/**
 * 赛程页(组装层)。
 *
 * D3(工程债): 原文件 ~1400 行,已拆分为:
 *   matches/types.ts                  — 类型与常量
 *   matches/ui.tsx                    — 原子 UI 小件(Spinner/Skeleton/Switch/日期工具)
 *   matches/hooks/useMatchesList.ts   — 列表/分页/进行中比赛加载
 *   matches/hooks/useMatchPredict.ts  — 预测流程状态机
 *   matches/components/MatchPredictPanel.tsx — 预测弹窗全套
 *   matches/components/MatchDetailSection.tsx — 赛程行 + 展开详情
 * 本文件只负责状态装配与版面组织,不含数据获取与展示细节。
 */
import { useEffect, useState } from 'react'
import { fetchMatchDetail, fetchMatchContext } from '../admin/dal'
import type { MatchDetailOut, MatchContextOut } from '../admin/types'
import { useMatchesList } from './matches/hooks/useMatchesList'
import { useMatchPredict } from './matches/hooks/useMatchPredict'
import { useLeagues } from './matches/hooks/useLeagues'
import { PredictModal } from './matches/components/MatchPredictPanel'
import { MatchRow } from './matches/components/MatchDetailSection'
import { Spinner, SkeletonRows, Switch, formatDateHeader, groupByDate, withinNext3Days } from './matches/ui'
import { type Match } from './matches/types'

export default function Matches() {
  const [error, setError] = useState<string | null>(null)  // 列表与预测共用(拆分前即如此)
  // P1-3: 联赛列表优先请求 /api/v1/leagues,失败/空回退本地五大联赛常量
  const leagues = useLeagues()
  const {
    league, setLeague,
    status, setStatus,
    matches,
    nextCursor,
    loading,
    loadingMore,
    showAllUpcoming, setShowAllUpcoming,
    liveMatches,
    load,
    loadMore,
  } = useMatchesList({ onError: setError })

  const {
    predictingId,
    prediction,
    predictionFor,
    predict,
    closePredict,
  } = useMatchPredict({ onError: setError })

  // ── 详情展开(懒加载,只读,不触发 LLM) ──
  const [expandedId, setExpandedId] = useState<number | null>(null)
  const [detailMap, setDetailMap] = useState<Record<number, MatchDetailOut>>({})
  const [contextMap, setContextMap] = useState<Record<number, MatchContextOut>>({})
  const [detailLoading, setDetailLoading] = useState<number | null>(null)

  // 监听滚动,超过 300px 显示回到顶部按钮
  const [showBackTop, setShowBackTop] = useState(false)
  useEffect(() => {
    const handleScroll = () => setShowBackTop(window.scrollY > 300)
    window.addEventListener('scroll', handleScroll, { passive: true })
    return () => window.removeEventListener('scroll', handleScroll)
  }, [])
  const scrollToTop = () => window.scrollTo({ top: 0, behavior: 'smooth' })

  const leagueName = leagues.find(l => l.code === league)?.name ?? league

  /** 未开赛默认仅展示未来 3 天;其余状态展示全部。showAllUpcoming=true 时展开全部。 */
  const isScheduledView = status === 'scheduled'
  const visibleMatches = (!isScheduledView || showAllUpcoming)
    ? matches
    : matches.filter(m => withinNext3Days(m.match_date))
  // 是否有被折叠的未开赛比赛(用于显示「展开」按钮)
  const hasHiddenUpcoming = isScheduledView && !showAllUpcoming && matches.length > visibleMatches.length

