servicio_social_api/server/helper/gmail.js

/* require('../config/config');           // mantiene tu carga de variables
const nodemailer = require('nodemailer');

const transporter = nodemailer.createTransport({
	host: 'smtp.gmail.com',          // o smtp‑relay.gmail.com (ver punto 2)
	port: 587,
	secure: false,
	requireTLS: true,                  // TLS STARTTLS
	auth: { user: process.env.USER_GMAIL, pass: process.env.PASS_GMAIL },
	pool: true,                      // <‑‑ activa reuse
	maxConnections: 1,               // una sola conexión viva
	maxMessages: 100,                // reabrir después de 100 envíos
	rateDelta: 2000,                 // ventana 1 s
	rateLimit: 1                     // máx. 5 mensajes/seg
});

const gmail = (subject, to, text) =>
  transporter.sendMail({
    from: process.env.USER_GMAIL,
    to,
    subject,
    text,
  });

module.exports = gmail;
 */
 




require('../config/config');
const nodemailer = require('nodemailer');
const { google } = require('googleapis');

const oAuth2Client = new google.auth.OAuth2(
  process.env.CLIENT_ID_GMAIL,
  process.env.CLIENT_SECRET_GMAIL,
  process.env.REDIRECT_URI_GMAIL // puedes usar "https://developers.google.com/oauthplayground"
);

oAuth2Client.setCredentials({
  refresh_token: process.env.REFRESH_TOKEN_GMAIL,
});

async function sendMail(subject, to, text) {
  try {
    const accessToken = await oAuth2Client.getAccessToken();

    const transporter = nodemailer.createTransport({
      service: 'gmail',
      auth: {
        type: 'OAuth2',
        user: process.env.USER_GMAIL_GMAIL,
        clientId: process.env.CLIENT_ID_GMAIL,
        clientSecret: process.env.CLIENT_SECRET_GMAIL,
        refreshToken: process.env.REFRESH_TOKEN_GMAIL,
        accessToken: accessToken.token,
      },
      pool: true,
      maxConnections: 1,
      maxMessages: 100,
      rateDelta: 2000,
      rateLimit: 1,
    });

    const result = await transporter.sendMail({
      from: process.env.USER_GMAIL_GMAIL,
      to,
      subject,
      text,
    });

    return result;
  } catch (error) {
    console.error('Error al enviar correo:', error);
    throw error;
  }
}

module.exports = sendMail;