import { BulkWriteOptions, Collection, Document, OptionalUnlessRequiredId } from 'mongodb';
import { ErrorEvents } from './ErrorEvents';
import { Timeout } from './Timeout';
import { TypedEventEmitter } from './TypedEventEmitter';
export interface BatchPublisherOptions {
    /**
     * Maximum number of messages per batch to bulk insert.
     */
    maxBatchSize?: number;
    /**
     * Delay before a batch insert.
     */
    batchDelayMs?: number;
    /**
     * With `bestEffort: true` (default),
     *
     * - batches are inserted with write concern `majority`,
     * - the `BatchPublisher` will emit `error` events on write failures,
     * - retry inserting messages,
     * - and attempt a bulk insert on closure.
     *
     * With `bestEffort: false`,
     *
     * - batches are inserted with write concern `0`,
     * - no errors will be emitted on failures,
     * - and unwritten messages will be dropped in case of failure or closure.
     */
    bestEffort?: boolean;
    bulkWriteOptions?: BulkWriteOptions;
}
export type BatchPublisherEvents<TMessage extends Document> = ErrorEvents<TMessage>;
export declare class BatchPublisher<TMessage extends Document> extends TypedEventEmitter<BatchPublisherEvents<TMessage>> {
    protected collection: Collection<TMessage>;
    protected maxBatchSize: number;
    protected delayMs: number;
    protected bestEffort: boolean;
    protected bulkWriteOptions: BulkWriteOptions;
    protected queue: OptionalUnlessRequiredId<TMessage>[];
    protected flushTimeout: Timeout;
    protected closed: boolean;
    constructor(collection: Collection<TMessage>, options?: BatchPublisherOptions);
    /**
     * Publish a message after a delay.
     * See `options.bestEffort` for behavior.
     */
    publish(message: OptionalUnlessRequiredId<TMessage>): void;
    close(): Promise<void>;
    protected flush(): Promise<void>;
}