import { useMemo } from 'react';
import { useSeoMeta } from '@unhead/react';
import { useParams, Link } from 'react-router-dom';
import ngeohash from 'ngeohash';
import { Layout } from '@/components/Layout';
import { SpotMap } from '@/components/SpotMap';
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
import { Badge } from '@/components/ui/badge';
import { Avatar, AvatarFallback, AvatarImage } from '@/components/ui/avatar';
import { Skeleton } from '@/components/ui/skeleton';
import { Button } from '@/components/ui/button';
import { ZapButton } from '@/components/ZapButton';
import { CommentsSection } from '@/components/comments/CommentsSection';
import { useSkateEvent } from '@/hooks/useSkateEvents';
import { useAuthor } from '@/hooks/useAuthor';
import { genUserName } from '@/lib/genUserName';
import { EVENT_TYPE_LABELS, SKATE_CREW_KIND, SKATE_MUSICIAN_KIND } from '@/lib/types';
import { Users } from 'lucide-react';
import NotFound from './NotFound';
import {
  Calendar,
  Clock,
  MapPin,
  ArrowLeft,
  Share2,
  Navigation,
  CalendarPlus,
  Pencil,
  Music,
} from 'lucide-react';
import { useCurrentUser } from '@/hooks/useCurrentUser';

function formatDate(timestamp: number): string {
  const date = new Date(timestamp * 1000);
  return date.toLocaleDateString('en-US', {
    weekday: 'long',
    year: 'numeric',
    month: 'long',
    day: 'numeric',
  });
}

function formatTime(timestamp: number): string {
  const date = new Date(timestamp * 1000);
  return date.toLocaleTimeString('en-US', {
    hour: 'numeric',
    minute: '2-digit',
  });
}

function EventDetailSkeleton() {
  return (
    <Layout>
      <div className="container px-4 py-8">
        <div className="grid lg:grid-cols-3 gap-8">
          <div className="lg:col-span-2 space-y-6">
            <Skeleton className="aspect-video w-full rounded-xl" />
            <div className="space-y-4">
              <Skeleton className="h-10 w-3/4" />
              <Skeleton className="h-6 w-1/2" />
              <div className="flex gap-2">
                <Skeleton className="h-6 w-20" />
                <Skeleton className="h-6 w-20" />
              </div>
              <Skeleton className="h-24 w-full" />
            </div>
          </div>
          <div className="space-y-6">
            <Skeleton className="h-48 w-full rounded-xl" />
            <Skeleton className="h-32 w-full rounded-xl" />
          </div>
        </div>
      </div>
    </Layout>
  );
}

export default function EventDetailPage() {
  const { pubkey, identifier } = useParams<{ pubkey: string; identifier: string }>();
  const { data: event, isLoading, error } = useSkateEvent(identifier || '', pubkey);
  const author = useAuthor(event?.pubkey);
  const { user } = useCurrentUser();

  const isOwner = user && event && user.pubkey === event.pubkey;

  useSeoMeta({
    title: event ? `${event.title} - SkateSpots` : 'Skate Event - SkateSpots',
    description: event?.description || 'View this skateboarding event on SkateSpots.',
  });

  const metadata = author.data?.metadata;
  const displayName = metadata?.name ?? genUserName(event?.pubkey || '');

  const coordinates = useMemo(() => {
    if (!event?.geohash) return null;
    const { latitude, longitude } = ngeohash.decode(event.geohash);
    return { lat: latitude, lng: longitude };
  }, [event?.geohash]);

  const isUpcoming = event ? event.start > Date.now() / 1000 : false;
  const isPast = event ? event.start < Date.now() / 1000 : false;

  // Crew host — an `a` tag pointing at a crew coordinate (35006:pubkey:d).
  const crewHost = useMemo(() => {
    if (!event) return null;
    const ref = event.event.tags
      .filter(([t]) => t === 'a')
      .map(([, v]) => v)
      .find((v) => v?.startsWith(`${SKATE_CREW_KIND}:`));
    if (!ref) return null;
    const [, hPubkey, hId] = ref.split(':');
    const name = event.event.tags.find(([t]) => t === 'crew-name')?.[1];
    return hPubkey && hId ? { pubkey: hPubkey, identifier: hId, name } : null;
  }, [event]);

