export default Pubst;
export type PubstConfig = {
    /**
     * - Logger to send warning messages to.
     */
    logger?: Object | undefined;
    /**
     * - If logger isn't provided, switches between ConsoleLogger and SilentLogger.
     */
    showWarnings?: boolean | undefined;
    /**
     * - A store implementation for persisting topic values.
     */
    store?: Object | undefined;
    /**
     * - An array of topic configurations.
     */
    topics?: TopicConfig[] | undefined;
};
export type TopicConfig = {
    /**
     * - The name of the topic (REQUIRED).
     */
    name: string;
    /**
     * - The default value presented to subscribers when the topic is undefined or null.
     */
    default?: any;
    /**
     * - Set to true if this topic will not have payload data.
     */
    eventOnly?: boolean | undefined;
    /**
     * - Should new subscribers automatically receive the last published value?
     */
    doPrime?: boolean | undefined;
    /**
     * - Alert subscribers of all publish events, even if unchanged.
     */
    allowRepeats?: boolean | undefined;
    /**
     * - Store-specific configuration passed to the store's registerTopic method.
     */
    storeConfig?: Object | undefined;
};
export type SubscriptionConfig = {
    /**
     * - The handler to call when the topic is updated.
     */
    handler: Function;
    /**
     * - Default value for this subscription.
     */
    default?: any;
    /**
     * - Should the handler be primed with the last value?
     */
    doPrime?: boolean | undefined;
    /**
     * - Should the handler be called when the value doesn't change?
     */
    allowRepeats?: boolean | undefined;
};
/**
 * @typedef {Object} PubstConfig
 * @property {Object} [logger] - Logger to send warning messages to.
 * @property {boolean} [showWarnings] - If logger isn't provided, switches between ConsoleLogger and SilentLogger.
 * @property {Object} [store] - A store implementation for persisting topic values.
 * @property {Array<TopicConfig>} [topics] - An array of topic configurations.
 */
/**
 * @typedef {Object} TopicConfig
 * @property {string} name - The name of the topic (REQUIRED).
 * @property {*} [default] - The default value presented to subscribers when the topic is undefined or null.
 * @property {boolean} [eventOnly=false] - Set to true if this topic will not have payload data.
 * @property {boolean} [doPrime=true] - Should new subscribers automatically receive the last published value?
 * @property {boolean} [allowRepeats=false] - Alert subscribers of all publish events, even if unchanged.
 * @property {Object} [storeConfig={}] - Store-specific configuration passed to the store's registerTopic method.
 */
/**
 * @typedef {Object} SubscriptionConfig
 * @property {Function} handler - The handler to call when the topic is updated.
 * @property {*} [default] - Default value for this subscription.
 * @property {boolean} [doPrime=true] - Should the handler be primed with the last value?
 * @property {boolean} [allowRepeats=false] - Should the handler be called when the value doesn't change?
 */
/**
 * @summary A slightly opinionated pub/sub utility for Javascript
 */
declare class Pubst {
    /**
     * @summary Set Pubst configuration.
     *
     * @param {PubstConfig} userConfig - Your configuration
     *
     * @returns {Promise<void>}
     *
     * @description
     * <p>
     * Available options are:
     *  <ul>
     *    <li>`logger` (default: ConsoleLogger) - Logger to send warning messages to.</li>
     *    <li>`showWarnings` - If logger isn't provided, this option switches between the use of ConsoleLogger and SilentLogger</li>
     *    <li>`store` (default: InMemoryStore) - A store implementation for persisting topic values.
     *        Custom stores must implement the same async interface as InMemoryStore:
     *        `registerTopic`, `getValue`, `setValue`, `clearValue`, and `getTopicNames`.</li>
     *    <li>`topics` - An array of topic configurations. (See: `addTopic` for topic configuration options)</li>
     *  </ul>
     * </p>
     */
    configure(userConfig?: PubstConfig): Promise<void>;
    /**
     * @summary Configure a new topic.
     *
     * @param {TopicConfig} newTopicConfig - Topic configuration
     *
     * @returns {Promise<Object>} Resolves with the result of registering
     *   the topic in the store.
     *
     * @description
     * <p>
     * Allows you to configure a new topic in pubst.
     *
     * Available options are:
     *  <ul>
     *    <li>`name` (<strong>REQUIRED</strong>) - A string representing the name of the topic.</li>
     *    <li>
  *         `default` (default: undefined) - The default value presented to subscribers when the topic is undefined or null.
  *         This can be overridden by subscribers.
