feat: SMTP server (#47)

* WIP: SMTP server * Card and minor changes in Server --------- Co-authored-by: KM Koushik <koushikmohan1996@gmail.com>
2024-08-11 05:27:13 +05:30
parent d74b20bac8
commit 0b82eb2266
8 changed files with 576 additions and 46 deletions
--- a/apps/smtp-server/src/server.ts
+++ b/apps/smtp-server/src/server.ts
@@ -0,0 +1,101 @@
+import { SMTPServer, SMTPServerOptions } from 'smtp-server';
+import { Readable } from 'stream';
+import dotenv from 'dotenv';
+import { simpleParser } from 'mailparser';
+
+dotenv.config();
+
+const AUTH_USERNAME = process.env.SMTP_AUTH_USERNAME!;
+const UNSEND_BASE_URL = process.env.UNSEND_BASE_URL!;
+let API_KEY = '';
+
+const ports = [25, 465, 2465, 587, 2587]; // Array of ports to listen on
+
+const serverOptions: SMTPServerOptions = {
+  onData(stream: Readable, session: any, callback: (error?: Error) => void) {
+    console.log('Receiving email data...'); // Debug statement
+    simpleParser(stream, (err, parsed) => {
+      if (err) {
+        console.error('Failed to parse email data:', err.message);
+        return callback(err);
+      }
+
+      const emailObject: any = {
+        to: Array.isArray(parsed.to) ? parsed.to.map(addr => addr.text).join(', ') : parsed.to?.text,
+        from: Array.isArray(parsed.from) ? parsed.from.map(addr => addr.text).join(', ') : parsed.from?.text,
+        subject: parsed.subject,
+        text: parsed.text,
+        html: parsed.html,
+      };
+
+      console.log('Parsed email data:', emailObject); // Debug statement
+
+      sendEmailToUnsend(emailObject)
+        .then(() => callback())
+        .catch((error) => {
+          console.error('Failed to send email:', error.message);
+          callback(error);
+        });
+    });
+  },
+  onAuth(auth: any, session: any, callback: (error?: Error, user?: any) => void) {
+    API_KEY = auth.password;
+    if (auth.username === AUTH_USERNAME) {
+      console.log('Authenticated successfully'); // Debug statement
+      callback(undefined, { user: AUTH_USERNAME });
+    } else {
+      console.error('Invalid username or password');
+      callback(new Error('Invalid username or password'));
+    }
+  },
+};
+
+async function sendEmailToUnsend(emailData: any) {
+  try {
+    const apiEndpoint = '/api/v1/emails';
+    const url = new URL(apiEndpoint, UNSEND_BASE_URL); // Combine base URL with endpoint
+    console.log('Sending email to Unsend API at:', url.href); // Debug statement
+
+    const response = await fetch(url.href, {
+      method: 'POST',
+      headers: {
+        'Authorization': `Bearer ${API_KEY}`,
+        'Content-Type': 'application/json',
+      },
+      body: JSON.stringify(emailData),
+    });
+
+    if (!response.ok) {
+      const errorData = await response.json();
+      console.error('Unsend API error response:', errorData);
+      throw new Error(`Failed to send email: ${errorData.message || 'Unknown error from server'}`);
+    }
+
+    const responseData = await response.json();
+    console.log('Unsend API response:', responseData);
+  } catch (error) {
+    if (error instanceof Error) {
+      console.error('Error message:', error.message);
+      throw new Error(`Failed to send email: ${error.message}`);
+    } else {
+      console.error('Unexpected error:', error);
+      throw new Error('Failed to send email: Unexpected error occurred');
+    }
+  }
+}
+
+function startServers() {
+  ports.forEach(port => {
+    const server = new SMTPServer(serverOptions);
+
+    server.listen(port, () => {
+      console.log(`SMTP server is listening on port ${port}`);
+    });
+
+    server.on('error', (err) => {
+      console.error(`Error occurred on port ${port}:`, err);
+    });
+  });
+}
+
+startServers();