'use client';
import { useState, useEffect, useCallback, useRef } from 'react';
import { Card, MediaItem } from '@/types';

const isVideoUrl = (url: string) => /\.(mp4|webm|mov|m4v|ogv)(\?|$)/i.test(url);

function MediaCarousel({
  items,
  onImageClick,
}: {
  items: MediaItem[];
  onImageClick?: (index: number) => void;
}) {
  const [current, setCurrent] = useState(0);
  const touchStartX = useRef<number | null>(null);
  const videoRefs = useRef<Record<number, HTMLVideoElement | null>>({});

  const prev = useCallback(() => setCurrent(i => (i - 1 + items.length) % items.length), [items.length]);
  const next = useCallback(() => setCurrent(i => (i + 1) % items.length), [items.length]);

  useEffect(() => {
    const onKey = (e: KeyboardEvent) => {
      if (e.key === 'ArrowLeft') prev();
      if (e.key === 'ArrowRight') next();
    };
    window.addEventListener('keydown', onKey);
    return () => window.removeEventListener('keydown', onKey);
  }, [prev, next]);

  useEffect(() => { setCurrent(0); }, [items]);

  // Pause non-current videos; autoplay current if flagged
  useEffect(() => {
    Object.entries(videoRefs.current).forEach(([key, vid]) => {
      if (!vid) return;
      const idx = parseInt(key, 10);
      if (idx !== current) { vid.pause(); return; }
      const item = items[idx];
      if (item && isVideoUrl(item.url) && item.autoplay) {
        vid.muted = true;
        vid.play().catch(() => {});
      }
    });
  }, [current, items]);

  const onTouchStart = (e: React.TouchEvent) => { touchStartX.current = e.touches[0].clientX; };
  const onTouchEnd = (e: React.TouchEvent) => {
    if (touchStartX.current === null) return;
    const delta = e.changedTouches[0].clientX - touchStartX.current;
    if (Math.abs(delta) > 50) delta < 0 ? next() : prev();
    touchStartX.current = null;
  };

  if (items.length === 0) {
    return <div className="h-72 w-full bg-gray-100 flex items-center justify-center text-gray-400 rounded-t-2xl">No Image</div>;
  }

  return (
    <div
      className="relative h-72 w-full bg-black overflow-hidden rounded-t-2xl select-none"
      onTouchStart={onTouchStart}
      onTouchEnd={onTouchEnd}
    >
      {items.map((item, i) => {
        const isActive = i === current;
        const video = isVideoUrl(item.url);
        return (
          <div
            key={item.url + i}
            className={`absolute inset-0 transition-opacity duration-300 ${isActive ? 'opacity-100' : 'opacity-0 pointer-events-none'}`}
          >
            {video ? (
              <video
                ref={el => { videoRefs.current[i] = el; }}
                src={item.url}
                className="w-full h-full object-contain bg-black"
                controls
                playsInline
                muted={!!item.autoplay}
                preload="metadata"
              />
            ) : (
              <img
                src={item.url}
                alt=""
                className="w-full h-full object-cover cursor-zoom-in"
                onClick={() => onImageClick?.(i)}
                title="Click to view fullscreen"
              />
            )}
          </div>
        );
      })}

      {items.length > 1 && (
        <>
          <button
            onClick={(e) => { e.stopPropagation(); prev(); }}
            className="absolute left-3 top-1/2 -translate-y-1/2 bg-black/50 hover:bg-black/80 text-white w-9 h-9 rounded-full flex items-center justify-center transition-colors shadow-lg z-10"
            aria-label="Previous"
          >‹</button>
          <button
            onClick={(e) => { e.stopPropagation(); next(); }}
            className="absolute right-3 top-1/2 -translate-y-1/2 bg-black/50 hover:bg-black/80 text-white w-9 h-9 rounded-full flex items-center justify-center transition-colors shadow-lg z-10"
            aria-label="Next"
          >›</button>

          <div className="absolute bottom-3 left-1/2 -translate-x-1/2 flex items-center gap-1.5 z-10">
            {items.map((_, i) => (
              <button
                key={i}
                onClick={(e) => { e.stopPropagation(); setCurrent(i); }}
                className={`rounded-full transition-all duration-200 ${i === current ? 'w-5 h-2 bg-white' : 'w-2 h-2 bg-white/50 hover:bg-white/80'}`}
                aria-label={`Go to slide ${i + 1}`}
              />
            ))}
          </div>

