"use client";

import { useCallback, useEffect, useRef, useState } from "react";
import { apiGet } from "@/lib/api";
import type { Stock } from "@/lib/types";
import {
  PageHeader,
  Card,
  Banner,
  Empty,
  Pill,
  SkeletonLines,
  SearchBox,
} from "@/components/ui";
import { Icon } from "@/components/icons";

const LIMIT = 300;

function marketOf(symbol: string): string {
  return symbol.slice(-2);
}

function statusView(s: Stock) {
  switch (s.status) {
    case "L":
      return (
        <Pill tone="pos">
          上市
        </Pill>
      );
    case "D":
      return <Pill tone="neg">退市</Pill>;
    case "P":
      return <Pill tone="warn">暂停</Pill>;
    default:
      return <Pill>{s.status}</Pill>;
  }
}

export default function StocksPage() {
  const [stocks, setStocks] = useState<Stock[]>([]);
  const [q, setQ] = useState("");
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState("");
  const [reloadKey, setReloadKey] = useState(0);
  const first = useRef(true);

  const load = useCallback(async () => {
    setError("");
    try {
      const list = await apiGet<Stock[]>(
        `/stocks?limit=${LIMIT}&q=${encodeURIComponent(q)}`,
      );
      setStocks(list);
    } catch (e) {
      setError((e as Error).message);
      setStocks([]);
    } finally {
      setLoading(false);
    }
  }, [q]);

  // 输入防抖 250ms 后再请求
  useEffect(() => {
    if (first.current) {
      first.current = false;
      void load();
      return;
    }
    setLoading(true);
    const t = window.setTimeout(() => void load(), 250);
    return () => window.clearTimeout(t);
  }, [q, reloadKey, load]);

  return (
    <>
      <PageHeader
        title="股票池"
        sub="本地股票基础信息（Tushare 同步）。支持按代码 / 名称模糊搜索，最多展示 300 条。"
        actions={
          <>
            <Pill tone="accent" icon="candles">
              共 {stocks.length} 条
            </Pill>
            <button
              type="button"
              className="btn btn--sm"
              aria-label="刷新列表"
              onClick={() => {
                setLoading(true);
                setReloadKey((k) => k + 1);
              }}
            >
              <Icon name="refresh" size={14} />
              刷新
            </button>
          </>
        }
      />

      {error ? (
        <Banner tone="error">加载失败：{error}</Banner>
      ) : null}

      <div className="row" style={{ marginBottom: 14 }}>
        <SearchBox
          value={q}
          onChange={setQ}
          onClear={() => setQ("")}
          placeholder="按代码 / 名称搜索，如 600519 或 茅台"
          label="搜索股票"
        />
      </div>

      <Card flush>
        <div className="table-wrap">
          <table className="tbl">
            <thead>
              <tr>
                <th>代码</th>
                <th>名称</th>
                <th>市场</th>
                <th>行业</th>
                <th>地区</th>
                <th>上市日</th>
                <th>状态</th>
              </tr>
            </thead>
            <tbody>
              {stocks.map((s) => (
                <tr key={s.symbol}>
                  <td className="cell-mono cell-strong">{s.symbol}</td>
                  <td>{s.name}</td>
                  <td>
                    <span className="tag tag--mono">{marketOf(s.symbol)}</span>
                  </td>
                  <td>{s.industry ? <span className="tag">{s.industry}</span> : <span className="hint">—</span>}</td>
                  <td className="hint">{s.area ?? "—"}</td>
                  <td className="cell-mono">{s.list_date}</td>
                  <td>{statusView(s)}</td>
                </tr>
              ))}
            </tbody>
          </table>
        </div>
        {loading && !error && stocks.length === 0 ? (
          <div style={{ padding: 18 }}>
            <SkeletonLines n={6} />
          </div>
        ) : null}
        {!loading && !error && stocks.length === 0 ? (
          <Empty
            icon="search"
            title={q ? "没有匹配的股票" : "股票池为空"}
            hint={
              q
                ? `「${q}」没有命中。试试更短的代码或名称关键词。`
                : "请先通过后端同步基础信息：uv run python -m app.cli.sync basic"
            }
          />
        ) : null}
        {stocks.length > 0 ? (
          <div
            className="hint"
            style={{
              padding: "8px 16px",
              borderTop: "1px solid var(--line)",
              display: "flex",
              alignItems: "center",
              gap: 14,
            }}
          >
            <span>显示前 {stocks.length} 条（接口上限 {LIMIT}）</span>
            <span className="row" style={{ gap: 4 }}>
              <Dot color="var(--pos)" />
              上市
            </span>
            <span className="row" style={{ gap: 4 }}>
              <Dot color="var(--warn)" />
              暂停
            </span>
            <span className="row" style={{ gap: 4 }}>
              <Dot color="var(--neg)" />
              退市
            </span>
          </div>
        ) : null}
      </Card>
    </>
  );
}

function Dot({ color }: { color: string }) {
  return (
    <span
      aria-hidden="true"
      style={{
        display: "inline-block",
        width: 8,
        height: 8,
        borderRadius: "50%",
        background: color,
      }}
    />
  );
}