import Link from 'next/link';
import { prisma } from '@/lib/prisma';

export const dynamic = 'force-dynamic';

type History = {
  id: bigint;
  userId: bigint;
  showName: string | null;
  startedAt: Date;
  endedAt: Date | null;
  listenersCount: number;
  notes: string | null;
};

function formatDate(d: Date | null): string {
  return d ? d.toISOString().slice(0, 16).replace('T', ' ') : '—';
}

/** Human-readable airtime between two timestamps (e.g. "1h 23m"). */
function formatDuration(start: Date, end: Date | null): string {
  if (!end) return '—';
  const ms = end.getTime() - start.getTime();
  if (ms <= 0) return '—';
  const mins = Math.round(ms / 60000);
  const h = Math.floor(mins / 60);
  const m = mins % 60;
  return h > 0 ? `${h}h ${m}m` : `${m}m`;
}

export default async function AdminRadioHistoryPage() {
  let history: History[] = [];
  let names = new Map<string, string>();
  let dbError = false;

  try {
    history = await prisma.radioHistory.findMany({
      select: {
        id: true,
        userId: true,
        showName: true,
        startedAt: true,
        endedAt: true,
        listenersCount: true,
        notes: true,
      },
      orderBy: { startedAt: 'desc' },
      take: 100,
    });

    // Resolve DJ usernames (users.id is Int, radio_history.user_id is BigInt).
    const ids = Array.from(new Set(history.map((h) => Number(h.userId)))).filter(
      (n) => Number.isFinite(n) && n > 0,
    );
    if (ids.length > 0) {
      const users = await prisma.user.findMany({
        where: { id: { in: ids } },
        select: { id: true, username: true },
      });
      names = new Map(users.map((u) => [String(u.id), u.username]));
    }
  } catch {
    dbError = true;
    history = [];
  }

  return (
    <main>
      <nav className="muted" style={{ marginBottom: '0.5rem' }}>
        <Link href="/admin/radio">Radio</Link> ·{' '}
        <Link href="/admin/radio/settings">Settings</Link> ·{' '}
        <Link href="/admin/radio/banners">Banners</Link> ·{' '}
        <Link href="/admin/radio/ranks">Ranks</Link> ·{' '}
        <Link href="/admin/radio/history">History</Link>
      </nav>

      <h1>Radio Play History</h1>
      <p className="muted">
        Past DJ shows and airtime (<code>radio_history</code>), most recent first.
        Read-only log of who was on air, when, and how many listeners tuned in.
      </p>

      {dbError ? (
        <div className="card" style={{ marginBottom: '1.5rem' }}>
          <p className="muted" style={{ margin: 0 }}>
            Could not load radio history (database unavailable).
          </p>
        </div>
      ) : null}

      {history.length === 0 ? (
        <p className="muted">No radio history recorded.</p>
      ) : (
        <table>
          <thead>
            <tr>
              <th>ID</th>
              <th>DJ</th>
              <th>Show</th>
              <th>Started</th>
              <th>Ended</th>
              <th>Airtime</th>
              <th>Listeners</th>
              <th>Notes</th>
            </tr>
          </thead>
          <tbody>
            {history.map((h) => (
              <tr key={String(h.id)}>
                <td>{String(h.id)}</td>
                <td>{names.get(String(h.userId)) ?? `#${String(h.userId)}`}</td>
                <td>{h.showName ?? '—'}</td>
                <td className="muted">{formatDate(h.startedAt)}</td>
                <td className="muted">{formatDate(h.endedAt)}</td>
                <td className="muted">{formatDuration(h.startedAt, h.endedAt)}</td>
                <td>{h.listenersCount}</td>
                <td className="muted">{h.notes ?? '—'}</td>
              </tr>
            ))}
          </tbody>
        </table>
      )}
    </main>
  );
}