Add email delivery for license keys (SMTP)

src/email.js

@@ -0,0 +1,107 @@
+import crypto from 'crypto';
+import nodemailer from 'nodemailer';
+
+const LICENSE_SECRET = process.env.DASHCADDY_LICENSE_SECRET || '';
+
+const ALPHABET = 'ABCDEFGHJKLMNPQRSTUVWXYZ23456789'; // Crockford-ish (no I, O, 0, 1)
+
+/**
+ * Generate a DashCaddy license code in the format `DC-XXXX-XXXX-XXXX-XXXX`.
+ * Deterministic for the same (licenseKey, durationDays) tuple — if a customer
+ * pays again, regenerate the code with the same key + new duration, and the
+ * code stays the same. That's what "the same key gets more time" means.
+ */
+export function generateLicenseCode(licenseKey, durationDays) {
+  if (!LICENSE_SECRET) {
+    throw new Error('DASHCADDY_LICENSE_SECRET not set');
+  }
+  const seed = crypto
+    .createHmac('sha256', LICENSE_SECRET)
+    .update(`${licenseKey}|${durationDays}`)
+    .digest();
+  const segments = [];
+  for (let i = 0; i < seed.length && segments.length < 4; i += 2) {
+    const b1 = seed[i];
+    const b2 = seed[i + 1] || 0;
+    segments.push(
+      ALPHABET[b1 % 32] +
+      ALPHABET[Math.floor(b1 / 32) % 32] +
+      ALPHABET[b2 % 32] +
+      ALPHABET[Math.floor(b2 / 32) % 32]
+    );
+  }
+  return 'DC-' + segments.join('-');
+}
+
+let transporter = null;
+function getTransporter() {
+  if (transporter) return transporter;
+  transporter = nodemailer.createTransport({
+    host: process.env.SMTP_HOST || '127.0.0.1',
+    port: parseInt(process.env.SMTP_PORT || '25', 10),
+    secure: process.env.SMTP_SECURE === 'true',
+    auth: process.env.SMTP_USERNAME ? {
+      user: process.env.SMTP_USERNAME,
+      pass: process.env.SMTP_PASSWORD
+    } : undefined,
+    tls: { rejectUnauthorized: false }
+  });
+  return transporter;
+}
+
+function formatDate(iso) {
+  if (!iso) return 'N/A';
+  return new Date(iso).toUTCString();
+}
+
+/**
+ * Send the license key email to the customer. Called after every payment
+ * (initial purchase or renewal extension).
+ */
+export async function sendLicenseEmail({ to, code, durationDays, planCode, expiresAt, extended = false }) {
+  const subject = extended
+    ? `Your DashCaddy Premium license has been extended (${durationDays} days added)`
+    : `Your DashCaddy Premium license key`;
+  const text = [
+    extended ? 'Your DashCaddy Premium license has been extended.' : 'Thank you for purchasing DashCaddy Premium.',
+    '',
+    `License key: ${code}`,
+    `Plan: ${planCode}`,
+    `License valid until: ${formatDate(expiresAt)}`,
+    '',
+    'To activate: paste this license key into your DashCaddy dashboard at Admin → License.',
+    '',
+    'Need help? Reply to this email or visit https://dashcaddy.net/about'
+  ].join('\n');
+  const html = `
+    <div style="font-family: system-ui, sans-serif; max-width: 600px; margin: 0 auto; padding: 20px;">
+      <h2 style="color: #0f172a;">${extended ? 'License extended' : 'Welcome to DashCaddy Premium'}</h2>
+      <p>${extended
+        ? 'Your DashCaddy Premium license has been extended. Same key, more time.'
+        : 'Thank you for purchasing DashCaddy Premium. Your license key is below.'}</p>
+      <div style="background: #f1f5f9; padding: 16px; border-radius: 8px; margin: 20px 0; font-family: monospace; font-size: 16px; text-align: center; letter-spacing: 2px;">
+        ${code}
+      </div>
+      <p><strong>Plan:</strong> ${planCode}</p>
+      <p><strong>License valid until:</strong> ${formatDate(expiresAt)}</p>
+      <p>To activate: paste this license key into your DashCaddy dashboard at <strong>Admin → License</strong>.</p>
+      <hr style="margin-top: 30px; border: none; border-top: 1px solid #e2e8f0;" />
+      <p style="color: #64748b; font-size: 14px;">Need help? Reply to this email or visit <a href="https://dashcaddy.net/about">dashcaddy.net/about</a></p>
+    </div>
+  `;
+
+  try {
+    const t = getTransporter();
+    await t.sendMail({
+      from: process.env.SMTP_FROM || 'licenses@dashcaddy.net',
+      to,
+      subject,
+      text,
+      html
+    });
+    return { delivered: true, via: 'smtp' };
+  } catch (err) {
+    console.error('Email delivery failed:', err.message);
+    return { delivered: false, error: err.message };
+  }
+}