  // Featured musician — an `a` tag pointing at a musician coordinate (35011:pubkey:d).
  const musicAct = useMemo(() => {
    if (!event) return null;
    const ref = event.event.tags
      .filter(([t]) => t === 'a')
      .map(([, v]) => v)
      .find((v) => v?.startsWith(`${SKATE_MUSICIAN_KIND}:`));
    if (!ref) return null;
    const [, mPubkey, mId] = ref.split(':');
    const name = event.event.tags.find(([t]) => t === 'music-act')?.[1];
    return mPubkey && mId ? { pubkey: mPubkey, identifier: mId, name } : null;
  }, [event]);

  const handleShare = async () => {
    if (navigator.share) {
      try {
        await navigator.share({
          title: event?.title,
          text: event?.description || `Check out this skate event: ${event?.title}`,
          url: window.location.href,
        });
      } catch {
        // User cancelled or share failed
      }
    } else {
      navigator.clipboard.writeText(window.location.href);
    }
  };

  const handleDirections = () => {
    if (coordinates) {
      window.open(
        `https://www.google.com/maps/dir/?api=1&destination=${coordinates.lat},${coordinates.lng}`,
        '_blank'
      );
    }
  };

  const handleAddToCalendar = () => {
    if (!event) return;

    const startDate = new Date(event.start * 1000);
    const endDate = event.end ? new Date(event.end * 1000) : new Date(event.start * 1000 + 3600000); // Default 1 hour

    const formatICSDate = (date: Date) => {
      return date.toISOString().replace(/[-:]/g, '').split('.')[0] + 'Z';
    };

    const icsContent = [
      'BEGIN:VCALENDAR',
      'VERSION:2.0',
      'BEGIN:VEVENT',
      `DTSTART:${formatICSDate(startDate)}`,
      `DTEND:${formatICSDate(endDate)}`,
      `SUMMARY:${event.title}`,
      `DESCRIPTION:${event.description || ''}`,
      `LOCATION:${event.location || ''}`,
      'END:VEVENT',
      'END:VCALENDAR',
    ].join('\n');

    const blob = new Blob([icsContent], { type: 'text/calendar' });
    const url = URL.createObjectURL(blob);
    const link = document.createElement('a');
    link.href = url;
    link.download = `${event.title.replace(/[^a-z0-9]/gi, '-')}.ics`;
    link.click();
    URL.revokeObjectURL(url);
  };

  if (isLoading) {
    return <EventDetailSkeleton />;
  }

  if (error || !event) {
    return <NotFound />;
  }

  return (
    <Layout>
      <div className="container px-4 py-8">
        {/* Back link */}
        <Link
          to="/events"
          className="inline-flex items-center text-muted-foreground hover:text-foreground transition-colors mb-6"
        >
          <ArrowLeft className="h-4 w-4 mr-2" />
          Back to Events
        </Link>

        <div className="grid lg:grid-cols-3 gap-8">
          {/* Main Content */}
          <div className="lg:col-span-2 space-y-6">
            {/* Cover Image */}
            {event.image ? (
              <div className="aspect-video rounded-xl overflow-hidden bg-muted">
                <img
                  src={event.image}
                  alt={event.title}
                  className="w-full h-full object-cover"
                />
              </div>
            ) : (
              <div className="aspect-video rounded-xl bg-gradient-to-br from-primary/20 to-accent/20 flex items-center justify-center">
                <Calendar className="h-16 w-16 text-primary/40" />
              </div>
            )}

            {/* Event Info */}
            <div className="space-y-4">
              <div className="flex items-start justify-between gap-4">
                <div>
                  <div className="flex items-center gap-2 mb-2">
                    {isUpcoming && (
                      <Badge className="bg-green-500">Upcoming</Badge>
                    )}
                    {isPast && (
                      <Badge variant="secondary">Past Event</Badge>
                    )}
                  </div>
                  <h1 className="text-3xl font-bold">{event.title}</h1>
                  <div className="mt-2 flex flex-wrap items-center gap-2">
                    {crewHost && (
                      <Link
                        to={`/crew/${crewHost.pubkey}/${crewHost.identifier}`}
                        className="inline-flex items-center gap-1.5 rounded-full border border-teal-500/40 bg-teal-500/10 px-3 py-1 text-sm font-bold text-teal-300 transition-colors hover:bg-teal-500/20"
                      >
                        <Users className="h-3.5 w-3.5" />
                        Hosted by {crewHost.name || 'a crew'}
                      </Link>
                    )}
                    {musicAct && (
                      <Link
                        to={`/coach/${musicAct.pubkey}/${musicAct.identifier}`}
                        className="inline-flex items-center gap-1.5 rounded-full border border-fuchsia-500/40 bg-fuchsia-500/10 px-3 py-1 text-sm font-bold text-fuchsia-300 transition-colors hover:bg-fuchsia-500/20"
                      >
                        <Music className="h-3.5 w-3.5" />
                        Live: {musicAct.name || 'live music'}
                      </Link>
                    )}
                  </div>
                </div>
                <div className="flex items-center gap-2">
                  {isOwner && (
                    <Link to={`/edit-event/${event.pubkey}/${event.identifier}`}>
                      <Button variant="outline" size="icon">
                        <Pencil className="h-4 w-4" />
                      </Button>
                    </Link>
                  )}
                  <Button variant="outline" size="icon" onClick={handleShare}>
                    <Share2 className="h-4 w-4" />
                  </Button>
                  {isUpcoming && (
                    <Button variant="outline" size="icon" onClick={handleAddToCalendar}>
                      <CalendarPlus className="h-4 w-4" />
                    </Button>
                  )}
                </div>
              </div>

