import { useState, useEffect, useRef, useCallback } from 'react'

const EXCHANGES = ['HyperLiquid', 'Bitget']

function formatPrice(p) {
  if (p == null || p <= 0) return '-'
  if (p >= 100) return p.toFixed(2)
  if (p >= 1) return p.toFixed(4)
  return p.toFixed(6)
}

function pnlClass(val) {
  if (val == null) return ''
  return val > 0 ? 'text-green' : val < 0 ? 'text-red' : ''
}

export default function App() {
  const [clock, setClock] = useState('--:--:--')
  const [connStatus, setConnStatus] = useState('● 未连接')
  const [connOnline, setConnOnline] = useState(false)
  const [connDetail, setConnDetail] = useState('')
  const [prices, setPrices] = useState([])
  const [pricesAge, setPricesAge] = useState('')
  const [opps, setOpps] = useState([])
  const [positions, setPositions] = useState([])
  const [blacklist, setBlacklist] = useState([])
  const [stats, setStats] = useState({})
  const [trades, setTrades] = useState([])
  const priceCacheRef = useRef({})

  // Clock
  useEffect(() => {
    const tick = () => setClock(new Date().toLocaleTimeString('zh-CN', { hour12: false }))
    tick()
    const id = setInterval(tick, 1000)
    return () => clearInterval(id)
  }, [])

  // SSE
  useEffect(() => {
    let es = new EventSource('/events')

    es.addEventListener('connected', () => {
      setConnStatus('● 已连接')
      setConnOnline(true)
    })

    es.onerror = () => {
      setConnStatus('● 已断开 (重连中...)')
      setConnOnline(false)
      setTimeout(() => {
        es = new EventSource('/events')
      }, 3000)
    }

    es.onmessage = (e) => {
      try {
        const msg = JSON.parse(e.data)
        switch (msg.event) {
          case 'prices':
            handlePrices(msg.data)
            break
          case 'arb':
            setOpps(msg.data || [])
            break
          case 'positions':
            setPositions(msg.data || [])
            break
          case 'blacklist':
            setBlacklist(msg.data || [])
            break
          case 'stats':
            setStats(msg.data || {})
            if (msg.data && msg.data.blacklist) {
              setBlacklist(msg.data.blacklist)
            }
            break
          case 'trade_close':
            loadTrades()
            break
        }
      } catch (err) {
        // ignore
      }
    }

    return () => es.close()
  }, [])

  // Load trades from API
  const loadTrades = useCallback(async () => {
    try {
      const resp = await fetch('/api/trades')
      const data = await resp.json()
      setTrades(data.trades || [])
    } catch (err) {
      // ignore
    }
  }, [])

  useEffect(() => {
    loadTrades()
    const id = setInterval(loadTrades, 10000)
    return () => clearInterval(id)
  }, [loadTrades])

  // Handle prices
  function handlePrices(data) {
    if (!data || data.length === 0) return
    setPrices(data)
    setPricesAge(new Date().toLocaleTimeString('zh-CN', { hour12: false }))

    // Update price cache for color changes
    const cache = priceCacheRef.current
    for (const row of data) {
      for (const ex of EXCHANGES) {
        const key = row.coin + '.' + ex
        const p = row[ex] || 0
        if (cache[key]) {
          cache[key].last = p
        } else {
          cache[key] = { last: p }
        }
      }
    }
  }

  // ---- Render helpers ----
  function getCoinList() {
    const seen = new Set()
    const coins = []
    if (!prices) return coins
    for (const row of prices) {
      if (!seen.has(row.coin)) {
        seen.add(row.coin)
        coins.push(row.coin)
      }
    }
    return coins
  }

  function getPrevPrice(coin, ex) {
    return priceCacheRef.current[coin + '.' + ex]?.last
  }

  function priceClass(last, cur) {
    if (last == null || cur == null) return ''
    return cur > last ? 'text-green' : cur < last ? 'text-red' : ''
  }

  const coins = getCoinList()

  return (
    <div id="app">
      <header>
        <h1>⚡ 跨交易所套利监控</h1>
        <div className="header-meta">
          <span>{clock}</span>
          <span className="sep">|</span>
          <span className={connOnline ? 'status-online' : 'status-offline'}>{connStatus}</span>
        </div>
      </header>