          <div className="absolute top-3 right-3 bg-black/50 text-white text-xs font-semibold px-2 py-0.5 rounded-full z-10">
            {current + 1} / {items.length}
          </div>
        </>
      )}
    </div>
  );
}

function FullscreenViewer({
  items,
  startIndex,
  onClose,
}: {
  items: MediaItem[];
  startIndex: number;
  onClose: () => void;
}) {
  const [current, setCurrent] = useState(startIndex);
  const touchStartX = useRef<number | null>(null);

  const prev = useCallback(() => setCurrent(i => (i - 1 + items.length) % items.length), [items.length]);
  const next = useCallback(() => setCurrent(i => (i + 1) % items.length), [items.length]);

  useEffect(() => {
    const onKey = (e: KeyboardEvent) => {
      if (e.key === 'Escape') onClose();
      else if (e.key === 'ArrowLeft') prev();
      else if (e.key === 'ArrowRight') next();
    };
    window.addEventListener('keydown', onKey);
    return () => window.removeEventListener('keydown', onKey);
  }, [prev, next, onClose]);

  const onTouchStart = (e: React.TouchEvent) => { touchStartX.current = e.touches[0].clientX; };
  const onTouchEnd = (e: React.TouchEvent) => {
    if (touchStartX.current === null) return;
    const delta = e.changedTouches[0].clientX - touchStartX.current;
    if (Math.abs(delta) > 50) delta < 0 ? next() : prev();
    touchStartX.current = null;
  };

  return (
    <div
      className="fixed inset-0 z-[100] bg-black/95 flex items-center justify-center select-none animate-in fade-in duration-200"
      onTouchStart={onTouchStart}
      onTouchEnd={onTouchEnd}
    >
      {/* Media — full resolution, contained */}
      {items.map((item, i) => {
        const isActive = i === current;
        const video = isVideoUrl(item.url);
        return (
          <div
            key={item.url + i}
            className={`absolute inset-0 flex items-center justify-center p-4 pb-28 transition-opacity duration-200 ${isActive ? 'opacity-100' : 'opacity-0 pointer-events-none'}`}
          >
            {video ? (
              <video
                src={item.url}
                className="max-w-full max-h-full"
                controls
                playsInline
                autoPlay={!!item.autoplay}
                muted={!!item.autoplay}
              />
            ) : (
              <img
                src={item.url}
                alt=""
                className="max-w-full max-h-full object-contain"
              />
            )}
          </div>
        );
      })}

      {/* Counter — top center */}
      {items.length > 1 && (
        <div className="absolute top-4 left-1/2 -translate-x-1/2 bg-black/60 text-white text-sm font-semibold px-3 py-1 rounded-full z-20">
          {current + 1} / {items.length}
        </div>
      )}

      {/* Side arrows */}
      {items.length > 1 && (
        <>
          <button
            onClick={(e) => { e.stopPropagation(); prev(); }}
            className="absolute left-4 top-1/2 -translate-y-1/2 bg-black/50 hover:bg-black/80 text-white w-12 h-12 rounded-full flex items-center justify-center text-2xl shadow-lg z-20"
            aria-label="Previous"
          >‹</button>
          <button
            onClick={(e) => { e.stopPropagation(); next(); }}
            className="absolute right-4 top-1/2 -translate-y-1/2 bg-black/50 hover:bg-black/80 text-white w-12 h-12 rounded-full flex items-center justify-center text-2xl shadow-lg z-20"
            aria-label="Next"
          >›</button>
        </>
      )}

      {/* Close button — bottom center, ABOVE the dots */}
      <button
        onClick={onClose}
        className="absolute bottom-12 left-1/2 -translate-x-1/2 bg-white/90 hover:bg-white text-black px-6 py-2.5 rounded-full font-semibold shadow-2xl flex items-center gap-2 z-20 transition-transform hover:scale-105"
        aria-label="Close fullscreen"
      >
        <span className="text-lg leading-none">✕</span>
        <span>Close</span>
      </button>

      {/* Dots — at the very bottom */}
      {items.length > 1 && (
        <div className="absolute bottom-4 left-1/2 -translate-x-1/2 flex items-center gap-1.5 z-20">
          {items.map((_, i) => (
            <button
              key={i}
              onClick={(e) => { e.stopPropagation(); setCurrent(i); }}
              className={`rounded-full transition-all duration-200 ${i === current ? 'w-6 h-2 bg-white' : 'w-2 h-2 bg-white/50 hover:bg-white/80'}`}
              aria-label={`Go to slide ${i + 1}`}
            />
          ))}
        </div>
      )}
    </div>
  );
}

export default function PublicGrid({ cards, maxCols = 5 }: { cards: Card[], maxCols?: number }) {
  const [activeCard, setActiveCard] = useState<Card | null>(null);
  const [fullscreenIndex, setFullscreenIndex] = useState<number | null>(null);

