'use client';

import { useState, useEffect, useRef, useCallback, useMemo } from 'react';
import { Swiper, SwiperSlide } from "swiper/react";
import { Navigation, Pagination, Thumbs, FreeMode } from "swiper/modules";

import "swiper/css";
import "swiper/css/navigation";
import "swiper/css/pagination";
import "swiper/css/thumbs";
import "swiper/css/free-mode";

const ImageWithRetry = ({ src, alt, className }) => {
  const [imageSrc, setImageSrc] = useState(src);
  const retryCountRef = useRef(0);

  useEffect(() => {
    setImageSrc(src);
    retryCountRef.current = 0;
  }, [src]);

  const handleError = useCallback(() => {
    if (retryCountRef.current >= 3) return;
    retryCountRef.current += 1;
    const delay = 300 * retryCountRef.current;
    setTimeout(() => {
      const url = new URL(imageSrc, typeof window !== 'undefined' ? window.location.origin : 'http://localhost');
      url.searchParams.set('v', String(Date.now()));
      setImageSrc(url.pathname + url.search);
    }, delay);
  }, [imageSrc]);

  return (
    <img
      src={imageSrc}
      alt={alt}
      className={className}
      loading="lazy"
      onError={handleError}
    />
  );
};

const ProductImageGallery = ({ data }) => {
  const [currentImageIndex, setCurrentImageIndex] = useState(0);
  const [thumbsSwiper, setThumbsSwiper] = useState(null);
  const thumbsSwiperRef = useRef(null);

  if (!data?.attachments || data.attachments.length === 0) {
    return null;
  }

  const mainImageIndex = useMemo(() => {
    if (!data.image) return 0;
    
    const mainImageIndex = data.attachments.findIndex(
      attachment => attachment.file_url === data.image
    );
    
    return mainImageIndex >= 0 ? mainImageIndex : 0;
  }, [data.image, data.attachments]);

  const currentImage = useMemo(() => {
    return data.attachments[currentImageIndex]?.file_url || data.attachments[0]?.file_url;
  }, [data.attachments, currentImageIndex]);

  const scrollThumbnailToIndex = useCallback((index) => {
    if (thumbsSwiperRef.current?.swiper) {
      try {
        const swiper = thumbsSwiperRef.current.swiper;
        
        if (index === 0) {
          swiper.scrollTo(0, 300);
        } else {
          swiper.slideTo(index, 300);
        }
      } catch (error) {
      }
    }
  }, []);

  const changeMainImage = useCallback((direction) => {
    if (data.attachments.length <= 1) return;
    
    let newIndex;
    if (direction === 'next') {
      newIndex = (currentImageIndex + 1) % data.attachments.length;
    } else {
      newIndex = (currentImageIndex - 1 + data.attachments.length) % data.attachments.length;
    }
    
    setCurrentImageIndex(newIndex);
    
    setTimeout(() => {
      scrollThumbnailToIndex(newIndex);
    }, 100);
  }, [currentImageIndex, data.attachments.length, scrollThumbnailToIndex]);

  const changeMainImageByIndex = useCallback((index) => {
    setCurrentImageIndex(index);
    
    setTimeout(() => {
      scrollThumbnailToIndex(index);
    }, 100);
  }, [scrollThumbnailToIndex]);

  useEffect(() => {
    setCurrentImageIndex(mainImageIndex);
  }, [mainImageIndex]);

  const handleKeyDown = useCallback((event) => {
    if (data.attachments.length <= 1) return;
    
    switch (event.key) {
      case 'ArrowLeft':
        event.preventDefault();
        changeMainImage('prev');
        break;
      case 'ArrowRight':
        event.preventDefault();
        changeMainImage('next');
        break;
      case 'Home':
        event.preventDefault();
        setCurrentImageIndex(0);
        setTimeout(() => scrollThumbnailToIndex(0), 100);
        break;
      case 'End':
        event.preventDefault();
        setCurrentImageIndex(data.attachments.length - 1);
        setTimeout(() => scrollThumbnailToIndex(data.attachments.length - 1), 100);
        break;
      default:
        break;
    }
  }, [data.attachments.length, changeMainImage, scrollThumbnailToIndex]);

  useEffect(() => {
    document.addEventListener('keydown', handleKeyDown);
    
