import { useState, useMemo } from 'react';
import { useSeoMeta } from '@unhead/react';
import { Link } from 'react-router-dom';
import { Layout } from '@/components/Layout';
import { Card, CardContent } from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { Skeleton } from '@/components/ui/skeleton';
import { Avatar, AvatarFallback, AvatarImage } from '@/components/ui/avatar';
import { CrewRepBadge, CrewActivityPulse } from '@/components/CrewBadge';
import { useCrews } from '@/hooks/useCrews';
import { useCrewsActivity, crewCoordinate } from '@/hooks/useCrewActivity';
import { useGeolocation } from '@/hooks/useGeolocation';
import { crewAccent, crewDistanceKm, formatDistance, type LatLng } from '@/lib/crewHelpers';
import { CREW_VIBE_LABELS, CREW_FOCUS_LABELS, type SkateCrew, type CrewFocus } from '@/lib/types';
import type { CrewActivity } from '@/lib/crewHelpers';
import { cn } from '@/lib/utils';
import { Users, Plus, Search, MapPin, X, HardHat, Camera, GraduationCap, Sparkles, Navigation, Loader2 } from 'lucide-react';

const FOCUS_FILTERS: { key: CrewFocus | 'all'; label: string; icon: typeof Users }[] = [
  { key: 'all', label: 'All', icon: Users },
  { key: 'builder', label: CREW_FOCUS_LABELS.builder, icon: HardHat },
  { key: 'photo', label: CREW_FOCUS_LABELS.photo, icon: Camera },
  { key: 'coaching', label: CREW_FOCUS_LABELS.coaching, icon: GraduationCap },
  { key: 'mixed', label: CREW_FOCUS_LABELS.mixed, icon: Sparkles },
];

const FOCUS_BADGE_ICONS: Record<CrewFocus, typeof Users> = {
  mixed: Sparkles,
  builder: HardHat,
  photo: Camera,
  coaching: GraduationCap,
};

function CrewCard({
  crew,
  activity,
  distanceKm,
}: {
  crew: SkateCrew;
  activity?: CrewActivity;
  distanceKm: number | null;
}) {
  const accent = crewAccent(crew);
  return (
    <Link
      to={`/crew/${crew.pubkey}/${crew.identifier}`}
      className={cn(
        'group flex items-center gap-3 rounded-2xl border p-3 transition-all active:scale-[0.99]',
        accent.border,
        accent.bg,
        accent.hoverBorder,
        'hover:bg-white/[0.06]',
      )}
    >
      <Avatar className="h-14 w-14 rounded-2xl border-2" style={{ borderColor: `${accent.hex}55` }}>
        <AvatarImage src={crew.image} alt={crew.name} className="object-cover" />
        <AvatarFallback className="rounded-2xl font-black" style={{ color: accent.hex, background: `${accent.hex}22` }}>
          {crew.name.slice(0, 2).toUpperCase()}
        </AvatarFallback>
      </Avatar>
      <div className="min-w-0 flex-1">
        <h3 className="flex items-center gap-1.5 truncate font-black leading-tight text-white">
          <span className="truncate">{crew.name}</span>
          <span
            className="inline-flex shrink-0 items-center gap-0.5 rounded-full px-1.5 py-0.5 text-[10px] font-bold"
            style={{ color: accent.hex, background: `${accent.hex}22` }}
          >
            <Users className="h-2.5 w-2.5" /> {crew.members.length}
          </span>
        </h3>

        <div className="mt-1 flex flex-wrap items-center gap-x-2 gap-y-1">
          <CrewRepBadge crew={crew} />
          <CrewActivityPulse activity={activity} />
          {crew.focus !== 'mixed' && (() => {
            const FocusIcon = FOCUS_BADGE_ICONS[crew.focus];
            return (
              <span className="inline-flex items-center gap-1 rounded-full border border-white/10 bg-white/[0.06] px-2 py-0.5 text-[10px] font-bold uppercase tracking-wide text-gray-300">
                <FocusIcon className="h-2.5 w-2.5" />
                {CREW_FOCUS_LABELS[crew.focus]}
              </span>
            );
          })()}
        </div>

        {(crew.location || distanceKm !== null) && (
          <p className="mt-0.5 flex items-center gap-1 truncate text-xs text-gray-400">
            <MapPin className="h-3 w-3 flex-shrink-0" style={{ color: accent.hex }} />
            {crew.location}
            {distanceKm !== null && (
              <span className="ml-1 font-bold" style={{ color: accent.hex }}>
                · {formatDistance(distanceKm)}
              </span>
            )}
          </p>
        )}

