import { IncomingHttpEvent } from '../IncomingHttpEvent.js';
import { OutgoingHttpResponse } from '../OutgoingHttpResponse.js';
import { IBlueprint, NextMiddleware, type MetaMiddleware } from '@stone-js/core';
/**
 * Kernel Middleware for adding Cross-Origin Resource Sharing (CORS) headers to HTTP responses.
 * It allows controlling how clients from different origins can access the server's resources.
 *
 * @template TEvent - Represents the type of the incoming HTTP event.
 * @template UResponse - Represents the type of the outgoing HTTP response.
 * @author Mr. Stone <evensstone@gmail.com>
 */
export declare class HandleCorsMiddleware {
    private readonly headers;
    private readonly headerVary;
    private readonly blueprint;
    /**
     * Construct an instance of HandleCorsMiddleware.
     *
     * @param blueprint - The configuration blueprint used for managing CORS settings.
     */
    constructor({ blueprint }: {
        blueprint: IBlueprint;
    });
    /**
     * Handle CORS by modifying the response headers based on the configuration.
     *
     * @param event - The incoming HTTP event.
     * @param next - The next middleware function to continue processing the event.
     * @returns The outgoing HTTP response with CORS headers.
     */
    handle(event: IncomingHttpEvent, next: NextMiddleware<IncomingHttpEvent, OutgoingHttpResponse>): Promise<OutgoingHttpResponse>;
    /**
     * Get the CORS options by merging the blueprint configuration with defaults.
     *
     * @returns The merged CORS options.
     */
    private getOptions;
    /**
     * Check if the given origin is allowed based on the provided configuration.
     *
     * @param origin - The origin to check.
     * @param allowedOrigin - The allowed origins configuration.
     * @returns Whether the origin is allowed.
     */
    private isOriginAllowed;
    /**
     * Configure the `Access-Control-Allow-Origin` header based on the event origin and CORS options.
     *
     * @param {origin} HttpCorsConfig - The CORS options.
     * @param event - The incoming event.
     * @returns The middleware instance for method chaining.
     */
    private configureOrigin;
    /**
     * Configure the `Access-Control-Allow-Methods` header based on the CORS options.
     *
     * @param {methods} HttpCorsConfig - The CORS options.
     * @returns The middleware instance for method chaining.
     */
    private configureMethods;
    /**
     * Configure the `Access-Control-Allow-Credentials` header if allowed.
     *
     * @param {credentials} HttpCorsConfig - The CORS options.
     * @returns The middleware instance for method chaining.
     */
    private configureCredentials;
    /**
     * Configure the `Access-Control-Allow-Headers` header based on the event headers and CORS options.
     *
     * @param {allowedHeaders} HttpCorsConfig - The CORS options.
     * @param event - The incoming event.
     * @returns The middleware instance for method chaining.
     */
    private configureAllowedHeaders;
    /**
     * Configure the `Access-Control-Expose-Headers` header based on the CORS options.
     *
     * @param {exposedHeaders} HttpCorsConfig - The CORS options.
     * @returns The middleware instance for method chaining.
     */
    private configureExposedHeaders;
    /**
     * Configure the `Access-Control-Max-Age` header if provided in the CORS options.
     *
     * @param {maxAge} HttpCorsConfig - The CORS options.
     * @returns The middleware instance for method chaining.
     */
    private configureMaxAge;
    /**
     * Set a response header.
     *
     * @param name - The name of the header to set.
     * @param value - The value of the header to set.
     * @returns The middleware instance for method chaining.
     */
    private setHeader;
    /**
     * Add a header to the `Vary` list for the response.
     *
     * @param value - The header name to add to `Vary`.
     * @returns The middleware instance for method chaining.
     */
    private addVary;
    /**
     * Get the default CORS options.
     *
     * @returns An object containing the default CORS options.
     */
    private getDefaults;
}
/**
 * Meta Middleware for processing CORS headers.
 */
export declare const MetaHandleCorsMiddleware: MetaMiddleware<IncomingHttpEvent, OutgoingHttpResponse>;