    return () => {
      document.removeEventListener('keydown', handleKeyDown);
    };
  }, [handleKeyDown]);

  const thumbnailSlides = useMemo(() => {
    return data.attachments.map((attachment, index) => (
      <SwiperSlide 
        key={index}
        className="!w-16 !h-16"
        onClick={() => changeMainImageByIndex(index)}
      >
        <div 
          className={`w-full h-full rounded-lg overflow-hidden cursor-pointer transition-all duration-300 hover:scale-105 focus-within:ring-2 focus-within:ring-blue-500 focus-within:ring-offset-2 ${
            index === currentImageIndex 
              ? 'border-2' 
              : 'border border-[#eee] hover:border-gray-300'
          }`}
          style={index === currentImageIndex ? { borderColor: '#1A1A1A', borderWidth: '2px' } : {}}
          tabIndex={0}
          role="button"
          aria-label={`View image ${index + 1} / ${data.attachments.length}`}
          onKeyDown={(e) => {
            if (e.key === 'Enter' || e.key === ' ') {
              e.preventDefault();
              changeMainImageByIndex(index);
            }
          }}
        >
          <ImageWithRetry
            src={attachment.file_url}
            alt={`${data?.title || 'Product'} - ${index + 1}`}
            className="w-full h-full object-cover"
          />
          <div className="absolute inset-0 bg-gray-100 flex items-center justify-center opacity-0 group-hover:opacity-100 transition-opacity duration-200">
            <div className="w-4 h-4 border-2 border-gray-300 border-t-blue-500 rounded-full animate-spin"></div>
          </div>
        </div>
      </SwiperSlide>
    ));
  }, [data.attachments, currentImageIndex, data?.title, changeMainImageByIndex]);

  return (
    <div className="w-full md:w-120 flex justify-center md:justify-start mb-4 md:mb-0 max-w-full">
      <div className="relative w-full max-w-[320px] md:max-w-full">
        <div className="relative overflow-hidden rounded-xl shadow-lg mb-6 group/main-image">
          <ImageWithRetry
            src={currentImage}
            alt={data?.title || 'Product Image'}
            className="w-full max-w-[320px] md:max-w-full object-contain"
          />
          
          {data.attachments.length > 1 && (
            <>
              <button 
                className="absolute left-2 top-1/2 transform -translate-y-1/2 w-12 h-12 bg-white/40 backdrop-blur-md rounded-full border-0 flex items-center justify-center shadow-[0_8px_32px_rgba(0,0,0,0.08)] hover:bg-white/60 hover:shadow-[0_12px_40px_rgba(0,0,0,0.12)] transition-all duration-500 ease-out z-10 focus:outline-none focus:ring-2 focus:ring-white/30 focus:ring-offset-2 focus:ring-offset-transparent opacity-0 group-hover/main-image:opacity-100 scale-90 group-hover/main-image:scale-100"
                onClick={() => changeMainImage('prev')}
                aria-label={`Previous image (${currentImageIndex === 0 ? data.attachments.length : currentImageIndex} / ${data.attachments.length})`}
                title="Previous image (←)"
              >
                <svg 
                  className="w-5 h-5 text-gray-700 hover:text-gray-900 transition-all duration-500 ease-out hover:scale-110" 
                  fill="none" 
                  stroke="currentColor" 
                  viewBox="0 0 24 24"
                  strokeWidth={1.5}
                  strokeLinecap="round"
                  strokeLinejoin="round"
                >
                  <path d="M15 18l-6-6 6-6" />
                </svg>
              </button>
              <button 
                className="absolute right-2 top-1/2 transform -translate-y-1/2 w-12 h-12 bg-white/40 backdrop-blur-md rounded-full border-0 flex items-center justify-center shadow-[0_8px_32px_rgba(0,0,0,0.08)] hover:bg-white/60 hover:shadow-[0_12px_40px_rgba(0,0,0,0.12)] transition-all duration-500 ease-out z-10 focus:outline-none focus:ring-2 focus:ring-white/30 focus:ring-offset-2 focus:ring-offset-transparent opacity-0 group-hover/main-image:opacity-100 scale-90 group-hover/main-image:scale-100"
                onClick={() => changeMainImage('next')}
                aria-label={`Next image (${currentImageIndex === data.attachments.length - 1 ? 1 : currentImageIndex + 2} / ${data.attachments.length})`}
                title="Next image (→)"
              >
                <svg 
                  className="w-5 h-5 text-gray-700 hover:text-gray-900 transition-all duration-500 ease-out hover:scale-110" 
                  fill="none" 
                  stroke="currentColor" 
                  viewBox="0 0 24 24"
                  strokeWidth={1.5}
                  strokeLinecap="round"
                  strokeLinejoin="round"
                >
                  <path d="M9 18l6-6-6-6" />
                </svg>
              </button>
            </>
          )}
        </div>
        
