import type { Metadata } from "next";
import { cookies } from "next/headers";
import Link from "next/link";
import { PenSquare, SearchX, MessagesSquare } from "lucide-react";
import {
  fetchPosts,
  fetchOverview,
  fetchBoardSidebar,
  fetchSidebar,
  fetchFriendLinks,
  type FriendLink,
  type OverviewResponse,
  type BoardSidebarResponse,
  type SidebarPublicPayload,
} from "@/lib/api";
import { defaultSidebarConfig, sidebarScopeLists } from "@/lib/sidebarMeta";
import SidebarRenderer, { type SidebarBlockProps } from "@/components/sidebar/SidebarRenderer";
import { authCookieHeader } from "@/lib/cookies";
import { getMeCached, getPublicSettingsCached } from "@/lib/serverData";
import { siteDocumentTitle } from "@/lib/brand";
import { isAdminOrAbove } from "@/lib/roles";
import Pagination from "@/components/Pagination";
import PostRow from "@/components/PostRow";
import FeedTabs from "@/components/home/FeedTabs";
import FeedNewTip from "@/components/home/FeedNewTip";
import { WorkspaceNavMobile } from "@/components/home/WorkspaceNav";
import { BoardMissingPanel } from "@/components/home/BoardPanels";
import { requestCanonical } from "@/lib/canonicalMeta";
import { defaultFeedSort, homeCanonicalQuery, normalizeFeedSort } from "@/lib/siteUrl";
import { listingJsonLd } from "@/lib/jsonLd";
import JsonLd from "@/components/JsonLd";

interface HomePageProps {
  searchParams: Promise<{ q?: string; page?: string; sort?: string; board?: string }>;
}

export async function generateMetadata({ searchParams }: HomePageProps): Promise<Metadata> {
  const settings = await getPublicSettingsCached();
  const sp = await searchParams;
  const allowComments = settings.allow_comments !== false;
  return {
    title: { absolute: siteDocumentTitle(settings.site_name, settings.site_slogan) },
    description: settings.site_description,
    ...(await requestCanonical("/", homeCanonicalQuery(sp, allowComments))),
  };
}

// 空结果面板（无帖 / 无搜索结果）
function EmptyState({ keyword }: { keyword: string }) {
  return (
    <div className="text-center py-20 px-6">
      <span
        className="inline-flex w-14 h-14 rounded-full items-center justify-center mb-4"
        style={{ background: "var(--accent-soft)", color: "var(--accent)" }}
      >
        {keyword ? <SearchX size={26} /> : <MessagesSquare size={26} />}
      </span>
      <p className="font-bold text-lg" style={{ color: "var(--ink)" }}>
        {keyword ? "没有找到相关帖子" : "还没有帖子"}
      </p>
      <p className="meta mt-1.5">
        {keyword ? `换个关键词试试，或者发起“${keyword}”相关的话题` : "成为第一个发起讨论的人吧"}
      </p>
      {keyword ? (
        <div className="flex items-center justify-center gap-3 mt-6">
          <Link href="/" className="btn btn-line">
            清除搜索
          </Link>
          <Link href="/compose" className="btn btn-primary">
            <PenSquare size={15} /> 发起这个话题
          </Link>
        </div>
      ) : (
        <Link href="/compose" className="btn btn-primary mt-6">
          <PenSquare size={15} /> 写新帖
        </Link>
      )}
    </div>
  );
}

export default async function HomePage({ searchParams }: HomePageProps) {
  const sp = await searchParams;
  const keyword = sp.q?.trim() || "";
  const page = Math.max(1, parseInt(sp.page || "1", 10) || 1);
  const boardId = Math.max(0, parseInt(sp.board || "0", 10) || 0);
  const isSearch = keyword.length > 0;

  const cookie = authCookieHeader(await cookies());
  const publicSettings = await getPublicSettingsCached();
  const allowComments = publicSettings.allow_comments !== false;
  const sort = normalizeFeedSort(sp.sort, allowComments);
  // 与 layout 共享同一份 /me 请求（React cache 去重）
  const mePromise = getMeCached(cookie || undefined);
  const postsPromise = fetchPosts(
    page,
    20,
    isSearch || boardId <= 0 ? undefined : boardId,
    sort,
    keyword,
    sort === "recommended",
    cookie
  );
  // 聚合面板失败不阻塞帖子流
  const overviewPromise: Promise<OverviewResponse | null> = fetchOverview(cookie).catch(() => null);
  const boardSidebarPromise: Promise<BoardSidebarResponse | null> =
    boardId > 0 && !isSearch
      ? fetchBoardSidebar(boardId, cookie).catch(() => null)
      : Promise.resolve(null);
  // 侧栏布局配置失败不阻塞页面，回落默认布局
  const sidebarPromise: Promise<SidebarPublicPayload | null> = isSearch
    ? Promise.resolve(null)
    : fetchSidebar(cookie).catch(() => null);
  // 友情链接列表失败不阻塞页面
  const friendLinksPromise: Promise<{ links: FriendLink[] } | null> = isSearch
    ? Promise.resolve(null)
    : fetchFriendLinks(cookie).catch(() => null);

