feat: add email notification settings and test email functionality

- Created a new migration to add email settings to the database.
- Implemented routes for managing notification settings, including retrieving and updating settings.
- Added functionality to send test emails using SMTP configuration from environment variables.

backend/src/routes/settings.ts

@@ -0,0 +1,123 @@
+import { FastifyInstance } from "fastify";
+import nodemailer from "nodemailer";
+import { readFileSync, writeFileSync, existsSync } from "fs";
+import { resolve } from "path";
+
+type SettingsBody = {
+  emailEnabled: boolean;
+  notificationEmail: string;
+  reminderDaysBefore: number;
+};
+
+type TestEmailBody = {
+  email: string;
+};
+
+// Notification settings are stored in a JSON file (user-configurable)
+// SMTP settings come from .env (admin-configured)
+const notificationSettingsFile = resolve(process.cwd(), "data", "notification-settings.json");
+
+type NotificationSettings = {
+  emailEnabled: boolean;
+  notificationEmail: string;
+  reminderDaysBefore: number;
+};
+
+function loadNotificationSettings(): NotificationSettings {
+  try {
+    if (existsSync(notificationSettingsFile)) {
+      return JSON.parse(readFileSync(notificationSettingsFile, "utf-8"));
+    }
+  } catch {
+    // ignore
+  }
+  return { emailEnabled: false, notificationEmail: "", reminderDaysBefore: 7 };
+}
+
+function saveNotificationSettings(settings: NotificationSettings): void {
+  writeFileSync(notificationSettingsFile, JSON.stringify(settings, null, 2));
+}
+
+export async function settingsRoutes(app: FastifyInstance) {
+  // Get settings - notification from JSON file, SMTP from process.env
+  app.get("/settings", async (_request, reply) => {
+    const notification = loadNotificationSettings();
+    
+    return reply.send({
+      // Notification settings (user-configurable, stored in JSON)
+      emailEnabled: notification.emailEnabled,
+      notificationEmail: notification.notificationEmail,
+      reminderDaysBefore: notification.reminderDaysBefore,
+      // SMTP settings (admin-configured, from .env)
+      smtpHost: process.env.SMTP_HOST ?? "",
+      smtpPort: parseInt(process.env.SMTP_PORT ?? "587"),
+      smtpUser: process.env.SMTP_USER ?? "",
+      smtpFrom: process.env.SMTP_FROM ?? "",
+      smtpSecure: process.env.SMTP_SECURE === "true",
+      hasSmtpPassword: !!process.env.SMTP_PASS,
+    });
+  });
+
+  // Update settings - only notification settings are saved (SMTP comes from .env)
+  app.put<{ Body: SettingsBody }>("/settings", async (request, reply) => {
+    const body = request.body;
+    
+    // Save notification settings to JSON file
+    saveNotificationSettings({
+      emailEnabled: body.emailEnabled,
+      notificationEmail: body.notificationEmail,
+      reminderDaysBefore: body.reminderDaysBefore,
+    });
+
+    return reply.send({ success: true });
+  });
+
+  // Test email - use SMTP settings from process.env
+  app.post<{ Body: TestEmailBody }>("/settings/test-email", async (request, reply) => {
+    const { email } = request.body;
+    
+    const smtpHost = process.env.SMTP_HOST;
+    const smtpUser = process.env.SMTP_USER;
+    const smtpPass = process.env.SMTP_PASS;
+    const smtpPort = parseInt(process.env.SMTP_PORT ?? "587");
+    const smtpSecure = process.env.SMTP_SECURE === "true";
+    const smtpFrom = process.env.SMTP_FROM ?? smtpUser;
+
+    if (!smtpHost || !smtpUser) {
+      return reply.status(400).send({ error: "SMTP not configured" });
+    }
+
+    try {
+      const transporter = nodemailer.createTransport({
+        host: smtpHost,
+        port: smtpPort,
+        secure: smtpSecure,
+        auth: {
+          user: smtpUser,
+          pass: smtpPass ?? "",
+        },
+      });
+
+      await transporter.sendMail({
+        from: smtpFrom,
+        to: email,
+        subject: "MedAssist - Test Email",
+        text: "This is a test email from MedAssist. If you received this, your email configuration is working correctly!",
+        html: `
+          <div style="font-family: system-ui, sans-serif; max-width: 600px; margin: 0 auto; padding: 20px;">
+            <h2 style="color: #2563eb;">MedAssist - Test Email</h2>
+            <p>This is a test email from MedAssist.</p>
+            <p style="color: #10b981; font-weight: 600;">✓ If you received this, your email configuration is working correctly!</p>
+            <hr style="border: none; border-top: 1px solid #e5e7eb; margin: 20px 0;" />
+            <p style="color: #6b7280; font-size: 14px;">Sent from MedAssist Medication Planner</p>
+          </div>
+        `,
+      });
+
+      return reply.send({ success: true, message: "Test email sent successfully" });
+    } catch (error) {
+      const errorMessage = error instanceof Error ? error.message : "Unknown error";
+      return reply.status(500).send({ error: `Failed to send email: ${errorMessage}` });
+    }
+  });
+}