'use client';

import { useState, useEffect } from 'react';
import { useSession } from 'next-auth/react';
import { useRouter } from 'next/navigation';
import Image from 'next/image';
import { Photo, Person } from '@prisma/client';
import { ChevronLeft, ChevronRight, X } from 'lucide-react';
import { Button } from '@/components/ui/button';
import { isUrl, getImageSrc } from '@/lib/photo-utils';

interface PhotoWithDetails extends Photo {
  faces?: Array<{
    person: Person | null;
  }>;
  photoTags?: Array<{
    tag: {
      tagName: string;
    };
  }>;
}

interface PhotoViewerProps {
  photo: PhotoWithDetails;
  previousId: number | null;
  nextId: number | null;
}


export function PhotoViewer({ photo, previousId, nextId }: PhotoViewerProps) {
  const router = useRouter();
  const [loading, setLoading] = useState(false);
  const { data: session } = useSession();
  const isLoggedIn = Boolean(session);

  // Keyboard navigation
  useEffect(() => {
    const handleKeyDown = (e: KeyboardEvent) => {
      if (e.key === 'ArrowLeft' && previousId) {
        navigateToPhoto(previousId);
      } else if (e.key === 'ArrowRight' && nextId) {
        navigateToPhoto(nextId);
      } else if (e.key === 'Escape') {
        router.back();
      }
    };

    window.addEventListener('keydown', handleKeyDown);
    return () => window.removeEventListener('keydown', handleKeyDown);
  }, [previousId, nextId, router]);

  const navigateToPhoto = (photoId: number) => {
    setLoading(true);
    router.push(`/photo/${photoId}`);
  };

  const handlePrevious = () => {
    if (previousId) {
      navigateToPhoto(previousId);
    }
  };

  const handleNext = () => {
    if (nextId) {
      navigateToPhoto(nextId);
    }
  };

  const handleClose = () => {
    // Use router.back() to return to the previous page without reloading
    // This preserves filters, pagination, and scroll position
    router.back();
  };

  const peopleNames = (photo as any).faces
    ?.map((face: any) => face.Person)
    .filter((person: any): person is Person => person !== null)
    .map((person: Person) => `${person.first_name} ${person.last_name}`.trim()) || [];

  const tags = (photo as any).PhotoTagLinkage?.map((pt: any) => pt.Tag.tag_name) || [];

  return (
    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black">
      {/* Close Button */}
      <Button
        variant="ghost"
        size="icon"
        className="absolute top-4 right-4 z-10 text-white hover:bg-white/20"
        onClick={handleClose}
        aria-label="Close"
      >
        <X className="h-6 w-6" />
      </Button>

      {/* Previous Button */}
      {previousId && (
        <Button
          variant="ghost"
          size="icon"
          className="absolute left-4 z-10 text-white hover:bg-white/20 disabled:opacity-30"
          onClick={handlePrevious}
          disabled={loading}
          aria-label="Previous photo"
        >
          <ChevronLeft className="h-8 w-8" />
        </Button>
      )}

      {/* Next Button */}
      {nextId && (
        <Button
          variant="ghost"
          size="icon"
          className="absolute right-4 z-10 text-white hover:bg-white/20 disabled:opacity-30"
          onClick={handleNext}
          disabled={loading}
          aria-label="Next photo"
        >
          <ChevronRight className="h-8 w-8" />
        </Button>
      )}

      {/* Photo Container */}
      <div className="relative h-full w-full flex items-center justify-center p-4">
        {loading ? (
          <div className="text-white">Loading...</div>
        ) : (
          <div className="relative h-full w-full max-h-[90vh] max-w-full">
            <Image
              src={getImageSrc(photo, { watermark: !isLoggedIn })}
              alt={photo.filename}
              fill
              className="object-contain"
              priority
              unoptimized={!isUrl(photo.path)}
              sizes="100vw"
            />
          </div>
        )}
      </div>

      {/* Photo Info Overlay */}
      <div className="absolute bottom-0 left-0 right-0 bg-gradient-to-t from-black/80 to-transparent p-6 text-white">
        <div className="container mx-auto">
          <h2 className="text-xl font-semibold mb-2">{photo.filename}</h2>
          {photo.date_taken && (
            <p className="text-sm text-gray-300 mb-2">
              {new Date(photo.date_taken).toLocaleDateString('en-US', {
                year: 'numeric',
                month: 'long',
                day: 'numeric',
              })}
            </p>
          )}
          {peopleNames.length > 0 && (
            <p className="text-sm text-gray-300 mb-1">
              <span className="font-medium">People: </span>
              {peopleNames.join(', ')}
            </p>
          )}
          {tags.length > 0 && (
            <p className="text-sm text-gray-300">
              <span className="font-medium">Tags: </span>
              {tags.join(', ')}
            </p>
          )}
        </div>
      </div>
    </div>
  );
}