import { Document } from '@tashmet/tashmet';
import { AggregatorFactory, OperatorPluginConfigurator } from '@tashmet/engine';
import { Container, Logger } from '@tashmet/core';
import { MingoOperatorContext } from './operator.js';
/**
 * Pipeline operators
 *
 * Since mingo does not support async interators we provide a means to go
 * around that limitation by allowing at least a subset of pipeline
 * operators to be streamed asynchronously, with the rest being async but
 * with buffering of the previous step.
 */
export declare class MingoStreamPipelineOpertors {
    private factory;
    private logger;
    constructor(factory: AggregatorFactory, logger: Logger);
    /**
     * Handler for all mingo pipeline operators that can be streamed.
     *
     * This generator will take one document at a time from the input and pass it
     * to the mingo operator as a list with a single item. All documents from the
     * result iterator will be yielded before continuing reading the next document
     * from the input.
     */
    operatorStreamed<T>(source: AsyncIterable<T>, expr: any, ctx: MingoOperatorContext): AsyncGenerator<any, void, unknown>;
    /**
     * Handler for all mingo pipeline operators that can not be streamed
     *
     * This generator will load a buffer of all documents from the input and then
     * proceed by passing that buffer to the mingo operator. the resulting
     * documents will be yielded one by one once the whole operation is done.
     */
    operatorBuffered<T>(source: AsyncIterable<T>, expr: any, ctx: MingoOperatorContext): AsyncGenerator<any, void, unknown>;
    /** Custom $match operator that enables streaming */
    $match(source: AsyncIterable<Document>, expr: Document, ctx: MingoOperatorContext): AsyncGenerator<Document, void, unknown>;
    /**
     * Since mingo seems to not take into account that replaceWith has a
     * different form than replaceRoot, we override it.
     */
    $replaceWith(source: AsyncIterable<Document>, expr: Document, ctx: MingoOperatorContext): AsyncGenerator<any, void, unknown>;
    /** Custom $skip operator that enables streaming */
    $skip(source: AsyncIterable<Document>, expr: number): AsyncGenerator<Document, void, unknown>;
    /** Custom $limit operator that enables streaming */
    $limit(source: AsyncIterable<Document>, expr: number): AsyncGenerator<Document, void, unknown>;
    /** No support for $documents operator in mingo so we provide our own */
    $documents(source: AsyncIterable<Document>, expr: Document[]): AsyncGenerator<Document, void, unknown>;
    /** Custom operator to allow for update expresssions in an aggregation pipeline */
    $update(source: AsyncIterable<Document>, expr: any): AsyncGenerator<any, void, unknown>;
    $facet(source: AsyncIterable<Document>, expr: Document): AsyncGenerator<Document, void, unknown>;
    $dump(source: AsyncIterable<Document>, expr: any, ctx: MingoOperatorContext): AsyncGenerator<Document, void, unknown>;
    $log(source: AsyncIterable<Document>, expr: any, ctx: MingoOperatorContext): AsyncGenerator<Document, void, unknown>;
}
declare const _default: () => (container: Container) => OperatorPluginConfigurator<MingoStreamPipelineOpertors>;
export default _default;