"use client";
import { useState, useEffect } from "react";
import { Swiper, SwiperSlide } from "swiper/react";
import { Navigation, Pagination, Grid } from "swiper/modules";
import Link from "next/link";
import Image from "next/image";
import PropTypes from "prop-types";

// This is now a "dumb" component. It receives all data via props and is only
// responsible for rendering the UI. All data fetching logic has been moved
// to the parent server component.
export default function SwiperItemsUI({ data, items, ...props }) {
  const [isMounted, setIsMounted] = useState(false);

  useEffect(() => {
    // This effect runs only on the client, after the component has mounted.
    setIsMounted(true);
  }, []);

  // Field mapping from data, with props as fallback.
  const title = data?.title || props.title;
  const subtitle = data?.subtitle || props.subtitle;
  const category_slug = data?.t3 || props.category_slug || "";
  const columns = data?.t5 || props.columns || 4;
  const button_text = data?.button_text || props.button_text || "查看详情";
  const rows = (data?.p1 && !isNaN(Number(data.p1))) ? Number(data.p1) : (props.rows || 1);

  // Loading and error states are now handled by the server component and React Suspense.
  // We only need to handle the case where there are no items to show.
  if (!items || items.length === 0) {
    return (
        <div className="w-full max-w-full mx-auto my-[150px] px-4 sm:px-6 md:px-8 xl:w-10/12 xl:px-0">
            {(title || subtitle) && (
            <div className="relative z-20 text-center mb-10 select-text">
                {title && <h2 className="text-3xl font-bold mb-2">{title}</h2>}
                {subtitle && <p className="text-lg text-gray-500">{subtitle}</p>}
            </div>
            )}
            <div className="text-center py-12 text-gray-400">暂无数据</div>
        </div>
    );
  }

  // Helper functions for rendering. They are pure and belong with the UI.
  function renderCardImage(post, idx) {
    // 多图轮播
    if (Array.isArray(post.images) && post.images.length > 1) {
      return (
        <Swiper
          className="swiper"
          modules={[Navigation, Pagination]}
          pagination={{ clickable: true, el: `.spdb${idx}` }}
          navigation={{ prevEl: `.snbpb${idx}`, nextEl: `.snbnb${idx}` }}
        >
          {post.images.map((img, i) => (
            <SwiperSlide key={i} className="swiper-slide">
              <Image
                className="!transition-all !duration-[0.35s] !ease-in-out group-hover:scale-105 w-full h-auto"
                alt={post.title || "image"}
                src={img}
                width={960}
                height={600}
              />
            </SwiperSlide>
          ))}
        </Swiper>
      );
    }
    // 视频
    if (post.video_src || post.videoId) {
      if (post.video_src && (post.video_src.endsWith('.mp4') || post.video_src.startsWith('/files/'))) {
        return (
          <video controls className="w-full h-56 rounded-xl object-cover">
            <source src={post.video_src} type="video/mp4" />
            您的浏览器不支持视频播放。
          </video>
        );
      }
      const vid = post.videoId || (post.video_src && post.video_src.includes('youtube') ? post.video_src.split('embed/')[1] : null);
      if (vid) {
        return (
          <iframe
            className="w-full h-56 rounded-xl"
            src={`https://www.youtube.com/embed/${vid}`}
            title="YouTube video"
            allow="accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture"
            allowFullScreen
          />
        );
      }
    }
    // 单图
    const img = post.image || (Array.isArray(post.images) && post.images[0]);
    if (img) {
      return (
        <Image
          className="!transition-all !duration-[0.35s] !ease-in-out group-hover:scale-105 w-full h-auto"
          alt={post.title || "image"}
          src={img}
          width={960}
          height={600}
        />
      );
    }
    return null;
  }

  function getSummary(text, maxLen = 58) {
    if (!text) return "";
    // 中文：直接按字符截断
    if (/[\u4e00-\u9fa5]/.test(text)) {
      return text.length > maxLen ? text.slice(0, maxLen) + "..." : text;
    }
    // 英文：按字符截断，但不截断单词
    if (text.length <= maxLen) return text;
    let cut = text.slice(0, maxLen);
    // 如果最后一个字符不是空格，向前找到最近的空格
    if (!/\s/.test(text[maxLen])) {
      const lastSpace = cut.lastIndexOf(" ");
      if (lastSpace > 0) cut = cut.slice(0, lastSpace);
    }
    return cut + "...";
  }

  // 日期格式化函数，支持自定义是否显示时分秒
  function formatDate(dateStr, options = {}) {
    if (!dateStr) return "";
    const d = new Date(dateStr);
    if (isNaN(d.getTime())) return dateStr;
    const { showTime = false } = options;
    const yyyy = d.getFullYear();
    const mm = String(d.getMonth() + 1).padStart(2, '0');
    const dd = String(d.getDate()).padStart(2, '0');
    let result = `${yyyy}-${mm}-${dd}`;
    if (showTime) {
      const hh = String(d.getHours()).padStart(2, '0');
      const min = String(d.getMinutes()).padStart(2, '0');
      const ss = String(d.getSeconds()).padStart(2, '0');
      result += ` ${hh}:${min}:${ss}`;
    }
    return result;
  }

