 h-40 bg-[#ff0040] opacity-0 group-hover:opacity-10 blur-3xl transition-opacity" />

      <div className="relative p-4">
        <div className="flex items-start gap-3">
          <div className="relative flex-shrink-0">
            <Avatar className="h-14 w-14 border-2 border-[#ff0040]/30 group-hover:border-[#ff0040]/60 transition-colors">
              <AvatarImage src={avatar} alt={name} className="object-cover" />
              <AvatarFallback className="bg-[#ff0040]/20 text-[#ff0040] font-black">
                {name.slice(0, 2).toUpperCase()}
              </AvatarFallback>
            </Avatar>
            {level ? (
              <span
                className="absolute -bottom-1.5 left-1/2 -translate-x-1/2 text-[9px] font-black uppercase tracking-wide px-1.5 py-0.5 rounded-full text-black whitespace-nowrap"
                style={{ backgroundColor: level.color }}
              >
                {level.emoji} {level.label}
              </span>
            ) : skater.customLevel ? (
              <span className="absolute -bottom-1.5 left-1/2 -translate-x-1/2 text-[9px] font-black uppercase tracking-wide px-1.5 py-0.5 rounded-full text-black whitespace-nowrap bg-[#ccff00] max-w-[90px] truncate">
                ✏️ {skater.customLevel}
              </span>
            ) : null}
          </div>

          <div className="min-w-0 flex-1 pt-0.5">
            <div className="flex items-center gap-1.5">
              <h3 className="font-black text-white truncate group-hover:text-[#ff0040] transition-colors">{name}</h3>
              {verified && (
                <span title={t('labUi.skaters.nip05Verified')} className="flex-shrink-0">
                  <ShieldCheck className="h-3.5 w-3.5 text-[#ccff00]" />
                </span>
              )}
            </div>
            {skater.location && (
              <p className="text-xs text-gray-400 flex items-center gap-1 mt-0.5 truncate">
                <MapPin className="h-3 w-3 flex-shrink-0" />
                {skater.location}
              </p>
            )}
            {skater.stance && (
              <p className="text-[11px] text-gray-500 mt-0.5">
                {SKATER_STANCES[skater.stance].emoji} {SKATER_STANCES[skater.stance].label}
                {skater.yearsSkating ? ` · ${skater.yearsSkating}y` : ''}
              </p>
            )}
          </div>
        </div>

        {/* Styles */}
        {skater.styles.length > 0 && (
          <div className="flex flex-wrap gap-1 mt-3">
            {skater.styles.slice(0, 4).map((s) => (
              <span key={s} className="text-[10px] font-bold px-2 py-0.5 rounded-full bg-white/8 text-gray-300 border border-white/10">
                {SKATER_STYLES[s].emoji} {SKATER_STYLES[s].label}
              </span>
            ))}
            {skater.styles.length > 4 && (
              <span className="text-[10px] font-bold px-2 py-0.5 rounded-full bg-white/5 text-gray-500">
                +{skater.styles.length - 4}
              </span>
            )}
          </div>
        )}

        {skater.bio && (
          <p className="text-xs text-gray-400 mt-3 line-clamp-2 leading-relaxed">{skater.bio}</p>
        )}
      </div>
    </Link>
  );
}

function SkaterCardSkeleton() {
  return (
    <div className="rounded-2xl border-2 border-white/10 bg-black/60 p-4">
      <div className="flex items-start gap-3">
        <Skeleton className="h-14 w-14 rounded-full" />
        <div className="flex-1 space-y-2 pt-1">
          <Skeleton className="h-4 w-28" />
          <Skeleton className="h-3 w-20" />
        </div>
      </div>
      <div className="flex gap-1 mt-3">
        <Skeleton className="h-4 w-14 rounded-full" />
        <Skeleton className="h-4 w-14 rounded-full" />
      </div>
    </div>
  );
}

// ─── Page ─────────────────────────────────────────────────────────────────
export default function SkatersPage() {
  const { t } = useTranslation();
  useSeoMeta({
    title: 'Skaters - SkateSpots',
    description: 'Discover skaters in the SkateSpots community. Browse by style, stance, level and location.',
  });

  const { data: skaters, isLoading } = useSkaters();
  const { user } = useCurrentUser();
  const { data: myProfile } = useUserSkaterProfile(user?.pubkey);

  const [query, setQuery] = useState('');
  const [styleFilter, setStyleFilter] = useState<SkaterStyle | 'all'>('all');
  const [verifiedOnly, setVerifiedOnly] = useState(false);