  const [me, postsData, overview, boardSidebar, sidebarData, friendLinksData] = await Promise.all([
    mePromise,
    postsPromise,
    overviewPromise,
    boardSidebarPromise,
    sidebarPromise,
    friendLinksPromise,
  ]);
  const sidebar = sidebarData ?? { config: defaultSidebarConfig(), widgets: [] };
  const user = me.user;
  const boards = overview?.boards ?? [];
  const canManageAnnouncements = !!user && isAdminOrAbove(user.role);
  const canManagePages = canManageAnnouncements;
  const sidebarPages = overview?.sidebar_pages ?? [];
  const activeBoard = boards.find((b) => b.id === boardId) || boardSidebar?.board || null;
  const showBoardPanels = boardId > 0 && !isSearch;
  // boardId 有效但接口失败 → 显示简卡；成功则板级右栏；否则全站右栏
  const boardPanelsMissing = showBoardPanels && !boardSidebar;

  // 侧栏布局：板块态右栏走 board 配置（左栏跟随首页），其余走 home 配置
  const scopeLists = sidebarScopeLists(sidebar.config, showBoardPanels ? "board" : "home");
  // 三栏竖向分隔线跟随左右栏显隐（空配置不画悬空线）
  const hasLeftRail = scopeLists.left.length > 0;
  const hasRightRail = showBoardPanels
    ? boardSidebar
      ? scopeLists.right.length > 0
      : boardPanelsMissing
    : !!(overview && scopeLists.right.length > 0);
  const sidebarProps: SidebarBlockProps = {
    allowComments,
    user,
    boards,
    checkin: (boardSidebar ?? overview)?.checkin ?? undefined,
    // 友链列表独立于 overview：即使聚合接口失败也保留「申请」入口
    friendLinks: friendLinksData?.links ?? [],
    ...(overview
      ? {
          stats: overview.stats,
          announcements: overview.announcements,
          canManageAnnouncements,
          ads: overview.ads ?? [],
          adsPanelTitle: overview.ads_panel_title || "自助推广",
          adsEnabled: overview.ads_enabled !== false,
          sponsors: overview.sponsors ?? [],
          sponsorsPanelTitle: overview.sponsors_panel_title || "赞助商",
          sponsorsEnabled: overview.sponsors_enabled !== false,
          hot: overview.hot,
          newUsers: overview.new_users,
          activeUsers: overview.active_users,
        }
      : {}),
    canManagePages,
    sidebarPages,
    siteDescription: publicSettings.site_description,
    ...(boardSidebar
      ? {
          board: boardSidebar.board,
          moderators: boardSidebar.moderators,
          boardStats: boardSidebar.stats,
          boardHot: boardSidebar.hot,
          boardActiveUsers: boardSidebar.active_users,
        }
      : {}),
  };

  const pageName = isSearch
    ? `搜索“${keyword}”`
    : activeBoard
      ? activeBoard.name
      : sort === "new"
        ? "最新发布"
        : sort === "recommended"
          ? "推荐帖"
          : "最新讨论";
  const listingLd = listingJsonLd({
    siteName: publicSettings.site_name || "姜十三论坛",
    siteDescription: publicSettings.site_description,
    pageName,
    path: "/",
    query: homeCanonicalQuery(sp, allowComments),
    items: postsData.posts.map((p) => ({ id: p.id, name: p.title })),
    page,
    pageSize: 20,
    urlStyle: publicSettings.url_style,
  });

  // 搜索态：单栏占满，无 Tabs/侧栏
  if (isSearch) {
    return (
      <div className="max-w-3xl mx-auto">
        <JsonLd data={listingLd} />
        <div className="mb-5">
          <h1 className="text-[24px] sm:text-[28px] font-extrabold tracking-tight" style={{ color: "var(--ink)" }}>
            搜索“<span style={{ color: "var(--accent)" }}>{keyword}</span>”
          </h1>
          <p className="meta mt-2">共 {postsData.total} 篇结果 · 按相关度与时间排序</p>
        </div>
        <div className="panel overflow-hidden max-sm:-mx-4 max-sm:rounded-none max-sm:border-x-0 max-sm:shadow-none">
          {postsData.posts.length > 0 ? (
            postsData.posts.map((post, i) => (
              <PostRow key={post.id} post={post} showBoard index={i} showViews={false} showLike={false} />
            ))
          ) : (
            <EmptyState keyword={keyword} />
          )}
        </div>
        <Pagination
          total={postsData.total}
          page={page}
          size={20}
          basePath="/"
          query={{
            q: keyword,
            ...(sort !== defaultFeedSort(allowComments) ? { sort } : {}),
          }}
        />
      </div>
    );
  }