      <div className="grid">
        {/* Stats Summary */}
        <StatsCard stats={stats} />

        {/* Open Positions */}
        <PositionsCard positions={positions} />

        {/* PnL Growth Chart */}
        <PnlChart />

        {/* Price Table */}
        <PriceTable coins={coins} prices={prices} getPrevPrice={getPrevPrice} priceClass={priceClass} pricesAge={pricesAge} />

        {/* Arbitrage Opportunities */}
        <ArbTable opps={opps} />

        {/* Recent Trades */}
        <TradesCard trades={trades} onRefresh={loadTrades} />

        {/* Blacklist */}
        <BlacklistCard blacklist={blacklist} />
      </div>
    </div>
  )
}

// ============ Components ============

function StatsCard({ stats }) {
  const d = stats.detail
  const capital = stats.capital
  // Format connection status
  let connHtml = ''
  if (stats.connections) {
    connHtml = Object.entries(stats.connections)
      .map(([ex, status]) => `${ex}:${status}`).join(' ')
  }
  // Format exchange funds
  let exFundsHtml = ''
  if (stats.exchange_funds) {
    exFundsHtml = Object.entries(stats.exchange_funds)
      .map(([ex, f]) => `${ex}: $${f.balance.toFixed(2)}`)
      .join('  |  ')
  }
  return (
    <section className="card" id="stats-card">
      <h2>📊 统计数据</h2>
      <div className="stats-row">
        <div className="stat"><label>总交易</label><span id="stat-total">{stats.total_trades || 0}</span></div>
        <div className="stat"><label>收敛</label><span className="pct-green">{stats.converged || 0}</span></div>
        <div className="stat"><label>发散</label><span className="pct-red">{stats.diverged || 0}</span></div>
        <div className="stat"><label>持平</label><span className="pct-gray">{stats.flat || 0}</span></div>
        <div className="stat"><label>持仓</label><span className="pct-yellow">{stats.open_positions || 0} / <span>5</span></span></div>
        <div className="stat"><label>币种</label><span className="pct-blue">{stats.coins || 0}</span></div>
        <div className="stat" id="conn-stats"><label>连接</label><span id="conn-detail" style={{fontSize:11}}>{connHtml}</span></div>
      </div>
      {exFundsHtml && (
        <div className="stats-row" style={{ marginTop: 2, fontSize: 11, opacity: 0.85 }}>
          <div className="stat" style={{gridColumn:'1 / -1'}}><label>资金</label><span style={{fontWeight:600}}>{exFundsHtml}</span></div>
        </div>
      )}
      {d && (
        <div className="stats-row detail-stats" style={{ marginTop: 4, fontSize: 12, opacity: 0.85 }}>
          <div className="stat"><label>总PnL</label><span>{(d.total_pnl_usd != null ? '$' + d.total_pnl_usd.toFixed(2) : '—') + (d.capital_pnl != null ? ' (' + d.capital_pnl.toFixed(4) + '%)' : '')}</span></div>
          <div className="stat"><label>本金</label><span>{capital != null ? '$' + capital.toFixed(0) : '—'}</span></div>
          <div className="stat"><label>胜率</label><span>{d.win_rate != null ? d.win_rate.toFixed(1) + '%' : '—'}</span></div>
          <div className="stat"><label>最多盈利</label><span className="text-green">{d.max_profit != null ? d.max_profit.toFixed(4) + '%' : '—'}</span></div>
          <div className="stat"><label>最多亏损</label><span className="text-red">{d.max_loss != null ? d.max_loss.toFixed(4) + '%' : '—'}</span></div>
          <div className="stat"><label>平均持仓</label><span>{d.avg_dur || '—'}</span></div>
        </div>
      )}
    </section>
  )
}

function PositionsCard({ positions }) {
  const [modalOpen, setModalOpen] = useState(false)
  const [modalTrade, setModalTrade] = useState(null)
  const [modalOrders, setModalOrders] = useState([])

