stack/apps/gateway/src/database/database.module.ts

import { Global, Inject, Module, type OnApplicationShutdown } from '@nestjs/common';
import { createDb, type Db, type DbHandle } from '@mosaic/db';

export const DB_HANDLE = 'DB_HANDLE';
export const DB = 'DB';

@Global()
@Module({
  providers: [
    {
      provide: DB_HANDLE,
      useFactory: (): DbHandle => createDb(),
    },
    {
      provide: DB,
      useFactory: (handle: DbHandle): Db => handle.db,
      inject: [DB_HANDLE],
    },
  ],
  exports: [DB],
})
export class DatabaseModule implements OnApplicationShutdown {
  constructor(@Inject(DB_HANDLE) private readonly handle: DbHandle) {}

  async onApplicationShutdown(): Promise<void> {
    await this.handle.close();
  }
}