"use client";
import { useMemo } from "react";
import useSWR from "swr";
import { Bar, Line, Pie } from "react-chartjs-2";
import {
  Chart as ChartJS,
  CategoryScale,
  LinearScale,
  BarElement,
  PointElement,
  LineElement,
  ArcElement,
  Tooltip,
  Legend,
  TimeScale,
} from "chart.js";
import Link from "next/link";

ChartJS.register(
  CategoryScale,
  LinearScale,
  BarElement,
  PointElement,
  LineElement,
  ArcElement,
  Tooltip,
  Legend,
  TimeScale,
);

type Analysis = import("@/lib/analyzeLogs").LogAnalysisResult;

const fetcher = (url: string) => fetch(url).then((r) => r.json());

export default function SiteDashboard({ params }: { params: { dir: string } }) {
  const { data, error, isLoading } = useSWR<Analysis>(
    `/api/sites/${encodeURIComponent(params.dir)}/analysis`,
    fetcher,
    { refreshInterval: 60_000 }
  );

  const topUrlsData = useMemo(() => {
    const labels = data?.topUrls.map((x) => x.url) ?? [];
    const values = data?.topUrls.map((x) => x.count) ?? [];
    return {
      labels,
      datasets: [{ label: "URL 访问次数", data: values, backgroundColor: "#60a5fa" }],
    };
  }, [data]);

  const statusPieData = useMemo(() => {
    const labels = Object.keys(data?.statusCodeDistribution || {});
    const values = Object.values(data?.statusCodeDistribution || {});
    return {
      labels,
      datasets: [{ data: values, backgroundColor: ["#34d399", "#60a5fa", "#fbbf24", "#f87171", "#a78bfa"] }],
    };
  }, [data]);

  const timelineData = useMemo(() => {
    const labels = (data?.timeAccess || []).map((p) => new Date(p.time).toLocaleString());
    const values = (data?.timeAccess || []).map((p) => p.count);
    return {
      labels,
      datasets: [{ label: "每小时请求量", data: values, borderColor: "#34d399", backgroundColor: "#34d39933" }],
    };
  }, [data]);

  const devicePieData = useMemo(() => {
    const entries = Object.entries(data?.deviceTypes || {});
    return {
      labels: entries.map(([k]) => k),
      datasets: [{ data: entries.map(([, v]) => v), backgroundColor: ["#60a5fa", "#f472b6", "#fbbf24", "#a78bfa"] }],
    };
  }, [data]);

  const provinceData = useMemo(() => {
    const entries = Object.entries(data?.provinceCityProportions || {}).sort((a, b) => b[1] - a[1]).slice(0, 15);
    return {
      labels: entries.map(([k]) => k),
      datasets: [{ label: "区域占比%", data: entries.map(([, v]) => v), backgroundColor: "#a78bfa" }],
    };
  }, [data]);

  return (
    <div className="max-w-7xl mx-auto py-8 space-y-8">
      <div className="flex items-center justify-between">
        <div>
          <h1 className="text-3xl font-semibold">{decodeURIComponent(params.dir)} · 访问分析</h1>
          <p className="text-gray-500 text-sm">版本 {data?.version ?? "-"}</p>
        </div>
        <div className="flex gap-3">
          <Link className="text-blue-600 hover:underline" href="/sites">返回列表</Link>
          <a className="text-blue-600 hover:underline" href={`/api/sites/${encodeURIComponent(params.dir)}/raw`} target="_blank">原始日志</a>
        </div>
      </div>

      {isLoading && <p>加载中...</p>}
      {error && <p className="text-red-500">加载失败：{String(error)}</p>}
      {data && (
        <div className="space-y-8">
          <div className="grid grid-cols-2 md:grid-cols-4 gap-4">
            <Stat label="独立 IP" value={data.uniqueIPCount} />
            <Stat label="首页访问" value={data.indexAccessCount} />
            <Stat label="总流量(bytes)" value={data.totalBytes} />
            <Stat label="状态码种类" value={Object.keys(data.statusCodeDistribution).length} />
          </div>

          <div className="grid grid-cols-1 lg:grid-cols-2 gap-8">
            <Card title="URL Top 20">
              <Bar data={topUrlsData} options={{ indexAxis: "y" as const, plugins: { legend: { display: false } } }} />
            </Card>
            <Card title="状态码分布">
              <Pie data={statusPieData} />
            </Card>
          </div>

          <Card title="每小时访问趋势">
            <Line data={timelineData} />
          </Card>

          <div className="grid grid-cols-1 lg:grid-cols-2 gap-8">
            <Card title="设备类型">
              <Pie data={devicePieData} />
            </Card>
            <Card title="区域占比 Top 15">
              <Bar data={provinceData} options={{ indexAxis: "y" as const, plugins: { legend: { display: false } } }} />
            </Card>
          </div>

          <Card title="浏览器版本 (前 10)">
            <BrowserOsTable kind="browser" data={data.browserVersions} />
          </Card>

          <Card title="操作系统版本 (前 10)">
            <BrowserOsTable kind="os" data={data.osVersions} />
          </Card>

          <Card title="最近 100 条原始日志">
            <pre className="text-xs whitespace-pre-wrap leading-5 max-h-96 overflow-auto bg-black/5 p-4 rounded">{data.recentRawLog.join("\n")}</pre>
          </Card>
        </div>
      )}
    </div>
  );
}

function Stat({ label, value }: { label: string; value: number | string }) {
  return (
    <div className="p-4 rounded border bg-white/50 dark:bg-white/5">
      <div className="text-sm text-gray-500">{label}</div>
      <div className="text-2xl font-semibold mt-1">{value}</div>
    </div>
  );
}

function Card({ title, children }: { title: string; children: React.ReactNode }) {
  return (
    <div className="p-4 rounded border bg-white/60 dark:bg-white/5">
      <h3 className="font-medium mb-3">{title}</h3>
      {children}
    </div>
  );
}

function BrowserOsTable({
  kind,
  data,
}: {
  kind: "browser" | "os";
  data: Record<string, Record<string, number>>;
}) {
  const rows = useMemo(() => {
    const out: { group: string; version: string; count: number }[] = [];
    Object.entries(data || {}).forEach(([g, versions]) => {
      Object.entries(versions).forEach(([v, c]) => out.push({ group: g, version: v, count: c }));
    });
    return out.sort((a, b) => b.count - a.count).slice(0, 10);
  }, [data]);

  return (
    <div className="overflow-x-auto">
      <table className="min-w-full text-sm">
        <thead>
          <tr className="text-left text-gray-500">
            <th className="py-2 pr-4">{kind === "browser" ? "浏览器" : "操作系统"}</th>
            <th className="py-2 pr-4">版本</th>
            <th className="py-2">次数</th>
          </tr>
        </thead>
        <tbody>
          {rows.map((r, i) => (
            <tr key={i} className="border-t">
              <td className="py-2 pr-4">{r.group}</td>
              <td className="py-2 pr-4">{r.version}</td>
              <td className="py-2">{r.count}</td>
            </tr>
          ))}
        </tbody>
      </table>
    </div>
  );
}