  function openPositionDetail(id) {
    if (!id) return
    setModalOpen(true)
    setModalTrade(null)
    setModalOrders([])
    fetch('/api/trade/' + id)
      .then(r => r.json())
      .then(data => {
        setModalTrade(data.trade)
        setModalOrders(data.orders || [])
      })
      .catch(() => {
        setModalTrade({ ID: id })
      })
  }

  function closeModal() {
    setModalOpen(false)
  }

  useEffect(() => {
    if (!modalOpen) return
    function handler(e) {
      if (e.key === 'Escape') closeModal()
    }
    document.addEventListener('keydown', handler)
    return () => document.removeEventListener('keydown', handler)
  }, [modalOpen])

  return (
    <>
      <section className="card" id="positions-card">
        <h2>🔒 当前持仓</h2>
        <div className="table-wrap">
          <table id="positions-table">
            <thead>
              <tr><th>币种</th><th>方向</th><th>规模</th><th>入价差</th><th>现价差</th><th>估盈亏</th><th>加仓</th><th>时长</th></tr>
            </thead>
            <tbody id="positions-body">
              {positions.length === 0 ? (
                <tr><td colSpan="8" className="loading">无持仓</td></tr>
              ) : (
                [...positions].sort((a, b) => a.coin.localeCompare(b.coin)).map(p => (
                  <tr key={p.coin} className="trade-row" onClick={() => openPositionDetail(p.db_trade_id)}>
                    <td><strong>{p.coin}</strong></td>
                    <td>{p.direction}</td>
                    <td className="text-right">${(p.amount_usd || 0).toFixed(0)}</td>
                    <td className="text-right">{(p.entry_spread || 0).toFixed(4)}%</td>
                    <td className="text-right">{p.current_spread != null ? p.current_spread.toFixed(4) + '%' : '-'}</td>
                    <td className={'text-right ' + pnlClass(p.pnl_est)}><strong>{p.pnl_est != null ? '$' + p.pnl_est.toFixed(4) : '-'}</strong></td>
                    <td className="text-right">{p.scales || 0}</td>
                    <td>{p.duration || '-'}</td>
                  </tr>
                ))
              )}
            </tbody>
          </table>
        </div>
      </section>
      {modalOpen && (
        <TradeDetailModal trade={modalTrade} orders={modalOrders} onClose={closeModal} />
      )}
    </>
  )
}

function BlacklistCard({ blacklist }) {
  return (
    <section className="card" id="bl-card">
      <h2>⛔ 黑名单</h2>
      <div className="stats-row" id="bl-body">
        {!blacklist || blacklist.length === 0 ? (
          <span className="text-dim">暂无</span>
        ) : (
          blacklist.map((item, i) => {
            const sec = item.remaining_sec || 0
            const remaining = sec > 0 ? `${Math.floor(sec/60)}m${sec%60}s` : ''
            return <span key={i} className="bl-item" title={`${item.coin}: ${remaining}`}>⛔ {item.coin}{remaining ? ` (${remaining})` : ''}</span>
          })
        )}
      </div>
    </section>
  )
}

