Bot WhatsApp NutriBox

// NutriBox WhatsApp Bot — index.js
// Meta Cloud API v21.0 + Express + Redis state

const express = require('express');
const { createClient } = require('redis');
const { handleMessage } = require('./messageHandler');

const app = express();
app.use(express.json());

const redis = createClient({ url: process.env.REDIS_URL });
redis.connect();

// Webhook verification (GET) — requerido por Meta
app.get('/webhook', (req, res) => {
  const mode      = req.query['hub.mode'];
  const token     = req.query['hub.verify_token'];
  const challenge = req.query['hub.challenge'];

  if (mode === 'subscribe' && token === process.env.WHATSAPP_VERIFY_TOKEN) {
    console.log('Webhook verificado correctamente');
    return res.status(200).send(challenge);
  }
  res.sendStatus(403);
});

// Recepcion de mensajes (POST) — responder 200 INMEDIATAMENTE
app.post('/webhook', async (req, res) => {
  res.sendStatus(200); // Responder antes de procesar (max 5s)

  const entry   = req.body.entry?.[0];
  const change  = entry?.changes?.[0];
  const message = change?.value?.messages?.[0];

  if (!message) return;

  // Deduplicacion: ignorar mensajes ya procesados
  const key = `msg:${message.id}`;
  const seen = await redis.setNX(key, 1);
  if (!seen) return;
  await redis.expire(key, 86400); // TTL 24h

  const phoneId = change.value.metadata.phone_number_id;
  await handleMessage(message, phoneId, redis);
});

app.listen(process.env.PORT || 3000, () =>
  console.log('NutriBox WhatsApp Bot iniciado')
);