     *    </li>
     *    <li>
     *      `eventOnly` (default: false) - Set this to true if this topic will not have payload data.
     *    </li>
     *    <li>
     *      `doPrime` (default: true) - Should new subscribers automatically receive the last published value on the topic?
     *      If no valid value is present, new subscribers will be primed with the default value (if configured).
     *      This can be overridden by subscribers.
     *    </li>
     *    <li>
     *      `allowRepeats` (default: false) - Alert subscribers of all publish events, even if the value is equal (by strict comparison) to the last value sent.
     *      This can be overridden by subscribers.
     *    </li>
     *    <li>
     *      `storeConfig` (default: {}) - Store-specific configuration that is passed through to the store's
     *      `registerTopic` method.  This allows custom store implementations to receive topic-level
     *      configuration (e.g. persistence keys, TTL settings, etc.).
     *    </li>
     *  </ul>
     * </p>
     */
    addTopic(newTopicConfig: TopicConfig): Promise<Object>;
    /**
     * @summary Configure new topics.
     *
     * @param {Array<TopicConfig>} topics - Topic configurations
     *
     * @returns {Promise<void>}
     *
     * @description
     * <p>
     * Allows you to configure new topics.  This will call `addTopic` with each item passed.
     * Topics are registered sequentially.
     * For available options, see `addTopic`.
     */
    addTopics(topics: Array<TopicConfig>): Promise<void>;
    /**
     * @summary Publish to a topic
     *
     * @param {string} topic - The topic to publish to
     * @param {*} payload The payload to publish
     *
     * @returns {Promise<void>}
     */
    publish(topic: string, payload: any): Promise<void>;
    /**
     * @summary Subscribe to one or more topics
     *
     * @param {string|Function} topic - The topic to receive updates for.
     *   If a string is provided, the handler will be called for all updates
     *   for that topic.  If a function is provided, it will be used as a
     *   matcher: it receives a topic name string and should return a truthy
     *   value if the subscriber should receive updates for that topic.
     *   If the matcher function throws an error, the error is logged as a
     *   warning and the match is skipped.
     * @param {Function|SubscriptionConfig} handler - Either your handler function or
     *                                    a subscription configuration object
     * @param {*} [def] - (Optional) Value to send when topic is empty
     *
     * @returns {Function} - A function that will remove this
     *                       subscription from getting further updates.
     *
     * @description
     * <p>
     * The first argument may be a string or a matcher function.
     * If a string is provided, the handler will be called for all
     * updates for that topic.  If a function is provided, it will be
     * called with each topic name and should return a truthy value to
     * indicate that the subscriber wishes to receive updates for that topic.
     * If the matcher function throws, the error is logged as a warning
     * and the subscriber will not receive the update for that topic.
     * </p>
     *
     * <p>
     * The second argument may be a function or an object.  The object
     * is necessary if you want to provide configuration options for
     * this subscription.  Available options are:
     *  <ul>
     *    <li>`default` - (Default: undefined) - Default value for this sub.</li>
     *    <li>`doPrime` - (Default: true) - Should the handler be primed with
     *        the last value?</li>
     *    <li>`allowRepeats` - (Default: false) - Should the handler be called
     *        when the value doesn't change?</li>
     *    <li>`handler` - (Required) - The handler to call.</li>
     *  </ul>
     * </p>
     *
     * <p>
     * The handler will be called on topic updates.  It will be passed
     * the new value of the topic as the first argument, and the name of
     * the topic as the second argument.
     * </p>
     *
     * <p>
     * Note: Subscribe is synchronous and returns an unsubscribe function
     * immediately.  Priming of subscribers with existing values happens
     * asynchronously via the store.
     * </p>
     */
    subscribe(topic: string | Function, handler: Function | SubscriptionConfig, def?: any): Function;
    /**
     * @summary Get the current value of a topic.
     *
     * @param {string} topic - The topic to get the value of.
     * @param {*} [def] - (Optional) a value to return if the topic is
     *                      empty.
     * @returns {Promise<*>} - Resolves with the current value or the default
     */
    currentVal(topic: string, def?: any): Promise<any>;
    /**
     * @summary Clears a given topic.
     *
     * @param {string} topic - The topic to clear
     *
     * @returns {Promise<void>}
     *
     * @description Clears the topic by publishing a `null` to it.
     */
    clear(topic: string): Promise<void>;
    /**
     * @summary Clears all known topics.
     *
     * @returns {Promise<void>}
     */
    clearAll(): Promise<void>;
    #private;
}