function PriceTable({ coins, prices, getPrevPrice, priceClass, pricesAge }) {
  return (
    <section className="card" id="prices-card">
      <h2>💰 实时价格 <span className="text-dim" style={{ fontSize: 11 }}>{pricesAge}</span></h2>
      <div className="table-wrap">
        <table id="price-table">
          <thead>
            <tr><th>币种</th><th>HyperLiquid</th><th>Bitget</th><th>毛价差</th><th>BG→HL净利</th><th>HL→BG净利</th></tr>
          </thead>
          <tbody id="price-body">
            {coins.length === 0 ? (
              <tr><td colSpan="6" className="loading">等待数据...</td></tr>
            ) : coins.map(coin => {
              const row = prices.find(p => p.coin === coin)
              if (!row) {
                return <tr key={coin}><td>{coin}</td><td className="text-dim">-</td><td className="text-dim">-</td><td className="text-dim">-</td><td className="text-dim">-</td><td className="text-dim">-</td></tr>
              }
              const cells = EXCHANGES.map(ex => {
                const p = row[ex]
                const prev = getPrevPrice(coin, ex)
                const cls = prev ? priceClass(prev, p || 0) : ''
                return <td key={ex} className={cls}>{formatPrice(p)}</td>
              })
              const spread = row['bg_hl_spread']
              const spreadCls = spread > 0.2 ? 'text-green' : spread < -0.2 ? 'text-red' : ''
              const nb = row['net_bg_to_hl']
              const nh = row['net_hl_to_bg']
              const nbCls = nb != null ? pnlClass(nb) : ''
              const nhCls = nh != null ? pnlClass(nh) : ''
              return (
                <tr key={coin}>
                  <td><strong>{coin}</strong></td>
                  {cells}
                  <td className={spreadCls}>{spread != null ? spread.toFixed(4) + '%' : '-'}</td>
                  <td className={nbCls}>{nb != null ? nb.toFixed(2) + '%' : '-'}</td>
                  <td className={nhCls}>{nh != null ? nh.toFixed(2) + '%' : '-'}</td>
                </tr>
              )
            })}
          </tbody>
        </table>
      </div>
    </section>
  )
}

function ArbTable({ opps }) {
  return (
    <section className="card" id="arb-card">
      <h2>🎯 套利机会 (BG↔HL)</h2>
      <div className="table-wrap">
        <table id="arb-table">
          <thead>
            <tr><th>币种</th><th>方向</th><th>买价</th><th>卖价</th><th>净利%</th></tr>
          </thead>
          <tbody id="arb-body">
            {!opps || opps.length === 0 ? (
              <tr><td colSpan="5" className="text-dim">暂无套利机会</td></tr>
            ) : opps.map((opp, i) => {
              const cls = opp.net_profit > 0.10 ? 'text-green' : opp.net_profit > 0.05 ? 'text-yellow' : ''
              return (
                <tr key={i}>
                  <td>{opp.coin}</td>
                  <td>{opp.direction}</td>
                  <td className="text-right">{formatPrice(opp.buy_price)}</td>
                  <td className="text-right">{formatPrice(opp.sell_price)}</td>
                  <td className={'text-right ' + cls}><strong>{(opp.net_profit || 0).toFixed(4)}</strong></td>
                </tr>
              )
            })}
          </tbody>
        </table>
      </div>
    </section>
  )
}

function TradesCard({ trades, onRefresh }) {
  const [modalTrade, setModalTrade] = useState(null)
  const [modalOrders, setModalOrders] = useState([])
  const [modalOpen, setModalOpen] = useState(false)

  function openTradeDetail(id) {
    setModalOpen(true)
    setModalTrade(null)
    setModalOrders([])
    fetch('/api/trade/' + id)
      .then(r => r.json())
      .then(data => {
        setModalTrade(data.trade)
        setModalOrders(data.orders || [])
      })
      .catch(() => {
        setModalTrade({ ID: id })
      })
  }

  function closeTradeDetail() {
    setModalOpen(false)
  }

  // Close on Escape
  useEffect(() => {
    if (!modalOpen) return
    function handler(e) {
      if (e.key === 'Escape') closeTradeDetail()
    }
    document.addEventListener('keydown', handler)
    return () => document.removeEventListener('keydown', handler)
  }, [modalOpen])

