import Link from "next/link";
import {
  Flame,
  Users,
  MessageCircle,
  Heart,
  UserPlus,
  Link2,
  Megaphone,
  BarChart3,
  PenLine,
  Activity,
  TrendingUp,
  Info,
  Pin,
} from "lucide-react";
import type {
  PostListItem,
  ActiveUser,
  OverviewStats,
  AnnouncementSummary,
  NewUser,
  CheckinStatus,
  SidebarPageItem,
} from "@/lib/api";
import Avatar from "@/components/Avatar";
import { PulseCheckin } from "./CheckinCard";
import { FRIEND_LINKS } from "@/lib/friendLinks";
import { formatCompact, formatShortDate } from "@/lib/format";

/* ---------- 站点数据（2×2 bento 统计瓦片） ---------- */

function PulseCard({
  stats,
  checkin,
  allowComments,
}: {
  stats: OverviewStats;
  checkin?: CheckinStatus | null;
  allowComments: boolean;
}) {
  const cells = [
    {
      icon: <Users size={12.5} />,
      label: "注册用户",
      value: formatCompact(stats.users),
      foot: `+${formatCompact(stats.today_users)} 今日`,
      up: true,
    },
    {
      icon: <PenLine size={12.5} />,
      label: "话题总数",
      value: formatCompact(stats.posts),
      foot: `+${formatCompact(stats.today_posts)} 今日`,
      up: true,
    },
    ...(allowComments
      ? [
          {
            icon: <MessageCircle size={12.5} />,
            label: "回复总数",
            value: formatCompact(stats.comments),
            foot: `+${formatCompact(stats.today_comments)} 今日`,
            up: true,
          },
        ]
      : [
          {
            icon: <TrendingUp size={12.5} />,
            label: "今日新帖",
            value: formatCompact(stats.today_posts),
            foot: "本日新增",
            up: stats.today_posts > 0,
          },
        ]),
    {
      icon: <Activity size={12.5} />,
      label: "在线用户",
      value: formatCompact(stats.online),
      foot: `峰值 ${formatCompact(stats.peak_online)}`,
      up: false,
    },
  ];
  return (
    <section className="j13-module" aria-label="站点数据">
      <div className="flex items-center justify-between">
        <p className="j13-module-title">
          <BarChart3 size={15} style={{ color: "var(--accent)" }} /> 站点数据
        </p>
        <span
          className="inline-flex items-center gap-1.5 text-[11px] font-normal normal-case tracking-normal"
          style={{ color: "var(--ink-3)" }}
          data-tip="近 5 分钟在线"
        >
          <span className="j13-pulse-dot" aria-hidden="true" />
          实时
        </span>
      </div>
      <div className="j13-pulse">
        {cells.map((c) => (
          <div key={c.label} className="j13-pulse-cell">
            <p className="j13-pulse-lab">
              <span style={{ color: "var(--accent)" }} aria-hidden="true">
                {c.icon}
              </span>
              {c.label}
            </p>
            <p className="j13-pulse-num">{c.value}</p>
            <p className={`j13-pulse-foot${c.up ? " is-up" : ""}`}>
              {c.up && <TrendingUp size={10.5} aria-hidden="true" />}
              {c.foot}
            </p>
          </div>
        ))}
      </div>
      <div className="j13-pulse-checkin">
        <PulseCheckin initial={checkin} />
      </div>
    </section>
  );
}

/* ---------- 关于本站（侧栏单页） ---------- */

function AboutSite({ pages }: { pages: SidebarPageItem[] }) {
  if (pages.length === 0) return null;

  if (pages.length === 1) {
    const p = pages[0];
    return (
      <section className="j13-module" aria-label="关于本站">
        <p className="j13-module-title">
          <Info size={15} style={{ color: "var(--accent)" }} /> 关于本站
        </p>
        <Link href={`/p/${p.slug}`} className="block mt-2 rounded-lg px-0.5 py-1 transition-colors hover:bg-[var(--accent-soft)]">
          <p className="text-[14px] font-semibold leading-snug" style={{ color: "var(--ink)" }}>
            {p.title}
          </p>
          {p.excerpt ? (
            <p className="meta text-[12.5px] mt-1.5 leading-relaxed line-clamp-3">{p.excerpt}</p>
          ) : null}
        </Link>
      </section>
    );
  }

  return (
    <section className="j13-module" aria-label="关于本站">
      <p className="j13-module-title mb-1.5">
        <Info size={15} style={{ color: "var(--accent)" }} /> 关于本站
      </p>
      <ul className="space-y-0.5">
        {pages.map((p) => (
          <li key={p.id}>
            <Link href={`/p/${p.slug}`} className="j13-raillink" data-tip={p.title}>
              <span className="flex-1 min-w-0 truncate text-[13px] font-medium" style={{ color: "var(--ink)" }}>
                {p.title}
              </span>
            </Link>
          </li>
        ))}
      </ul>
    </section>
  );
}

