import 'dotenv/config';
import nodemailer from 'nodemailer';
import logger from './logger.js';

const FROM_EMAIL = process.env.MAIL_FROM || 'smtp@korrith.com';
const REPLY_TO_EMAIL = process.env.MAIL_REPLY_TO || 'noreply@korrith.com';

const smtpPort = parseInt(process.env.SMTP_PORT, 10) || 587;

// Initialize nodemailer transporter with SMTP credentials
const transporter = nodemailer.createTransport({
  host: process.env.SMTP_HOST,
  port: smtpPort,
  secure: smtpPort === 465, // SSL on port 465, STARTTLS otherwise (e.g. 587)
  auth: {
    user: process.env.SMTP_USER,
    pass: process.env.SMTP_PASSWORD,
  },
});

/**
 * Send email using nodemailer with SMTP
 * @param {string|string[]} to - Recipient email address(es)
 * @param {string} subject - Email subject
 * @param {string} htmlBody - HTML email body
 * @returns {Promise<Object>} - Mail service response
 * @throws {Error} - If email sending fails
 */
async function sendEmail(to, subject, htmlBody) {
  const recipients = Array.isArray(to) ? to : [to];

  logger.info('Attempting to send email via SMTP', {
    recipients: recipients.join(', '),
    subject,
    from: FROM_EMAIL,
    timestamp: new Date().toISOString()
  });

  try {
    const mailOptions = {
      from: FROM_EMAIL,
      to: recipients.join(', '),
      subject,
      html: htmlBody,
      replyTo: REPLY_TO_EMAIL,
    };

    const result = await transporter.sendMail(mailOptions);

    logger.info('Email sent successfully via SMTP', {
      recipients: recipients.join(', '),
      subject,
      from: FROM_EMAIL,
      messageId: result.messageId,
      timestamp: new Date().toISOString()
    });

    return result;
  } catch (error) {
    logger.error('Email send failed', {
      recipients: recipients.join(', '),
      subject,
      from: FROM_EMAIL,
      errorMessage: error.message,
      timestamp: new Date().toISOString()
    });

    throw new Error(`SMTP email error: ${error.message}`);
  }
}

export { sendEmail };
export default sendEmail;