/**
 * Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 * SPDX-License-Identifier: Apache-2.0.
 */
/**
 * HTTP protocol version
 *
 * @module aws-crt
* @category HTTP
 */
export declare enum HttpVersion {
    Unknown = 0,
    /** HTTP/1.0 */
    Http1_0 = 1,
    /** HTTP/1.1 */
    Http1_1 = 2,
    /** HTTP/2 */
    Http2 = 3
}
/**
 * Headers are exposed as 2 element arrays: [name, value]
 *
 * @module aws-crt
* @category HTTP
 */
export declare type HttpHeader = [string, string];
/** @internal */
export interface HttpHeaders {
    readonly length: number;
    /**
     * Add a name/value pair
     * @param name - The header name
     * @param value - The header value
    */
    add(name: string, value: string): void;
    /**
     * Set a name/value pair, replacing any existing values for the name
     * @param name - The header name
     * @param value - The header value
    */
    set(name: string, value: string): void;
    /**
     * Get the list of values for the given name
     * @param name - The header name to look for
     * @return List of values, or empty list if none exist
     */
    get_values(name: string): string[];
    /**
     * Gets the first value for the given name, ignoring any additional values
     * @param name - The header name to look for
     * @param default_value - Value returned if no values are found for the given name
     * @return The first header value, or default if no values exist
     */
    get(name: string, default_value?: string): string;
    /**
     * Removes all values for the given name
     * @param name - The header to remove all values for
     */
    remove(name: string): void;
    /**
     * Removes a specific name/value pair
     * @param name - The header name to remove
     * @param value - The header value to remove
     */
    remove_value(name: string, value: string): void;
    /** Clears the entire header set */
    clear(): void;
    /**
     * Iterator. Allows for:
     * let headers = new HttpHeaders();
     * ...
     * for (const header of headers) { }
    */
    [Symbol.iterator](): Iterator<HttpHeader>;
    /** @hidden */
    _flatten(): HttpHeader[];
}
/**
 * Proxy authentication types
 *
 * @module aws-crt
 * @category HTTP
 */
export declare enum HttpProxyAuthenticationType {
    None = 0,
    Basic = 1
}
/**
 * Options used when connecting to an HTTP endpoint via a proxy
 *
 * @module aws-crt
 * @category HTTP
 */
export declare class HttpProxyOptions {
    host_name: string;
    port: number;
    auth_method: HttpProxyAuthenticationType;
    auth_username?: string | undefined;
    auth_password?: string | undefined;
    constructor(host_name: string, port: number, auth_method?: HttpProxyAuthenticationType, auth_username?: string | undefined, auth_password?: string | undefined);
}