/* ---------- 站点公告 ---------- */

function Announcements({
  items,
  canManageAnnouncements,
}: {
  items: AnnouncementSummary[];
  canManageAnnouncements?: boolean;
}) {
  return (
    <section className="j13-module" aria-label="站点公告">
      <div className="flex items-center justify-between gap-2">
        <p className="j13-module-title !mb-0">
          <Megaphone size={15} style={{ color: "var(--accent)" }} /> 站点公告
        </p>
        <span className="inline-flex items-center gap-2 shrink-0">
          <Link
            href="/announcements"
            className="meta text-[12px] font-normal transition-colors hover:text-[var(--accent)]"
          >
            全部
          </Link>
          {canManageAnnouncements ? (
            <Link
              href="/admin/announcements"
              className="meta text-[12px] font-normal transition-colors hover:text-[var(--accent)]"
            >
              管理
            </Link>
          ) : null}
        </span>
      </div>
      {items.length === 0 ? (
        <p className="meta mt-2 px-0.5">暂无公告</p>
      ) : (
        <ul className="j13-anno-list">
          {items.map((a) => (
            <li key={a.id}>
              <Link
                href={`/announcement/${a.id}`}
                className="j13-anno-item"
                data-tip={a.title}
              >
                <span className="j13-anno-item-body">
                  <span className="j13-anno-item-title truncate inline-flex items-center gap-1 min-w-0">
                    {a.pinned ? (
                      <Pin
                        size={11}
                        className="shrink-0"
                        style={{ color: "var(--accent)" }}
                        aria-label="置顶"
                      />
                    ) : null}
                    <span className="truncate">{a.title}</span>
                  </span>
                  <span className="j13-anno-item-meta">
                    {a.tag ? (
                      <span className={`j13-anno-tag is-${a.tag_color}`}>{a.tag}</span>
                    ) : null}
                    <span className="meta text-[11px] tabular-nums">
                      {formatShortDate(a.created_at)}
                    </span>
                  </span>
                </span>
              </Link>
            </li>
          ))}
        </ul>
      )}
    </section>
  );
}

/* ---------- 热门榜 ---------- */

function HotRanking({ posts, allowComments }: { posts: PostListItem[]; allowComments: boolean }) {
  return (
    <section className="j13-module" aria-label="热门讨论">
      <p className="j13-module-title mb-1.5">
        <Flame size={15} style={{ color: "var(--clay)" }} /> 热门讨论
      </p>
      {posts.length === 0 ? (
        <p className="meta px-1.5 py-3">还没有热门讨论</p>
      ) : (
        <ol className="j13-ranklist">
          {posts.map((p, i) => (
            <li key={p.id}>
              <Link href={`/post/${p.id}`} className="j13-rank" data-tip={p.title}>
                <span className="j13-rank-no">{i + 1}</span>
                <span className="min-w-0 flex-1">
                  <span className="j13-rank-title truncate">
                    {p.title}
                  </span>
                  <span className="mt-1 flex items-center gap-2.5 meta text-[11.5px]">
                    {allowComments ? (
                      <span className="inline-flex items-center gap-1">
                        <MessageCircle size={11.5} /> {p.comment_count}
                      </span>
                    ) : null}
                    <span className="inline-flex items-center gap-1">
                      <Heart size={11.5} /> {p.like_count}
                    </span>
                  </span>
                </span>
              </Link>
            </li>
          ))}
        </ol>
      )}
    </section>
  );
}

/* ---------- 最新注册 ---------- */

function NewUsers({ users }: { users: NewUser[] }) {
  if (users.length === 0) return null;
  return (
    <section className="j13-module" aria-label="最新注册">
      <p className="j13-module-title mb-3">
        <UserPlus size={15} style={{ color: "var(--accent)" }} /> 最新注册
      </p>
      <ul className="grid grid-cols-4 gap-y-3">
        {users.map((u) => {
          const name = u.nickname || u.username;
          return (
            <li key={u.id}>
              <Link
                href={`/u/${u.id}`}
                className="flex flex-col items-center gap-1.5 rounded-lg px-1 py-1 transition-colors hover:bg-[var(--accent-soft)] focus-visible:bg-[var(--accent-soft)]"
              >
                <Avatar name={name} src={u.avatar} size={38} />
                <span
                  className="w-full truncate text-center text-[11px]"
                  style={{ color: "var(--ink-2)" }}
                  data-tip={name}
                >
                  {name}
                </span>
              </Link>
            </li>
          );
        })}
      </ul>
    </section>
  );
}

