import { useQuery } from "@tanstack/react-query";
import { type Dashboard, DownloadBoard, type HealthLevel } from "@umt/contracts";
import { ArrowRight, Download, Gauge, type LucideIcon } from "lucide-react";
import type { ReactNode } from "react";
import { Link } from "react-router";
import { useSitesWithAccounts } from "~/api/dashboard.ts";
import { apiParsed } from "~/api/parse.ts";
import { useSystemHealth, useSystemResources } from "~/api/system.ts";
import { EmptyState, ErrorState, LoadingState } from "~/components/console/empty-state.tsx";
import { consolePath } from "~/components/console/nav.ts";
import { StatusBadge, type StatusTone } from "~/components/console/status-badge.tsx";
import { Sparkline, usageTone } from "~/components/status/resource-section.tsx";
import { formatRelative } from "~/lib/labels.ts";
import { cn, formatBytes } from "~/lib/utils.ts";

const LEVEL: Record<HealthLevel, { label: string; tone: StatusTone }> = {
  ok: { label: "正常", tone: "success" },
  warn: { label: "需要关注", tone: "warning" },
  critical: { label: "需要处理", tone: "destructive" },
  unknown: { label: "用量未知", tone: "neutral" },
};
const SCOPE = { data_dir: "系统数据", library_root: "媒体库", download_dir: "下载目录" };

function OverviewCard({
  title,
  icon: Icon,
  to,
  children,
}: {
  title: string;
  icon: LucideIcon;
  to: string;
  children: ReactNode;
}) {
  return (
    <section className="pg-slab min-w-0 rounded-xl p-5">
      <div className="mb-3 flex items-center gap-2">
        <Icon className="h-4 w-4 text-muted-foreground" aria-hidden />
        <h2 className="text-body font-semibold text-foreground">{title}</h2>
        <Link
          to={to}
          className="ml-auto inline-flex items-center gap-1 text-meta text-muted-foreground hover:text-foreground"
        >
          详情
          <ArrowRight className="h-3.5 w-3.5" />
        </Link>
      </div>
      {children}
    </section>
  );
}

const BAD_ACCOUNT = ["invalid", "expired", "challenge"];

/** 一行「名称 正常数 / 总数」;有异常时数值标黄 */
function SummaryItem({ label, ok, total, to }: { label: string; ok: number; total: number; to: string }) {
  if (!total) return null;
  return (
    <Link to={to} className="inline-flex items-center gap-1 hover:text-foreground">
      <span
        aria-hidden
        className={cn("inline-block size-1.5 rounded-full", ok < total ? "bg-warning" : "bg-success")}
      />
      {label}
      <span className={cn("tabular-nums", ok < total ? "text-warning" : "text-foreground")}>
        {ok}/{total}
      </span>
    </Link>
  );
}

/**
 * 运行状态简版(界面第二轮,参考 MP 仪表盘):整体健康、CPU、内存、磁盘,以及下载器 / 站点 / 媒体库目录在线摘要。
 * 详细版在系统 → 运行状态。
 */
function RuntimeOverview({ downloaders }: { downloaders?: Dashboard["sources"]["downloaders"] }) {
  const q = useSystemHealth(60_000);
  const r = useSystemResources(30, 10_000);
  const sites = useSitesWithAccounts();
  const h = q.data;
  const res = r.data;
  const mediaDisks = h?.disks.filter((d) => d.scope !== "data_dir") ?? [];
  const disks = (mediaDisks.length ? mediaDisks : (h?.disks ?? []))
    .filter((d) => d.usedRatio !== null)
    .sort((a, b) => (b.usedRatio ?? 0) - (a.usedRatio ?? 0))
    .slice(0, 3);
  const enabledDl = (downloaders ?? []).filter((d) => d.enabled);
  const okDl = enabledDl.filter((d) => !["offline", "failing"].includes(d.health)).length;
  const siteRows = (sites.data?.items ?? []).filter((s) => s.enabled);
  const okSites = siteRows.filter((s) => !(s.accountStatus && BAD_ACCOUNT.includes(s.accountStatus))).length;
  const roots = h?.mounts.filter((m) => m.kind === "library_root") ?? [];
  const okRoots = roots.filter((m) => m.status === "online").length;
  const level = h ? LEVEL[h.level === "unknown" ? "unknown" : h.level] : null;
  return (
    <OverviewCard title="运行状态" icon={Gauge} to={consolePath("status")}>
      {q.isPending ? (
        <LoadingState rows={3} />
      ) : q.isError ? (
        <ErrorState plain title="运行状态加载失败" onRetry={() => q.refetch()} className="py-6" />
      ) : h ? (
        <>
          <div className="mb-3 flex items-center gap-2">
            {level ? <StatusBadge tone={level.tone}>{h.level === "ok" ? "全部正常" : level.label}</StatusBadge> : null}
            <span className="text-meta text-muted-foreground">检查于 {formatRelative(h.checkedAt)}</span>
          </div>
          <div className="grid grid-cols-2 gap-3">
            {[
              { label: "CPU", v: res?.cpu.percent, key: "cpuPercent" as const },
              { label: "内存", v: res?.memory.percent, key: "memoryPercent" as const },
            ].map((x) => (
              <div key={x.label} className="min-w-0 rounded-lg border border-border/70 px-3 py-2">
                <p className="flex items-center justify-between text-meta text-muted-foreground">
                  {x.label}
                  <span className={cn("text-body font-semibold tabular-nums", usageTone(x.v))}>
                    {x.v == null ? "—" : `${Math.round(x.v)}%`}
                  </span>
                </p>
                {res ? (
                  <Sparkline
                    samples={res.samples}
                    keys={[{ key: x.key, name: x.label }]}
                    format={(v) => `${v.toFixed(1)}%`}
                    max={100}
                    height={32}
                    label={`${x.label}占用趋势（最近 30 分钟）`}
                  />
                ) : (
                  <div className="h-8" />
                )}
              </div>
            ))}
          </div>
          {disks.length ? (
            <ul className="mt-3 space-y-2">
              {disks.map((d) => {
                const pct = (d.usedRatio ?? 0) * 100;
                return (
                  <li key={`${d.scope}-${d.id ?? d.path}`} className="min-w-0">
                    <div className="flex items-center justify-between gap-2 text-meta">
                      <span className="min-w-0 truncate" title={d.path}>
                        <span className="mr-1 text-muted-foreground">{SCOPE[d.scope]}</span>
                        {d.name}
                      </span>
                      <span className="shrink-0 tabular-nums text-muted-foreground">
                        {Math.round(pct)}% · 剩余{" "}
                        {d.availableBytes === null ? "未知" : formatBytes(d.availableBytes, 1)}
                      </span>
                    </div>
                    <div className="mt-1 h-1.5 overflow-hidden rounded-full bg-foreground/[0.08]" aria-hidden>
                      <div
                        className={cn(
                          "h-full rounded-full",
                          d.level === "critical"
                            ? "bg-destructive"
                            : d.level === "warn"
                              ? "bg-warning"
                              : "bg-foreground/60",
                        )}
                        style={{ width: `${pct}%` }}
                      />
                    </div>
                  </li>
                );
              })}
            </ul>
          ) : null}
          <p className="mt-3 flex flex-wrap gap-x-4 gap-y-1 text-meta text-muted-foreground">
            <SummaryItem label="下载器" ok={okDl} total={enabledDl.length} to={consolePath("downloads")} />
            <SummaryItem label="站点" ok={okSites} total={siteRows.length} to={consolePath("sites")} />
            <SummaryItem label="媒体库目录" ok={okRoots} total={roots.length} to={consolePath("status")} />
          </p>
        </>
      ) : (
        <EmptyState plain icon={Gauge} title="没有运行状态数据" className="py-6" />
      )}
    </OverviewCard>
  );
}