  // 置顶帖直接按后端 pinned DESC 顺序并入统一信息流；标题仅供屏幕阅读器
  const pageQuery: Record<string, string> = {};
  if (boardId > 0) pageQuery.board = String(boardId);
  if (sort !== defaultFeedSort(allowComments)) pageQuery.sort = sort;

  return (
    <div className="j13-fluid-home">
      <JsonLd data={listingLd} />
      {/* 移动端：顶部横向板块条 = 左右抽屉的触发行——
          ☰ 打开左抽屉（桌面左栏：板块目录 + 工作台），▦ 打开右抽屉（桌面右栏面板） */}
      <WorkspaceNavMobile
        boards={boards}
        left={
          scopeLists.left.length > 0 ? (
            <SidebarRenderer
              blocks={scopeLists.left}
              widgets={sidebar.widgets}
              props={sidebarProps}
              className="space-y-4"
            />
          ) : undefined
        }
        right={
          scopeLists.right.length > 0 ? (
            <SidebarRenderer
              blocks={scopeLists.right}
              widgets={sidebar.widgets}
              props={sidebarProps}
              className="space-y-4"
            />
          ) : undefined
        }
      />

      <div className={`flex items-start gap-6 xl:gap-7 flex-1 ${activeBoard ? "" : "lg:mt-0"}`}>
        {/* 左栏：按配置渲染（缺省 = 板块目录） */}
        {scopeLists.left.length > 0 && (
          <aside className="j13-rail-left hidden lg:block w-56 xl:w-60 shrink-0 sticky top-[var(--rail-top)] max-h-[var(--rail-max-h)]">
            <SidebarRenderer blocks={scopeLists.left} widgets={sidebar.widgets} props={sidebarProps} />
          </aside>
        )}

        {/* 中栏：tab 栏与帖子流为同一个整体（左栏切板块只替换这一列）；self-stretch 撑满行高供分隔线贯通 */}
        <div
          className={`flex-1 min-w-0 self-stretch ${hasLeftRail ? "j13-home-sep-l" : ""} ${
            hasRightRail ? "j13-home-sep-r" : ""
          }`}
        >
          <h1 className="sr-only">{pageName}</h1>

          <div className="max-sm:-mx-4">
            <div className="j13-feed-head flex items-stretch justify-between gap-2 px-3 sm:px-4">
              <FeedTabs current={sort} boardId={boardId} />
              <span className="meta self-center shrink-0 text-[12px] tabular-nums">
                共 {postsData.total} 篇
              </span>
            </div>
            {user && (
              <FeedNewTip
                sort={sort}
                boardId={boardId}
                page={page}
                userId={user.id}
              />
            )}
            {postsData.posts.length > 0 ? (
              postsData.posts.map((post, i) => (
                <PostRow
                  key={post.id}
                  post={post}
                  showBoard={!activeBoard}
                  compact
                  index={i}
                  showViews={false}
                  showLike={false}
                />
              ))
            ) : (
              <EmptyState keyword="" />
            )}
          </div>

          <Pagination
            total={postsData.total}
            page={page}
            size={20}
            basePath="/"
            query={Object.keys(pageQuery).length > 0 ? pageQuery : undefined}
          />
        </div>

        {/* 右栏：选中板块时切板级面板，否则全站社区面板；均按配置渲染 */}
        {showBoardPanels ? (
          boardSidebar ? (
            scopeLists.right.length > 0 ? (
              <aside className="hidden w-[280px] shrink-0 lg:block xl:w-[300px]" aria-label="板块面板">
                <SidebarRenderer
                  blocks={scopeLists.right}
                  widgets={sidebar.widgets}
                  props={sidebarProps}
                  className="space-y-4"
                />
              </aside>
            ) : null
          ) : boardPanelsMissing ? (
            <BoardMissingPanel />
          ) : null
        ) : overview && scopeLists.right.length > 0 ? (
          <aside className="hidden w-[280px] shrink-0 lg:block xl:w-[300px]" aria-label="社区面板">
            <SidebarRenderer
              blocks={scopeLists.right}
              widgets={sidebar.widgets}
              props={sidebarProps}
              className="space-y-4"
            />
          </aside>
        ) : null}
      </div>
    </div>
  );
}