/**
 * utils/smtpMailer.js
 * Fallback SMTP per l'invio email via nodemailer.
 * Usato se AZURE_TENANT_ID non è configurato ma SMTP_HOST lo è.
 */
'use strict';

const nodemailer = require('nodemailer');

let _transporter = null;

function getTransporter() {
  if (_transporter) return _transporter;

  _transporter = nodemailer.createTransport({
    host: process.env.SMTP_HOST,
    port: parseInt(process.env.SMTP_PORT || '587', 10),
    secure: process.env.SMTP_SECURE === 'true',
    auth: {
      user: process.env.SMTP_USER,
      pass: process.env.SMTP_PASSWORD,
    },
  });

  return _transporter;
}

/**
 * Invia una email tramite SMTP (nodemailer).
 * Stessa interfaccia di graphMailer.sendMail.
 */
async function sendMail({ to, cc = [], bcc = [], subject, bodyHtml, attachments = [], inlineImages = [] }) {
  const transporter = getTransporter();

  const mailOptions = {
    from: process.env.SMTP_FROM || process.env.SMTP_USER,
    to: to.join(', '),
    cc: cc.length ? cc.join(', ') : undefined,
    bcc: bcc.length ? bcc.join(', ') : undefined,
    subject,
    html: bodyHtml,
    attachments: [
      ...attachments.map(a => ({
        filename: a.filename,
        content: Buffer.from(a.content, 'base64'),
        contentType: a.contentType || 'application/octet-stream',
      })),
      ...inlineImages.map(img => ({
        filename: img.cid,
        cid: img.cid,
        content: Buffer.from(img.content, 'base64'),
        contentType: img.contentType || 'image/png',
      })),
    ],
  };

  await transporter.sendMail(mailOptions);
}

module.exports = { sendMail };