function DownloaderOverview({ downloaders }: { downloaders?: Dashboard["sources"]["downloaders"] }) {
  // 首页仅取一条面板记录，速度和计数仍是完整汇总；无需拉取下载任务列表。
  const q = useQuery({
    queryKey: ["downloads", "home-overview"],
    queryFn: ({ signal }) =>
      apiParsed(DownloadBoard, "/api/v1/download-tasks/board", { params: { state: "active", limit: 1 }, signal }),
    refetchInterval: 15_000,
    refetchIntervalInBackground: false,
  });
  const board = q.data;
  const instances = board?.transfer.instances ?? [];
  const sources =
    downloaders ??
    instances.map((d) => ({ id: d.instanceId, name: d.name, enabled: true, health: "unknown", lastSeenAt: null }));
  return (
    <OverviewCard title="下载器" icon={Download} to={consolePath("downloads")}>
      {q.isPending ? (
        <LoadingState rows={2} />
      ) : q.isError ? (
        <ErrorState plain title="下载器状态加载失败" onRetry={() => q.refetch()} className="py-6" />
      ) : !sources.length ? (
        <EmptyState plain icon={Download} title={downloaders ? "还没有下载器" : "没有启用的下载器"} className="py-6" />
      ) : (
        <>
          <p className="mb-3 text-title-sm font-semibold tabular-nums">
            {board?.counts.active}
            <span className="ml-1.5 text-caption font-normal text-muted-foreground">个下载进行中</span>
          </p>
          <ul className="divide-y divide-border/60">
            {sources.map((d) => {
              const live = instances.find((i) => i.instanceId === d.id);
              const state = !d.enabled
                ? { label: "已停用", tone: "neutral" as const }
                : !live
                  ? { label: "状态未知", tone: "neutral" as const }
                  : live.reachable
                    ? { label: "在线", tone: "success" as const }
                    : { label: "连接失败", tone: "warning" as const };
              const readable = d.enabled && live?.reachable;
              return (
                <li key={d.id} className="py-2 first:pt-0 last:pb-0">
                  <div className="flex items-center justify-between gap-2">
                    <span className="min-w-0 truncate text-sm font-medium" title={d.name}>
                      {d.name}
                    </span>
                    <StatusBadge tone={state.tone}>{state.label}</StatusBadge>
                  </div>
                  {d.enabled ? (
                    <p className="mt-1.5 flex flex-wrap gap-x-4 gap-y-1 text-meta text-muted-foreground tabular-nums">
                      <span>
                        下载{" "}
                        <span className="text-foreground">
                          {readable ? `${formatBytes(live.dlSpeed, 1)}/s` : "未知"}
                        </span>
                      </span>
                      <span>
                        上传{" "}
                        <span className="text-foreground">
                          {readable ? `${formatBytes(live.upSpeed, 1)}/s` : "未知"}
                        </span>
                      </span>
                    </p>
                  ) : null}
                </li>
              );
            })}
          </ul>
          <p className="mt-3 text-meta text-muted-foreground">
            进行中包括还没提交、已暂停和出错的下载 · 速度是下载器里全部任务的合计
          </p>
          {board?.liveAt ? (
            <p className="mt-1 text-meta text-muted-foreground">速度更新于 {formatRelative(board.liveAt)}</p>
          ) : null}
        </>
      )}
    </OverviewCard>
  );
}

export function HomeRuntime({ downloaders }: { downloaders?: Dashboard["sources"]["downloaders"] }) {
  return (
    <div className="mb-4 grid gap-4 lg:grid-cols-2">
      <RuntimeOverview downloaders={downloaders} />
      <DownloaderOverview downloaders={downloaders} />
    </div>
  );
}