/**
 * AI 资讯（文章）模块共用逻辑
 *
 * 栏目与路由完全沿用原 PC 站，保证 SEO 不断链：
 *   col_id 1 前沿资讯 → /info/new      详情 /info/new/{id}.html
 *   col_id 2 使用教程 → /info/course   详情 /info/course/{id}.html
 *   col_id 3 AI 问答  → /info/what     详情 /info/what/{id}.html
 *   标签页 → /info/tag/{key}
 *   资讯首页（全部） → /info
 */
import dayjs from 'dayjs'
import {
  LEGACY_DEFAULT_DESCRIPTION,
  LEGACY_DEFAULT_KEYWORDS,
  legacyPageTitle,
} from '~/composables/useLegacySeo'

/** 栏目定义 */
export const COLUMNS = [
  { colId: 1, key: 'new', name: '前沿资讯', path: '/info/new', icon: 'i-lucide-newspaper' },
  { colId: 2, key: 'course', name: '使用教程', path: '/info/course', icon: 'i-lucide-graduation-cap' },
  { colId: 3, key: 'what', name: 'AI 问答', path: '/info/what', icon: 'i-lucide-circle-help' },
]

/** col_id → 详情 URL（保留 .html 后缀，与原站一致） */
export function articleUrl(item) {
  const col = COLUMNS.find(c => c.colId === Number(item?.col_id)) || COLUMNS[0]
  return `${col.path}/${item.id}.html`
}

/** col_id → 栏目名 */
export function colName(colId) {
  return COLUMNS.find(c => c.colId === Number(colId))?.name || '资讯'
}

/** col_id → 栏目列表页路径 */
export function colPath(colId) {
  return COLUMNS.find(c => c.colId === Number(colId))?.path || '/info'
}

/** 列表分页 URL（沿用原站：/info2、/info/new2、/info/tag/key-2.html） */
export function pageUrl(basePath, page, tagKey) {
  if (tagKey) return page > 1 ? `/info/tag/${tagKey}-${page}.html` : `/info/tag/${tagKey}.html`
  return page > 1 ? `${basePath}${page}` : basePath
}

/** 秒级时间戳格式化 */
export function formatTime(value, fmt = 'YYYY-MM-DD HH:mm') {
  if (!value) return ''
  return dayjs(Number(value) * 1000).format(fmt)
}

/** 从路由参数中取出文章 id（去掉 .html 后缀） */
export function parseArticleId(param) {
  return String(param || '').replace(/\.html$/i, '')
}

/**
 * 资讯页共用数据：列表 + 热门排行 + 热门标签
 * 用 useAsyncData 做 SSR，保证爬虫可直接抓到内容
 */
export function useArticleData(options) {
  const { key, colId, tagKey, page, pageSize = 10, isRecommend } = options
  const { post } = useApi()

  return useAsyncData(
    key,
    async () => {
      const listParams = { page_no: unref(page) || 1, page_size: pageSize }
      if (colId) listParams.col_id = colId
      if (tagKey) listParams.tag_key = unref(tagKey)
      if (isRecommend) listParams.is_recommend = 1

      const [listRes, hotRes, tagRes] = await Promise.all([
        post('/article/getlist', listParams).catch(() => ({ list: [], data: {} })),
        post('/article/gethotlist', { page_no: 1, page_size: 10 }).catch(() => ({ list: [] })),
        post('/article/gettaglist', { is_hot: 1, page_size: 20 }).catch(() => ({ list: [] })),
      ])

      return {
        list: (listRes.list || []).map(i => ({ ...i, url: articleUrl(i), time: formatTime(i.publish_time) })),
        total: Number(listRes.data?.total || 0),
        tagName: listRes.data?.tag_name || '',
        hotList: (hotRes.list || []).map((i, idx) => ({ ...i, rank: idx + 1, url: articleUrl(i) })),
        tagList: tagRes.list || [],
      }
    },
    { watch: [page, tagKey].filter(Boolean) },
  )
}

/**
 * 文章详情共用数据（SSR），并统一处理 SEO
 * @param {number} colId 当前栏目（用于校验路由与文章栏目是否一致）
 */
export async function useArticleDetail(colId) {
  const route = useRoute()
  const nuxtApp = useNuxtApp()
  const { post } = useApi()
  const id = parseArticleId(route.params.id)

  const asyncData = await useAsyncData(`article-${id}`, async () => {
    const [detailRes, hotRes, tagRes] = await Promise.all([
      post('/article/getdetail', { id, prev_next: 1 }),
      post('/article/gethotlist', { page_no: 1, page_size: 10 }).catch(() => ({ list: [] })),
      post('/article/gettaglist', { is_hot: 1, page_size: 20 }).catch(() => ({ list: [] })),
    ])
    return {
      detail: detailRes.data || {},
      hotList: (hotRes.list || []).map((i, idx) => ({ ...i, rank: idx + 1, url: articleUrl(i) })),
      tagList: tagRes.list || [],
    }
  })

  const { data, error } = asyncData
  const detail = computed(() => data.value?.detail || {})
  const canonical = computed(() => `https://tool.aionline.cc${articleUrl(detail.value)}`)

  if (error.value) {
    console.error('[article:ssr] load detail failed', {
      id,
      colId,
      message: error.value.message,
      code: error.value.code || error.value.statusCode,
      cause: error.value.cause?.message,
    })
    throw createError({
      statusCode: 502,
      message: '文章加载失败，请稍后重试',
      fatal: true,
      cause: error.value,
    })
  }

  // 仅接口成功但确实没有数据时返回 404，避免把网络异常误判为文章不存在。
  if (!data.value?.detail?.id) {
    throw createError({ statusCode: 404, message: '文章不存在', fatal: true })
  }

  await nuxtApp.runWithContext(() => {
    useSeoMeta({
      title: () => legacyPageTitle(detail.value.title),
      description: () => detail.value.info || LEGACY_DEFAULT_DESCRIPTION,
      keywords: () => detail.value.title || LEGACY_DEFAULT_KEYWORDS,
      ogTitle: () => detail.value.title,
      ogDescription: () => detail.value.info || detail.value.title,
      ogType: 'article',
      ogImage: () => detail.value.cover || '',
      articlePublishedTime: () => formatTime(detail.value.publish_time, 'YYYY-MM-DDTHH:mm:ssZ'),
    })

    useHead({
      link: [{ rel: 'canonical', href: canonical }],
      // 结构化数据，利于搜索结果富摘要
      script: [{
        type: 'application/ld+json',
        innerHTML: computed(() => JSON.stringify({
          '@context': 'https://schema.org',
          '@type': 'Article',
          headline: detail.value.title,
          description: detail.value.info || '',
          image: detail.value.cover ? [detail.value.cover] : undefined,
          datePublished: formatTime(detail.value.publish_time, 'YYYY-MM-DD'),
          author: { '@type': 'Organization', name: 'AI在线' },
          publisher: { '@type': 'Organization', name: 'AI在线' },
          mainEntityOfPage: { '@type': 'WebPage', '@id': canonical.value },
        })),
      }],
    })
  })

  // 访问的栏目路径与文章实际栏目不一致 → 301 到规范地址（避免重复内容）
  if (colId && Number(detail.value.col_id) !== Number(colId)) {
    await nuxtApp.runWithContext(() =>
      navigateTo(articleUrl(detail.value), { redirectCode: 301, replace: true }))
  }

  return { data, detail }
}