  return (
    <>
      <section className="card card-wide" id="trades-card">
        <h2>📋 历史交易</h2>
        <div className="table-wrap">
          <table id="trades-table">
            <thead>
              <tr><th>时间</th><th>币种</th><th>方向</th><th>入价差</th><th>出价差</th><th>净利%</th><th>结果</th><th>原因</th></tr>
            </thead>
            <tbody id="trades-body">
              {trades.length === 0 ? (
                <tr><td colSpan="8" className="text-dim">暂无交易记录</td></tr>
              ) : trades.slice(0, 20).map(t => {
                const pnlCls = t.NetPnl > 0 ? 'text-green' : t.NetPnl < 0 ? 'text-red' : ''
                const convCls = t.Convergence === '价差收敛' ? 'text-green' : t.Convergence === '价差发散' ? 'text-red' : 'text-yellow'
                return (
                  <tr key={t.ID} className="trade-row" onClick={() => openTradeDetail(t.ID)}>
                    <td className="text-dim">{t.ClosedAt ? new Date(t.ClosedAt).toLocaleTimeString('zh-CN', { hour12: false }) : '-'}</td>
                    <td><strong>{t.Coin}</strong></td>
                    <td>{t.Direction}</td>
                    <td className="text-right">{t.EntrySpread != null ? t.EntrySpread.toFixed(4) : '-'}</td>
                    <td className="text-right">{t.ExitSpread != null ? t.ExitSpread.toFixed(4) : '-'}</td>
                    <td className={'text-right ' + pnlCls}><strong>{t.NetPnl != null ? t.NetPnl.toFixed(4) + '%' : '-'}</strong></td>
                    <td className={convCls}>{t.Convergence || '-'}</td>
                    <td>{t.ExitReason || '-'}</td>
                  </tr>
                )
              })}
            </tbody>
          </table>
        </div>
      </section>

      {/* Trade Detail Modal */}
      {modalOpen && (
        <TradeDetailModal trade={modalTrade} orders={modalOrders} onClose={closeTradeDetail} />
      )}
    </>
  )
}

function TradeDetailModal({ trade, orders, onClose }) {
  function handleOverlayClick(e) {
    if (e.target === e.currentTarget) onClose()
  }

  if (!trade) {
    return (
      <div className="modal-overlay" onClick={handleOverlayClick}>
        <div className="modal-content">
          <div className="modal-header">
            <h2>📋 交易详情</h2>
            <button className="modal-close" onClick={onClose}>✕</button>
          </div>
          <div id="trade-detail-body">
            <div className="loading">加载中...</div>
          </div>
        </div>
      </div>
    )
  }

  const opened = new Date(trade.OpenedAt)
  const closed = trade.ClosedAt ? new Date(trade.ClosedAt) : null
  const dur = closed ? Math.round((closed - opened) / 1000) + 's' : '-'
  const pnlCls = trade.NetPnl > 0 ? 'text-green' : trade.NetPnl < 0 ? 'text-red' : ''

  // Sort orders: by Exchange ascending, then by CreatedAt ascending
  const sortedOrders = [...(orders || [])].sort((a, b) => {
    const exCmp = (a.Exchange || '').localeCompare(b.Exchange || '')
    if (exCmp !== 0) return exCmp
    return new Date(a.CreatedAt) - new Date(b.CreatedAt)
  })

  // Compute USD PnL per leg: AmountUSD * Pnl% / 100
  const longPnlUSD = trade.AmountUSD && trade.LongPnl != null ? trade.AmountUSD * trade.LongPnl / 100 : null
  const shortPnlUSD = trade.AmountUSD && trade.ShortPnl != null ? trade.AmountUSD * trade.ShortPnl / 100 : null
  // Net PnL USD = total capital (both sides) * NetPnl% / 100
  const netPnlUSD = trade.AmountUSD && trade.NetPnl != null ? 2 * trade.AmountUSD * trade.NetPnl / 100 : null