  // Soft NIP-05 verification for the whole list (never a gate — powers the
  // "Verified only" toggle and the ✓ badge, so trust is opt-in, not enforced).
  const skaterPubkeys = useMemo(() => (skaters ?? []).map((s) => s.pubkey), [skaters]);
  const { data: verifiedSet, isLoading: verifying } = useSkaterVerifications(skaterPubkeys);
  const verifiedCount = verifiedSet?.size ?? 0;

  // Which styles actually appear (to avoid empty filter chips).
  const availableStyles = useMemo(() => {
    const set = new Set<SkaterStyle>();
    for (const s of skaters ?? []) for (const st of s.styles) set.add(st);
    return (Object.keys(SKATER_STYLES) as SkaterStyle[]).filter((s) => set.has(s));
  }, [skaters]);

  const filtered = useMemo(() => {
    let list = skaters ?? [];
    if (verifiedOnly) list = list.filter((s) => verifiedSet?.has(s.pubkey));
    if (styleFilter !== 'all') list = list.filter((s) => s.styles.includes(styleFilter));
    if (query.trim()) {
      const q = query.trim().toLowerCase();
      list = list.filter(
        (s) =>
          s.title.toLowerCase().includes(q) ||
          s.location?.toLowerCase().includes(q) ||
          s.bio.toLowerCase().includes(q) ||
          nip19.npubEncode(s.pubkey).toLowerCase().includes(q),
      );
    }
    return list;
  }, [skaters, styleFilter, query, verifiedOnly, verifiedSet]);

  const total = skaters?.length ?? 0;

  return (
    <>
      <div className="min-h-screen">
        {/* ── Hero header ── */}
        <div className="relative overflow-hidden border-b border-white/10 bg-gradient-to-br from-[#ff0040]/15 via-black to-[#ccff00]/5">
          <div className="absolute -top-24 -left-16 w-72 h-72 bg-[#ff0040] opacity-15 rounded-full blur-[100px]" />
          <div className="absolute -bottom-24 -right-16 w-72 h-72 bg-[#ccff00] opacity-10 rounded-full blur-[100px]" />
          <div className="container relative px-4 py-10 sm:py-14 max-w-6xl">
            <div className="flex items-center gap-2 text-[#ff0040] mb-3">
              <PersonStanding className="h-5 w-5" />
              <span className="text-xs font-black uppercase tracking-[0.2em]">{t('labUi.skaters.community')}</span>
            </div>
            <h1
              className="text-4xl sm:text-6xl font-black uppercase tracking-tight leading-none"
              style={{ fontFamily: 'Impact, "Arial Black", sans-serif' }}
            >
              Skaters
            </h1>
            <p className="text-gray-300 mt-3 max-w-xl text-base sm:text-lg">
              {t('labUi.skaters.heroDesc')}
            </p>

            <div className="flex flex-wrap items-center gap-3 mt-6">
              {!myProfile ? (
                <Link to="/become/skater">
                  <Button className="h-11 bg-[#ff0040] hover:bg-[#ff0040]/90 font-black uppercase gap-2">
                    <Sparkles className="h-4 w-4" />
                    {t('labUi.skaterForm.putOnMap')}
                  </Button>
                </Link>
              ) : (
                <Link to="/become/skater">
                  <Button variant="outline" className="h-11 border-[#ff0040]/50 text-[#ff0040] hover:bg-[#ff0040]/10 font-bold gap-2">
                    <Check className="h-4 w-4" />
                    {t('labUi.skaters.editProfile')}
                  </Button>
                </Link>
              )}
              {total > 0 && (
                <span className="flex items-center gap-1.5 text-sm text-gray-400">
                  <Users className="h-4 w-4" />
                  <span className="font-black text-white">{total}</span> {t(total === 1 ? 'labUi.skaters.countOne' : 'labUi.skaters.countMany', { count: total })}
                </span>
              )}
            </div>
          </div>
        </div>

        {/* ── Search + filters ── */}
        <div className="sticky top-0 z-20 bg-black/95 backdrop-blur-md border-b border-white/10">
          <div className="container px-4 py-3 max-w-6xl space-y-3">
            <div className="relative">
              <Search className="absolute left-3 top-1/2 -translate-y-1/2 h-4 w-4 text-gray-500 pointer-events-none" />
              <Input
                placeholder={t('labUi.skaters.searchPlaceholder')}
                value={query}
                onChange={(e) => setQuery(e.target.value)}
                className="pl-9 h-10 bg-white/5 border-white/10"
              />
              {query && (
                <button
                  onClick={() => setQuery('')}
                  className="absolute right-3 top-1/2 -translate-y-1/2 text-gray-500 hover:text-white"
                  aria-label={t('labUi.skaters.clearSearch')}
                >
                  <X className="h-4 w-4" />
                </button>
              )}
            </div>

