"use client";

import { useEffect, useState } from "react";
import { apiGet } from "@/lib/api";
import { submitJob, waitJob } from "@/lib/jobs";
import type { FactorMeta, FactorTestReport, ResearchSpec } from "@/lib/types";
import { recentRange } from "@/lib/dates";

export default function FactorsPage() {
  const [factors, setFactors] = useState<FactorMeta[]>([]);
  const [checked, setChecked] = useState<Set<string>>(new Set());
  const [expanded, setExpanded] = useState<Set<string>>(new Set());
  const [start, setStart] = useState("");
  const [end, setEnd] = useState("");
  const [reports, setReports] = useState<Record<string, FactorTestReport>>({});
  const [running, setRunning] = useState(false);
  const [current, setCurrent] = useState<{ idx: number; total: number; name: string } | null>(null);
  const [jobId, setJobId] = useState("");
  const [error, setError] = useState("");

  useEffect(() => {
    apiGet<FactorMeta[]>("/factors")
      .then((list) => {
        setFactors(list);
        // 默认勾选两个代表性因子
        const picks = ["momentum_60", "volatility_60"].filter((n) => list.some((f) => f.name === n));
        setChecked(new Set(picks));
      })
      .catch((e: Error) => setError(e.message));
    // 区间默认：近 6 个月（客户端设置，避免 SSR 日期不一致）
    const { start: s, end: e } = recentRange();
    setStart(s);
    setEnd(e);
  }, []);

  function toggleCheck(name: string) {
    setChecked((prev) => {
      const next = new Set(prev);
      if (next.has(name)) next.delete(name);
      else next.add(name);
      return next;
    });
  }

  function toggleExpand(name: string) {
    setExpanded((prev) => {
      const next = new Set(prev);
      if (next.has(name)) next.delete(name);
      else next.add(name);
      return next;
    });
  }

  async function run() {
    const names = factors.map((f) => f.name).filter((n) => checked.has(n));
    if (names.length === 0) {
      setError("请至少选择一个因子");
      return;
    }
    setRunning(true);
    setError("");
    setJobId("");
    setReports({});
    try {
      let index = 0;
      for (const name of names) {
        index += 1;
        setCurrent({ idx: index, total: names.length, name });
        const spec: ResearchSpec = {
          type: "factor_test",
          universe: { exclude_st: true, min_listing_days: 0 },
          factors: [{ name, weight: 1 }],
          selection: { top_n: 10 },
          rebalance: "monthly",
          period: [start, end],
        };
        const { job_id } = await submitJob(spec);
        setJobId(job_id);
        const out = await waitJob<FactorTestReport>(job_id);
        if (out.status === "success" && out.result) {
          const report = out.result;
          setReports((prev) => ({ ...prev, [name]: report }));
        } else {
          const msg = `因子 ${name}：${out.status}${out.error ? `：${out.error}` : ""}`;
          setError((prev) => (prev ? `${prev}\n${msg}` : msg));
        }
      }
    } catch (e) {
      setError((e as Error).message);
    } finally {
      setRunning(false);
      setCurrent(null);
      setJobId("");
    }
  }

  const selectedCount = checked.size;
  const doneCount = Object.keys(reports).length;

  return (
    <>
      <h1>因子研究</h1>
      <div className="card">
        <h2>因子目录（行情因子 · 无未来函数）</h2>
        <div className="muted" style={{ marginBottom: 8 }}>
          勾选因子后可多选；点击行展开详细说明。每个因子运行一次独立的 IC/RankIC 测试并归档。
          <a href="/factors/compose" style={{ marginLeft: 8, color: "#38bdf8" }}>
            用这些因子搭建选股组合 → 因子组合
          </a>
        </div>
        <table>
          <thead>
            <tr>
              <th></th>
              <th>因子</th>
              <th>回看</th>
              <th>方向</th>
              <th>简介（用法 / 何时有效）</th>
            </tr>
          </thead>
          <tbody>
            {factors.map((f) => (
              <FactorRow
                key={f.name}
                factor={f}
                checked={checked.has(f.name)}
                expanded={expanded.has(f.name)}
                onToggleCheck={() => toggleCheck(f.name)}
                onToggleExpand={() => toggleExpand(f.name)}
              />
            ))}
          </tbody>
        </table>
        <div className="muted" style={{ marginTop: 6 }}>
          计分规则：每因子在每日横截面上 z-score 标准化（低为好自动取负），组合页可按权重叠加得分选股；
          本页单个因子测试各自归档为 Experiment，可去「实验」页查看与复跑。
        </div>
      </div>

