"use client";

import { useEffect, useState } from "react";
import { AdminChartCard, NamedBarChart, NamedPieChart } from "@/components/admin/charts";
import { apiStatsSources, type VisitSources } from "@/lib/api";
import { RangeSegmented, StatsState, TableEmpty, formatInt, refKindLabel } from "../ui";

/** 来源按日表：固定展示四类主要来源列 */
const TREND_KINDS = ["direct", "search", "social", "external"] as const;

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

  useEffect(() => {
    let alive = true;
    setLoading(true);
    apiStatsSources(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 kinds = data.kinds.map((k) => ({ label: refKindLabel(k.key), count: k.count }));

  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]">按浏览来源（Referer）自动分类；爬虫与探测请求不计入。</p>
        <RangeSegmented value={range} onChange={setRange} />
      </div>

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

      <AdminChartCard title="来源类别占比" hint={`近 ${data.range_days} 日浏览`}>
        {kinds.length ? <NamedPieChart data={kinds} /> : <TableEmpty />}
      </AdminChartCard>

      <div className="grid gap-4 lg:grid-cols-2">
        <AdminChartCard title="站内搜索词 Top 10" hint="搜索结果页（/?q=）浏览量 Top 10">
          {data.search_terms.length ? (
            <ul className="flex flex-col divide-y max-h-[360px] overflow-y-auto" style={{ borderColor: "var(--line)" }}>
              {data.search_terms.map((t, i) => (
                <li key={`${i}-${t.key}`} className="py-2 flex items-center gap-3 text-[13px]">
                  <span className="w-5 text-right tabular-nums shrink-0" style={{ color: "var(--ink-3)" }}>
                    {i + 1}
                  </span>
                  <span className="flex-1 min-w-0 truncate" style={{ color: "var(--ink)" }} title={t.key}>
                    {t.key}
                  </span>
                  <span className="tabular-nums shrink-0" style={{ color: "var(--ink-2)" }}>
                    {formatInt(t.count)}
                  </span>
                </li>
              ))}
            </ul>
          ) : (
            <TableEmpty text="暂无站内搜索" />
          )}
        </AdminChartCard>
        <AdminChartCard title="外部链接明细" hint="其他站点跳转来源 Top 10">
          {data.external.length ? (
            <NamedBarChart data={data.external.map((h) => ({ label: h.key, count: h.count }))} />
          ) : (
            <TableEmpty text="暂无外链来源" />
          )}
        </AdminChartCard>
      </div>

      <AdminChartCard title="来源按日分布" hint="各来源类别每日浏览量">
        {data.trend.length ? (
          <div className="overflow-x-auto">
            <table className="w-full text-[13px]">
              <thead>
                <tr className="text-left" style={{ color: "var(--ink-3)" }}>
                  <th className="py-2 pr-3 font-medium">日期</th>
                  {TREND_KINDS.map((k) => (
                    <th key={k} className="py-2 pr-3 font-medium text-right">
                      {refKindLabel(k)}
                    </th>
                  ))}
                </tr>
              </thead>
              <tbody>
                {data.trend.map((row) => {
                  const byKey = new Map(row.items.map((i) => [i.key, i.count]));
                  return (
                    <tr key={row.date} style={{ borderTop: "1px solid var(--line)" }}>
                      <td className="py-2 pr-3 tabular-nums" style={{ color: "var(--ink-2)" }}>
                        {row.date.slice(0, 10)}
                      </td>
                      {TREND_KINDS.map((k) => (
                        <td key={k} className="py-2 pr-3 text-right tabular-nums" style={{ color: "var(--ink)" }}>
                          {(byKey.get(k) ?? 0) === 0 ? (
                            <span style={{ color: "var(--ink-3)" }}>—</span>
                          ) : (
                            (byKey.get(k) ?? 0).toLocaleString("zh-CN")
                          )}
                        </td>
                      ))}
                    </tr>
                  );
                })}
              </tbody>
            </table>
          </div>
        ) : (
          <TableEmpty />
        )}
      </AdminChartCard>
    </div>
  );
}