/**
 * Copyright (c) Trimble Inc.
 */
import { TokenProvider } from '../interfaces/TokenProvider';
import { EndpointProvider } from '../interfaces/EndpointProvider';
/**
 * The On Behalf grant flow allows an application to act on behalf of a user.
 * The On Behalf grant is only supported for access tokens. It does not work
 * with any other type of token, including refresh tokens.
 */
export default class OnBehalfGrantTokenProvider implements TokenProvider {
    private readonly _endpointProvider;
    private readonly _clientId;
    private readonly _clientSecret;
    private readonly _accessToken;
    private readonly _httpClient;
    private _scopes;
    private _refreshableTokenProvider?;
    /**
     * Public constructor for OnBehalfGrantTokenProvider class
     *
     * @param endpointProvider - An endpoint provider that provides the URL for the Trimble Identity token endpoints.
     * It can be be OpenIdEndpointProvider/FixedEndpointProvider
     * @param clientId - The client id for the calling application
     * @param clientSecret - The client secret for the calling application
     * @param accessToken - The access token that this application wishes to act on behalf of when calling another API
     */
    constructor(endpointProvider: EndpointProvider, clientId: string, clientSecret: string, accessToken: string);
    /**
     * Fluent extension to add scopes
     *
     * @param scopes - The scopes to add to the token provider
     * @returns This token provider instance for method chaining
     */
    WithScopes(scopes: string[]): OnBehalfGrantTokenProvider;
    /**
     * Retrieves an access token for the application
     *
     * @returns A Promise that resolves to the value of the access token on completion
     * @throws When a token endpoint is not provided by the endpoint provider
     * @throws When a call to the token endpoint fails
     */
    RetrieveToken(): Promise<string>;
    private _retrieveToken;
}