import { useCallback, useEffect, useState } from "react";
import { apiFetch } from "../api/client";

export type FundsSummary = {
  ok: boolean;
  exchange: string;
  mode?: string;
  trading_day: string;
  total_trades: number;
  win_rate: number;
  profit_loss_ratio: number | null;
  total_funds: number | null;
  funding_usdt: number | null;
  trading_usdt: number | null;
  funding_usdc?: number | null;
  trading_usdc?: number | null;
  funding_label?: string;
  trading_label?: string;
  realtime_pnl: number | null;
  usdc_usdt_rate?: number;
  perp_inst_id?: string;
  detail?: string;
};

function fmtU(n: number | null | undefined) {
  if (n == null || Number.isNaN(n)) return "—";
  return `${n.toFixed(2)}U`;
}

function fmtUsdc(n: number | null | undefined) {
  if (n == null || Number.isNaN(n)) return "—";
  return `${n.toFixed(2)} USDC`;
}

function pnlClass(n: number | null | undefined) {
  if (n == null || Number.isNaN(n) || n === 0) return "";
  return n > 0 ? "pos-pnl-profit" : "pos-pnl-loss";
}

function DualCcy({
  usdt,
  usdc,
}: {
  usdt: number | null | undefined;
  usdc: number | null | undefined;
}) {
  return (
    <div className="funds-dual">
      <div className="funds-value mono">{fmtU(usdt)}</div>
      <div className="funds-value funds-value--sub mono">{fmtUsdc(usdc)}</div>
    </div>
  );
}

export default function FundsBar() {
  const [s, setS] = useState<FundsSummary | null>(null);
  const [err, setErr] = useState("");

  const load = useCallback(() => {
    apiFetch<FundsSummary>("/api/funds/summary")
      .then((r) => {
        setS(r);
        setErr(r.ok ? "" : r.detail || "资金摘要不可用");
      })
      .catch((e) => {
        setErr(e instanceof Error ? e.message : String(e));
      });
  }, []);

  useEffect(() => {
    load();
    const t = window.setInterval(load, 5000);
    const onRefresh = () => load();
    window.addEventListener("funds-refresh", onRefresh);
    return () => {
      window.clearInterval(t);
      window.removeEventListener("funds-refresh", onRefresh);
    };
  }, [load]);

  if (!s?.ok) {
    if (!err) return null;
    return (
      <div className="funds-bar-shell">
        <div className="funds-bar-inner">
          <div className="funds-bar funds-bar--err" aria-label="资金摘要异常">
            <span className="meta">{err}</span>
          </div>
        </div>
      </div>
    );
  }

  return (
    <div className="funds-bar-shell">
      <div className="funds-bar-inner">
        <div className="funds-bar" aria-label="资金与统计">
          <div className="funds-item funds-item--primary">
            <div className="funds-label">交易所</div>
            <div className="funds-value">{s.exchange || "—"}</div>
          </div>
          <div className="funds-item">
            <div className="funds-label">交易日</div>
            <div className="funds-value mono">{s.trading_day}</div>
          </div>
          <div className="funds-item funds-item--primary">
            <div className="funds-label">总交易</div>
            <div className="funds-value mono">{s.total_trades}</div>
          </div>
          <div className="funds-item">
            <div className="funds-label">胜率</div>
            <div className="funds-value mono">
              {(s.win_rate * 100).toFixed(0)}%
            </div>
          </div>
          <div className="funds-item" title="平均盈利 ÷ 平均亏损">
            <div className="funds-label">盈亏比</div>
            <div className="funds-value mono">
              {s.profit_loss_ratio != null
                ? s.profit_loss_ratio.toFixed(2)
                : "—"}
            </div>
          </div>
          <div className="funds-item">
            <div className="funds-label">总资金</div>
            <div className="funds-value mono">{fmtU(s.total_funds)}</div>
          </div>
          <div className="funds-item funds-item--dual">
            <div className="funds-label">资金账户</div>
            <DualCcy usdt={s.funding_usdt} usdc={s.funding_usdc} />
          </div>
          <div className="funds-item funds-item--dual">
            <div className="funds-label">交易账户</div>
            <DualCcy usdt={s.trading_usdt} usdc={s.trading_usdc} />
          </div>
          <div className="funds-item funds-item--pnl">
            <div className="funds-label">实时盈亏</div>
            <div className={`funds-value mono ${pnlClass(s.realtime_pnl)}`}>
              {s.realtime_pnl == null
                ? "—"
                : `${s.realtime_pnl > 0 ? "+" : ""}${fmtU(s.realtime_pnl)}`}
            </div>
          </div>
        </div>
      </div>
    </div>
  );
}