'use client';

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

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

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

  // 如果没有attachments，不显示组件
  if (!data?.attachments || data.attachments.length === 0) {
    return null;
  }

  // 使用useMemo优化主图索引计算
  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]);

  // 使用useMemo优化当前图片URL
  const currentImage = useMemo(() => {
    return data.attachments[currentImageIndex]?.file_url || data.attachments[0]?.file_url;
  }, [data.attachments, currentImageIndex]);

  // 使用useCallback优化缩略图滚动函数
  const scrollThumbnailToIndex = useCallback((index) => {
    if (thumbsSwiperRef.current?.swiper) {
      try {
        const swiper = thumbsSwiperRef.current.swiper;
        
        if (index === 0) {
          // 第一张图片，滚动到最左侧
          swiper.scrollTo(0, 300);
        } else {
          // 其他图片使用原有的slideTo方法，保持正常滚动
          swiper.slideTo(index, 300);
        }
      } catch (error) {
        // 静默处理错误
      }
    }
  }, []);

  // 使用useCallback优化主图切换函数
  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);
    
    // 自动滚动缩略图到对应位置
    setTimeout(() => {
      scrollThumbnailToIndex(newIndex);
    }, 100);
  }, [currentImageIndex, data.attachments.length, scrollThumbnailToIndex]);

  // 使用useCallback优化按索引切换主图函数
  const changeMainImageByIndex = useCallback((index) => {
    setCurrentImageIndex(index);
    
    // 智能滚动缩略图到可见区域
    setTimeout(() => {
      scrollThumbnailToIndex(index);
    }, 100);
  }, [scrollThumbnailToIndex]);

  // 初始化当前索引为主图索引
  useEffect(() => {
    setCurrentImageIndex(mainImageIndex);
  }, [mainImageIndex]);

  // 键盘导航支持 - 使用useCallback优化
  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]);

  // 使用useMemo优化缩略图渲染
  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-blue-500 ring-2 ring-blue-200' 
              : 'border border-gray-200 hover:border-gray-300'
          }`}
          tabIndex={0}
          role="button"
          aria-label={`查看图片 ${index + 1} / ${data.attachments.length}`}
          onKeyDown={(e) => {
            if (e.key === 'Enter' || e.key === ' ') {
              e.preventDefault();
              changeMainImageByIndex(index);
            }
          }}
        >
          <img
            src={attachment.file_url}
            alt={`${data?.title || 'Product'} - ${index + 1}`}
            className="w-full h-full object-cover"
            loading="lazy"
            onError={(e) => {
              e.target.style.display = 'none';
            }}
          />
          {/* 缩略图加载状态指示 */}
          <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">
        {/* 主图显示区域 */}
        <div className="relative overflow-hidden rounded-xl shadow-lg mb-6 group/main-image">
          <img
            src={currentImage}
            alt={data?.title || 'Product Image'}
            className="w-full max-w-[320px] md:max-w-full object-contain"
            loading="lazy"
          />
          
          {/* 图片计数器 */}
          {data.attachments.length > 1 && (
            <div className="absolute bottom-3 right-3 bg-black/60 text-white text-xs px-2 py-1 rounded-full backdrop-blur-sm">
              {currentImageIndex + 1} / {data.attachments.length}
            </div>
          )}
          
          {/* 导航箭头 - 悬浮时显示 */}
          {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={`上一张图片 (${currentImageIndex === 0 ? data.attachments.length : currentImageIndex} / ${data.attachments.length})`}
                title="上一张图片 (←)"
              >
                <svg 
                  className="w-5 h-5 text-gray-700 hover:text-gray-900 transition-all duration-500 ease-out hover:scale-110" 
                  fill="none" 
                  stroke="currentColor" 
                  viewBox="0 0 24 24"
                  strokeWidth={1.5}
                  strokeLinecap="round"
                  strokeLinejoin="round"
                >
                  <path d="M15 18l-6-6 6-6" />
                </svg>
              </button>
              <button 
                className="absolute right-2 top-1/2 transform -translate-y-1/2 w-12 h-12 bg-white/40 backdrop-blur-md rounded-full border-0 flex items-center justify-center shadow-[0_8px_32px_rgba(0,0,0,0.08)] hover:bg-white/60 hover:shadow-[0_12px_40px_rgba(0,0,0,0.12)] transition-all duration-500 ease-out z-10 focus:outline-none focus:ring-2 focus:ring-white/30 focus:ring-offset-2 focus:ring-offset-transparent opacity-0 group-hover/main-image:opacity-100 scale-90 group-hover/main-image:scale-100"
                onClick={() => changeMainImage('next')}
                aria-label={`下一张图片 (${currentImageIndex === data.attachments.length - 1 ? 1 : currentImageIndex + 2} / ${data.attachments.length})`}
                title="下一张图片 (→)"
              >
                <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>
        
        {/* 缩略图列表 - 使用Swiper实现最佳滚动效果 */}
        {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>

      {/* 内联样式 */}
      <style jsx>{`
        /* 缩略图悬停效果 */
        .thumbs-swiper .swiper-slide {
          transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
          width: 64px !important; /* 确保宽度为64px */
          margin-right: 16px !important; /* 确保右边距为16px */
        }
        
        .thumbs-swiper .swiper-slide:hover {
          transform: scale(1.05);
        }
        
        .thumbs-swiper .swiper-slide:last-child {
          margin-right: 0 !important; /* 最后一个缩略图不需要右边距 */
        }
        
        /* 当前选中的缩略图样式 */
        .border-2.border-blue-500 {
          border-color: #3b82f6;
        }
        
        .ring-2.ring-blue-200 {
          box-shadow: 0 0 0 2px rgba(191, 219, 254, 0.5);
        }
        
        /* 导航按钮样式增强 */
        .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);
        }
        
        /* 响应式优化 */
        @media (max-width: 768px) {
          .thumbs-swiper .swiper-slide {
            width: 4rem !important;
            height: 4rem !important;
          }
        }
        
        /* 隐藏Swiper默认滚动条 */
        .thumbs-swiper .swiper-scrollbar {
          display: none;
        }
        
        /* 优化Swiper滑动体验 */
        .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;
        }
        
        /* 加载状态动画 */
        @keyframes spin {
          to {
            transform: rotate(360deg);
          }
        }
        
        .animate-spin {
          animation: spin 1s linear infinite;
        }
        
        /* 焦点状态优化 */
        .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;
        }
        
        /* 触摸设备优化 */
        @media (hover: none) and (pointer: coarse) {
          .thumbs-swiper .swiper-slide:hover {
            transform: none;
          }
        }
        
        /* 强制导航箭头为圆形 */
        .group\/main-image button {
          border-radius: 50% !important;
          -webkit-border-radius: 50% !important;
        }
        
        /* 高对比度模式支持 */
        @media (prefers-contrast: high) {
          .border-gray-200 {
            border-color: #000;
          }
          
          .border-blue-500 {
            border-color: #0066cc;
          }
          
          .text-gray-600 {
            color: #000;
          }
        }
        
        /* 减少动画偏好 */
        @media (prefers-reduced-motion: reduce) {
          .thumbs-swiper .swiper-slide,
          .backdrop-blur-sm {
            transition: none;
          }
          
          .animate-spin {
            animation: none;
          }
        }
      `}</style>
    </div>
  );
};

export default ProductImageGallery;