/**
 * Abstract interface class for an application cache object.
 */
export abstract class Cache {
    /**
     * Fetch a value from the cache by its key.
     * @param {string} key
     * @return Promise<any|undefined>
     */
    public abstract fetch(key: string): string | undefined | Promise<string | undefined>;

    /**
     * Store the given value in the cache by key.
     * @param {string} key
     * @param {string} value
     * @param {Date} [expires]
     */
    public abstract put(key: string, value: string, expires?: Date): void | Promise<void>;

    /**
     * Check if the cache has the given key.
     * @param {string} key
     * @return Promise<boolean>
     */
    public abstract has(key: string): boolean | Promise<boolean>;

    /**
     * Drop the given key from the cache.
     * @param {string} key
     */
    public abstract drop(key: string): void | Promise<void>;
}