Add email service with queue processing

backend/src/services/emailService.js

@@ -0,0 +1,65 @@
+const nodemailer = require('nodemailer');
+const { db } = require('../database/db');
+const { emailTemplates } = require('./emailTemplates');
+const logger = require('../utils/logger');
+
+// Create transporter
+const transporter = nodemailer.createTransport({
+  host: process.env.SMTP_HOST,
+  port: process.env.SMTP_PORT,
+  secure: process.env.SMTP_SECURE === 'true',
+  auth: {
+    user: process.env.SMTP_USER,
+    pass: process.env.SMTP_PASS
+  }
+});
+
+async function sendEmail(to, type, data) {
+  try {
+    const template = emailTemplates[type](data);
+    
+    const info = await transporter.sendMail({
+      from: process.env.EMAIL_FROM,
+      to: to,
+      subject: template.subject,
+      html: template.html,
+      text: template.text
+    });
+    
+    logger.info(`Email sent: ${info.messageId}`);
+    return info;
+  } catch (error) {
+    logger.error('Error sending email:', error);
+    throw error;
+  }
+}
+
+// Process email queue
+async function processEmailQueue() {
+  const pendingEmails = await db('email_queue')
+    .where('status', 'pending')
+    .where('retry_count', '<', 3)
+    .limit(10);
+  
+  for (const email of pendingEmails) {
+    try {
+      const emailData = JSON.parse(email.email_data);
+      await sendEmail(email.recipient_email, email.email_type, emailData);
+      
+      await db('email_queue').where('id', email.id).update({
+        status: 'sent',
+        sent_at: new Date()
+      });
+    } catch (error) {
+      await db('email_queue').where('id', email.id).update({
+        retry_count: email.retry_count + 1,
+        error_message: error.message
+      });
+    }
+  }
+}
+
+// Start email queue processor
+setInterval(processEmailQueue, 60000); // Process every minute
+
+module.exports = { sendEmail, processEmailQueue };