import { useState, useMemo, useEffect } from 'react'
import Taro from '@tarojs/taro'
import { View, Text, ScrollView } from '@tarojs/components'
import { Search, Tag } from '@antmjs/vantui'
import { shops } from '@/mock/shops'
import { forumPosts } from '@/mock/forum'
import ShopCard from '@/components/ShopCard'
import ForumPostCard from '@/components/ForumPostCard'
import type { Article } from '@/types/article'
import type { Shop } from '@/types/shop'
import './index.less'

/** 状态栏 + 导航栏高度 */
function getNavBarHeight() {
  try {
    const sys = Taro.getSystemInfoSync()
    return { statusBarHeight: sys.statusBarHeight || 20, navBarHeight: 44 }
  } catch {
    return { statusBarHeight: 20, navBarHeight: 44 }
  }
}

/** 搜索结果项的联合类型 */
type SearchResult =
  | { kind: 'shop'; data: Shop }
  | { kind: 'post'; data: Article }

export default function SearchPage() {
  const [keyword, setKeyword] = useState('')
  const [submittedKeyword, setSubmittedKeyword] = useState('')
  const [history, setHistory] = useState<string[]>(['麻辣烫', '二手 iPad', '考研资料'])
  const [navBarHeight, setNavBarHeight] = useState({ statusBarHeight: 20, navBarHeight: 44 })

  useEffect(() => {
    setNavBarHeight(getNavBarHeight())
  }, [])

  /** 热门搜索 */
  const hotKeywords = ['麻辣烫', '奶茶', '二手 iPad', '考研资料', '黄焖鸡', '失物招领', '六级', '外卖红包']

  /** 执行搜索（综合匹配商家和帖子） */
  const results = useMemo<SearchResult[]>(() => {
    if (!submittedKeyword.trim()) return []
    const kw = submittedKeyword.toLowerCase().trim()

    const matchedShops: Shop[] = shops.filter(
      (s) =>
        s.name.toLowerCase().includes(kw) ||
        s.description.toLowerCase().includes(kw) ||
        s.tags.some((t) => t.toLowerCase().includes(kw)),
    )

    const matchedPosts: Article[] = forumPosts.filter(
      (p) =>
        p.title.toLowerCase().includes(kw) ||
        p.excerpt.toLowerCase().includes(kw) ||
        p.source.toLowerCase().includes(kw),
    )

    return [
      ...matchedShops.map((s) => ({ kind: 'shop' as const, data: s })),
      ...matchedPosts.map((p) => ({ kind: 'post' as const, data: p })),
    ]
  }, [submittedKeyword])

  /** 返回 */
  const handleBack = () => {
    Taro.navigateBack()
  }

  /** 点击搜索 */
  const handleSearch = () => {
    const kw = keyword.trim()
    if (!kw) {
      Taro.showToast({ title: '请输入搜索关键词', icon: 'none' })
      return
    }
    setSubmittedKeyword(kw)
    // 保存到历史（去重，最多 8 条）
    setHistory((prev) => {
      const next = [kw, ...prev.filter((h) => h !== kw)]
      return next.slice(0, 8)
    })
  }

  /** 点击历史/热门 */
  const handleQuickKeyword = (kw: string) => {
    setKeyword(kw)
    setSubmittedKeyword(kw)
    setHistory((prev) => {
      const next = [kw, ...prev.filter((h) => h !== kw)]
      return next.slice(0, 8)
    })
  }

  /** 清空历史 */
  const handleClearHistory = () => {
    setHistory([])
  }

  /** 商家点击 */
  const handleShopClick = (shop: Shop) => {
    Taro.navigateTo({ url: `/pages/shop-detail/index?id=${shop.id}` })
  }

  /** 帖子点击 */
  const handlePostClick = (post: Article) => {
    Taro.navigateTo({ url: `/pages/article/index?id=${post.id}` })
  }

  return (
    <View className='search-page'>
      {/* ========== 自定义导航栏（带返回 + 搜索框 + 搜索按钮） ========== */}
      <View
        className='custom-navbar'
        style={{ paddingTop: `${navBarHeight.statusBarHeight}px` }}
      >
        <View
          className='navbar-content'
          style={{ height: `${navBarHeight.navBarHeight}px` }}
        >
          <View className='navbar-back' onClick={handleBack}>
            <Text className='back-icon'>‹</Text>
          </View>
          <View className='navbar-search'>
            <Search
              value={keyword}
              placeholder='搜索商家、菜品、帖子'
              shape='round'
              background='#f2f3f5'
              onChange={(e) => setKeyword(e.detail.value)}
              onSearch={handleSearch}
            />
          </View>
          <View className='navbar-search-btn' onClick={handleSearch}>
            <Text className='search-btn-text'>搜索</Text>
          </View>
        </View>
      </View>

      {/* 占位 */}
      <View style={{ height: `${navBarHeight.statusBarHeight + navBarHeight.navBarHeight}px` }} />

      <ScrollView className='search-scroll' scrollY enhanced showScrollbar={false}>
        {/* ========== 搜索结果（已提交关键词时显示） ========== */}
        {submittedKeyword ? (
          <View className='results-section'>
            <View className='results-header'>
              <Text className='results-title'>
                搜索 "<Text className='results-keyword'>{submittedKeyword}</Text>" 的结果
              </Text>
              <Text className='results-count'>共 {results.length} 条</Text>
            </View>

            {results.length > 0 ? (
              <View className='results-list'>
                {results.map((r) =>
                  r.kind === 'shop' ? (
                    <ShopCard
                      key={`shop-${r.data.id}`}
                      shop={r.data}
                      onClick={handleShopClick}
                    />
                  ) : (
                    <View key={`post-${r.data.id}`} className='result-post-wrap'>
                      <ForumPostCard post={r.data} onClick={handlePostClick} />
                    </View>
                  ),
                )}
              </View>
            ) : (
              <View className='empty-tip'>
                <Text className='empty-icon'>🔍</Text>
                <Text className='empty-text'>未找到相关内容，换个词试试</Text>
              </View>
            )}
          </View>
        ) : (
          <>
            {/* ========== 搜索历史 ========== */}
            {history.length > 0 && (
              <View className='section'>
                <View className='section-header'>
                  <Text className='section-title'>搜索历史</Text>
                  <View className='clear-btn' onClick={handleClearHistory}>
                    <Text className='clear-icon'>🗑</Text>
                  </View>
                </View>
                <View className='tag-list'>
                  {history.map((h) => (
                    <View
                      key={h}
                      className='tag-item'
                      onClick={() => handleQuickKeyword(h)}
                    >
                      <Text className='tag-text'>{h}</Text>
                    </View>
                  ))}
                </View>
              </View>
            )}

            {/* ========== 热门搜索 ========== */}
            <View className='section'>
              <View className='section-header'>
                <Text className='section-title'>热门搜索</Text>
              </View>
              <View className='tag-list'>
                {hotKeywords.map((kw, idx) => (
                  <View
                    key={kw}
                    className={`tag-item ${idx < 3 ? 'hot' : ''}`}
                    onClick={() => handleQuickKeyword(kw)}
                  >
                    {idx < 3 && <Text className='rank'>{idx + 1}</Text>}
                    <Text className='tag-text'>{kw}</Text>
                  </View>
                ))}
              </View>
            </View>
          </>
        )}
        <View className='bottom-safe' />
      </ScrollView>
    </View>
  )
}