'use strict';

const nodemailer = require('nodemailer'),
  debug = require('debug')('app:mailer');

const createConfig = (env) => {
  const isSecure = env?.SMTP_SECURE || process.env.SMTP_SECURE || false;
  const port = env?.SMTP_PORT || process.env.SMTP_PORT || 587;

  const config = {
    host: env?.SMTP_HOST || process.env.SMTP_HOST,
    port: port,
    secure: isSecure,
    auth: {
      user: env?.SMTP_USR || process.env.SMTP_USR,
      pass: env?.SMTP_PWD || process.env.SMTP_PWD,
    },
    sender: env?.SMTP_SENDER || process.env.SMTP_SENDER || `"AgNav Inc." <noreply@agnav.com>`
  };

  if (!config.host || !config.port || !config.auth.user || !config.auth.pass) {
    throw new Error('SMTP configuration is missing required fields (host, port, user, pass).');
  }
  return config;
};

const createMailOptions = (from, to, subject, body) => ({
  from: from, to: to, subject: subject, text: body
});

function createMailer(env) {
  const config = createConfig(env);

  const transporter = nodemailer.createTransport(config);

  return {
    sendMail: async (to, subject, body) => {
      try {
        if (!to || !subject || !body) {
          throw new Error('Missing required fields: to, subject, or body');
        }

        const mailOptions = createMailOptions(config.sender, to, subject, body);
        const info = await transporter.sendMail(mailOptions);

        return { success: true, message: 'Mail sent successfully', messageId: info.messageId };
      } catch (error) {
        debug('Error sending mail:', error.message);
        return { success: false, error: error.message };
      }
    },
  };
}

/**
 * Send a text email
 * @param {Object} options Email options
 * @param {string} options.from Sender of the email (Optional)
 * @param {string} options.subject Subject of the email
 * @param {string} options.to Recipient of the email
 * @param {string} options.text Text content of the email
 */
async function sendTextMail(options, env) {
  const { from, to, subject, body } = options;
  if (!to || !subject || !body) {
    throw new Error('Missing required fields: to, subject, or body');
  }
  const config = createConfig(env);

  const transporter = nodemailer.createTransport(config);
  const mailOptions = createMailOptions(from || config.sender, to, subject, body);

  try {
    const info = await transporter.sendMail(mailOptions);
    return { success: true, messageId: info.messageId };
  } catch (error) {
    debug('Error sending email:', error.message);
    return { success: false, error: error.message };
  }
}

module.exports = {
  createMailer, sendTextMail
};