  useEffect(() => {
    if (activeCard || fullscreenIndex !== null) document.body.style.overflow = 'hidden';
    else document.body.style.overflow = 'unset';
    return () => { document.body.style.overflow = 'unset'; };
  }, [activeCard, fullscreenIndex]);

  const gridClasses: Record<number, string> = {
    3: 'xl:grid-cols-3 lg:grid-cols-3 md:grid-cols-2 grid-cols-1',
    4: 'xl:grid-cols-4 lg:grid-cols-3 md:grid-cols-2 grid-cols-1',
    5: 'xl:grid-cols-5 lg:grid-cols-4 md:grid-cols-3 grid-cols-1',
    6: 'xl:grid-cols-6 lg:grid-cols-4 md:grid-cols-3 grid-cols-2',
    7: 'xl:grid-cols-7 lg:grid-cols-5 md:grid-cols-4 grid-cols-2',
    8: 'xl:grid-cols-8 lg:grid-cols-6 md:grid-cols-4 grid-cols-2',
  };

  const activeGridClass = gridClasses[maxCols] || gridClasses[5];

  const carouselItems: MediaItem[] = activeCard
    ? [
        ...(activeCard.imageUrl ? [{ url: activeCard.imageUrl }] : []),
        ...(activeCard.extraMedia || []),
      ]
    : [];

  return (
    <>
      <div className={`grid gap-4 ${activeGridClass}`}>
        {cards.map((card) => {
          const galleryCount = (card.extraMedia?.length || 0) + (card.imageUrl ? 1 : 0);
          return (
            <div
              key={card.id}
              onClick={() => setActiveCard(card)}
              className="group relative cursor-pointer overflow-hidden rounded-xl shadow-md aspect-square bg-gray-200 transition-all duration-300 hover:shadow-xl hover:-translate-y-1"
            >
              {card.imageUrl ? (
                <img src={card.imageUrl} alt={card.title} className="absolute inset-0 w-full h-full object-cover" />
              ) : (
                <div className="absolute inset-0 flex items-center justify-center bg-gradient-to-br from-blue-100 to-gray-200 text-gray-400">No Image</div>
              )}
              {galleryCount > 1 && (
                <div className="absolute top-2 right-2 bg-black/60 text-white text-xs font-semibold px-1.5 py-0.5 rounded-full flex items-center gap-1">
                  <span>⊞</span>
                  <span>{galleryCount}</span>
                </div>
              )}
              <div className="absolute inset-0 bg-gradient-to-t from-black/90 via-black/30 to-transparent flex flex-col justify-end p-5 text-white">
                <h3 className="text-xl font-bold drop-shadow-md">{card.title}</h3>
                <p className="text-sm opacity-0 group-hover:opacity-100 transition-opacity duration-300 line-clamp-2 mt-1 text-gray-200 drop-shadow">
                  {card.shortDescription}
                </p>
              </div>
            </div>
          );
        })}
      </div>

      {activeCard && (
        <div
          className="fixed inset-0 z-50 flex items-center justify-center bg-black/70 backdrop-blur-md p-4"
          onClick={() => setActiveCard(null)}
        >
          <div
            className="bg-white rounded-2xl w-full max-w-2xl max-h-[90vh] overflow-y-auto shadow-2xl animate-in fade-in zoom-in-95 duration-200"
            onClick={(e) => e.stopPropagation()}
          >
            <div className="relative">
              <MediaCarousel
                items={carouselItems}
                onImageClick={(i) => setFullscreenIndex(i)}
              />
              <button
                onClick={() => setActiveCard(null)}
                className="absolute top-4 right-4 bg-black/60 text-white w-10 h-10 flex items-center justify-center rounded-full hover:bg-black hover:scale-110 transition-all shadow-lg z-20"
                title="Close"
              >✕</button>
            </div>
            <div className="p-8">
              <div className="text-xs text-blue-600 font-bold tracking-wider uppercase mb-2">{activeCard.cardType.replace('_', ' ')}</div>
              <h2 className="text-3xl font-bold mb-4 text-gray-900">{activeCard.title}</h2>
              {activeCard.fullContent ? (
                <div className="prose max-w-none text-gray-700" dangerouslySetInnerHTML={{ __html: activeCard.fullContent }} />
              ) : (
                <p className="text-gray-500 italic text-lg">{activeCard.shortDescription}</p>
              )}
            </div>
          </div>
        </div>
      )}

      {fullscreenIndex !== null && activeCard && (
        <FullscreenViewer
          items={carouselItems}
          startIndex={fullscreenIndex}
          onClose={() => setFullscreenIndex(null)}
        />
      )}
    </>
  );
}
