/**
 * This module provides a pair of classes for creating readable and writable streams
 * over the Chrome Extension Runtime messaging API.
 *
 * These streams utilize `chrome.runtime.sendMessage` for sending data and
 * `chrome.runtime.onMessage.addListener` for receiving data. This allows for
 * communication between different parts of a Chrome extension (e.g., background scripts,
 * content scripts, and popup pages).
 *
 * Note that unlike e.g. the `MessagePort` API, the Chrome Extension Runtime messaging API
 * doesn't have a built-in way to close the connection. The streams will continue to operate
 * as long as the extension is running, unless manually ended.
 *
 * @module ChromeRuntime streams
 */
import type { Json } from "@metamask/utils";
import type { ChromeRuntime } from "./chrome.d.cjs";
import { BaseDuplexStream } from "../BaseDuplexStream.cjs";
import type { BaseReaderArgs, ValidateInput, BaseWriterArgs } from "../BaseStream.cjs";
import { BaseReader, BaseWriter } from "../BaseStream.cjs";
export type ChromeRuntimeTarget = 'background' | 'offscreen' | 'popup';
export type MessageEnvelope<Payload> = {
    target: ChromeRuntimeTarget;
    source: ChromeRuntimeTarget;
    payload: Payload;
};
/**
 * A readable stream over the Chrome Extension Runtime messaging API.
 *
 * This class is a naive passthrough mechanism for data using `chrome.runtime.onMessage`.
 * Expects exclusive read access to the messaging API.
 *
 * @see
 * - {@link ChromeRuntimeWriter} for the corresponding writable stream.
 * - The module-level documentation for more details.
 */
export declare class ChromeRuntimeReader<Read extends Json> extends BaseReader<Read> {
    #private;
    /**
     * Constructs a new {@link ChromeRuntimeReader}.
     *
     * @param runtime - The Chrome runtime API object.
     * @param target - The target context (e.g., 'background', 'offscreen', 'popup').
     * @param source - The source context that messages are expected from.
     * @param options - Options bag for configuring the reader.
     * @param options.validateInput - A function that validates input from the transport.
     * @param options.onEnd - A function that is called when the stream ends.
     */
    constructor(runtime: ChromeRuntime, target: ChromeRuntimeTarget, source: ChromeRuntimeTarget, { validateInput, onEnd }?: BaseReaderArgs<Read>);
}
/**
 * A writable stream over the Chrome Extension Runtime messaging API.
 *
 * This class is a naive passthrough mechanism for data using `chrome.runtime.sendMessage`.
 *
 * @see
 * - {@link ChromeRuntimeReader} for the corresponding readable stream.
 * - The module-level documentation for more details.
 */
export declare class ChromeRuntimeWriter<Write extends Json> extends BaseWriter<Write> {
    /**
     * Constructs a new {@link ChromeRuntimeWriter}.
     *
     * @param runtime - The Chrome runtime API object.
     * @param target - The target context to send messages to.
     * @param source - The source context identifying where messages originate.
     * @param options - Options bag for configuring the writer.
     * @param options.name - The name of the stream, for logging purposes.
     * @param options.onEnd - A function that is called when the stream ends.
     */
    constructor(runtime: ChromeRuntime, target: ChromeRuntimeTarget, source: ChromeRuntimeTarget, { name, onEnd }?: Omit<BaseWriterArgs<Write>, 'onDispatch'>);
}
/**
 * A duplex stream over the Chrome Extension Runtime messaging API.
 *
 * This class is a naive passthrough mechanism for data using `chrome.runtime.onMessage`.
 *
 * @see
 * - {@link ChromeRuntimeReader} for the corresponding readable stream.
 * - {@link ChromeRuntimeWriter} for the corresponding writable stream.
 */
export declare class ChromeRuntimeDuplexStream<Read extends Json, Write extends Json = Read> extends BaseDuplexStream<Read, ChromeRuntimeReader<Read>, Write, ChromeRuntimeWriter<Write>> {
    /**
     * Constructs a new {@link ChromeRuntimeDuplexStream}.
     *
     * @param runtime - The Chrome runtime API object.
     * @param localTarget - The local target context for this stream.
     * @param remoteTarget - The remote target context to communicate with.
     * @param validateInput - A function that validates input from the transport.
     */
    constructor(runtime: ChromeRuntime, localTarget: ChromeRuntimeTarget, remoteTarget: ChromeRuntimeTarget, validateInput?: ValidateInput<Read>);
    /**
     * Creates and synchronizes a new {@link ChromeRuntimeDuplexStream}.
     *
     * @param runtime - The Chrome runtime API object.
     * @param localTarget - The local target context for this stream.
     * @param remoteTarget - The remote target context to communicate with.
     * @param validateInput - A function that validates input from the transport.
     * @returns A synchronized duplex stream.
     */
    static make<Read extends Json, Write extends Json = Read>(runtime: ChromeRuntime, localTarget: ChromeRuntimeTarget, remoteTarget: ChromeRuntimeTarget, validateInput?: ValidateInput<Read>): Promise<ChromeRuntimeDuplexStream<Read, Write>>;
}
//# sourceMappingURL=ChromeRuntimeStream.d.cts.map