  return (
    <div className="modal-overlay" onClick={handleOverlayClick}>
      <div className="modal-content">
        <div className="modal-header">
          <h2>📋 交易详情</h2>
          <button className="modal-close" onClick={onClose}>✕</button>
        </div>
        <div id="trade-detail-body">
          <div className="detail-grid">
            <div className="detail-section">
              <h3>概览</h3>
              <div className="detail-row"><span className="label">币种</span><span className="value"><strong>{trade.Coin}</strong>/USDT</span></div>
              <div className="detail-row"><span className="label">方向</span><span className="value">{trade.Direction || '-'}</span></div>
              <div className="detail-row"><span className="label">状态</span><span className="value">{trade.Status === 'closed' ? '已平仓' : trade.Status}</span></div>
              <div className="detail-row"><span className="label">加仓次数</span><span className="value">{trade.ScaleCount || 0} 次</span></div>
              <div className="detail-row"><span className="label">总规模</span><span className="value">${(trade.AmountUSD || 0).toFixed(0)}</span></div>
            </div>
            <div className="detail-section">
              <h3>时间</h3>
              <div className="detail-row"><span className="label">开仓</span><span className="value">{opened.toLocaleString('zh-CN', { hour12: false })}</span></div>
              <div className="detail-row"><span className="label">平仓</span><span className="value">{closed ? closed.toLocaleString('zh-CN', { hour12: false }) : '-'}</span></div>
              <div className="detail-row"><span className="label">持仓时长</span><span className="value">{dur}</span></div>
            </div>
            <div className="detail-section">
              <h3>价差</h3>
              <div className="detail-row"><span className="label">入场价差</span><span className="value">{trade.EntrySpread != null ? trade.EntrySpread.toFixed(4) + '%' : '-'}</span></div>
              <div className="detail-row"><span className="label">出场价差</span><span className="value">{trade.ExitSpread != null ? trade.ExitSpread.toFixed(4) + '%' : '-'}</span></div>
              <div className="detail-row"><span className="label">收敛情况</span><span className={'value ' + (trade.Convergence === '价差收敛' ? 'text-green' : trade.Convergence === '价差发散' ? 'text-red' : '')}>{trade.Convergence || '-'}</span></div>
              <div className="detail-row"><span className="label">平仓原因</span><span className="value">{trade.ExitReason || '-'}</span></div>
            </div>
            <div className="detail-section">
              <h3>手续费</h3>
              <div className="detail-row"><span className="label">开仓费</span><span className="value">${(trade.FeeEntry || 0).toFixed(4)}</span></div>
              <div className="detail-row"><span className="label">平仓费</span><span className="value">${(trade.FeeExit || 0).toFixed(4)}</span></div>
              <div className="detail-row"><span className="label">总手续费</span><span className="value">${((trade.FeeEntry || 0) + (trade.FeeExit || 0)).toFixed(4)}</span></div>
            </div>
            <div className="detail-section">
              <h3>多仓 {trade.LongExchange || '-'}</h3>
              <div className="detail-row"><span className="label">入场价</span><span className="value">${(trade.LongEntry || 0).toFixed(6)}</span></div>
              <div className="detail-row"><span className="label">出场价</span><span className="value">${(trade.LongExit || 0).toFixed(6)}</span></div>
              <div className="detail-row"><span className="label">盈亏</span><span className={'value ' + (trade.LongPnl > 0 ? 'text-green' : trade.LongPnl < 0 ? 'text-red' : '')}>{trade.LongPnl != null ? trade.LongPnl.toFixed(4) + '%' : '-'} {longPnlUSD != null ? <span style={{fontSize:11,opacity:0.8}}>(${longPnlUSD.toFixed(4)})</span> : null}</span></div>
            </div>
            <div className="detail-section">
              <h3>空仓 {trade.ShortExchange || '-'}</h3>
              <div className="detail-row"><span className="label">入场价</span><span className="value">${(trade.ShortEntry || 0).toFixed(6)}</span></div>
              <div className="detail-row"><span className="label">出场价</span><span className="value">${(trade.ShortExit || 0).toFixed(6)}</span></div>
              <div className="detail-row"><span className="label">盈亏</span><span className={'value ' + (trade.ShortPnl > 0 ? 'text-green' : trade.ShortPnl < 0 ? 'text-red' : '')}>{trade.ShortPnl != null ? trade.ShortPnl.toFixed(4) + '%' : '-'} {shortPnlUSD != null ? <span style={{fontSize:11,opacity:0.8}}>(${shortPnlUSD.toFixed(4)})</span> : null}</span></div>
            </div>
            <div className="detail-section detail-section-full">
              <h3>净收益</h3>
              <div className="detail-row" style={{ fontSize: 16 }}>
                <span className="label">总计</span>
                <span className={'value ' + pnlCls} style={{ fontWeight: 700 }}>{trade.NetPnl != null ? trade.NetPnl.toFixed(4) + '%' : '-'} {netPnlUSD != null ? <span style={{fontSize:12,opacity:0.8}}>(${netPnlUSD.toFixed(4)})</span> : null}</span>
              </div>
            </div>
          </div>
          {orders.length > 0 && (
            <div className="detail-section detail-section-full" style={{ borderTop: '1px solid var(--border)' }}>
              <h3>订单明细 ({orders.length})</h3>
              <table className="detail-orders">
                <thead>
                  <tr><th>交易所</th><th>类型</th><th>方向</th><th>价格</th><th>仓位</th><th>手续费</th><th>订单ID</th></tr>
                </thead>
                <tbody>
                  {sortedOrders.map((o, i) => (
                    <tr key={i}>
                      <td>{o.Exchange}</td>
                      <td>{o.Type === 'entry' ? '开仓' : o.Type === 'exit' ? '平仓' : o.Type === 'scale' ? '加仓' : o.Type}</td>
                      <td>{o.Side === 'buy' ? '买' : '卖'}</td>
                      <td>${(o.Price || 0).toFixed(6)}</td>
                      <td className="text-right">{o.Size != null ? Number(o.Size).toFixed(4) : '-'}</td>
                      <td>{o.Fee != null ? '$' + (o.Fee).toFixed(4) : '-'}</td>
                      <td>{o.OrderID ? o.OrderID.substring(0, 12) + '...' : '-'}</td>
                    </tr>
                  ))}
                </tbody>
              </table>
            </div>
          )}
        </div>
      </div>
    </div>
  )
}

