import { useParams, Link, useNavigate } from 'react-router-dom';
import { useSeoMeta } from '@unhead/react';
import { useNostr } from '@nostrify/react';
import { useQuery } from '@tanstack/react-query';
import { PageError } from '@/components/ErrorState';
import { SpotCard, SpotCardSkeleton } from '@/components/SpotCard';
import { SpotMap } from '@/components/SpotMap';
import { Card, CardContent, CardHeader, CardTitle } from '@/components/ui/card';
import { Button } from '@/components/ui/button';
import { Skeleton } from '@/components/ui/skeleton';
import { Badge } from '@/components/ui/badge';
import { AlertDialog, AlertDialogAction, AlertDialogCancel, AlertDialogContent, AlertDialogDescription, AlertDialogFooter, AlertDialogHeader, AlertDialogTitle } from '@/components/ui/alert-dialog';
import { useToast } from '@/hooks/useToast';
import { useCurrentUser } from '@/hooks/useCurrentUser';
import { useRelays } from '@/lib/relays';
import { useSpotCollection, useRemoveSpotFromCollection, useDeleteSpotCollection } from '@/hooks/useSpotCollections';
import type { NostrEvent } from '@nostrify/nostrify';
import { SKATE_SPOT_KIND, parseSkateSpot, type SkateSpot } from '@/lib/types';
import { ArrowLeft, FolderOpen, MapPin, Calendar, Trash2, X, Share2, Loader2, AlertTriangle } from 'lucide-react';
import NotFound from './NotFound';
import { useState } from 'react';

function CollectionDetailSkeleton() {
  return (
    <>
      <div className="container px-4 py-8">
        <Skeleton className="h-6 w-32 mb-6" />
        <div className="space-y-6">
          <Skeleton className="h-12 w-3/4" />
          <Skeleton className="h-6 w-1/2" />
          <div className="grid gap-6 sm:grid-cols-2 lg:grid-cols-3">
            {Array.from({ length: 6 }).map((_, i) => (
              <SpotCardSkeleton key={i} />
            ))}
          </div>
        </div>
      </div>
    </>
  );
}

export default function CollectionDetailPage() {
  const { pubkey, identifier } = useParams<{ pubkey: string; identifier: string }>();
  const { data: collection, isLoading, error, refetch } = useSpotCollection(identifier || '', pubkey);
  const { user } = useCurrentUser();
  const { nostr } = useNostr();
  const { read } = useRelays();
  const { removeSpotFromCollection, isPending: isRemoving } = useRemoveSpotFromCollection();
  const { deleteCollection, isPending: isDeleting } = useDeleteSpotCollection();
  const { toast } = useToast();
  const navigate = useNavigate();

  const [showDeleteDialog, setShowDeleteDialog] = useState(false);
  const [removingSpotId, setRemovingSpotId] = useState<string | null>(null);

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

  useSeoMeta({
    title: collection ? `${collection.title} - SkateSpots Collection` : 'Spot Collection - SkateSpots',
    description: collection?.description || 'A curated collection of skate spots',
  });

  // Fetch all spots referenced in the collection
  const { data: spots, isLoading: isSpotsLoading } = useQuery({
    queryKey: ['collection-spots', collection?.id, collection?.spotRefs],
    queryFn: async (c) => {
      if (!collection || collection.spotRefs.length === 0) return [];

      const signal = AbortSignal.any([c.signal, AbortSignal.timeout(15000)]);
      const readRelays = read;

      // Parse spot references to build filters
      const spotFilters = collection.spotRefs.map((ref) => {
        const [kind, pubkey, d] = ref.split(':');
        return { kind: parseInt(kind), pubkey, d };
      }).filter(f => f.kind === SKATE_SPOT_KIND);

      if (spotFilters.length === 0) return [];

      const allEvents: NostrEvent[] = [];

      // Query each relay for all spots
      for (const relayUrl of readRelays) {
        try {
          const relay = nostr.relay(relayUrl);
          // Query each spot individually (addressable events need specific filters)
          for (const filter of spotFilters) {
            const events = await relay.query(
              [{
                kinds: [SKATE_SPOT_KIND],
                authors: [filter.pubkey],
                '#d': [filter.d],
                limit: 1,
              }],
              { signal }
            );
            allEvents.push(...events);
          }
        } catch (error) {
          console.warn(`[CollectionDetail] Failed to query relay ${relayUrl}:`, error);
        }
      }