/* ---------- 活跃成员（本周发帖 / 回复） ---------- */

function ActiveUsers({ users, allowComments }: { users: ActiveUser[]; allowComments: boolean }) {
  return (
    <section className="j13-module" aria-label="本周活跃成员">
      <p className="j13-module-title mb-2">
        <Users size={15} style={{ color: "var(--accent)" }} /> 活跃成员
        <span className="ml-auto font-normal normal-case tracking-normal text-[11px]" style={{ color: "var(--ink-3)" }}>
          本周
        </span>
      </p>
      {users.length === 0 ? (
        <p className="meta px-1.5 py-2">本周还没有人互动</p>
      ) : (
        <ul className="space-y-0.5">
          {users.map((u) => {
            const name = u.nickname || u.username;
            return (
              <li key={u.id}>
                <Link href={`/u/${u.id}`} className="j13-raillink" data-tip={name}>
                  <Avatar name={name} src={u.avatar} size={30} />
                  <span className="flex-1 min-w-0">
                    <span
                      className="block truncate text-[13px] font-medium leading-tight"
                      style={{ color: "var(--ink)" }}
                    >
                      {name}
                    </span>
                    <span className="mt-px flex items-center gap-2.5 text-[11px] meta">
                      <span className="inline-flex items-center gap-1">
                        <PenLine size={10.5} /> 发帖 {u.post_count}
                      </span>
                      {allowComments ? (
                        <span className="inline-flex items-center gap-1">
                          <MessageCircle size={10.5} /> 回复 {u.comment_count}
                        </span>
                      ) : null}
                    </span>
                  </span>
                  <span
                    className="shrink-0 text-[13px] tabular-nums"
                    style={{ color: "var(--accent)" }}
                    aria-label={
                      allowComments
                        ? `本周共 ${u.post_count + u.comment_count} 次互动`
                        : `本周发帖 ${u.post_count}`
                    }
                  >
                    {allowComments ? u.post_count + u.comment_count : u.post_count}
                  </span>
                </Link>
              </li>
            );
          })}
        </ul>
      )}
    </section>
  );
}

/* ---------- 友情链接 ---------- */

function FriendLinks() {
  return (
    <section className="j13-module" aria-label="友情链接">
      <p className="j13-module-title mb-3">
        <Link2 size={15} style={{ color: "var(--accent)" }} /> 友情链接
        <Link
          href="/compose"
          className="meta ml-auto text-[12px] font-normal transition-colors hover:text-[var(--accent)]"
        >
          申请
        </Link>
      </p>
      <div className="flex flex-wrap gap-2">
        {FRIEND_LINKS.map((l) =>
          l.href.startsWith("http") ? (
            <a
              key={l.name}
              href={l.href}
              target="_blank"
              rel="noopener noreferrer"
              className="j13-chip"
            >
              {l.name}
            </a>
          ) : (
            <span key={l.name} className="j13-chip" data-tip="友链待配置">
              {l.name}
            </span>
          )
        )}
      </div>
    </section>
  );
}

/* ---------- 桌面 / 移动两种装配 ---------- */

type PanelsProps = {
  stats: OverviewStats;
  hot: PostListItem[];
  activeUsers: ActiveUser[];
  announcements: AnnouncementSummary[];
  newUsers: NewUser[];
  checkin?: CheckinStatus | null;
  allowComments: boolean;
  canManageAnnouncements?: boolean;
  sidebarPages?: SidebarPageItem[];
};

function CommunityPanelsBody({
  stats,
  hot,
  activeUsers,
  announcements,
  newUsers,
  checkin,
  allowComments,
  canManageAnnouncements,
  sidebarPages = [],
}: PanelsProps) {
  return (
    <>
      <PulseCard stats={stats} checkin={checkin} allowComments={allowComments} />
      <AboutSite pages={sidebarPages} />
      <Announcements items={announcements} canManageAnnouncements={canManageAnnouncements} />
      <HotRanking posts={hot} allowComments={allowComments} />
      <NewUsers users={newUsers} />
      <ActiveUsers users={activeUsers} allowComments={allowComments} />
      <FriendLinks />
    </>
  );
}

export function CommunityPanels(props: PanelsProps) {
  return (
    <aside className="hidden w-[280px] shrink-0 lg:block xl:w-[300px]" aria-label="社区面板">
      <div className="sticky top-24 space-y-4">
        <CommunityPanelsBody {...props} />
      </div>
    </aside>
  );
}

export function CommunityPanelsMobile(props: PanelsProps) {
  return (
    <div className="space-y-4 lg:hidden" aria-label="社区面板">
      <CommunityPanelsBody {...props} />
    </div>
  );
}