import {
  useCallback,
  useEffect,
  useRef,
  useState,
  type ReactNode,
} from "react";
import {
  Banner,
  Button,
  Card,
  SideSheet,
  Spin,
  Tag,
} from "@douyinfe/semi-ui-19";
import {
  CalendarClock,
  ExternalLink,
  Megaphone,
  RefreshCw,
  Sparkles,
  Trophy,
  TrendingUp,
} from "lucide-react";
import { api, formatTime } from "../api";
import "./home-information.css";

type Item = {
  id: string;
  title: string;
  description: string;
  date?: string;
  type?: string;
  start?: string;
  end?: string;
  timezone?: string;
  original_start?: string;
  original_end?: string;
  date_status?: string;
  status?: string;
  rank?: number | null;
  alphas?: number | null;
  robustness_score?: number | null;
  progress?: string | null;
  url: string;
  links: string[];
};
type Content = {
  items?: Item[];
  total?: number;
  next_offset?: number | null;
  rank?: number | null;
  change?: number | null;
  label?: string;
  url?: string;
  detail?: Item;
  sources?: { id: string; text: string }[];
  agreement_updated?: string;
  agreement_title?: string;
  agreement_url?: string;
};
type Analysis = {
  items: {
    title: string;
    text: string;
    evidence: { source_id: string; quote: string }[];
  }[];
  suggestions: string[];
  model: string;
  generated_at: string;
  outdated: boolean;
};
type Snapshot = {
  ephemeral?: boolean;
  content: Content | null;
  fetched_at: string | null;
  error: string | null;
  stale: boolean;
  source_version: string;
  analysis: Analysis | null;
  can_generate: boolean;
};

function useInformation(
  module: string,
  refresh: number,
  query = "",
  dependency = "",
) {
  const [data, setData] = useState<Snapshot>();
  const [busy, setBusy] = useState("");
  const [error, setError] = useState("");
  const sequence = useRef(0);
  const controller = useRef<AbortController | null>(null);
  const previousRefresh = useRef(refresh);
  const generating = useRef(false);
  const deferredRead = useRef<string | null>(null);
  const load = useCallback(
    async function loadInformation(action = "") {
      if (generating.current) {
        if (action !== "generate")
          deferredRead.current =
            deferredRead.current === "refresh" ? "refresh" : action;
        return;
      }
      generating.current = action === "generate";
      const id = ++sequence.current;
      controller.current?.abort();
      const abort = new AbortController();
      controller.current = abort;
      setBusy(action || "read");
      setError("");
      try {
        const result = await api<Snapshot>(
          `/dashboard/information/${module}${action ? `/${action}` : ""}${query}`,
          {
            method: action ? "POST" : "GET",
            signal: abort.signal,
          },
        );
        if (id === sequence.current) setData(result);
      } catch (e) {
        if (!abort.signal.aborted && id === sequence.current)
          setError((e as Error).message);
      } finally {
        if (id === sequence.current) {
          generating.current = false;
          setBusy("");
          const deferred = deferredRead.current;
          deferredRead.current = null;
          if (deferred !== null) void loadInformation(deferred);
        }
      }
    },
    [module, query],
  );
  useEffect(() => {
    const action = previousRefresh.current === refresh ? "" : "refresh";
    previousRefresh.current = refresh;
    void load(action);
  }, [load, refresh, dependency]);
  useEffect(
    () => () => {
      controller.current?.abort();
      sequence.current++;
    },
    [],
  );
  useEffect(() => {
    const update = () => {
      void load();
    };
    window.addEventListener("ai-settings-changed", update);
    return () => window.removeEventListener("ai-settings-changed", update);
  }, [load]);
  return { data, busy, error, load };
}
type Resource = ReturnType<typeof useInformation>;

function SourceLink({
  url,
  children = "查看来源",
}: {
  url?: string;
  children?: ReactNode;
}) {
  if (!url || !/^https?:\/\//i.test(url)) return null;
  return (
    <a className="home-info-link" href={url} target="_blank" rel="noreferrer">
      {children}
      <ExternalLink size={12} aria-hidden="true" />
    </a>
  );
}
function DateLabel({ value, zone }: { value?: string | null; zone: string }) {
  // Date-only/naive timestamps have no proven timezone; preserve instead of guessing.
