/**
 * @license
 * Copyright 2021 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
import { FirebaseApp } from '@firebase/app';
import { CustomProvider, ReCaptchaEnterpriseProvider, ReCaptchaV3Provider } from './providers';
export { Unsubscribe, PartialObserver } from '@firebase/util';
/**
 * The Firebase App Check service interface.
 *
 * @public
 */
export interface AppCheck {
    /**
     * The {@link @firebase/app#FirebaseApp} this `AppCheck` instance is associated with.
     */
    app: FirebaseApp;
}
/**
 * The token returned from an App Check provider.
 * @public
 */
export interface AppCheckToken {
    readonly token: string;
    /**
     * The local timestamp after which the token will expire.
     */
    readonly expireTimeMillis: number;
}
/**
 * @internal
 */
export declare type _AppCheckComponentName = 'app-check';
/**
 * Options for App Check initialization.
 * @public
 */
export interface AppCheckOptions {
    /**
     * A reCAPTCHA V3 provider, reCAPTCHA Enterprise provider, or custom provider.
     */
    provider: CustomProvider | ReCaptchaV3Provider | ReCaptchaEnterpriseProvider;
    /**
     * If set to true, enables automatic background refresh of App Check token.
     */
    isTokenAutoRefreshEnabled?: boolean;
}
/**
 * Options when creating a {@link CustomProvider}.
 * @public
 */
export interface CustomProviderOptions {
    /**
     * Function to get an App Check token through a custom provider
     * service.
     */
    getToken: () => Promise<AppCheckToken>;
}
/**
 * Result returned by `getToken()`.
 * @public
 */
export interface AppCheckTokenResult {
    /**
     * The token string in JWT format.
     */
    readonly token: string;
}
/**
 * A listener that is called whenever the App Check token changes.
 * @public
 */
export declare type AppCheckTokenListener = (token: AppCheckTokenResult) => void;
