"use client";

import { useEffect, useState } from "react";
import { apiGet } from "@/lib/api";
import { submitJob, waitJob } from "@/lib/jobs";
import type { BacktestResult, FactorMeta, ResearchSpec } from "@/lib/types";
import { recentRange } from "@/lib/dates";
import {
  PageHeader,
  Card,
  Pill,
  Field,
  Btn,
  Banner,
  Progress,
  Signed,
  BacktestMetrics,
  MonthlyReturnsTable,
  UnimplementedNote,
} from "@/components/ui";
import { LineChart } from "@/components/LineChart";
import { Icon } from "@/components/icons";

interface Pick {
  name: string;
  weight: number;
}

export default function ComposePage() {
  const [factors, setFactors] = useState<FactorMeta[]>([]);
  const [picks, setPicks] = useState<Pick[]>([]);
  const [topN, setTopN] = useState(10);
  const [rebalance, setRebalance] = useState<"monthly" | "weekly">("monthly");
  const [excludeSt, setExcludeSt] = useState(true);
  const [start, setStart] = useState("");
  const [end, setEnd] = useState("");
  const [result, setResult] = useState<BacktestResult | null>(null);
  const [running, setRunning] = useState(false);
  const [jobId, setJobId] = useState("");
  const [error, setError] = useState("");

  useEffect(() => {
    let alive = true;
    apiGet<FactorMeta[]>("/factors")
      .then((list) => {
        if (!alive) return;
        setFactors(list);
        setPicks([
          { name: "momentum_60", weight: 1.5 },
          { name: "volatility_60", weight: 1.0 },
        ]);
      })
      .catch((e: Error) => alive && setError(e.message));
    const { start: s, end: e } = recentRange();
    setStart(s);
    setEnd(e);
    return () => {
      alive = false;
    };
  }, []);

  function togglePick(name: string) {
    setPicks((prev) =>
      prev.some((p) => p.name === name)
        ? prev.filter((p) => p.name !== name)
        : [...prev, { name, weight: 1 }],
    );
  }

  function setWeight(name: string, weight: number) {
    setPicks((prev) => prev.map((p) => (p.name === name ? { ...p, weight } : p)));
  }

  function removePick(name: string) {
    setPicks((prev) => prev.filter((p) => p.name !== name));
  }

  async function run() {
    const valid = picks.filter((p) => Number.isFinite(p.weight) && p.weight > 0);
    if (valid.length === 0) {
      setError("请选择至少一个因子并设置大于 0 的权重");
      return;
    }
    setRunning(true);
    setError("");
    setJobId("");
    setResult(null);
    try {
      const spec: ResearchSpec = {
        type: "backtest",
        universe: { exclude_st: excludeSt, min_listing_days: 0 },
        factors: valid.map((p) => ({ name: p.name, weight: p.weight })),
        selection: { top_n: topN },
        rebalance,
        period: [start, end],
      };
      const { job_id } = await submitJob(spec);
      setJobId(job_id);
      const out = await waitJob<BacktestResult>(job_id);
      if (out.status === "success" && out.result) {
        setResult(out.result);
      } else {
        setError(`任务${out.status}${out.error ? `：${out.error}` : ""}`);
      }
    } catch (e) {
      setError((e as Error).message);
    } finally {
      setRunning(false);
      setJobId("");
    }
  }

  return (
    <>
      <PageHeader
        title="因子组合"
        sub="多因子横截面 z-score 标准化后按权重叠加成综合分，每期取 Top N 等权持有。"
        actions={
          <Pill tone="accent" icon="layers">
            {picks.length} 个因子
          </Pill>
        }
      />

      <Card title="组合方式（如何合成一个分数）" icon="scale">
        <ol className="steplist">
          <li>选择若干因子并设置权重（默认 1；低为好方向由引擎自动反向）。</li>
          <li>
            每个交易日：每个因子在全体股票横截面上做 <b>z-score 标准化</b>（当日缺失因子值的股票不参与该因子得分）。
          </li>
          <li>
            综合得分 = <b>Σ（权重 × 标准化后因子得分）</b>，得分越高越优先。
          </li>
          <li>每期按综合得分取 Top N 等权持有，到下一调仓日再平衡（含成本 / 涨跌停 / 停牌近似）。</li>
        </ol>
      </Card>

      <Card
        title="选择因子并设置权重"
        icon="target"
        sub="权重可为小数（如 1.5 = 更侧重该因子）"
        flush
      >
        <div className="table-wrap">
          <table className="tbl">
            <thead>
              <tr>
                <th style={{ width: 46 }}></th>
                <th>因子</th>
                <th>方向</th>
                <th style={{ width: 120 }}>权重</th>
                <th>简介</th>
              </tr>
            </thead>
            <tbody>
              {factors.map((f) => {
                const pick = picks.find((p) => p.name === f.name);
                return (
                  <tr key={f.name} className={pick ? "row-active" : undefined}>
                    <td>
                      <input
                        type="checkbox"
                        checked={!!pick}
                        onChange={() => togglePick(f.name)}
                        aria-label={`选择因子 ${f.name}`}
                      />
                    </td>
                    <td className="cell-strong">
                      <span className="mono">{f.name}</span>
                    </td>
                    <td>
                      <Pill tone={f.direction === "higher_is_better" ? "accent" : "violet"}>
                        {f.direction === "higher_is_better" ? "高为好" : "低为好"}
                      </Pill>
                    </td>
                    <td>
                      <input
                        type="number"
                        className="input"
                        step="0.1"
                        min="0.1"
                        style={{ width: 92 }}
                        value={pick?.weight ?? 1}
                        disabled={!pick}
                        onChange={(e) => setWeight(f.name, Number(e.target.value))}
                        aria-label={`${f.name} 权重`}
                      />
                    </td>
                    <td className="hint">{f.brief ?? f.description}</td>
                  </tr>
                );
              })}
            </tbody>
          </table>
        </div>
      </Card>