  if (!value) return <span>日期不明</span>;
  if (!/(Z|[+-]\d{2}:\d{2})$/i.test(value))
    return <span>{value}（时区未知）</span>;
  return (
    <time dateTime={value} title={`平台原始时间：${value}`}>
      {formatTime(value, zone)} · {zone}
    </time>
  );
}
function Interpretation({ state, zone }: { state: Resource; zone: string }) {
  const analysis = state.data?.analysis;
  return (
    <div className="home-info-analysis">
      <div className="home-info-row">
        <strong>
          <Sparkles size={15} aria-hidden="true" /> AI 解读
        </strong>
        <Button
          size="small"
          icon={<Sparkles size={14} aria-hidden="true" />}
          loading={state.busy === "generate"}
          disabled={!!state.busy || !state.data?.can_generate}
          onClick={() => void state.load("generate")}
        >
          {analysis ? "重新生成" : "生成解读"}
        </Button>
      </div>
      {!state.data?.can_generate && (
        <p className="home-info-muted">
          配置基础信息处理模型并读取平台信息后，可手动生成解读。
        </p>
      )}
      {analysis ? (
        <>
          <div className="home-info-meta">
            <span>
              {analysis.model} · {formatTime(analysis.generated_at, zone)}
            </span>
            {analysis.outdated && <Tag color="orange">解读待更新</Tag>}
          </div>
          {analysis.outdated && (
            <p className="home-info-muted">
              来源或模型配置已变化，以下为上次解读。
            </p>
          )}
          {analysis.items.map((item, index) => (
            <div className="home-insight" key={index}>
              <strong>{item.title}</strong>
              <p>{item.text}</p>
              {item.evidence.map((e, i) => (
                <details key={i}>
                  <summary>原文依据 · {e.source_id}</summary>
                  <blockquote>{e.quote}</blockquote>
                </details>
              ))}
            </div>
          ))}
          {!!analysis.suggestions.length && (
            <>
              <strong>建议安排 · 仅供参考</strong>
              <ul>
                {analysis.suggestions.map((s, i) => (
                  <li key={i}>{s}</li>
                ))}
              </ul>
            </>
          )}
        </>
      ) : (
        <p className="home-info-muted">
          {state.data?.ephemeral
            ? "解读仅暂存在内存，不写入数据库；重启或缓存到期后清除。"
            : "手动生成并保存，重新打开首页不会调用模型。"}
        </p>
      )}
    </div>
  );
}
function InformationCard({
  title,
  icon,
  state,
  zone,
  children,
  analysis = true,
}: {
  title: string;
  icon: ReactNode;
  state: Resource;
  zone: string;
  children: ReactNode;
  analysis?: boolean;
}) {
  return (
    <Card
      className="home-card home-information-card"
      title={
        <h2 className="home-panel-title">
          {icon}
          {title}
        </h2>
      }
      headerExtraContent={
        <Button
          size="small"
          type="tertiary"
          aria-label={`刷新${title}`}
          icon={<RefreshCw size={14} aria-hidden="true" />}
          disabled={!!state.busy}
          loading={state.busy === "refresh"}
          onClick={() => void state.load("refresh")}
        >
          刷新
        </Button>
      }
    >
      <div className="home-info-meta">
        <span>更新：{formatTime(state.data?.fetched_at, zone)}</span>
        {(state.data?.stale || (state.error && state.data?.content)) && (
          <Tag color="orange">缓存已过期</Tag>
        )}
      </div>
      {(state.error || state.data?.error) && (
        <Banner type="warning" description={state.error || state.data?.error} />
      )}
      {!state.data && state.busy && (
        <div className="home-info-loading">
          <Spin /> 正在读取{title}…
        </div>
      )}
      {state.data?.content && children}
      {analysis && <Interpretation state={state} zone={zone} />}
    </Card>
  );
}
function Empty({ children }: { children: ReactNode }) {
  return <p className="home-info-empty">{children}</p>;
}

function MessageCard({ refresh, zone }: { refresh: number; zone: string }) {
  const [offsets, setOffsets] = useState([0]);
  const offset = offsets[offsets.length - 1];
  return (
    <MessagePage
      key={offset}
      offset={offset}
      refresh={refresh}
      zone={zone}
      back={
        offsets.length > 1 ? () => setOffsets(offsets.slice(0, -1)) : undefined
      }
      next={(value) => setOffsets([...offsets, value])}
    />
  );
}
function MessagePage({
  offset,
  refresh,
  zone,
  back,
  next,
}: {
  offset: number;
  refresh: number;
  zone: string;
  back?: () => void;
