// SMTP delivery for account notifications.

const nodemailer = require('nodemailer');

function getSmtpConfig(settings) {
  return {
    enabled: Boolean(settings['email.smtp_enabled']),
    host: String(settings['email.smtp_host'] || '').trim(),
    port: Number(settings['email.smtp_port']) || 587,
    security: String(settings['email.smtp_security'] || 'starttls'),
    username: String(settings['email.smtp_username'] || '').trim(),
    password: String(settings['email.smtp_password'] || ''),
    fromAddress: String(settings['email.from_address'] || '').trim(),
    fromName: String(settings['email.from_name'] || '').trim()
  };
}

function createMailTransport(settings) {
  const config = getSmtpConfig(settings);
  if (!config.enabled || !config.host || !config.fromAddress) {
    return null;
  }
  return nodemailer.createTransport({
    host: config.host,
    port: config.port,
    secure: config.security === 'tls',
    requireTLS: config.security === 'starttls',
    auth: config.username ? { user: config.username, pass: config.password } : undefined
  });
}

async function sendAccountEmail(settings, message) {
  const transport = createMailTransport(settings);
  if (!transport) {
    throw new Error('Email delivery is not configured.');
  }
  const config = getSmtpConfig(settings);
  return transport.sendMail(Object.assign({}, message, {
    from: config.fromName ? '"' + config.fromName.replace(/"/g, '') + '" <' + config.fromAddress + '>' : config.fromAddress,
  }));
}

module.exports = { getSmtpConfig, createMailTransport, sendAccountEmail };