            {/* Style chips + verified toggle */}
            {(availableStyles.length > 0 || verifiedCount > 0) && (
              <div className="flex items-center gap-1.5 overflow-x-auto scrollbar-none pb-0.5">
                <button
                  onClick={() => setStyleFilter('all')}
                  className={cn(
                    'flex-shrink-0 px-3 py-1.5 rounded-full text-xs font-bold border transition-all whitespace-nowrap',
                    styleFilter === 'all' ? 'bg-white text-black border-white' : 'bg-white/5 border-white/10 text-gray-400 hover:text-white hover:border-white/25',
                  )}
                >
                  {t('labUi.all')}
                </button>

                {/* Verified only — soft trust filter, not a gate */}
                <button
                  onClick={() => setVerifiedOnly((v) => !v)}
                  disabled={verifiedCount === 0 && !verifiedOnly}
                  className={cn(
                    'flex-shrink-0 px-3 py-1.5 rounded-full text-xs font-bold border transition-all whitespace-nowrap flex items-center gap-1 disabled:opacity-40 disabled:cursor-not-allowed',
                    verifiedOnly
                      ? 'bg-[#ccff00] border-[#ccff00] text-black'
                      : 'bg-white/5 border-white/10 text-gray-400 hover:text-white hover:border-[#ccff00]/40',
                  )}
                  title={t('labUi.skaters.verifiedFilterTitle')}
                >
                  <ShieldCheck className="h-3.5 w-3.5" />
                  {t('common.verified')}
                  {verifying ? (
                    <span className="opacity-60">…</span>
                  ) : (
                    verifiedCount > 0 && <span className="opacity-70">({verifiedCount})</span>
                  )}
                </button>

                {availableStyles.map((s) => (
                  <button
                    key={s}
                    onClick={() => setStyleFilter(styleFilter === s ? 'all' : s)}
                    className={cn(
                      'flex-shrink-0 px-3 py-1.5 rounded-full text-xs font-bold border transition-all whitespace-nowrap flex items-center gap-1',
                      styleFilter === s ? 'bg-[#ff0040] border-[#ff0040] text-white' : 'bg-white/5 border-white/10 text-gray-400 hover:text-white hover:border-[#ff0040]/40',
                    )}
                  >
                    {SKATER_STYLES[s].emoji} {SKATER_STYLES[s].label}
                  </button>
                ))}
              </div>
            )}
          </div>
        </div>

        {/* ── Grid ── */}
        <div className="container px-4 py-6 max-w-6xl">
          {isLoading ? (
            <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-4">
              {Array.from({ length: 6 }).map((_, i) => <SkaterCardSkeleton key={i} />)}
            </div>
          ) : (() => {
            const shown = filtered;
            return shown.length === 0 ? (
              <Card className="border-dashed border-2 border-white/10 bg-black/40">
                <CardContent className="py-16 px-6 text-center">
                  <div className="inline-flex items-center justify-center w-16 h-16 rounded-2xl bg-white/5 mb-4">
                    <PersonStanding className="h-8 w-8 text-gray-600" />
                  </div>
                  {total === 0 ? (
                    <>
                      <p className="text-xl font-black uppercase text-white mb-2">{t('labUi.skaters.noneTitle')}</p>
                      <p className="text-gray-400 max-w-sm mx-auto mb-6">
                        {t('labUi.skaters.noneDesc')}
                      </p>
                      <Link to="/become/skater">
                        <Button className="bg-[#ff0040] hover:bg-[#ff0040]/90 font-black uppercase gap-2">
                          <Sparkles className="h-4 w-4" />
                          {t('labUi.skaterForm.putOnMap')}
                        </Button>
                      </Link>
                    </>
                  ) : (
                    <>
                      <p className="text-lg font-bold text-white mb-1">
                        {verifiedOnly ? t('labUi.skaters.noVerifiedMatch') : t('labUi.skaters.noMatches')}
                      </p>
                      <p className="text-gray-400 text-sm mb-4">
                        {verifiedOnly
                          ? t('labUi.skaters.tryTurnOffVerified')
                          : t('labUi.skaters.tryDifferentSearch')}
                      </p>
                      <button
                        onClick={() => { setQuery(''); setStyleFilter('all'); setVerifiedOnly(false); }}
                        className="text-xs font-black uppercase tracking-wider text-[#ff0040] hover:underline"
                      >
                        {t('common.clearFilters')}
                      </button>
                    </>
                  )}
                </CardContent>
              </Card>
            ) : (
              <div className="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-4">
                {shown.map((s) => (
                  <LazyMount key={s.pubkey} className="h-full">
                    <SkaterCard skater={s} verified={verifiedSet?.has(s.pubkey)} />
                  </LazyMount>
                ))}
              </div>
            );
          })()}
        </div>
      </div>
    </>
  );
}