'use client';

import { useState } from 'react';
import { useRouter } from 'next/navigation';

type UserRow = { id: string; name: string | null; email: string | null; role: 'learner' | 'admin' | 'suspended'; createdAt: Date };

export default function AdminUsersClient({ users, selfId }: { users: UserRow[]; selfId: string }) {
  const router = useRouter();
  const [busy, setBusy] = useState<string | null>(null);

  const action = async (id: string, body: object) => {
    setBusy(id);
    await fetch(`/api/admin/users/${id}`, {
      method: 'PATCH',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(body),
    });
    setBusy(null);
    router.refresh();
  };

  const del = async (id: string) => {
    if (!confirm('Delete this user permanently?')) return;
    setBusy(id);
    await fetch(`/api/admin/users/${id}`, { method: 'DELETE' });
    setBusy(null);
    router.refresh();
  };

  return (
    <div>
      <h1 style={s.heading}>Users</h1>
      <div style={{ overflowX: 'auto' }}>
        <table style={s.table}>
          <thead>
            <tr>
              {['Email', 'Name', 'Role', 'Joined', 'Actions'].map((h) => (
                <th key={h} style={s.th}>{h}</th>
              ))}
            </tr>
          </thead>
          <tbody>
            {users.map((u) => (
              <tr key={u.id}>
                <td style={s.td}>{u.email ?? '—'}</td>
                <td style={s.td}>{u.name ?? '—'}</td>
                <td style={s.td}>{u.role}</td>
                <td style={s.td}>{new Date(u.createdAt).toLocaleDateString()}</td>
                <td style={{ ...s.td, display: 'flex', gap: 'var(--space-2)', flexWrap: 'wrap' as const }}>
                  {u.id === selfId ? (
                    <span style={s.selfNote}>You</span>
                  ) : (
                    <>
                      {u.role !== 'admin' && (
                        <button disabled={busy === u.id} onClick={() => action(u.id, { role: 'admin' })} style={s.btn}>
                          Make admin
                        </button>
                      )}
                      {u.role === 'admin' && (
                        <button disabled={busy === u.id} onClick={() => action(u.id, { role: 'learner' })} style={s.btn}>
                          Make learner
                        </button>
                      )}
                      {u.role !== 'suspended' && (
                        <button disabled={busy === u.id} onClick={() => action(u.id, { role: 'suspended' })} style={s.btn}>
                          Suspend
                        </button>
                      )}
                      {u.role === 'suspended' && (
                        <button disabled={busy === u.id} onClick={() => action(u.id, { role: 'learner' })} style={s.btn}>
                          Unsuspend
                        </button>
                      )}
                      <button disabled={busy === u.id} onClick={() => del(u.id)} style={s.dangerBtn}>
                        Delete
                      </button>
                    </>
                  )}
                </td>
              </tr>
            ))}
          </tbody>
        </table>
      </div>
    </div>
  );
}

const s = {
  heading: { fontFamily: 'var(--font-display)', fontSize: '1.5rem', fontWeight: 500, color: 'var(--color-ink)', marginBottom: 'var(--space-6)' },
  table: { width: '100%', borderCollapse: 'collapse' as const, fontFamily: 'var(--font-display)', fontSize: '0.875rem' },
  th: { textAlign: 'left' as const, padding: 'var(--space-2) var(--space-3)', borderBottom: '2px solid var(--color-border)', color: 'var(--color-ink-faint)', fontWeight: 600 },
  td: { padding: 'var(--space-2) var(--space-3)', borderBottom: '1px solid var(--color-border-subtle)', color: 'var(--color-ink)' },
  btn: { padding: 'var(--space-1) var(--space-3)', background: 'var(--color-accent-subtle)', color: 'var(--color-accent)', border: '1px solid var(--color-accent)', borderRadius: '4px', cursor: 'pointer', fontSize: '0.8125rem' },
  dangerBtn: { padding: 'var(--space-1) var(--space-3)', background: 'var(--color-misconception-subtle)', color: 'var(--color-misconception)', border: '1px solid var(--color-misconception)', borderRadius: '4px', cursor: 'pointer', fontSize: '0.8125rem' },
  selfNote: { color: 'var(--color-ink-faint)', fontSize: '0.8125rem' },
} as const;