import type { HttpMiddleware } from "@egomobile/http-server";
import type { Schema } from "../types/index.js";
import type { Nilable, Nullable } from "../types/internal.js";
/**
 * A validation error.
 */
export interface IValidationError {
    /**
     * A context, if available.
     */
    context: Nullable<string>;
    /**
     * The details.
     */
    details: string;
    /**
     * The message text.
     */
    message: string;
}
/**
 * A function, that is invoked, when validation of body data
 * fails against a schema fails.
 *
 * @param {IValidationError[]} errors The errors.
 * @param {TRequest} request The request context.
 * @param {TResponse} response The response context.
 */
export type ValidationFailedHandler<TRequest, TResponse> = (errros: IValidationError[], request: TRequest, response: TResponse) => any;
/**
 * The default function, which is invoked when validation of body data
 * fails against a schema fails.
 *
 * @param {IValidationError[]} errors The list of errors.
 * @param {any} request The request context.
 * @param {any} response The response context.
 */
export declare const defaultValidationFailedHandler: ValidationFailedHandler<any, any>;
/**
 * Creates a new middleware, which validates value in
 * `body` property of request context against a schema.
 *
 * @param {Schema} schema The schema.
 * @param {Nilable<ValidationFailedHandler<any, any>>} [onValidationFailed] The custom validation error handler.
 *
 * @returns {HttpMiddleware<any, any>} The new middleare.
 */
export declare function validate(schema: Schema, onValidationFailed?: Nilable<ValidationFailedHandler<any, any>>): HttpMiddleware<any, any>;