const nodemailer = require('nodemailer');
const EmailTemplate = require('../models/EmailTemplate');

const sendEmail = async ({ templateName, to, variables = {} }) => {
  try {
    const template = await EmailTemplate.findOne({ name: templateName });
    let subject = variables.subject || 'Antigravity Guitars Update';
    let htmlContent = `<p>Thank you for contacting Antigravity Guitars!</p>`;

    if (template) {
      subject = template.subject;
      htmlContent = template.bodyHtml;

      // Replace placeholders e.g. {{customerName}} -> variables.customerName
      Object.keys(variables).forEach((key) => {
        const regex = new RegExp(`{{${key}}}`, 'g');
        subject = subject.replace(regex, variables[key] || '');
        htmlContent = htmlContent.replace(regex, variables[key] || '');
      });
    }

    const transporter = nodemailer.createTransport({
      host: process.env.EMAIL_HOST || 'smtp.mailtrap.io',
      port: process.env.EMAIL_PORT || 2525,
      auth: {
        user: process.env.EMAIL_USER || '',
        pass: process.env.EMAIL_PASS || ''
      }
    });

    const mailOptions = {
      from: process.env.EMAIL_FROM || '"Antigravity Guitars" <noreply@guitars.com>',
      to,
      subject,
      html: htmlContent
    };

    if (process.env.NODE_ENV !== 'test' && process.env.EMAIL_USER) {
      await transporter.sendMail(mailOptions);
      console.log(`[Email Sent]: Template "${templateName}" to ${to}`);
    } else {
      console.log(`[Email Logged (Mock)] To: ${to} | Subject: ${subject}`);
    }
    return true;
  } catch (error) {
    console.error(`[Email Sender Exception]: ${error.message}`);
    return false;
  }
};

module.exports = { sendEmail };