"use client";

import { useEffect, useState } from "react";
import { Users, UserPlus, Repeat, LogIn } from "lucide-react";
import { AdminStatCard } from "@/components/admin";
import { AdminChartCard, NamedBarChart, NamedPieChart } from "@/components/admin/charts";
import { apiStatsVisitors, type VisitVisitors } from "@/lib/api";
import { RangeSegmented, StatsState, TableEmpty, formatInt } from "../ui";

export default function VisitorsPage() {
  const [range, setRange] = useState<"7d" | "30d">("7d");
  const [data, setData] = useState<VisitVisitors | null>(null);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState("");

  useEffect(() => {
    let alive = true;
    setLoading(true);
    apiStatsVisitors(range)
      .then((d) => {
        if (alive) {
          setData(d);
          setError("");
        }
      })
      .catch(() => alive && setError("加载失败，请稍后重试"))
      .finally(() => alive && setLoading(false));
    return () => {
      alive = false;
    };
  }, [range]);

  if (!data) return <StatsState loading={loading} error={error || undefined} />;

  const devices = data.devices.map((d) => ({ label: d.label || "未知", count: d.count }));
  const oses = data.oses.map((d) => ({ label: d.label || "未知", count: d.count }));
  const browsers = data.browsers.map((d) => ({ label: d.label || "未知", count: d.count }));
  const hourly = data.hourly.map((h) => ({ label: `${h.key}时`, count: h.count }));
  const totalPv = data.logged_in_pv + data.guest_pv;
  const totalVisitors = data.new_visitors + data.returning;

  return (
    <div className="flex flex-col gap-4">
      <div className="flex items-center justify-between gap-2 flex-wrap">
        <p className="meta text-[12.5px]">基于匿名访客标识（仅存哈希）与登录用户统计。</p>
        <RangeSegmented value={range} onChange={setRange} />
      </div>

      {error ? <StatsState error={error} /> : null}

      <div className="grid gap-3 grid-cols-2 xl:grid-cols-4">
        <AdminStatCard label="登录用户浏览" value={formatInt(data.logged_in_pv)} icon={<LogIn size={17} />} />
        <AdminStatCard
          label="游客浏览"
          value={formatInt(data.guest_pv)}
          icon={<Users size={17} />}
          color="var(--ok)"
          soft="var(--ok-soft, var(--panel-2))"
        />
        <AdminStatCard
          label="新访客"
          value={formatInt(data.new_visitors)}
          sub={totalVisitors > 0 ? `${Math.round((data.new_visitors / totalVisitors) * 100)}%` : undefined}
          hint="统计期内首次出现"
          icon={<UserPlus size={17} />}
          color="var(--gold)"
          soft="var(--gold-soft)"
        />
        <AdminStatCard
          label="回访"
          value={formatInt(data.returning)}
          sub={totalVisitors > 0 ? `${Math.round((data.returning / totalVisitors) * 100)}%` : undefined}
          icon={<Repeat size={17} />}
          color="var(--ink-2)"
          soft="var(--panel-2)"
        />
      </div>

      {totalPv > 0 ? (
        <AdminChartCard title="登录 vs 游客" hint={`近 ${data.range_days} 日浏览占比`}>
          <NamedPieChart
            data={[
              { label: "登录用户", count: data.logged_in_pv },
              { label: "游客", count: data.guest_pv },
            ]}
          />
        </AdminChartCard>
      ) : null}

      <div className="grid gap-4 lg:grid-cols-3">
        <AdminChartCard title="设备分布">
          {devices.length ? <NamedPieChart data={devices} /> : <TableEmpty />}
        </AdminChartCard>
        <AdminChartCard title="操作系统 Top 8">
          {oses.length ? <NamedPieChart data={oses} /> : <TableEmpty />}
        </AdminChartCard>
        <AdminChartCard title="浏览器 Top 8">
          {browsers.length ? <NamedPieChart data={browsers} /> : <TableEmpty />}
        </AdminChartCard>
      </div>

      <AdminChartCard title="24 小时活跃分布" hint="各小时浏览量（本地时区）">
        {hourly.length ? (
          <NamedBarChart data={hourly} />
        ) : (
          <TableEmpty />
        )}
      </AdminChartCard>
    </div>
  );
}