// ============ PnL Growth Chart ============
function PnlChart() {
  const canvasRef = useRef(null)
  const [data, setData] = useState([])
  const [totalPnl, setTotalPnl] = useState(0)

  // Fetch trades for chart
  useEffect(() => {
    async function fetchTrades() {
      try {
        const resp = await fetch('/api/trades?limit=1000')
        const json = await resp.json()
        const trades = (json.trades || [])
          .filter(t => t.ClosedAt && t.NetPnl != null)
          .sort((a, b) => new Date(a.ClosedAt) - new Date(b.ClosedAt))
        setData(trades)
        const total = trades.reduce((sum, t) => sum + 2 * (t.AmountUSD || 0) * (t.NetPnl || 0) / 100, 0)
        setTotalPnl(total)
      } catch (e) {}
    }
    fetchTrades()
    const id = setInterval(fetchTrades, 10000)
    return () => clearInterval(id)
  }, [])

  // Draw chart
  useEffect(() => {
    const canvas = canvasRef.current
    if (!canvas || data.length < 2) return

    const rect = canvas.parentElement.getBoundingClientRect()
    const dpr = window.devicePixelRatio || 1
    const W = rect.width
    const H = rect.height
    canvas.width = W * dpr
    canvas.height = H * dpr
    canvas.style.width = W + 'px'
    canvas.style.height = H + 'px'

    const ctx = canvas.getContext('2d')
    ctx.scale(dpr, dpr)

    const pad = { top: 20, right: 20, bottom: 35, left: 55 }
    const plotW = W - pad.left - pad.right
    const plotH = H - pad.top - pad.bottom

    // Compute cumulative PnL
    const points = []
    let cum = 0
    // Prepend a zero point so single-trade chart still draws
    if (data.length > 0) {
      const t0 = new Date(data[0].ClosedAt).getTime() - 1000
      points.push({ x: t0, y: 0 })
    }
    for (const t of data) {
      cum += 2 * (t.AmountUSD || 0) * (t.NetPnl || 0) / 100
      points.push({ x: new Date(t.ClosedAt).getTime(), y: cum })
    }

    const minT = points[0].x
    const maxT = points[points.length - 1].x
    const yVals = points.map(p => p.y)
    const minY = Math.min(0, ...yVals)
    const maxY = Math.max(0, ...yVals)
    const yRange = Math.max(maxY - minY, 0.01)
    const yPad = yRange * 0.15

    const toX = t => pad.left + (t - minT) / Math.max(maxT - minT, 1) * plotW
    const toY = y => pad.top + plotH - (y - (minY - yPad)) / (yRange + 2 * yPad) * plotH