  /** 展开时懒加载详情: 缓存命中则不再请求 */
  async function toggleExpand(m: Match) {
    if (expandedId === m.id) { setExpandedId(null); return }
    setExpandedId(m.id)
    if (!detailMap[m.id] || !contextMap[m.id]) {
      setDetailLoading(m.id)
      try {
        const [d, c] = await Promise.all([
          fetchMatchDetail(m.id).catch(() => null),
          fetchMatchContext(m.id).catch(() => null),
        ])
        if (d) setDetailMap(prev => ({ ...prev, [m.id]: d }))
        if (c) setContextMap(prev => ({ ...prev, [m.id]: c }))
      } finally {
        setDetailLoading(null)
      }
    }
  }

  return (
    <div className="space-y-5">
      {/* ── 联赛版面切换 ── */}
      <nav className="flex items-center gap-6 overflow-x-auto border-b border-ink-900" aria-label="联赛">
        {leagues.map(l => (
          <button
            key={l.code}
            onClick={() => setLeague(l.code)}
            className={`relative tab ${league === l.code ? 'tab-on' : ''} font-serif`}
          >
            {l.name}
          </button>
        ))}
      </nav>

      {/* ── 第二行:状态 / 模式 / 日期 / 计数 / 刷新(小屏 flex-wrap) ── */}
      <div className="flex flex-wrap items-center gap-x-4 gap-y-2 text-xs text-ink-500 sm:gap-x-5">
        <span className="inline-flex items-center gap-2">
          <span className="text-2xs text-ink-400">状态</span>
          <Switch
            value={status}
            onChange={setStatus}
            items={[
              { v: 'scheduled', label: '未开赛' },
              { v: 'finished', label: '已完赛' },
              { v: '', label: '全部' },
            ]}
          />
        </span>

        <span className="ml-auto inline-flex items-center gap-3">
          <span className="tabular-nums">
            {isScheduledView && !showAllUpcoming && hasHiddenUpcoming
              ? `未来3天 ${visibleMatches.length} / 共 ${matches.length} 场`
              : `共 ${visibleMatches.length} 场`}
          </span>
          <button onClick={load} disabled={loading} className="btn btn-sm">
            {loading ? (<><Spinner /> 获取中</>) : '刷新'}
          </button>
        </span>
      </div>

      {/* ── 错误提示(统一 error-banner 样式) ── */}
      {error && (
        <div className="error-banner">
          <div>
            <p className="error-banner-title">请求失败</p>
            <p className="error-banner-detail">{error}</p>
          </div>
          <button onClick={() => setError(null)} className="text-ink-400 transition-colors hover:text-ink-900 text-lg leading-none p-1" aria-label="关闭">×</button>
        </div>
      )}

      {/* ── 预测弹窗:进行中可视化 / 结果面板 ── */}
      {predictionFor && (
        <PredictModal
          match={predictionFor}
          predicting={predictingId === predictionFor.id}
          prediction={predictingId === predictionFor.id ? null : prediction}
          error={predictingId === predictionFor.id ? null : error}
          onClose={closePredict}
        />
      )}

      {/* ── 进行中比赛(顶部独立区块,仅未开赛视图展示) ── */}
      {isScheduledView && liveMatches.length > 0 && (
        <section aria-label="进行中" className="border border-ink-900 bg-paper-100">
          <div className="flex items-center gap-2 border-b border-ink-900 px-3 py-2">
            <span className="inline-block h-2 w-2 animate-pulse rounded-full bg-press" />
            <span className="text-xs font-medium tracking-wide text-ink-700">进行中 · 实时比分</span>
            <span className="text-2xs text-ink-400">{liveMatches.length} 场</span>
          </div>
          <div className="divide-y divide-ink-200">
            {liveMatches.map(m => {
              const homeName = m.home_team_zh || m.home_team
              const awayName = m.away_team_zh || m.away_team
              return (
                <div key={m.id} className="flex items-center justify-between gap-3 px-3 py-2.5">
                  <div className="flex items-center gap-2 min-w-0">
                    <span className="w-12 shrink-0 text-center font-serif text-lg font-bold tabular-nums text-ink-900">
                      {m.home_goals ?? '-'}
                    </span>
                    <span className="min-w-0 truncate text-xs text-ink-700">{homeName}</span>
                  </div>
                  <span className="shrink-0 text-2xs text-ink-400">vs</span>
                  <div className="flex items-center gap-2 min-w-0">
                    <span className="min-w-0 truncate text-right text-xs text-ink-700">{awayName}</span>
                    <span className="w-12 shrink-0 text-center font-serif text-lg font-bold tabular-nums text-ink-900">
                      {m.away_goals ?? '-'}
                    </span>
                  </div>
                </div>
              )
            })}
          </div>
        </section>
      )}