  next: (offset: number) => void;
}) {
  const state = useInformation("messages", refresh, `?offset=${offset}`);
  const content = state.data?.content;
  return (
    <InformationCard
      title="公告与社区资讯"
      icon={<Megaphone size={18} />}
      state={state}
      zone={zone}
    >
      <p className="home-info-muted">
        仅展示最近一个月的公告、更新及社区资讯（按美东时间筛选），不写入数据库。
      </p>
      {content?.items?.length ? (
        <div className="home-info-feed">
          {content.items.map((item, index) => (
            <article className="home-info-item" key={item.id || index}>
              <div className="home-info-row">
                <strong>{item.title}</strong>
                {item.type && <Tag>{item.type}</Tag>}
              </div>
              <p className="home-info-muted">
                <DateLabel value={item.date} zone={zone} />
              </p>
              <details>
                <summary>查看消息正文</summary>
                <p className="home-info-prose">
                  {item.description || "平台未提供正文"}
                </p>
                {item.links.map((link) => (
                  <div key={link}>
                    <SourceLink url={link}>{link}</SourceLink>
                  </div>
                ))}
              </details>
              <SourceLink url={item.url} />
            </article>
          ))}
        </div>
      ) : (
        <Empty>最近一个月本页暂无平台消息</Empty>
      )}
      <div className="home-info-row home-info-pagination">
        <span className="home-info-muted">
          从第 {offset + 1} 条开始
          {content?.total != null
            ? ` · 最近一个月共 ${content.total} 条`
            : ""}{" "}
          · 解读仅针对本页
        </span>
        <div className="home-info-actions">
          <Button size="small" disabled={!back || !!state.busy} onClick={back}>
            上一页
          </Button>
          <Button
            size="small"
            disabled={content?.next_offset == null || !!state.busy}
            onClick={() => next(content!.next_offset!)}
          >
            下一页
          </Button>
        </div>
      </div>
    </InformationCard>
  );
}
function LeaderboardCard({ refresh, zone }: { refresh: number; zone: string }) {
  const state = useInformation("leaderboard", refresh);
  const data = state.data?.content;
  return (
    <InformationCard
      title="顾问排行榜"
      icon={<TrendingUp size={18} />}
      state={state}
      zone={zone}
      analysis={false}
    >
      <p className="home-info-muted">{data?.label}</p>
      <div className="home-info-rank">
        {data?.rank?.toLocaleString() ?? "—"}
      </div>
      <p>
        {data?.rank == null
          ? "平台未提供有效名次"
          : data?.change == null
            ? "暂无可比较的历史快照"
            : data.change === 0
              ? "较上次有效快照持平"
              : `较上次有效快照${data.change > 0 ? "上升" : "下降"} ${Math.abs(data.change)} 名`}
      </p>
      <p className="home-info-muted">
        仅比较同一账户、美东同日的顾问日度榜快照。比赛排名在比赛卡片中单独展示。
      </p>
      <SourceLink url={data?.url} />
    </InformationCard>
  );
}
function CompetitionDetail({
  id,
  zone,
  refresh,
}: {
  id: string;
  zone: string;
  refresh: number;
}) {
  const state = useInformation(
    "competition",
    refresh,
    `?competition_id=${encodeURIComponent(id)}`,
  );
  const data = state.data?.content;
  return (
    <InformationCard
      title="比赛详情与规则"
      icon={<Trophy size={18} />}
      state={state}
      zone={zone}
    >
      {data?.detail && (
        <>
          <h3>{data.detail.title}</h3>
          <p className="home-info-prose">{data.detail.description}</p>
          <p>
            截止：
            <DateLabel value={data.detail.end} zone={zone} />
          </p>
          <p>
            比赛排名：{data.detail.rank ?? "平台未提供"} · Alpha 数：
            {data.detail.alphas ?? "平台未提供"}
          </p>
          <p>
            进度：{data.detail.progress ?? "平台未提供"} · 稳健性分数：
            {data.detail.robustness_score ?? "平台未提供"}
          </p>
          <SourceLink url={data.detail.url}>平台比赛页面</SourceLink>
        </>
      )}
      <h3>{data?.agreement_title || "比赛协议"}</h3>
      <p className="home-info-muted">
        协议更新：
        <DateLabel value={data?.agreement_updated} zone={zone} />
      </p>
      <SourceLink url={data?.agreement_url}>协议原文入口</SourceLink>
      <details className="home-info-agreement">
        <summary>展开协议原文</summary>
        {data?.sources?.length ? (
          data.sources.map((s) => (
            <section key={s.id}>
              <strong>{s.id}</strong>
