import { Context } from "../index.js";
import { HttpBaseResponse, Middleware } from "../types/index.js";
/**
 * Options for Bearer Authentication middleware.
 */
export type BearerAuthOptions = {
    /**
     * Function to validate the token.
     * Can be synchronous or asynchronous.
     * @param token - The Bearer token from the request.
     * @param ctx - The current request context.
     * @returns Boolean indicating if the token is valid.
     */
    validate: (token: string, ctx: Context) => boolean | Promise<boolean>;
    /**
     * Realm name shown in the `WWW-Authenticate` header.
     * Defaults to `"API"`.
     */
    realm?: string;
    /**
     * Custom handler for unauthorized requests.
     * @param ctx - The current request context.
     * @param error - Optional error object describing the reason.
     * @returns HttpBaseResponse to send to the client.
     */
    onUnauthorized?: (ctx: Context, error?: Error) => HttpBaseResponse;
};
/**
 * Bearer Authentication Middleware
 *
 * Verifies that incoming requests contain a valid Bearer token
 * in the `Authorization` header. Supports async token validation
 * and custom error handling.
 *
 * @param options - Configuration options for token validation, realm, and error handling.
 * @returns Middleware function to use in routes.
 *
 * @example
 * ```ts
 * import { bearerAuth } from "./middleware/bearerAuth.js";
 *
 * const auth = bearerAuth({
 *   validate: async (token) => token === "secret-token",
 * });
 *
 * app.use("/api", auth, (ctx) => {
 *   ctx.json({ message: "Access granted" });
 * });
 * ```
 */
export declare const bearerAuth: <T extends Record<string, any> = {}, Path extends string = any>(options: BearerAuthOptions) => Middleware<T, Path>;
export default bearerAuth;