  // By default, the component is rendered with opacity-0. 
  // Once the client-side JS loads and the component mounts, isMounted becomes true,
  // and the component smoothly fades in, preventing any layout flash.
  const containerClasses = `
    w-full max-w-full mx-auto my-[150px] px-4 sm:px-6 md:px-8 xl:w-10/12 xl:px-0
    transition-opacity duration-500 ease-in-out
    ${isMounted ? 'opacity-100' : 'opacity-0'}
  `;

  return (
    <div className={containerClasses}>
      {/* 新增模块标题和副标题显示 */}
      {(title || subtitle) && (
        <div className="relative z-20 text-center mb-10 select-text">
          {title && <h2 className="text-3xl font-bold mb-2">{title}</h2>}
          {subtitle && <p className="text-lg text-gray-500">{subtitle}</p>}
        </div>
      )}
      <div className="swiper-container blog classic-view !mb-[7rem] xl:!mb-[10rem] lg:!mb-[10rem] md:!mb-[10rem]">
        <div className="relative">
          <Swiper
            className="swiper w-full"
            modules={[Navigation, Pagination, Grid]}
            spaceBetween={16}
            slidesPerView={columns}
            slidesPerGroup={columns * rows}
            grid={{ rows }}
            pagination={{ clickable: true, el: ".spdb15" }}
            navigation={{ 
              prevEl: '.swiper-nav-prev-swiperitems', 
              nextEl: '.swiper-nav-next-swiperitems' 
            }}
            breakpoints={{
              0: { slidesPerView: 1, slidesPerGroup: 1, grid: { rows: 1 } },
              575: { slidesPerView: 1, slidesPerGroup: 1, grid: { rows: 1 } },
              768: { slidesPerView: 2, slidesPerGroup: 2, grid: { rows: rows > 1 ? 2 : 1 } },
              992: { slidesPerView: columns, slidesPerGroup: columns * rows, grid: { rows } },
            }}
          >
            {items.map((post, idx) => (
              <SwiperSlide key={post.slug || post.id || idx} className="swiper-slide">
                <article className="post !mb-8">
                  <div className="card">
                    {/* 图片/轮播/视频部分 */}
                    <figure className="card-img-top overlay overlay-1 hover-scale group">
                      <Link href={post.slug ? `/${category_slug}/${post.slug}` : "#"} className="block relative">
                        {renderCardImage(post, idx)}
                        <span className="bg"></span>
                        <figcaption className="group-hover:opacity-100 absolute w-full h-full opacity-0 text-center px-4 py-3 inset-0 z-[5] pointer-events-none p-2">
                          <h5 className="from-top !mb-0 absolute w-full translate-y-[-80%] p-[.75rem_1rem] left-0 top-2/4">
                            {button_text}
                          </h5>
                        </figcaption>
                      </Link>
                    </figure>
                    {/* 文字内容 */}
                    <div className="card-body flex-[1_1_auto] p-[40px] xl:!p-[2rem_2.5rem_1.25rem] lg:!p-[2rem_2.5rem_1.25rem] md:!p-[2rem_2.5rem_1.25rem] max-md:pb-4">
                      <div className="post-header !mb-[.9rem]">
                        <div className="inline-flex !mb-[.4rem] uppercase !tracking-[0.02rem] text-[0.7rem] font-bold !text-[#aab0bc] relative align-top !pl-[1.4rem] before:content-[''] before:absolute before:inline-block before:translate-y-[-60%] before:w-3 before:h-[0.05rem] before:left-0 before:top-2/4 before:bg-[#1fc76f]">
                          {post.additional_title || ""}
                        </div>
                        <h2 className="post-title !mt-1 !leading-[1.35] !mb-0 text-base md:!text-[0.85rem]">
                          <Link
                            className="!text-[#333333] hover:!text-[#1fc76f]"
                            href={post.slug ? `/${category_slug}/${post.slug}` : "#"}
                          >
                            {post.title}
                          </Link>
                        </h2>
                      </div>
                      <div className="!relative !text-[0.7rem]">
                        <p>{getSummary(post.subtitle)}</p>
                      </div>
                    </div>
                  </div>
                </article>
              </SwiperSlide>
            ))}
          </Swiper>
          {/* 美化后的导航按钮 */}
          <button
            className="swiper-nav-prev-swiperitems absolute left-[-32px] top-1/2 z-20 -translate-y-1/2 w-10 h-10 flex items-center justify-center !rounded-full border-2 border-[#e5e7eb] bg-transparent transition-all duration-200 hover:border-[#1fc76f] group"
            style={{ color: '#b0b7c3' }}
            aria-label="上一页"
          >
            <svg width="22" height="22" viewBox="0 0 24 24" fill="none">
              <path d="M15.5 19L9.5 12L15.5 5" stroke="currentColor" strokeWidth="1.8" strokeLinecap="round" strokeLinejoin="round" className="transition-all duration-200 group-hover:stroke-[#1fc76f]"/>
            </svg>
          </button>
          <button
            className="swiper-nav-next-swiperitems absolute right-[-32px] top-1/2 z-20 -translate-y-1/2 w-10 h-10 flex items-center justify-center !rounded-full border-2 border-[#e5e7eb] bg-transparent transition-all duration-200 hover:border-[#1fc76f] group"
            style={{ color: '#b0b7c3' }}
            aria-label="下一页"
          >
            <svg width="22" height="22" viewBox="0 0 24 24" fill="none">
              <path d="M8.5 5L14.5 12L8.5 19" stroke="currentColor" strokeWidth="1.8" strokeLinecap="round" strokeLinejoin="round" className="transition-all duration-200 group-hover:stroke-[#1fc76f]"/>
            </svg>
          </button>
        </div>
        <div className="swiper-controls">
          <div className="swiper-pagination spdb15"></div>
        </div>
      </div>
    </div>
  );
}

SwiperItemsUI.propTypes = {
  data: PropTypes.object,
  items: PropTypes.array,
  pagetype: PropTypes.string,
  category: PropTypes.string,
  count: PropTypes.oneOfType([
    PropTypes.string,
    PropTypes.number
  ]),
  columns: PropTypes.number,
  category_slug: PropTypes.string,
  rows: PropTypes.number,
}; 