    // Clear
    ctx.clearRect(0, 0, W, H)

    // Grid lines
    ctx.strokeStyle = 'rgba(48,54,61,0.5)'
    ctx.lineWidth = 1
    ctx.font = '11px sans-serif'
    ctx.fillStyle = '#8b949e'

    const ySteps = 5
    for (let i = 0; i <= ySteps; i++) {
      const yVal = (minY - yPad) + (yRange + 2 * yPad) * i / ySteps
      const yPos = toY(yVal)
      ctx.beginPath()
      ctx.moveTo(pad.left, yPos)
      ctx.lineTo(W - pad.right, yPos)
      ctx.stroke()
      ctx.fillText('$' + yVal.toFixed(2), 2, yPos + 4)
    }

    // Zero line
    if (minY < 0 && maxY > 0) {
      const y0 = toY(0)
      ctx.strokeStyle = 'rgba(248,81,73,0.3)'
      ctx.lineWidth = 1
      ctx.setLineDash([4, 4])
      ctx.beginPath()
      ctx.moveTo(pad.left, y0)
      ctx.lineTo(W - pad.right, y0)
      ctx.stroke()
      ctx.setLineDash([])
    }

    // X axis labels
    const xSteps = Math.min(6, points.length)
    for (let i = 0; i < xSteps; i++) {
      const idx = Math.floor(i * (points.length - 1) / (xSteps - 1))
      const xPos = toX(points[idx].x)
      const date = new Date(points[idx].x)
      ctx.fillStyle = '#8b949e'
      ctx.textAlign = 'center'
      ctx.fillText(date.toLocaleTimeString('zh-CN', { hour: '2-digit', minute: '2-digit' }), xPos, H - 5)
    }

    // Line
    ctx.beginPath()
    ctx.strokeStyle = '#58a6ff'
    ctx.lineWidth = 2
    for (let i = 0; i < points.length; i++) {
      const x = toX(points[i].x)
      const y = toY(points[i].y)
      if (i === 0) ctx.moveTo(x, y)
      else ctx.lineTo(x, y)
    }
    ctx.stroke()

    // Fill gradient
    const gradient = ctx.createLinearGradient(0, pad.top, 0, H - pad.bottom)
    gradient.addColorStop(0, 'rgba(88,166,255,0.15)')
    gradient.addColorStop(1, 'rgba(88,166,255,0.01)')
    ctx.lineTo(toX(points[points.length - 1].x), toY(minY - yPad))
    ctx.lineTo(toX(points[0].x), toY(minY - yPad))
    ctx.closePath()
    ctx.fillStyle = gradient
    ctx.fill()

    // Latest value dot
    const last = points[points.length - 1]
    const lx = toX(last.x)
    const ly = toY(last.y)
    ctx.beginPath()
    ctx.arc(lx, ly, 4, 0, Math.PI * 2)
    ctx.fillStyle = last.y >= 0 ? '#3fb950' : '#f85149'
    ctx.fill()
    ctx.strokeStyle = '#0d1117'
    ctx.lineWidth = 2
    ctx.stroke()

    // Latest value label
    ctx.fillStyle = '#c9d1d9'
    ctx.font = 'bold 13px sans-serif'
    ctx.textAlign = 'center'
    ctx.fillText('$' + last.y.toFixed(2), lx, ly - 12)
  }, [data])

  return (
    <section className="card card-wide" id="pnl-chart-card">
      <h2>📈 总PnL成长曲线 <span className="text-dim" style={{fontSize:11}}>{data.length > 0 ? `$${totalPnl.toFixed(2)}` : ''}</span></h2>
      <div className="chart-container" style={{height:260}}>
        {data.length < 1 ? (
          <div className="loading" style={{paddingTop:100}}>暂无数据...</div>
        ) : (
          <canvas ref={canvasRef} />
        )}
      </div>
    </section>
  )
}