/**
 * 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';

// 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(
  mongoDbUrl: string,
  mongoDbName?: string
): Promise<plugins.smartdata.SmartdataDb> {
  if (isInitialized && db) {
    return db;
  }

  // Create the database instance with actual configuration
  db = new plugins.smartdata.SmartdataDb({
    mongoDbUrl: mongoDbUrl,
    mongoDbName: mongoDbName || 'stackregistry',
  });

  await db.init();
  isInitialized = true;
  console.log('Database connected successfully');

  // 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 (for backward compatibility)
 */
export function getDb(): plugins.smartdata.SmartdataDb {
  return db;
}

/**
 * Close database connection
 */
export async function closeDb(): Promise<void> {
  if (db && isInitialized) {
    await db.close();
    isInitialized = false;
    console.log('Database connection closed');
  }
}

/**
 * Check if database is connected
 */
export function isDbConnected(): boolean {
  return isInitialized;
}