import { SSM } from 'aws-sdk';
/**
 * Options for the *SSMParameters*.
 */
export interface SSMParametersOptions {
    /** Return decrypted values for secure string parameters */
    withDecryption?: boolean;
    /** Maximum number of seconds the parameters will be considered fresh */
    maxAge?: number;
    /** https://docs.aws.amazon.com/AWSJavaScriptSDK/latest/AWS/SSM.html */
    ssmConfiguration?: SSM.ClientConfiguration;
}
/**
 * Options when loading or getting the parameters.
 */
export interface SSMParametersLoadOptions {
    /** Ignore any existing cache and load the parameters */
    ignoreCache: boolean;
}
/**
 * Class responsible to load and cache parameters from the AWS SSM Parameters
 * Store.
 */
export declare class SSMParameters<Parameters extends Record<string, string>> {
    private readonly DEFAULT_WITH_DECRYPTION;
    private readonly DEFAULT_MAX_AGE_IN_SECONDS;
    private readonly MAX_PARAMETERS_PER_REQUEST;
    private readonly withDecryption;
    private readonly maxAge;
    private readonly ssmClient;
    private parametersName;
    private parametersValue;
    private parameterLoaded;
    private lastLoadTime;
    /**
     * Create an instance of the *SSMParameters*.
     *
     * @example
     * new SSMParameters({ LogLevel: '/LogLevel' });
     * new SSMParameters({ LogLevel: '/LogLevel' }, { maxAge: 60 });
     *
     * @param parameters Map with parameter's keys and parameter's names on AWS.
     * @param options *SSMParametersOptions*
     */
    constructor(parameters: Parameters, options?: SSMParametersOptions);
    /**
     * Load parameters from AWS SSM Parameter Store.
     *
     * @note
     *  - If the parameters have not been loaded yet, they will be loaded.
     *  - If the parameters have been loaded and cache didn't expired yet,
     *    it uses the cache.
     *  - If the parameters have been loaded but the cache has expired, it loads
     *    the parameters again.
     *
     * @param options *SSMParametersLoadOptions*
     * @returns Promise to when parameters have been loaded or cache is used.
     */
    load(options?: SSMParametersLoadOptions): Promise<void>;
    /**
     * Get parameter.
     *
     * @note
     *  - If the parameters have not been loaded yet, they will be loaded.
     *  - If the parameters have been loaded and cache didn't expired yet,
     *    it uses the cache.
     *  - If the parameters have been loaded but the cache has expired, it loads
     *    the parameters again.
     *
     * @param key Key of the parameter.
     * @param options *SSMParametersLoadOptions*
     * @returns Promise to parameter's value or undefined if it does not exist.
     */
    get(key: keyof Parameters, options?: SSMParametersLoadOptions): Promise<string | undefined>;
    /**
     * Get parameters.
     *
     * @note
     *  - If the parameters have not been loaded yet, they will be loaded.
     *  - If the parameters have been loaded and cache didn't expired yet,
     *    it uses the cache.
     *  - If the parameters have been loaded but the cache has expired, it loads
     *    the parameters again.
     *
     * @param options *SSMParametersLoadOptions*
     * @returns Promise to all parameters.
     */
    getAll(options?: SSMParametersLoadOptions): Promise<Record<keyof Parameters, string | undefined>>;
    /**
     * Get parameters to load.
     *
     * @note The array returned by this function contains a maximum number of
     *       parameters defined by `MAX_PARAMETERS_PER_REQUEST`.
     *
     * @returns Array of parameters to load.
     */
    private getParametersToLoad;
    /**
     * Load parameters from AWS SSM.
     *
     * @param parameters Parameters to load from AWS SSM.
     * @returns Promise to when parameters have been loaded.
     */
    private loadParameters;
}