import type { Metadata } from "next";
import Link from "next/link";
import { cookies } from "next/headers";
import {
  ClipboardCheck,
  ChevronRight,
  Eye,
  FileText,
  MessageSquareText,
  LayoutDashboard,
  Coins,
  Users,
  Activity,
} from "lucide-react";
import {
  fetchOverview,
  fetchAdminPendingCounts,
  fetchAdminAnalytics,
  type PendingCounts,
  type AnalyticsOverview,
} from "@/lib/api";
import { authCookieHeader } from "@/lib/cookies";
import { getMeCached } from "@/lib/serverData";
import { canModerateAny, isSuperOrOwner, isAdminOrAbove } from "@/lib/roles";
import { AdminPageHeader, AdminStatCard } from "@/components/admin";
import DashboardClient from "./DashboardClient";

export const metadata: Metadata = {
  title: "管理仪表盘",
};

const fmt = (n: number) => n.toLocaleString("zh-CN");

function greeting(hour: number) {
  if (hour < 6) return "凌晨好";
  if (hour < 12) return "上午好";
  if (hour < 14) return "中午好";
  if (hour < 18) return "下午好";
  return "晚上好";
}

/** 紧凑待审条：跳转内容管理待审筛选 */
function PendingStrip({ counts }: { counts: PendingCounts }) {
  const total = counts.posts + counts.comments;
  const idle = total === 0;
  const href =
    counts.posts > 0 || counts.comments === 0
      ? "/admin/content?status=pending"
      : "/admin/content?status=pending&kind=comments";

  return (
    <Link
      href={href}
      className="panel hover-lift mb-4 px-4 sm:px-5 py-3 flex items-center gap-3 group"
    >
      <span
        className="w-9 h-9 rounded-lg flex items-center justify-center shrink-0"
        style={{
          background: idle ? "var(--tint)" : "var(--ok-soft)",
          color: idle ? "var(--ink-3)" : "var(--ok)",
        }}
        aria-hidden
      >
        <ClipboardCheck size={18} />
      </span>
      <div className="min-w-0 flex-1 flex items-center gap-3 sm:gap-5 flex-wrap">
        <span className="text-[13.5px] font-semibold" style={{ color: "var(--ink)" }}>
          待审内容
        </span>
        {idle ? (
          <span className="admin-status is-muted">暂无待审</span>
        ) : (
          <span className="admin-status is-ok tabular-nums">{fmt(total)} 项</span>
        )}
        <span className="inline-flex items-center gap-1 text-[12.5px]" style={{ color: "var(--ink-2)" }}>
          <FileText size={13} style={{ color: "var(--ink-3)" }} aria-hidden />
          帖子
          <strong className="tabular-nums font-bold" style={{ color: "var(--ink)" }}>
            {fmt(counts.posts)}
          </strong>
        </span>
        <span className="inline-flex items-center gap-1 text-[12.5px]" style={{ color: "var(--ink-2)" }}>
          <MessageSquareText size={13} style={{ color: "var(--ink-3)" }} aria-hidden />
          评论
          <strong className="tabular-nums font-bold" style={{ color: "var(--ink)" }}>
            {fmt(counts.comments)}
          </strong>
        </span>
      </div>
      <ChevronRight
        size={16}
        className="shrink-0 transition-transform group-hover:translate-x-0.5"
        style={{ color: "var(--ink-3)" }}
      />
    </Link>
  );
}

const emptyAnalytics = (): AnalyticsOverview => ({
  range_days: 7,
  today_pv: 0,
  today_uv: 0,
  visits: [],
  posts_series: [],
  comments_series: [],
  registers_series: [],
  boards: [],
  post_types: [],
  top_viewed: [],
});

export default async function AdminDashboardPage() {
  const cookie = authCookieHeader(await cookies());
  const me = await getMeCached(cookie || undefined);
  const canMod = canModerateAny(me.user);
  const canUsers = isSuperOrOwner(me.user?.role);
  const canEconomy = isAdminOrAbove(me.user?.role);

  const [overview, pendingCounts, analytics] = await Promise.all([
    fetchOverview(cookie).catch(() => null),
    canMod
      ? fetchAdminPendingCounts(cookie).catch(() => ({ posts: 0, comments: 0 }))
      : Promise.resolve(null),
    fetchAdminAnalytics(cookie, "7d").catch(() => emptyAnalytics()),
  ]);

  const now = new Date();
  const dateLabel = new Intl.DateTimeFormat("zh-CN", {
    year: "numeric",
    month: "long",
    day: "numeric",
    weekday: "long",
  }).format(now);

  const stats = overview?.stats;
  const newUsers = overview?.new_users ?? [];

  return (
    <div>
      <AdminPageHeader
        icon={LayoutDashboard}
        title={`${greeting(now.getHours())}，${me.user?.nickname ?? ""}`}
        description={`${dateLabel} · 站点管理`}
        actions={
          canEconomy ? (
            <Link href="/admin/economy" className="btn btn-ghost text-[13px] gap-1.5">
              <Coins size={15} aria-hidden />
              积分看板
            </Link>
          ) : undefined
        }
      />

      <div className="grid grid-cols-2 lg:grid-cols-4 gap-3 mb-4">
        <AdminStatCard
          label="今日 PV"
          value={fmt(analytics.today_pv)}
          hint={`独立访客 UV ${fmt(analytics.today_uv)}`}
          icon={<Eye size={16} />}
        />
        <AdminStatCard
          label="今日 UV"
          value={fmt(analytics.today_uv)}
          hint="独立访客"
          icon={<Users size={16} />}
          color="var(--ok)"
          soft="var(--ok-soft)"
        />
        <AdminStatCard
          label="今日内容"
          value={fmt(stats?.today_posts ?? 0)}
          sub="帖"
          hint={`评论 ${fmt(stats?.today_comments ?? 0)} · 注册 ${fmt(stats?.today_users ?? 0)}`}
          icon={<FileText size={16} />}
          color="var(--gold)"
          soft="var(--gold-soft)"
        />
        <AdminStatCard
          label="在线"
          value={fmt(stats?.online ?? 0)}
          hint={`峰值 ${fmt(stats?.peak_online ?? 0)}`}
          icon={<Activity size={16} />}
          color="var(--clay)"
          soft="var(--clay-soft)"
        />
      </div>

      {canMod && pendingCounts && <PendingStrip counts={pendingCounts} />}

      <DashboardClient
        initialAnalytics={analytics}
        newUsers={newUsers}
        totalUsers={stats?.users}
        canUsers={canUsers}
      />
    </div>
  );
}