      // Deduplicate by event id
      const eventMap = new Map<string, typeof allEvents[0]>();
      for (const event of allEvents) {
        const d = event.tags.find(([name]: [string]) => name === 'd')?.[1];
        if (d) {
          const key = `${event.pubkey}:${event.kind}:${d}`;
          const existing = eventMap.get(key);
          if (!existing || event.created_at > existing.created_at) {
            eventMap.set(key, event);
          }
        }
      }

      const spots: SkateSpot[] = [];
      for (const event of Array.from(eventMap.values())) {
        const spot = parseSkateSpot(event);
        if (spot) spots.push(spot);
      }

      return spots;
    },
    enabled: !!collection && collection.spotRefs.length > 0,
    staleTime: 30000,
  });

  const handleRemoveSpot = async (spot: SkateSpot) => {
    if (!collection || !isOwner) return;

    setRemovingSpotId(spot.id);
    try {
      await removeSpotFromCollection({
        collection,
        spotPubkey: spot.pubkey,
        spotIdentifier: spot.identifier,
      });
      toast({
        title: 'Spot removed',
        description: `"${spot.title}" has been removed from this collection`,
      });
    } catch (error) {
      toast({
        title: 'Failed to remove spot',
        description: error instanceof Error ? error.message : 'Something went wrong',
        variant: 'destructive',
      });
    } finally {
      setRemovingSpotId(null);
    }
  };

  const handleDeleteCollection = async () => {
    if (!collection) return;

    try {
      await deleteCollection(collection);
      toast({
        title: 'Collection deleted',
        description: `"${collection.title}" has been removed`,
      });
      navigate('/collections');
    } catch (error) {
      toast({
        title: 'Failed to delete collection',
        description: error instanceof Error ? error.message : 'Something went wrong',
        variant: 'destructive',
      });
    }
    setShowDeleteDialog(false);
  };

  const handleShare = async () => {
    if (navigator.share) {
      try {
        await navigator.share({
          title: collection?.title,
          text: collection?.description || `Check out this spot collection: ${collection?.title}`,
          url: window.location.href,
        });
      } catch {
        // User cancelled or share failed
      }
    } else {
      navigator.clipboard.writeText(window.location.href);
      toast({
        title: 'Link copied!',
        description: 'Collection link has been copied to clipboard',
      });
    }
  };

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

  if (error) {
    return <PageError onRetry={() => refetch()} />;
  }

  if (!collection) {
    return <NotFound />;
  }

  return (
    <>
      <div className="container px-4 py-4 sm:py-8">
        {/* Back link */}
        <Link
          to="/collections"
          className="inline-flex items-center text-muted-foreground hover:text-foreground transition-colors mb-4 sm:mb-6 text-sm"
        >
          <ArrowLeft className="h-4 w-4 mr-1.5 sm:mr-2" />
          Back to Collections
        </Link>

        {/* Header */}
        <div className="flex flex-col gap-4 mb-6 sm:mb-8">
          <div className="flex items-start justify-between gap-3">
            <div className="flex-1 min-w-0">
              <div className="flex items-center gap-2 sm:gap-3 mb-1 sm:mb-2">
                <FolderOpen className="h-6 w-6 sm:h-8 sm:w-8 text-[#ccff00] flex-shrink-0" />
                <h1 className="text-xl sm:text-3xl font-black uppercase tracking-wider text-white truncate">
                  {collection.title}
                </h1>
              </div>
              {collection.description && (
                <p className="text-gray-400 mt-1 sm:mt-2 max-w-2xl text-sm sm:text-base">
                  {collection.description}
                </p>
              )}
            </div>

            <div className="flex items-center gap-1.5 sm:gap-2 flex-shrink-0">
              <Button
                variant="outline"
                size="icon"
                onClick={handleShare}
                className="border-gray-700 h-9 w-9 sm:h-10 sm:w-10"
              >
                <Share2 className="h-4 w-4" />
              </Button>
              {isOwner && (
                <Button
                  variant="outline"
                  size="icon"
                  onClick={() => setShowDeleteDialog(true)}
                  className="border-red-500/50 hover:bg-red-500/10 hover:text-red-500 h-9 w-9 sm:h-10 sm:w-10"
                >
                  <Trash2 className="h-4 w-4" />
                </Button>
              )}
            </div>
          </div>
          
          <div className="flex flex-wrap items-center gap-2 sm:gap-4 text-xs sm:text-sm text-gray-500">
            <Badge variant="outline" className="border-[#ccff00]/50 text-[#ccff00]">
              <MapPin className="h-2.5 w-2.5 sm:h-3 sm:w-3 mr-1" />
              {collection.spotRefs.length} spot{collection.spotRefs.length !== 1 ? 's' : ''}
            </Badge>
            <span className="flex items-center gap-1">
              <Calendar className="h-2.5 w-2.5 sm:h-3 sm:w-3" />
              Created {new Date(collection.createdAt * 1000).toLocaleDateString()}
            </span>
          </div>
        </div>

