import type { Db } from 'mongodb';
import type { IContainer } from 'node-cqrs';
/**
 * Abstract base class for accessing a MongoDB database.
 *
 * Manages the database connection lifecycle, ensuring initialization via `assertConnection`.
 * Supports providing a Db instance directly or a factory function for lazy initialization.
 *
 * Subclasses must implement the `initialize` method for specific setup tasks
 * (e.g. creating collections or indexes).
 */
export declare abstract class AbstractMongoAccessor {
    #private;
    protected db: Db | undefined;
    constructor(c: Partial<Pick<IContainer, 'viewModelMongoDb' | 'viewModelMongoDbFactory'>>);
    protected abstract initialize(db: Db): Promise<void> | void;
    /**
     * Ensures that the MongoDB connection is initialized.
     * Uses a lock to prevent race conditions during concurrent initialization attempts.
     * If the database is not already set, it creates one using the provided factory
     * and then calls the `initialize` method.
     *
     * This method is idempotent and safe to call multiple times.
     */
    assertConnection(): Promise<void>;
}