      <div className="card">
        <h2>运行单因子测试（IC / RankIC / 分层）</h2>
        <div className="row">
          <label className="muted">
            开始 <input type="date" value={start} onChange={(e) => setStart(e.target.value)} />
          </label>
          <label className="muted">
            结束 <input type="date" value={end} onChange={(e) => setEnd(e.target.value)} />
          </label>
          <button
            className="primary"
            onClick={run}
            disabled={running || selectedCount === 0}
          >
            {running ? `运行中 ${doneCount}/${selectedCount}…` : `运行因子测试（已选 ${selectedCount} 个）`}
          </button>
        </div>
        {running && (
          <div className="muted">
            正在运行：{current?.name}（{current?.idx}/{current?.total}）—— 后台任务 {jobId}，请稍候…
          </div>
        )}
        {error && <div className="error" style={{ whiteSpace: "pre-line" }}>{error}</div>}
      </div>

      {Object.entries(reports).map(([name, report]) => {
        const meta = factors.find((f) => f.name === name);
        return (
          <div className="card" key={name}>
            <h2>
              {name} · 测试报告
              {meta?.brief ? (
                <span className="muted" style={{ fontWeight: 400, fontSize: 13 }}>
                  {" "}— {meta.brief}
                </span>
              ) : null}
            </h2>
            <ReportView report={report} />
          </div>
        );
      })}
    </>
  );
}

function FactorRow(props: {
  factor: FactorMeta;
  checked: boolean;
  expanded: boolean;
  onToggleCheck: () => void;
  onToggleExpand: () => void;
}) {
  const { factor: f } = props;
  return (
    <>
      <tr style={{ cursor: "pointer" }} onClick={props.onToggleExpand}>
        <td onClick={(e) => { e.stopPropagation(); props.onToggleCheck(); }}>
          <input type="checkbox" checked={props.checked} onChange={props.onToggleCheck} />
        </td>
        <td>{f.name}</td>
        <td>{f.lookback}</td>
        <td>{f.direction === "higher_is_better" ? "高为好" : "低为好"}</td>
        <td>{f.brief ?? f.description}</td>
      </tr>
      {props.expanded && (
        <tr>
          <td colSpan={5}>
            <div style={{ background: "var(--panel-2)", padding: 10, borderRadius: 6 }}>
              <b>{f.name}</b> · {f.description}
              <div className="muted" style={{ marginTop: 4 }}>
                公式：{f.formula}；回看 {f.lookback} 个交易日；频率 {f.frequency}；
                方向：{f.direction === "higher_is_better" ? "因子值越高得分越高" : "因子值越低得分越高（引擎自动反向）"}
              </div>
              <div style={{ marginTop: 6 }}>{f.brief}</div>
            </div>
          </td>
        </tr>
      )}
    </>
  );
}

function ReportView({ report }: { report: FactorTestReport }) {
  return (
    <>
      <div className="stat-grid">
        <div className="stat">
          <div className="label">IC 均值</div>
          <div className="value">{report.ic_mean.toFixed(4)}</div>
        </div>
        <div className="stat">
          <div className="label">RankIC 均值</div>
          <div className="value">{report.rank_ic_mean.toFixed(4)}</div>
        </div>
        <div className="stat">
          <div className="label">ICIR</div>
          <div className="value">{report.icir.toFixed(3)}</div>
        </div>
        <div className="stat">
          <div className="label">正收益占比</div>
          <div className="value">{report.positive_ratio_pct.toFixed(1)}%</div>
        </div>
        <div className="stat">
          <div className="label">样本日数</div>
          <div className="value">{report.sample_days}</div>
        </div>
      </div>
      {report.quantile_returns.length > 0 && (
        <table style={{ marginTop: 12 }}>
          <thead>
            <tr>
              <th>分层（1 最低 → 5 最高）</th>
              {report.quantile_returns.map((q) => (
                <th key={q.quantile}>Q{q.quantile + 1}</th>
              ))}
            </tr>
          </thead>
          <tbody>
            <tr>
              <td>未来 21 日平均收益</td>
              {report.quantile_returns.map((q) => (
                <td key={q.quantile}>{q.return_pct.toFixed(2)}%</td>
              ))}
            </tr>
          </tbody>
        </table>
      )}
      <div className="muted" style={{ marginTop: 6 }}>
        读数：IC/RankIC 为正表示与未来收益正相关；ICIR 越大越稳定；分层收益若高分层显著高于低分层说明单调性好。
        单因子测试≠策略有效，需结合样本外与稳健性分析。
      </div>
    </>
  );
}