      {/* ── 赛程栏:表格化,行间细线,按日期分组 ── */}
      <section aria-label="赛程">
        {loading && <SkeletonRows n={4} />}

        {!loading && visibleMatches.length === 0 && (
          <div className="empty-state">
            {matches.length > 0 ? (
              <>
                <p className="empty-state-title">未来 3 天暂无 {leagueName} 比赛</p>
                <p className="empty-state-sub">已导入 {matches.length} 场未开赛,点击下方按钮查看</p>
              </>
            ) : (
              <>
                <p className="empty-state-title">本版暂无赛程</p>
                <p className="empty-state-sub">请先通过「数据采集」导入 {leagueName} 的比赛数据</p>
                <a href="/admin/collection" className="empty-state-action">
                  前往数据采集 <span aria-hidden="true">→</span>
                </a>
              </>
            )}
          </div>
        )}

        {!loading && groupByDate(visibleMatches).map(([dateKey, group]) => (
          <div key={dateKey}>
            {/* 日期分组头:sticky 但 z 低于弹窗 z-50 */}
            <div className="sticky top-0 z-20 border-b border-ink-900 bg-paper-100 px-3 py-2 text-xs font-medium tracking-wide text-ink-600">
              {formatDateHeader(dateKey)}
              <span className="ml-2 text-2xs font-normal text-ink-400">{group.length} 场</span>
            </div>
            {group.map(m => (
              <MatchRow
                key={m.id}
                m={m}
                busy={predictingId === m.id}
                expanded={expandedId === m.id}
                detail={detailMap[m.id]}
                ctx={contextMap[m.id]}
                detailLoading={detailLoading === m.id}
                onToggle={() => toggleExpand(m)}
                onPredict={predict}
              />
            ))}
          </div>
        ))}

        {/* 单一「加载更多」按钮:3 天视图时先展开,展开后从服务器拉取下一页 */}
        {!loading && (hasHiddenUpcoming || nextCursor) && (
          <div className="flex justify-center pt-4">
            {hasHiddenUpcoming ? (
              <button
                onClick={() => setShowAllUpcoming(true)}
                className="btn btn-outline min-h-[44px] w-full max-w-xs sm:w-auto"
              >
                显示后续 {matches.length - visibleMatches.length} 场未开赛
              </button>
            ) : (
              <button onClick={loadMore} disabled={loadingMore} className="btn min-h-[44px] w-full max-w-xs sm:w-auto">
                {loadingMore ? (<><Spinner /> 获取中</>) : '载入更多赛程'}
              </button>
            )}
          </div>
        )}

        {/* 已展开全部但未开赛:提供「收起」回未来 3 天 */}
        {!loading && isScheduledView && showAllUpcoming && matches.length > 0 && (
          <div className="flex justify-center pt-2">
            <button
              onClick={() => setShowAllUpcoming(false)}
              className="text-xs text-ink-400 hover:text-ink-700 transition-colors"
            >
              收起,仅显示未来 3 天
            </button>
          </div>
        )}
      </section>

      {/* 回到顶部按钮 */}
      <button
        onClick={scrollToTop}
        className={`fixed bottom-6 right-6 z-40 flex h-10 w-10 items-center justify-center rounded-full border border-ink-200 bg-paper-50 text-ink-600 shadow-lg transition-all duration-300 hover:border-ink-400 hover:text-ink-900 ${
          showBackTop ? 'translate-y-0 opacity-100' : 'translate-y-4 opacity-0 pointer-events-none'
        }`}
        aria-label="回到顶部"
      >
        <svg className="h-4 w-4" fill="none" viewBox="0 0 24 24" stroke="currentColor" strokeWidth={2}>
          <path strokeLinecap="round" strokeLinejoin="round" d="M5 15l7-7 7 7" />
        </svg>
      </button>
    </div>
  )
}