        {crew.vibes.length > 0 && (
          <div className="mt-1.5 flex flex-wrap gap-1">
            {crew.vibes.slice(0, 3).map((v) => (
              <span
                key={v}
                className="inline-flex items-center rounded-full border px-2 py-0.5 text-[10px] font-bold"
                style={{ color: accent.hex, borderColor: `${accent.hex}55`, background: `${accent.hex}18` }}
              >
                {CREW_VIBE_LABELS[v] || v}
              </span>
            ))}
          </div>
        )}
      </div>
    </Link>
  );
}

export default function CrewsPage() {
  useSeoMeta({
    title: 'Crews - SkateSpots',
    description: 'Find your people. Discover local skate crews, collectives and communities near you.',
  });

  const { data: crews, isLoading } = useCrews(200);
  const { data: activityMap } = useCrewsActivity(crews);
  const geo = useGeolocation();
  const [query, setQuery] = useState('');
  const [focusFilter, setFocusFilter] = useState<CrewFocus | 'all'>('all');
  const [nearMe, setNearMe] = useState(false);

  const userLoc: LatLng | null = geo.coords;

  // Stats: crew count + distinct cities (social proof header).
  const { cityCount } = useMemo(() => {
    const cities = new Set(
      (crews ?? [])
        .map((c) => c.location?.trim().toLowerCase())
        .filter((c): c is string => !!c),
    );
    return { cityCount: cities.size };
  }, [crews]);

  const filtered = useMemo(() => {
    if (!crews) return [];
    const q = query.trim().toLowerCase();
    let list = crews.filter((c) => {
      if (focusFilter !== 'all' && c.focus !== focusFilter) return false;
      if (!q) return true;
      return (
        c.name.toLowerCase().includes(q) ||
        c.location?.toLowerCase().includes(q) ||
        c.bio?.toLowerCase().includes(q)
      );
    });

    // Near-me: sort by distance ascending, crews without geo sink to the bottom.
    if (nearMe && userLoc) {
      list = [...list].sort((a, b) => {
        const da = crewDistanceKm(a, userLoc);
        const db = crewDistanceKm(b, userLoc);
        if (da === null && db === null) return 0;
        if (da === null) return 1;
        if (db === null) return -1;
        return da - db;
      });
    }
    return list;
  }, [crews, query, focusFilter, nearMe, userLoc]);

  const handleNearMe = () => {
    if (nearMe) {
      setNearMe(false);
      return;
    }
    if (!userLoc) geo.request();
    setNearMe(true);
  };

  return (
    <Layout>
      <div className="container max-w-3xl px-4 py-6">
        {/* Header */}
        <div className="mb-4 flex items-start justify-between gap-4">
          <div>
            <h1
              className="flex items-center gap-2 text-3xl font-black uppercase text-teal-400"
              style={{ fontFamily: 'Impact, "Arial Black", sans-serif' }}
            >
              <Users className="h-7 w-7" /> Crews
            </h1>
            <p className="mt-1 text-sm text-gray-400">Find your people — local crews, collectives &amp; communities</p>
            {/* Social-proof stat line */}
            {!isLoading && crews && crews.length > 0 && (
              <p className="mt-1 text-xs font-bold text-teal-500/80">
                {crews.length} crew{crews.length === 1 ? '' : 's'}
                {cityCount > 0 && ` · ${cityCount} ${cityCount === 1 ? 'city' : 'cities'}`}
              </p>
            )}
          </div>
          <Link to="/create-crew">
            <Button className="gap-2 bg-teal-500 text-sm font-black uppercase text-black hover:bg-teal-600">
              <Plus className="h-4 w-4" />
              <span className="hidden sm:inline">Start a Crew</span>
              <span className="sm:hidden">Start</span>
            </Button>
          </Link>
        </div>

        {/* Search */}
        <div className="relative mb-3">
          <Search className="pointer-events-none absolute left-3 top-1/2 h-4 w-4 -translate-y-1/2 text-gray-500" />
          <input
            type="text"
            value={query}
            onChange={(e) => setQuery(e.target.value)}
            placeholder="Search crews by name or city…"
            className="h-10 w-full rounded-xl border border-white/10 bg-white/5 pl-9 pr-9 text-sm text-white placeholder:text-gray-600 transition-all focus:border-teal-500/50 focus:outline-none"
          />
          {query && (
            <button
              onClick={() => setQuery('')}
              className="absolute right-3 top-1/2 -translate-y-1/2 text-gray-500 hover:text-white"
            >
              <X className="h-4 w-4" />
            </button>
          )}
        </div>

