/// <reference types="vinyl" />
/// <reference types="node" />
import { EventEmitter } from 'events';
import * as Vinyl from 'vinyl';
import { ParserOptions } from './Parser';
export declare type LinkerOptions = ParserOptions;
interface Linker {
    on(event: 'file', listener: (file: Vinyl, requirements: string[]) => void): this;
    on(event: 'build', listener: () => void): this;
    emit(event: 'file', file: Vinyl, requirements: string[]): boolean;
    emit(event: 'build'): boolean;
}
declare class Linker extends EventEmitter {
    private options;
    private parser;
    private buildListeners;
    /** Contains the paths to all modules that have been imported. */
    private history;
    /** The number of files that have been imported but are not emitted yet. */
    private queueLength;
    /** Contains all paths to all files. */
    private paths;
    constructor(options: LinkerOptions);
    /**
     * Parses the file and imports external dependencies.
     * The returned promise resolves to an array of Vinyl file objects representing the dependencies.
     * All importet files will also be emitted in the "file" event.
     * @param origin - The file to parse.
     */
    update(origin: Vinyl): Promise<void>;
    build(): Promise<void>;
    /**
     * Adds a listener for the "build" event. Removes the old listener if one exists for the same origin.
     * Returns true if an old listener was removed.
     * @param origin - The file that will be emitted by the listener.
     * @param listener - A function that will be executed when the build event is emitted.
     */
    private listenForBuild(origin, listener);
    private verifyRequirements(files);
    /**
     * Returns a vinyl object representing the exported file of the module
     * @param fileHandle - An object representing the location of the module.
     */
    private import(fileHandle);
    /**
     * Wraps the contents of the file into a registerModule() function.
     * @param requirements - An array of arrays representing the requirements for the file.
     * @param file - A vinyl object representing the file.
     */
    private wrap(requirements, file);
}
export default Linker;