'use client';

import { useCallback, useEffect, useRef, useState } from 'react';
import { useSuperAdmin } from '../../_lib/super-admin-context';
import { useRouter } from 'next/navigation';

export default function BotsPage() {
  const { admin, loading } = useSuperAdmin();
  const router = useRouter();
  const [bots, setBots] = useState<any[]>([]);
  const [initiating, setInitiating] = useState(false);
  const [pairingInfo, setPairingInfo] = useState<{ pairingToken: string; expiresAt: string } | null>(null);
  const [qrDataUrl, setQrDataUrl] = useState<string | null>(null);
  const [qrStatus, setQrStatus] = useState<string>('PAIRING');
  const pollRef = useRef<ReturnType<typeof setInterval> | null>(null);

  async function load() {
    const res = await fetch('/api/admin/bots');
    if (res.ok) setBots(await res.json());
  }

  useEffect(() => {
    if (loading) return;
    if (!admin) { router.replace('/admin/login'); return; }
    void load();
  }, [admin, loading, router]);

  const pollQr = useCallback(async (token: string) => {
    const res = await fetch(`/api/admin/bots/qr/${token}`);
    if (!res.ok) { clearInterval(pollRef.current!); return; }
    const data = await res.json();
    setQrStatus(data.status);
    if (data.qrDataUrl) {
      setQrDataUrl(data.qrDataUrl);
      clearInterval(pollRef.current!);
    }
    if (data.status === 'ACTIVE') {
      clearInterval(pollRef.current!);
      setPairingInfo(null);
      void load();
    }
  }, []);

  useEffect(() => {
    return () => { if (pollRef.current) clearInterval(pollRef.current); };
  }, []);

  async function initiateBot() {
    setInitiating(true);
    setQrDataUrl(null);
    setQrStatus('PAIRING');
    try {
      const res = await fetch('/api/admin/bots', {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({}),
      });
      if (res.ok) {
        const data = await res.json();
        setPairingInfo(data);
        pollRef.current = setInterval(() => void pollQr(data.pairingToken), 2000);
        void pollQr(data.pairingToken);
      }
    } finally {
      setInitiating(false);
      void load();
    }
  }

  async function removeBot(id: string) {
    if (!confirm('Remove this bot? Only possible if no tenants are assigned.')) return;
    const res = await fetch(`/api/admin/bots/${id}`, { method: 'DELETE' });
    if (res.ok) {
      void load();
    } else {
      const err = await res.json();
      alert(err.message ?? 'Failed to remove bot');
    }
  }

  if (loading) return <p className="text-gray-500">Loading...</p>;
  if (!admin) return null;

  return (
    <div>
      <div className="flex items-center justify-between mb-6">
        <h1 className="text-2xl font-bold">Bot Pool</h1>
        <button
          onClick={initiateBot}
          disabled={initiating}
          className="bg-blue-600 text-white rounded-lg px-4 py-2 text-sm disabled:opacity-50"
        >
          {initiating ? 'Creating...' : 'Add Bot'}
        </button>
      </div>

      {pairingInfo && (
        <div className="bg-yellow-50 border border-yellow-200 rounded-xl p-4 mb-6 flex items-start gap-6">
          <div className="flex-1">
            <p className="text-sm font-medium mb-1">
              {qrStatus === 'ACTIVE' ? 'Bot connected!' : 'New bot created — waiting for QR scan...'}
            </p>
            <p className="text-xs text-gray-600">Status: {qrStatus}</p>
            <p className="text-xs text-gray-600">Expires: {pairingInfo.expiresAt}</p>
          </div>
          {qrDataUrl ? (
            <img src={qrDataUrl} alt="QR Code" className="w-40 h-40 border-2 border-gray-300 rounded-lg" />
          ) : (
            <div className="w-40 h-40 bg-gray-100 border-2 border-dashed border-gray-300 rounded-lg flex items-center justify-center text-xs text-gray-400">
              {qrStatus === 'ACTIVE' ? 'Connected' : 'Waiting for QR...'}
            </div>
          )}
        </div>
      )}

      <div className="bg-white rounded-xl border overflow-hidden">
        <table className="w-full text-sm">
          <thead className="bg-gray-50 text-left">
            <tr>
              <th className="px-4 py-3 font-medium">JID</th>
              <th className="px-4 py-3 font-medium">Name</th>
              <th className="px-4 py-3 font-medium">Status</th>
              <th className="px-4 py-3 font-medium">Tenants</th>
              <th className="px-4 py-3 font-medium">Created</th>
              <th className="px-4 py-3 font-medium"></th>
            </tr>
          </thead>
          <tbody className="divide-y">
            {bots.map((b: any) => (
              <tr key={b.id} className="hover:bg-gray-50">
                <td className="px-4 py-3 font-mono text-xs">{b.jid?.slice(0, 30) ?? 'pending...'}</td>
                <td className="px-4 py-3">{b.displayName ?? '—'}</td>
                <td className="px-4 py-3">
                  <span className={`text-xs font-medium px-2 py-1 rounded-full ${
                    b.status === 'ACTIVE' ? 'bg-green-100 text-green-700' :
                    b.status === 'PAIRING' ? 'bg-yellow-100 text-yellow-700' :
                    'bg-gray-100 text-gray-500'
                  }`}>{b.status}</span>
                </td>
                <td className="px-4 py-3">{b.tenantCount}</td>
                <td className="px-4 py-3 text-xs text-gray-500">{new Date(b.createdAt).toLocaleDateString()}</td>
                <td className="px-4 py-3">
                  <button
                    onClick={() => removeBot(b.id)}
                    className="text-red-600 text-xs hover:underline"
                  >
                    Remove
                  </button>
                </td>
              </tr>
            ))}
          </tbody>
        </table>
        {bots.length === 0 && <p className="p-4 text-gray-400">No bots in the pool.</p>}
      </div>
    </div>
  );
}