import type { Readable, Transform, Writable } from 'node:stream';
import type { CommonLogger, CommonLogLevel } from '@naturalcycles/js-lib/log';
import type { Promisable } from '@naturalcycles/js-lib/types';
export interface ReadableSignalOptions {
    /** allows destroying the stream if the signal is aborted. */
    signal?: AbortSignal;
}
export interface ReadableArrayOptions {
    /** the maximum concurrent invocations of `fn` to call on the stream at once. **Default: 1**. */
    concurrency?: number;
    /** allows destroying the stream if the signal is aborted. */
    signal?: AbortSignal;
}
export type ReadableMapper<IN, OUT = unknown> = (data: IN, opt?: ReadableSignalOptions) => Promisable<OUT>;
export type ReadableFlatMapper<IN, OUT = unknown> = (data: IN, opt?: ReadableSignalOptions) => Promisable<OUT[]>;
export type ReadableVoidMapper<IN> = (data: IN, opt?: ReadableSignalOptions) => void | Promise<void>;
export type ReadablePredicate<IN> = (data: IN, opt?: ReadableSignalOptions) => boolean | Promise<boolean>;
export interface ReadableTyped<T = unknown> extends Readable {
    toArray: (opt?: ReadableSignalOptions) => Promise<T[]>;
    map: <OUT>(mapper: ReadableMapper<T, OUT>, opt?: ReadableArrayOptions) => ReadableTyped<OUT>;
    flatMap: <OUT>(mapper: ReadableFlatMapper<T, OUT>, opt?: ReadableArrayOptions) => ReadableTyped<OUT>;
    filter: (predicate: ReadablePredicate<T>, opt?: ReadableArrayOptions) => ReadableTyped<T>;
    forEach: (mapper: ReadableVoidMapper<T>, opt?: ReadableArrayOptions) => Promise<void>;
    take: (limit: number, opt?: ReadableSignalOptions) => ReadableTyped<T>;
    drop: (limit: number, opt?: ReadableSignalOptions) => ReadableTyped<T>;
}
export interface WritableTyped<_T> extends Writable {
}
export interface TransformTyped<_IN = unknown, _OUT = unknown> extends Transform {
}
export interface TransformOptions {
    /**
     * @default true
     */
    objectMode?: boolean;
    /**
     * @default 16
     */
    highWaterMark?: number;
    /**
     * Defaults to `console`.
     */
    logger?: CommonLogger;
    /**
     * Not every Transform implements it.
     * Can be one of:
     * debug - most verbose, when debugging is needed
     * log - default level
     * error - logs errors and warnings only
     *
     * Default is 'log'.
     *
     */
    logLevel?: CommonLogLevel;
}