        {/* Map showing all spots */}
        {spots && spots.length > 0 && (
          <Card className="mb-6 sm:mb-8 border-2 border-[#ccff00]/30">
            <CardHeader className="p-3 sm:p-6 pb-2 sm:pb-4">
              <CardTitle className="text-base sm:text-lg flex items-center gap-2">
                <MapPin className="h-4 w-4 sm:h-5 sm:w-5 text-[#ccff00]" />
                Collection Map
              </CardTitle>
            </CardHeader>
            <CardContent className="p-3 sm:p-6 pt-0">
              <div className="aspect-[4/3] sm:aspect-[2/1] rounded-lg overflow-hidden">
                <SpotMap
                  spots={spots}
                  className="h-full"
                  zoom={5}
                />
              </div>
            </CardContent>
          </Card>
        )}

        {/* Spots grid */}
        {isSpotsLoading ? (
          <div className="grid gap-4 sm:gap-6 grid-cols-2 lg:grid-cols-3">
            {Array.from({ length: collection.spotRefs.length || 3 }).map((_, i) => (
              <SpotCardSkeleton key={i} />
            ))}
          </div>
        ) : spots && spots.length > 0 ? (
          <div className="grid gap-4 sm:gap-6 grid-cols-2 lg:grid-cols-3">
            {spots.map((spot) => (
              <div key={spot.id} className="relative group">
                <SpotCard spot={spot} />
                {isOwner && (
                  <Button
                    size="icon"
                    variant="destructive"
                    className="absolute top-2 right-2 h-8 w-8 opacity-100 sm:opacity-0 sm:group-hover:opacity-100 transition-opacity z-10 touch-manipulation"
                    onClick={(e) => {
                      e.preventDefault();
                      e.stopPropagation();
                      handleRemoveSpot(spot);
                    }}
                    disabled={isRemoving}
                  >
                    {removingSpotId === spot.id ? (
                      <Loader2 className="h-4 w-4 animate-spin" />
                    ) : (
                      <X className="h-4 w-4" />
                    )}
                  </Button>
                )}
              </div>
            ))}
          </div>
        ) : (
          <Card className="border-dashed border-2 border-gray-700">
            <CardContent className="py-16 text-center">
              <MapPin className="h-16 w-16 mx-auto mb-4 text-gray-600" />
              <h2 className="text-xl font-bold mb-2">No spots in this collection</h2>
              <p className="text-gray-400 mb-6">
                {isOwner 
                  ? 'Add spots to your collection by clicking "Save to Collection" on any spot'
                  : 'This collection is empty'}
              </p>
              {isOwner && (
                <Link to="/map">
                  <Button className="bg-[#ccff00] text-black hover:bg-[#ccff00]/90 font-bold uppercase">
                    Browse Spots
                  </Button>
                </Link>
              )}
            </CardContent>
          </Card>
        )}
      </div>

      {/* Delete Confirmation Dialog */}
      <AlertDialog open={showDeleteDialog} onOpenChange={setShowDeleteDialog}>
        <AlertDialogContent className="bg-black border-2 border-red-500/50 mx-4 max-w-[calc(100vw-2rem)] sm:max-w-lg">
          <AlertDialogHeader>
            <AlertDialogTitle className="text-white flex items-center gap-2">
              <AlertTriangle className="h-5 w-5 text-red-500" />
              Delete Collection?
            </AlertDialogTitle>
            <AlertDialogDescription className="text-gray-400 text-sm">
              This will permanently delete "{collection.title}". The spots themselves won't be affected.
            </AlertDialogDescription>
          </AlertDialogHeader>
          <AlertDialogFooter className="flex-col sm:flex-row gap-2 sm:gap-0">
            <AlertDialogCancel className="border-gray-700 h-11 sm:h-auto">Cancel</AlertDialogCancel>
            <AlertDialogAction
              onClick={handleDeleteCollection}
              disabled={isDeleting}
              className="bg-red-500 hover:bg-red-600 text-white h-11 sm:h-auto"
            >
              {isDeleting ? (
                <>
                  <Loader2 className="h-4 w-4 mr-2 animate-spin" />
                  Deleting...
                </>
              ) : (
                'Delete'
              )}
            </AlertDialogAction>
          </AlertDialogFooter>
        </AlertDialogContent>
      </AlertDialog>
    </>
  );
}