import { SigilPlugin, SigilPluginConstructor } from './misc';
import { SigilMiddleware, SigilMiddlewareCallback } from './misc/sigil-middleware';
import { default as SigilCore } from './sigil-core';
import { MaybePromise, SigilOptions } from './types';
/**
 * Plugin system extension of the Sigil core.
 * Manages plugin retrieval and middleware registration.
 *
 * @template T type of Sigil runtime options.
 */
export default class SigilPluginSystem<T extends Partial<SigilOptions>> extends SigilCore<T> {
    /**
     * Constructs the SigilPluginSystem with optional configuration.
     *
     * @param options partial SigilOptions for core initialization.
     */
    constructor(options?: T);
    /**
     * Retrieves a registered plugin instance by its constructor.
     * Logs an error if the plugin has not been loaded.
     *
     * @param plugin plugin constructor to retrieve.
     * @returns plugin instance, or undefined if not loaded.
     */
    plugin<P extends SigilPlugin>(plugin: SigilPluginConstructor<P>): P;
    /**
     * Checks if a specific plugin is registered within the system.
     *
     * @param {SigilPluginConstructor} plugin constructor of the plugin to check.
     * @return {boolean} true if the plugin is registered, otherwise false.
     */
    hasPlugin<P extends SigilPlugin>(plugin: SigilPluginConstructor<P>): boolean;
    /**
     * Executes a callback with the plugin instance if it exists.
     * Returns null if the plugin is not registered.
     *
     * @param plugin plugin constructor to use.
     * @param callback function to execute with the plugin.
     * @returns result of the callback or null.
     */
    withPlugin<P extends SigilPlugin, R = any>(plugin: SigilPluginConstructor<P>, callback: (plugin: P) => R): MaybePromise<R>;
    /**
     * Adds global middleware to the Sigil framework.
     * Generates a unique ID for the middleware and logs its registration.
     * Returns a SigilMiddleware instance that can be used to unregister.
     *
     * @param callback the middleware function to register.
     * @returns SigilMiddleware object for managing the middleware lifecycle.
     */
    addMiddleware(callback: SigilMiddlewareCallback): SigilMiddleware;
}