              {/* Date & Time */}
              <div className="flex flex-wrap gap-4 text-muted-foreground">
                <div className="flex items-center gap-2">
                  <Calendar className="h-5 w-5" />
                  <span>{formatDate(event.start)}</span>
                </div>
                <div className="flex items-center gap-2">
                  <Clock className="h-5 w-5" />
                  <span>
                    {formatTime(event.start)}
                    {event.end && ` - ${formatTime(event.end)}`}
                  </span>
                </div>
              </div>

              {/* Location */}
              {event.location && (
                <p className="text-muted-foreground flex items-center gap-2">
                  <MapPin className="h-5 w-5" />
                  {event.location}
                </p>
              )}

              {/* Types */}
              {event.types.length > 0 && (
                <div className="flex flex-wrap gap-2">
                  {event.types.map((type) => (
                    <Badge key={type} variant="secondary">
                      {EVENT_TYPE_LABELS[type] || type}
                    </Badge>
                  ))}
                </div>
              )}

              {/* Description */}
              {event.description && (
                <Card>
                  <CardContent className="pt-6">
                    <p className="whitespace-pre-wrap">{event.description}</p>
                  </CardContent>
                </Card>
              )}

              {/* Comments Section */}
              {event.event && <CommentsSection root={event.event} />}
            </div>
          </div>

          {/* Sidebar */}
          <div className="space-y-6">
            {/* Date Card */}
            <Card className="bg-gradient-to-br from-primary/5 to-accent/5">
              <CardContent className="pt-6">
                <div className="text-center">
                  <div className="text-sm font-medium text-primary uppercase mb-1">
                    {new Date(event.start * 1000).toLocaleDateString('en-US', { month: 'long' })}
                  </div>
                  <div className="text-5xl font-bold mb-2">
                    {new Date(event.start * 1000).getDate()}
                  </div>
                  <div className="text-muted-foreground">
                    {new Date(event.start * 1000).toLocaleDateString('en-US', { weekday: 'long' })}
                  </div>
                  <div className="text-lg font-medium mt-2">
                    {formatTime(event.start)}
                  </div>
                </div>

                {isUpcoming && (
                  <Button className="w-full mt-4 gap-2" onClick={handleAddToCalendar}>
                    <CalendarPlus className="h-4 w-4" />
                    Add to Calendar
                  </Button>
                )}
              </CardContent>
            </Card>

            {/* Map (if has location) */}
            {coordinates && (
              <Card>
                <CardHeader className="pb-3">
                  <CardTitle className="text-lg flex items-center gap-2">
                    <MapPin className="h-5 w-5 text-primary" />
                    Location
                  </CardTitle>
                </CardHeader>
                <CardContent>
                  <div className="aspect-square rounded-lg overflow-hidden">
                    <SpotMap
                      spots={[]}
                      center={[coordinates.lat, coordinates.lng]}
                      zoom={15}
                      className="h-full"
                    />
                  </div>
                  <Button
                    variant="outline"
                    className="w-full mt-4 gap-2"
                    onClick={handleDirections}
                  >
                    <Navigation className="h-4 w-4" />
                    Get Directions
                  </Button>
                </CardContent>
              </Card>
            )}

            {/* Organizer Card */}
            <Card>
              <CardHeader className="pb-3">
                <CardTitle className="text-lg">Organizer</CardTitle>
              </CardHeader>
              <CardContent>
                <div className="flex items-center gap-3">
                  <Avatar className="h-12 w-12">
                    <AvatarImage src={metadata?.picture} alt={displayName} />
                    <AvatarFallback>
                      {displayName.slice(0, 2).toUpperCase()}
                    </AvatarFallback>
                  </Avatar>
                  <div className="flex-1 min-w-0">
                    <p className="font-medium truncate">{displayName}</p>
                    <p className="text-sm text-muted-foreground">Event Organizer</p>
                  </div>
                </div>

                <div className="mt-4 flex items-center gap-2">
                  <ZapButton
                    target={event.event}
                    className="flex-1 justify-center"
                  />
                </div>
              </CardContent>
            </Card>
          </div>
        </div>
      </div>
    </Layout>
  );
}