const cron = require('node-cron');
const webPush = require('web-push');
const pool = require('../config/db');

const publicVapidKey = process.env.VAPID_PUBLIC_KEY;
const privateVapidKey = process.env.VAPID_PRIVATE_KEY;

if (publicVapidKey && privateVapidKey) {
  webPush.setVapidDetails('mailto:pierre@secourit.fr', publicVapidKey, privateVapidKey);
}

const REMINDER_MESSAGES = [
  {
    title: 'Dyna Biz Coignières',
    body: 'Pensez à mettre à jour vos invités et recommandations !',
    icon: '/logo.svg',
    badge: '/favicon.svg',
  },
];

function getNextReminderDate(days) {
  const d = new Date();
  d.setDate(d.getDate() + days);
  d.setHours(9, 0, 0, 0);
  return d;
}

async function sendReminders() {
  console.log('[Push Cron] Checking reminders...');
  try {
    const [subscriptions] = await pool.query(
      `SELECT ps.*, u.prenom, u.nom
       FROM push_subscriptions ps
       JOIN users u ON u.id = ps.user_id
       WHERE ps.last_sent_at IS NULL
          OR DATE_ADD(ps.last_sent_at, INTERVAL ps.reminder_days DAY) <= NOW()`
    );

    console.log(`[Push Cron] Found ${subscriptions.length} subscription(s) to notify`);

    for (const sub of subscriptions) {
      try {
        const msg = REMINDER_MESSAGES[0];
        const payload = JSON.stringify({
          title: msg.title,
          body: msg.body,
          icon: msg.icon,
          badge: msg.badge,
          data: { url: '/' },
        });

        await webPush.sendNotification(
          { endpoint: sub.endpoint, keys: { p256dh: sub.p256dh, auth: sub.auth } },
          payload
        );

        await pool.query('UPDATE push_subscriptions SET last_sent_at = NOW() WHERE id = ?', [sub.id]);
        console.log(`[Push Cron] Sent to ${sub.prenom} ${sub.nom}`);
      } catch (err) {
        if (err.statusCode === 410 || err.statusCode === 404) {
          await pool.query('DELETE FROM push_subscriptions WHERE id = ?', [sub.id]);
          console.log(`[Push Cron] Removed expired subscription for ${sub.prenom} ${sub.nom}`);
        } else {
          console.error(`[Push Cron] Error sending to ${sub.prenom} ${sub.nom}:`, err.message);
        }
      }
    }
  } catch (err) {
    console.error('[Push Cron] Error:', err);
  }
}

function startPushCron() {
  if (!publicVapidKey || !privateVapidKey) {
    console.log('[Push Cron] VAPID keys not configured — skipping cron start');
    return;
  }

  cron.schedule('0 9 * * *', () => {
    sendReminders();
  });

  console.log('[Push Cron] Scheduled daily at 09:00');
}

module.exports = { startPushCron, sendReminders };