'use client';

import Link from 'next/link';
import { useRouter } from 'next/navigation';
import { useState } from 'react';
import useSWR from 'swr';
import { REPORT_REASON_LABELS, timeAgo, type AdminReportDTO, type AdminStatsDTO, type ReportReason } from '@musicshare/shared';
import { Avatar } from '@/components/Avatar';
import { Modal } from '@/components/ProfileMenu';
import { client, fetcher, useMe } from '@/lib/api';

/** Moderation for the server's admin (the first account): reports and suspensions. */
export default function AdminPage() {
  const { me, loggedOut } = useMe();
  const router = useRouter();
  const [status, setStatus] = useState<'open' | 'resolved'>('open');
  const isAdmin = me?.role === 'admin';
  const { data: stats, mutate: refreshStats } = useSWR<AdminStatsDTO>(isAdmin ? '/admin/stats' : null, fetcher);
  const { data: reports, mutate } = useSWR<AdminReportDTO[]>(isAdmin ? `/admin/reports?status=${status}` : null, fetcher);
  const [confirm, setConfirm] = useState<AdminReportDTO | null>(null);

  if (loggedOut) router.replace('/login');
  if (!me) return null;
  if (!isAdmin) return <p className="muted">Admins only.</p>;

  const refresh = () => Promise.all([mutate(), refreshStats()]);
  const resolve = async (r: AdminReportDTO) => (await client.resolveReport(r.id), refresh());
  const toggleSuspend = async (r: AdminReportDTO) => {
    setConfirm(null);
    await (r.reported.suspended ? client.unsuspend(r.reported.username) : client.suspend(r.reported.username));
    await refresh();
  };

  return (
    <div className="stack">
      <h1>Admin</h1>
      {stats && (
        <div className="admin-stats">
          <Stat label="Accounts" value={stats.users} />
          <Stat label="Listening now" value={stats.listeningNow} />
          <Stat label="Open reports" value={stats.openReports} />
          <Stat label="Suspended" value={stats.suspended} />
        </div>
      )}

      <section className="card">
        <div className="row" style={{ justifyContent: 'space-between' }}>
          <h2>Reports</h2>
          <div className="row">
            {(['open', 'resolved'] as const).map((s) => (
              <button key={s} className={`btn btn-small ${status === s ? 'btn-primary' : ''}`} onClick={() => setStatus(s)}>
                {s === 'open' ? 'Open' : 'Resolved'}
              </button>
            ))}
          </div>
        </div>
        {reports?.length === 0 && <p className="muted">{status === 'open' ? 'Nothing to review. 🎉' : 'No resolved reports yet.'}</p>}
        <ul className="reports">
          {reports?.map((r) => (
            <li key={r.id} className="report">
              <div className="row" style={{ justifyContent: 'space-between' }}>
                <Link href={`/u/${r.reported.username}`} className="user-chip">
                  <Avatar user={r.reported} size={36} />
                  <span className="user-name">{r.reported.displayName ?? r.reported.username}</span>
                  <span className="muted">@{r.reported.username}</span>
                  {r.reported.suspended && <span className="chip-small danger">Suspended</span>}
                </Link>
                <span className="muted">{timeAgo(r.createdAt)}</span>
              </div>
              <p>
                <strong>{REPORT_REASON_LABELS[r.reason as ReportReason] ?? r.reason}</strong>
                {r.reporter && <span className="muted"> · reported by @{r.reporter.username}</span>}
              </p>
              {r.comment && (
                <p className="muted small">
                  Their comment{r.comment.id ? '' : ' (since deleted)'}: <q>{r.comment.body}</q>
                </p>
              )}
              {r.note && <blockquote>{r.note}</blockquote>}
              <div className="row">
                {r.status === 'open' && (
                  <button className="btn btn-small" onClick={() => resolve(r)}>
                    Mark resolved
                  </button>
                )}
                <button className={`btn btn-small ${r.reported.suspended ? '' : 'btn-danger'}`} onClick={() => setConfirm(r)}>
                  {r.reported.suspended ? 'Unsuspend' : 'Suspend account'}
                </button>
              </div>
            </li>
          ))}
        </ul>
      </section>

      {confirm && (
        <Modal
          title={`${confirm.reported.suspended ? 'Unsuspend' : 'Suspend'} @${confirm.reported.username}?`}
          onClose={() => setConfirm(null)}
        >
          <p>
            {confirm.reported.suspended
              ? 'They can sign in again and their profile is visible again. Sharing stays paused until they turn it back on.'
              : "They're signed out everywhere, can't sign in, their profile is hidden and nothing they play is shared."}
          </p>
          <div className="row">
            <button className={`btn ${confirm.reported.suspended ? 'btn-primary' : 'btn-danger'}`} onClick={() => toggleSuspend(confirm)}>
              {confirm.reported.suspended ? 'Unsuspend' : 'Suspend'}
            </button>
            <button className="btn" onClick={() => setConfirm(null)}>
              Cancel
            </button>
          </div>
        </Modal>
      )}
    </div>
  );
}

function Stat({ label, value }: { label: string; value: number }) {
  return (
    <div className="card admin-stat">
      <div className="admin-stat-value">{value}</div>
      <div className="muted">{label}</div>
    </div>
  );
}