/**
 * This file is part of the @egodigital/egoose distribution.
 * Copyright (c) e.GO Digital GmbH, Aachen, Germany (https://www.e-go-digital.com/)
 *
 * @egodigital/egoose is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, version 3.
 *
 * @egodigital/egoose is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
/**
 * Describes a cache (client).
 */
export interface Cache {
    /**
     * Tries to return a value from the cache.
     *
     * @param {any} key The key.
     * @param {TDefault} [defaultValue] The custom default value.
     *
     * @return {Promise<TValue|TDefault>} The promise with the value or the default value.
     */
    get<TValue = any, TDefault = TValue>(key: any, defaultValue?: TValue): Promise<TValue | TDefault>;
    /**
     * Sets a value.
     *
     * @param {any} key The key.
     * @param {any} value The value.
     * @param {SetCacheValueOptions|null|undefined} [opts] Additional and custom options.
     *
     * @return {Promise<boolean>} The promise that indicates if operation was successful or not.
     */
    set(key: any, value: any, opts?: SetCacheValueOptions | null | undefined): Promise<boolean>;
}
/**
 * Options for 'Cache.set()' method.
 */
export declare type SetCacheValueOptions = {
    [key: string]: any;
};
/**
 * A basic cache (client).
 */
export declare abstract class CacheBase implements Cache {
    /** @inheritdoc */
    get<TValue = any, TDefault = TValue>(key: any, defaultValue?: TValue): Promise<TValue | TDefault>;
    /** @inheritdoc */
    protected abstract getInner(key: string, defaultValue: any): Promise<any>;
    /**
     * Tries to return a value from a key/value pair.
     *
     * @param {Object|undefined|null} opts The key/value pair.
     * @param {any} key The key.
     * @param {TDefault} [defaultValue] The custom default value.
     *
     * @return {TValue|TDefault} The value or the default value if not found.
     */
    protected getOptionValue<TValue = any, TDefault = TValue>(opts: {
        [key: string]: any;
    } | undefined | null, key: any, defaultValue?: TDefault): TValue | TDefault;
    /** @inheritdoc */
    set(key: any, value: any, opts?: SetCacheValueOptions | null | undefined): Promise<boolean>;
    /**
     * The logic for 'set()' method.
     *
     * @param {string} key The key.
     * @param {string} defaultValue The default value.
     * @param {SetCacheValueOptions} opts Custom options.
     */
    protected abstract setInner(key: string, defaultValue: any, opts: SetCacheValueOptions): Promise<void>;
}