        {data.attachments.length > 1 && (
          <div className="relative">
            <Swiper
              ref={thumbsSwiperRef}
              onSwiper={setThumbsSwiper}
              spaceBetween={16}
              slidesPerView="auto"
              freeMode={true}
              watchSlidesProgress={true}
              modules={[FreeMode, Navigation, Pagination, Thumbs]}
              className="thumbs-swiper"
              grabCursor={true}
              resistance={true}
              resistanceRatio={0.85}
            >
              {thumbnailSlides}
            </Swiper>
          </div>
        )}
      </div>

      <style jsx>{`
        .thumbs-swiper .swiper-slide {
          transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
          width: 64px !important;
          margin-right: 16px !important;
        }
        
        .thumbs-swiper .swiper-slide:hover {
          transform: scale(1.05);
        }
        
        .thumbs-swiper .swiper-slide:last-child {
          margin-right: 0 !important;
        }
        
        .thumbs-swiper .swiper-slide .border-2 {
        }
        
        .backdrop-blur-sm {
          backdrop-filter: blur(8px);
          -webkit-backdrop-filter: blur(8px);
        }
        
        .group:hover .backdrop-blur-sm {
          backdrop-filter: blur(12px);
          -webkit-backdrop-filter: blur(12px);
        }
        
        @media (max-width: 768px) {
          .thumbs-swiper .swiper-slide {
            width: 4rem !important;
            height: 4rem !important;
          }
        }
        
        .thumbs-swiper .swiper-scrollbar {
          display: none;
        }
        
        .thumbs-swiper {
          touch-action: pan-y pinch-zoom;
          -webkit-user-select: none;
          -moz-user-select: none;
          -ms-user-select: none;
          user-select: none;
        }
        
        .thumbs-swiper .swiper-slide {
          touch-action: manipulation;
        }
        
        @keyframes spin {
          to {
            transform: rotate(360deg);
          }
        }
        
        .animate-spin {
          animation: spin 1s linear infinite;
        }
        
        .focus-within\\:ring-2:focus-within {
          --tw-ring-offset-shadow: var(--tw-ring-inset) 0 0 0 var(--tw-ring-offset-width) var(--tw-ring-offset-color);
          --tw-ring-shadow: var(--tw-ring-inset) 0 0 0 calc(2px + var(--tw-ring-offset-width)) var(--tw-ring-color);
          box-shadow: var(--tw-ring-offset-shadow), var(--tw-ring-shadow), var(--tw-shadow, 0 0 #0000);
        }
        
        .focus-within\\:ring-blue-500:focus-within {
          --tw-ring-opacity: 1;
          --tw-ring-color: rgb(59 130 246 / var(--tw-ring-opacity));
        }
        
        .focus-within\\:ring-offset-2:focus-within {
          --tw-ring-offset-width: 2px;
        }
        
        @media (hover: none) and (pointer: coarse) {
          .thumbs-swiper .swiper-slide:hover {
            transform: none;
          }
        }
        
        .group\/main-image button {
          border-radius: 50% !important;
          -webkit-border-radius: 50% !important;
        }
        
        @media (prefers-contrast: high) {
          .border-gray-200 {
            border-color: #000;
          }
          
          .border-blue-500 {
            border-color: #0066cc;
          }
          
          .text-gray-600 {
            color: #000;
          }
        }
        
        @media (prefers-reduced-motion: reduce) {
          .thumbs-swiper .swiper-slide,
          .backdrop-blur-sm {
            transition: none;
          }
          
          .animate-spin {
            animation: none;
          }
        }
      `}</style>
    </div>
  );
};

export default ProductImageGallery;