Refactor code structure for improved readability and maintainability

ts/models/db.ts

@@ -1,50 +1,65 @@
 /**
  * Database connection singleton
+ *
+ * SmartData models need a db reference at class definition time via lazy getter.
+ * The actual .init() is called later when the server starts.
  */
 
 import * as plugins from '../plugins.ts';
+import { User } from './user.ts';
 
-let dbInstance: plugins.smartdata.SmartdataDb | null = null;
+// Database instance - created lazily in initDb()
+// The @Collection(() => db) decorator uses a lazy getter, so db can be undefined
+// until initDb() is called. Default admin is seeded after db.init() completes.
+export let db: plugins.smartdata.SmartdataDb;
+
+let isInitialized = false;
 
 /**
  * Initialize database connection
  */
-export async function initDb(config: {
-  mongoDbUrl: string;
-  mongoDbName?: string;
-}): Promise<plugins.smartdata.SmartdataDb> {
-  if (dbInstance) {
-    return dbInstance;
+export async function initDb(
+  mongoDbUrl: string,
+  mongoDbName?: string
+): Promise<plugins.smartdata.SmartdataDb> {
+  if (isInitialized && db) {
+    return db;
   }
 
-  dbInstance = new plugins.smartdata.SmartdataDb({
-    mongoDbUrl: config.mongoDbUrl,
-    mongoDbName: config.mongoDbName || 'stackregistry',
+  // Create the database instance with actual configuration
+  db = new plugins.smartdata.SmartdataDb({
+    mongoDbUrl: mongoDbUrl,
+    mongoDbName: mongoDbName || 'stackregistry',
   });
 
-  await dbInstance.init();
+  await db.init();
+  isInitialized = true;
   console.log('Database connected successfully');
 
-  return dbInstance;
+  // Seed default admin user if none exists
+  try {
+    await User.seedDefaultAdmin();
+  } catch (err) {
+    console.warn('[Database] Failed to seed default admin:', err);
+  }
+
+  return db;
 }
 
 /**
- * Get database instance (must call initDb first)
+ * Get database instance (for backward compatibility)
  */
 export function getDb(): plugins.smartdata.SmartdataDb {
-  if (!dbInstance) {
-    throw new Error('Database not initialized. Call initDb() first.');
-  }
-  return dbInstance;
+  return db;
 }
 
 /**
  * Close database connection
  */
 export async function closeDb(): Promise<void> {
-  if (dbInstance) {
-    await dbInstance.close();
-    dbInstance = null;
+  if (db && isInitialized) {
+    await db.close();
+    isInitialized = false;
     console.log('Database connection closed');
   }
 }
@@ -53,5 +68,5 @@ export async function closeDb(): Promise<void> {
  * Check if database is connected
  */
 export function isDbConnected(): boolean {
-  return dbInstance !== null;
+  return isInitialized;
 }