              <p className="home-info-prose">{s.text}</p>
            </section>
          ))
        ) : (
          <Empty>平台未提供可解读的协议正文</Empty>
        )}
      </details>
    </InformationCard>
  );
}
function EventsCard({
  refresh,
  zone,
  dependency,
}: {
  refresh: number;
  zone: string;
  dependency: string;
}) {
  const state = useInformation("events", refresh, "", dependency);
  return (
    <InformationCard
      title="未来活动"
      icon={<CalendarClock size={18} />}
      state={state}
      zone={zone}
    >
      {state.data?.content?.items?.length ? (
        <div className="home-event-grid">
          {state.data.content.items.map((item, i) => (
            <article key={item.id || i} className="home-info-item">
              <div className="home-info-row">
                <strong>{item.title}</strong>
                <Tag
                  color={item.date_status === "日期不明" ? "orange" : "blue"}
                >
                  {item.date_status}
                </Tag>
              </div>
              <p>
                开始：
                <DateLabel value={item.start} zone={zone} />
                <br />
                结束：
                <DateLabel value={item.end} zone={zone} />
              </p>
              <p className="home-info-muted">
                平台时区：{item.timezone || "未知"} · 原始时间：
                {item.original_start || item.start || "未知"} 至{" "}
                {item.original_end || item.end || "未知"}
              </p>
              <p className="home-info-prose">{item.description}</p>
              <SourceLink url={item.url} />
            </article>
          ))}
        </div>
      ) : (
        <Empty>暂无尚未结束的活动</Empty>
      )}
    </InformationCard>
  );
}
export function HomeInformation({ timezone: zone }: { timezone: string }) {
  const [refresh, setRefresh] = useState(0);
  const [selected, setSelected] = useState("");
  const competitions = useInformation("competitions", refresh);
  return (
    <div className="home-information">
      <div className="home-info-row">
        <h2>平台动向</h2>
        <Button
          icon={<RefreshCw size={15} />}
          onClick={() => setRefresh(refresh + 1)}
        >
          刷新信息
        </Button>
      </div>
      <div className="home-platform-grid">
        <MessageCard refresh={refresh} zone={zone} />
        <LeaderboardCard refresh={refresh} zone={zone} />
      </div>
      <InformationCard
        title="比赛参与与进度"
        icon={<Trophy size={18} />}
        state={competitions}
        zone={zone}
      >
        <p className="home-info-muted">
          优先展示未结束比赛，按截止时间排序；点击查看当前协议及规则解读。
        </p>
        {competitions.data?.content?.items?.length ? (
          <div className="home-competition-grid">
            {competitions.data.content.items.map((item) => (
              <article className="home-info-item" key={item.id}>
                <div className="home-info-row">
                  <strong>{item.title}</strong>
                  <Tag
                    color={
                      item.date_status === "已结束"
                        ? "grey"
                        : item.date_status === "日期不明"
                          ? "orange"
                          : "green"
                    }
                  >
                    {item.date_status}
                  </Tag>
                </div>
                <p>
                  截止：
                  <DateLabel value={item.end} zone={zone} />
                </p>
                <p className="home-info-muted">
                  平台状态：{item.status || "平台未提供"}
                  <br />
                  比赛排名：{item.rank ?? "平台未提供"} · Alpha 数：
                  {item.alphas ?? "平台未提供"}
                </p>
                <Button size="small" onClick={() => setSelected(item.id)}>
                  查看详情与规则
                </Button>
              </article>
            ))}
          </div>
        ) : (
          <Empty>暂无已参加的比赛</Empty>
        )}
      </InformationCard>
      <EventsCard
        refresh={refresh}
        zone={zone}
        dependency={competitions.data?.source_version || ""}
      />
      <SideSheet
        title="比赛信息"
        visible={!!selected}
        onCancel={() => setSelected("")}
        width="min(760px, 100vw)"
        closeOnEsc
      >
        {selected && (
          <CompetitionDetail
            key={selected}
            id={selected}
            zone={zone}
            refresh={refresh}
          />
        )}
      </SideSheet>
    </div>
  );
}