// Admin: the access log for everyone, with filters and a CSV download (phase 9).
import { useEffect, useState, type FormEvent } from "react";
import { admin9Api, type AccessLogFilters, type AccessLogRow } from "../../api/admin";
import { errorText, fmtDetail, fmtTime } from "../../lib/format";
import { Notice, type Msg } from "./common";

const PAGE = 200;

/** A datetime-local value as an ISO time, or undefined. */
function iso(local: string): string | undefined {
  if (!local) return undefined;
  const d = new Date(local);
  return Number.isNaN(d.getTime()) ? undefined : d.toISOString();
}

interface Form {
  since: string;
  until: string;
  q: string;
  kind: string;
  ok: "" | "true" | "false";
  ip: string;
}

const EMPTY: Form = { since: "", until: "", q: "", kind: "", ok: "", ip: "" };

function toFilters(f: Form): AccessLogFilters {
  const out: AccessLogFilters = {};
  const since = iso(f.since);
  const until = iso(f.until);
  if (since) out.since = since;
  if (until) out.until = until;
  if (f.q.trim()) out.q = f.q.trim();
  if (f.kind.trim()) out.kind = f.kind.trim();
  if (f.ok) out.ok = f.ok;
  if (f.ip.trim()) out.ip = f.ip.trim();
  return out;
}

export function AccessLogTab() {
  const [form, setForm] = useState<Form>(EMPTY);
  const [filters, setFilters] = useState<AccessLogFilters>({});
  const [rows, setRows] = useState<AccessLogRow[]>([]);
  const [next, setNext] = useState<string | null>(null);
  const [loading, setLoading] = useState(true);
  const [msg, setMsg] = useState<Msg>(null);

  const fetchPage = async (f: AccessLogFilters, before: string | null) => {
    setLoading(true);
    setMsg(null);
    try {
      const r = await admin9Api.accessLog({ ...f, limit: PAGE, ...(before ? { before } : {}) });
      setRows((cur) => (before ? [...cur, ...r.rows] : r.rows));
      setNext(r.next_before);
    } catch (err) {
      setMsg({ ok: false, text: errorText(err) });
    } finally {
      setLoading(false);
    }
  };

  // The first page, once. Later pages come from the search and the load-more button.
  useEffect(() => {
    void fetchPage({}, null);
  }, []);

  const set = (patch: Partial<Form>) => setForm((cur) => ({ ...cur, ...patch }));

  const search = (e: FormEvent) => {
    e.preventDefault();
    const f = toFilters(form);
    setFilters(f);
    void fetchPage(f, null);
  };

  const csvHref = admin9Api.accessLogCsvUrl(filters);

  return (
    <div className="stack">
      <form className="panel stack" onSubmit={search} noValidate role="search" aria-label="Access log filters">
        <div className="frow">
          <label className="f">
            From
            <input className="in" type="datetime-local" value={form.since} onChange={(e) => set({ since: e.target.value })} />
          </label>
          <label className="f">
            To
            <input className="in" type="datetime-local" value={form.until} onChange={(e) => set({ until: e.target.value })} />
          </label>
          <label className="f">
            Name or account
            <input className="in" type="search" value={form.q} onChange={(e) => set({ q: e.target.value })} />
          </label>
          <label className="f">
            Kind
            <input className="in mono" placeholder="auth.signin, password, pin" value={form.kind} onChange={(e) => set({ kind: e.target.value })} />
          </label>
          <label className="f">
            Result
            <select className="in" aria-label="Result" value={form.ok} onChange={(e) => set({ ok: e.target.value === "true" ? "true" : e.target.value === "false" ? "false" : "" })}>
              <option value="">All</option>
              <option value="true">OK only</option>
              <option value="false">Failed only</option>
            </select>
          </label>
          <label className="f">
            Address
            <input className="in mono" value={form.ip} onChange={(e) => set({ ip: e.target.value })} />
          </label>
        </div>
        <div className="chips">
          <button className="btn pri" type="submit" disabled={loading}>
            Search access log
          </button>
          <button
            className="btn ghost"
            type="button"
            onClick={() => {
              setForm(EMPTY);
              setFilters({});
              void fetchPage({}, null);
            }}
          >
            Clear filters
          </button>
          <a className="btn" href={csvHref} download>
            Download CSV
          </a>
        </div>
        <div className="small muted">The CSV has the rows the last search matched, up to 50,000. The download is logged.</div>
      </form>
      <Notice msg={msg} />
      <div className="tw">
        <table aria-label="Access log">
          <thead>
            <tr>
              <th>When</th>
              <th>Who</th>
              <th>Kind</th>
              <th>Result</th>
              <th>Address</th>
              <th>Detail</th>
            </tr>
          </thead>
          <tbody>
            {rows.map((r) => (
              <tr key={`${r.source}-${r.id}`}>
                <td className="small mono nowrap">{fmtTime(r.at)}</td>
                <td>
                  {r.display_name ?? ""} {r.account ? <span className="mono small muted">{r.account}</span> : null}
                </td>
                <td className="mono small">{r.kind}</td>
                <td>{r.ok ? <span className="pill st-ok">OK</span> : <span className="pill st-bad">Failed</span>}</td>
                <td className="mono small">{r.ip ?? "-"}</td>
                <td className="small">{fmtDetail(r.detail)}</td>
              </tr>
            ))}
            {!loading && rows.length === 0 ? (
              <tr>
                <td colSpan={6} className="muted">
                  Nothing matches.
                </td>
              </tr>
            ) : null}
          </tbody>
        </table>
      </div>
      {loading ? <div className="empty slim">Loading</div> : null}
      {next && !loading ? (
        <div>
          <button className="btn sm" type="button" onClick={() => void fetchPage(filters, next)}>
            Load older rows
          </button>
        </div>
      ) : null}
    </div>
  );
}