      <Card title="回测条件" icon="gauge">
        {picks.length > 0 ? (
          <div className="chips" style={{ marginBottom: 14 }}>
            {picks.map((p) => (
              <span className="chip" key={p.name}>
                <b className="mono">{p.name}</b>
                权重 {p.weight}
                <button
                  type="button"
                  className="chip__x"
                  aria-label={`移除 ${p.name}`}
                  onClick={() => removePick(p.name)}
                >
                  <Icon name="x" size={12} />
                </button>
              </span>
            ))}
          </div>
        ) : (
          <div className="hint" style={{ marginBottom: 14 }}>
            尚未选择因子 —— 在上方勾选并设置权重。
          </div>
        )}

        <div className="form-grid">
          <Field label="Top N">
            <input
              type="number"
              className="input"
              min={1}
              max={200}
              value={topN}
              onChange={(e) => setTopN(Number(e.target.value))}
            />
          </Field>
          <Field label="调仓频率">
            <select
              className="input"
              value={rebalance}
              onChange={(e) => setRebalance(e.target.value as "monthly" | "weekly")}
            >
              <option value="monthly">月度</option>
              <option value="weekly">周度</option>
            </select>
          </Field>
          <Field label="开始日期">
            <input type="date" className="input" value={start} onChange={(e) => setStart(e.target.value)} />
          </Field>
          <Field label="结束日期">
            <input type="date" className="input" value={end} onChange={(e) => setEnd(e.target.value)} />
          </Field>
          <Field label="标的范围">
            <label className="row" style={{ gap: 6, color: "var(--text-2)", fontSize: 13, cursor: "pointer" }}>
              <input type="checkbox" checked={excludeSt} onChange={(e) => setExcludeSt(e.target.checked)} />
              剔除 ST
            </label>
          </Field>
          <Btn
            variant="primary"
            icon="play"
            loading={running}
            disabled={running || picks.length === 0}
            onClick={run}
          >
            {running ? "后台运行中…" : `回测组合（${picks.length} 个因子）`}
          </Btn>
        </div>

        {running ? (
          <div style={{ marginTop: 14 }}>
            <Progress
              value={30}
              label={
                <>
                  任务 <span className="mono">{jobId || "排队中…"}</span> 后台执行中，完成后结果自动展示在本页。
                </>
              }
            />
          </div>
        ) : null}
        {error ? <div style={{ marginTop: 12 }}><Banner tone="error">{error}</Banner></div> : null}
      </Card>

      {result ? <ResultView result={result} params={{ picks, topN, rebalance, excludeSt, start, end }} /> : null}
    </>
  );
}

function ResultView({
  result,
  params,
}: {
  result: BacktestResult;
  params: { picks: Pick[]; topN: number; rebalance: string; excludeSt: boolean; start: string; end: string };
}) {
  const s = result.summary;
  return (
    <>
      <div className="between" style={{ margin: "6px 0 14px" }}>
        <div className="row">
          <Pill tone="pos" icon="check">
            回测完成
          </Pill>
          <Pill tone="violet" icon="target">Top {params.topN}</Pill>
          <Pill>{params.rebalance === "monthly" ? "月度调仓" : "周度调仓"}</Pill>
          {params.excludeSt ? <Pill>剔除 ST</Pill> : null}
          <Pill>{params.start} ~ {params.end}</Pill>
        </div>
        <div className="row" style={{ fontSize: 22, fontWeight: 700 }}>
          区间收益 <Signed value={s.total_return_pct} suffix="%" />
        </div>
      </div>

      <BacktestMetrics s={s} />

      <div className="chart-grid">
        <Card icon="chartLine" title="净值曲线" tools={<Pill tone="pos">期末 {s.final_equity.toLocaleString()}</Pill>}>
          <LineChart data={result.equity_curve} color="#3ddc97" fill height={300} xFmt={(d) => d.slice(5)} yFmt={(v) => v.toFixed(2)} />
        </Card>
        <Card icon="chartLine" title="回撤（%）" tools={<Pill tone="neg">最大 {s.max_drawdown_pct.toFixed(2)}%</Pill>}>
          <LineChart data={result.drawdown} color="#ff7a7a" height={300} xFmt={(d) => d.slice(5)} yFmt={(v) => v.toFixed(2) + "%"} />
        </Card>
      </div>

      <Card icon="calendar" title="月度收益（%）">
        <MonthlyReturnsTable rows={result.monthly_returns} />
      </Card>

      <UnimplementedNote items={result.unimplemented} />
    </>
  );
}