import { useCallback, useEffect } from 'react';
import { ChevronLeft, ChevronRight, Users } from 'lucide-react';
import {
  Dialog,
  DialogContent,
  DialogTitle,
  DialogDescription,
} from '@/components/ui/dialog';
import { Button } from '@/components/ui/button';
import { ImageWithFallback } from '@/components/ImageWithFallback';

export interface LightboxImage {
  url: string;
  caption?: string;
  /** Owner-uploaded images carry no "Community" badge. */
  isOwner?: boolean;
}

interface ImageLightboxProps {
  images: LightboxImage[];
  /** Index of the open image, or null when closed. */
  index: number | null;
  onIndexChange: (index: number) => void;
  onClose: () => void;
}

/**
 * Full-screen photo viewer for spot/shop galleries.
 *
 * Detail-page grids previously rendered images that did nothing on click and
 * showed at most five of them. This lets users view every photo at full size,
 * with arrow-key / button navigation. Images come from arbitrary Blossom hosts,
 * so it reuses ImageWithFallback to degrade gracefully on dead URLs.
 */
export function ImageLightbox({ images, index, onIndexChange, onClose }: ImageLightboxProps) {
  const open = index !== null && index >= 0 && index < images.length;
  const current = open ? images[index as number] : undefined;

  const go = useCallback(
    (delta: number) => {
      if (images.length === 0) return;
      const base = index ?? 0;
      onIndexChange((base + delta + images.length) % images.length);
    },
    [images.length, index, onIndexChange],
  );

  useEffect(() => {
    if (!open) return;
    const onKey = (e: KeyboardEvent) => {
      if (e.key === 'ArrowLeft') {
        e.preventDefault();
        go(-1);
      } else if (e.key === 'ArrowRight') {
        e.preventDefault();
        go(1);
      } else if (e.key === 'Escape') {
        e.preventDefault();
        onClose();
      }
    };
    window.addEventListener('keydown', onKey);
    return () => window.removeEventListener('keydown', onKey);
  }, [open, go, onClose]);

  return (
    <Dialog open={open} onOpenChange={(o) => { if (!o) onClose(); }}>
      <DialogContent className="max-w-5xl w-[calc(100%-1rem)] p-0 gap-0 bg-black/95 border-white/10 overflow-hidden">
        <DialogTitle className="sr-only">{current?.caption || 'Photo'}</DialogTitle>
        <DialogDescription className="sr-only">Photo viewer</DialogDescription>

        {current && (
          <div className="relative flex flex-col">
            <div className="flex items-center justify-center bg-black">
              <ImageWithFallback
                src={current.url}
                alt={current.caption || 'Photo'}
                className="max-h-[80vh] max-h-[80dvh] w-auto max-w-full object-contain"
              />
            </div>

            {/* Position counter */}
            <div className="absolute top-3 left-3 rounded bg-black/70 px-2 py-1 text-xs font-mono text-white/90">
              {(index as number) + 1} / {images.length}
            </div>

            {/* Prev / next */}
            {images.length > 1 && (
              <>
                <Button
                  type="button"
                  size="icon"
                  variant="ghost"
                  aria-label="Previous photo"
                  onClick={() => go(-1)}
                  className="absolute left-2 top-1/2 h-11 w-11 -translate-y-1/2 rounded-full bg-black/50 text-white hover:bg-black/80 hover:text-white"
                >
                  <ChevronLeft className="h-6 w-6" />
                </Button>
                <Button
                  type="button"
                  size="icon"
                  variant="ghost"
                  aria-label="Next photo"
                  onClick={() => go(1)}
                  className="absolute right-2 top-1/2 h-11 w-11 -translate-y-1/2 rounded-full bg-black/50 text-white hover:bg-black/80 hover:text-white"
                >
                  <ChevronRight className="h-6 w-6" />
                </Button>
              </>
            )}

            {/* Caption / attribution */}
            {((current.caption ?? '') !== '' || current.isOwner === false) && (
              <div className="absolute bottom-0 left-0 right-0 bg-gradient-to-t from-black/95 to-transparent px-4 pb-4 pt-8">
                {current.caption && (
                  <p className="break-words text-sm text-white">{current.caption}</p>
                )}
                {current.isOwner === false && (
                  <span className="mt-1 inline-flex items-center gap-1 text-xs text-[#ccff00]">
                    <Users className="h-3 w-3" /> Community photo
                  </span>
                )}
              </div>
            )}
          </div>
        )}
      </DialogContent>
    </Dialog>
  );
}