        {/* Filters row: focus chips + Near me */}
        <div className="mb-5 flex flex-wrap items-center gap-2">
          {FOCUS_FILTERS.map(({ key, label, icon: Icon }) => {
            const active = focusFilter === key;
            return (
              <button
                key={key}
                type="button"
                onClick={() => setFocusFilter(key)}
                className={cn(
                  'inline-flex items-center gap-1.5 rounded-full border px-3 py-1.5 text-xs font-bold transition-all active:scale-95',
                  active
                    ? 'border-teal-500 bg-teal-500 text-black'
                    : 'border-white/10 bg-white/5 text-gray-300 hover:border-teal-500/40 hover:text-teal-300',
                )}
              >
                <Icon className="h-3.5 w-3.5" />
                {label}
              </button>
            );
          })}

          <button
            type="button"
            onClick={handleNearMe}
            className={cn(
              'ml-auto inline-flex items-center gap-1.5 rounded-full border px-3 py-1.5 text-xs font-bold transition-all active:scale-95',
              nearMe
                ? 'border-orange-500 bg-orange-500 text-black'
                : 'border-white/10 bg-white/5 text-gray-300 hover:border-orange-500/40 hover:text-orange-300',
            )}
          >
            {geo.loading ? (
              <Loader2 className="h-3.5 w-3.5 animate-spin" />
            ) : (
              <Navigation className="h-3.5 w-3.5" />
            )}
            Near me
          </button>
        </div>

        {geo.error && nearMe && (
          <p className="mb-4 text-xs text-orange-400">{geo.error}</p>
        )}

        {/* List */}
        {isLoading ? (
          <div className="space-y-3">
            {Array.from({ length: 5 }).map((_, i) => (
              <div key={i} className="flex items-center gap-3 rounded-2xl border border-white/5 p-3">
                <Skeleton className="h-14 w-14 rounded-2xl" />
                <div className="flex-1 space-y-2">
                  <Skeleton className="h-4 w-32" />
                  <Skeleton className="h-3 w-24" />
                </div>
              </div>
            ))}
          </div>
        ) : filtered.length === 0 ? (
          <EmptyState query={query} onNearMe={handleNearMe} hasLocation={!!userLoc} />
        ) : (
          <div className="grid grid-cols-1 gap-3 sm:grid-cols-2">
            {filtered.map((crew) => (
              <CrewCard
                key={`${crew.pubkey}:${crew.identifier}`}
                crew={crew}
                activity={activityMap?.get(crewCoordinate(crew))}
                distanceKm={nearMe && userLoc ? crewDistanceKm(crew, userLoc) : null}
              />
            ))}
          </div>
        )}
      </div>
    </Layout>
  );
}

function EmptyState({
  query,
  onNearMe,
  hasLocation,
}: {
  query: string;
  onNearMe: () => void;
  hasLocation: boolean;
}) {
  if (query) {
    return (
      <div className="flex flex-col items-center justify-center px-4 py-20 text-center">
        <div className="mb-4 flex h-16 w-16 items-center justify-center rounded-2xl bg-white/5">
          <Users className="h-8 w-8 text-gray-600" />
        </div>
        <h3 className="mb-2 text-lg font-black text-white">No crews match</h3>
        <p className="max-w-xs text-sm text-gray-500">Try a different search.</p>
      </div>
    );
  }

  // Rich empty state — never feels dead. Prompts to claim the local scene.
  return (
    <Card className="border-2 border-dashed border-teal-500/30 bg-gradient-to-br from-teal-500/[0.06] to-transparent">
      <CardContent className="px-6 py-12 text-center">
        <div className="mx-auto max-w-sm space-y-5">
          <div className="mx-auto flex h-20 w-20 items-center justify-center rounded-3xl bg-teal-500/10 text-4xl">
            🛹
          </div>
          <div className="space-y-1.5">
            <h3 className="text-xl font-black uppercase text-white">Claim your local scene</h3>
            <p className="text-sm text-gray-400">
              No crews planted here yet. Be the first — start your crew, link your home spots,
              and put your scene on the map for everyone to find.
            </p>
          </div>
          <div className="flex flex-col gap-2 sm:flex-row sm:justify-center">
            <Link to="/create-crew">
              <Button className="w-full gap-2 bg-teal-500 font-black uppercase text-black hover:bg-teal-600 sm:w-auto">
                <Plus className="h-4 w-4" /> Start a Crew
              </Button>
            </Link>
            {!hasLocation && (
              <Button
                variant="outline"
                onClick={onNearMe}
                className="w-full gap-2 border-orange-500/40 font-bold text-orange-300 hover:bg-orange-500/10 sm:w-auto"
              >
                <Navigation className="h-4 w-4" /> Find crews near me
              </Button>
            )}
          </div>
        </div>
      </CardContent>
    </Card>
  );
}