Send login codes via SMTP using Mailpit-compatible transport

src/mailer.js

@@ -0,0 +1,69 @@
+import nodemailer from 'nodemailer';
+
+let cachedTransporter = null;
+
+function getSmtpConfig() {
+  const host = process.env.SMTP_HOST;
+  const portRaw = process.env.SMTP_PORT;
+  const from = process.env.SMTP_FROM;
+  const secureRaw = process.env.SMTP_SECURE ?? 'false';
+  const user = process.env.SMTP_USER;
+  const pass = process.env.SMTP_PASS;
+
+  if (!host) {
+    throw new Error('SMTP_HOST is required for email login code delivery.');
+  }
+  if (!portRaw) {
+    throw new Error('SMTP_PORT is required for email login code delivery.');
+  }
+  if (!from) {
+    throw new Error('SMTP_FROM is required for email login code delivery.');
+  }
+
+  const port = Number(portRaw);
+  if (!Number.isInteger(port) || port <= 0) {
+    throw new Error('SMTP_PORT must be a valid integer port number.');
+  }
+
+  const secure = String(secureRaw).toLowerCase() === 'true';
+  const hasUser = Boolean(user);
+  const hasPass = Boolean(pass);
+
+  if (hasUser !== hasPass) {
+    throw new Error('SMTP_USER and SMTP_PASS must be set together.');
+  }
+
+  return {
+    from,
+    transport: {
+      host,
+      port,
+      secure,
+      ...(hasUser && hasPass ? { auth: { user, pass } } : {}),
+    },
+  };
+}
+
+function getTransporter() {
+  if (cachedTransporter) {
+    return cachedTransporter;
+  }
+
+  const config = getSmtpConfig();
+  cachedTransporter = nodemailer.createTransport(config.transport);
+  return cachedTransporter;
+}
+
+export async function sendLoginCodeEmail({ to, code, expiresAt }) {
+  const { from } = getSmtpConfig();
+  const transporter = getTransporter();
+  const expiresText = new Date(expiresAt).toLocaleString('ru-RU', { hour12: false });
+
+  await transporter.sendMail({
+    from,
+    to,
+    subject: 'Код входа в личный кабинет Fregat',
+    text: `Код входа: ${code}\nДействует до: ${expiresText}`,
+    html: `<p>Код входа: <b>${code}</b></p><p>Действует до: ${expiresText}</p>`,
+  });
+}

src/resolvers.js

@@ -8,6 +8,7 @@ import {
   maskAuthDestination,
   verifyLoginChallengeCode,
 } from './auth.js';
+import { sendLoginCodeEmail } from './mailer.js';
 import { dispatchToUserConnections, sendMessengerMessage } from './messenger.js';
 import { dateTimeScalar, jsonScalar } from './scalars.js';
 
@@ -287,7 +288,11 @@ export const resolvers = {
       });
 
       const code = getStaticAuthCode();
-      console.info(`[auth] login code for ${destination}: ${code}`);
+      await sendLoginCodeEmail({
+        to: destination,
+        code,
+        expiresAt: challenge.expiresAt,
+      });
 
       return {
         challengeToken: challenge.challengeToken,