/*! Copyright (c) 2021 Siemens AG. Licensed under the MIT License. */
/// <reference types="node" />
/// <reference types="node" />
import Debug from "debug";
import { AgvId, ConnectionStateChangeCallback, ExtensionValidator, Headerless, SubscriptionHandler, SubscriptionId, Topic, TopicObject, Vda5050Object } from "..";
/**
 * Create a new Version 4 UUID to be used as a unique identifier for nodes,
 * edges, actions, etc.
 *
 * @returns a unique Version 4 UUID
 *
 * @category Common
 */
export declare function createUuid(): string;
/**
 * Defines configuration options of a VDA 5050 client, including MQTT transport
 * options.
 *
 * @category Client
 */
export interface ClientOptions {
    /**
     * Name of the used interface (required).
     *
     * The interface name defines a common namespace for communication among
     * clients of a driverless transport system. Communication messages are only
     * routed between clients specifying a common interface name. The interface
     * name is part of the underlying MQTT topics and used to isolate different
     * transport systems sharing the same MQTT infrastructure.
     *
     * @remarks
     * As this property is used as a topic level of an MQTT topic, it must not
     * include the characters `NULL (U+0000)`, `# (U+0023)`, `+ (U+002B)`, and
     * `/ (U+002F)`.
     *
     * This property may also be an empty string according to VDA 5050
     * specification.
     */
    interfaceName: string;
    /**
     * Determines whether runtime validation checks of VDA 5050 communication
     * topic-objects should be performed for inbound and/or outbound messages
     * (optional).
     *
     * Validation passes if the message payload object structure conforms to the
     * VDA 5050 communication topic. For example, if an `"order"` topic is
     * given, the object's properties must satisfy the structure and constraints
     * of a VDA 5050 Order as defined by its JSON schema.
     *
     * By default, validation checks are enabled for both inbound and outbound
     * messages. Thus, if not specified, value defaults to `{ inbound: true,
     * outbound: true }`.
     *
     * @remarks
     * An object may include additional properties which are not defined in the
     * corresponding JSON schema. These properties are ignored, i.e. not
     * validated.
     *
     * If your MQTT broker supports VDA 5050 conformant topic-payload validation
     * of published messages and the client connections are secured, you may
     * turn off client-side validation completely by setting this property to `{
     * inbound: false, outbound: false }`.
     */
    topicObjectValidation?: {
        inbound: boolean;
        outbound: boolean;
    };
    /**
     * MQTT-specific transport options for a VDA 5050 client (required).
     */
    transport: MqttTransportOptions;
    /**
     * Represents the selected VDA5050 version (required).
     */
    vdaVersion: VdaVersion;
}
/**
 * Represents the supported VDA5050 specification versions.
 */
export type VdaVersion = "1.1.0" | "2.0.0" | "2.1.0" | "3.0.0";
/**
 * Defines MQTT transport options for a VDA 5050 client.
 *
 * @category Client
 */
export interface MqttTransportOptions {
    /**
     * Connection URL to MQTT broker (schema `protocol://host:port`, e.g.
     * `mqtt://localhost:1883`).
     *
     * Supported protocols include `mqtt`, `mqtts`, `tcp`, `tls`, `ws`, `wss`,
     * `wx`, `wxs` (WeChat Mini), `ali`, `alis` (Ali Mini).
     *
     * @remarks You can also specify `mqtt` or `mqtts` if the client runs in a
     * browser to open a (secure) websocket connection.
     */
    brokerUrl: string;
    /**
     * Defines the MQTT topic structure as a formatted string with placeholders
     * according to the VDA 5050 protocol specification (optional).
     *
     * Used to create MQTT topics for publication and subscription based on the
     * following format specifiers:
     *
     * - `%interfaceName%` - Name of the used interface
     * - `%majorVersion%` - Major version number prepended by a `"v"`
     * - `%manufacturer%` - Manufacturer of the AGV (e.g. RobotCompany)
     * - `%serialNumber%` - Unique AGV Serial Number consisting of the following
     *   characters: `A-Z a-z 0-9 _ . : -`
     * - `%topic%` - VDA 5050 subtopic name (see enum `Topic`)
     *
     * @remarks
     * The MQTT topic structure is not strictly defined to support a mandatory
     * topic structure of cloud-based MQTT brokers. While the `%topic%`
     * placeholder *must* be present in any case the other ones *may* be
     * omitted.
     *
     * Note that any of the defined placeholders must always make up a complete
     * MQTT topic level.
     *
     * If this option is not specified, the default format looks like this:
     * `%interfaceName%/%majorVersion%/%manufacturer%/%serialNumber%/%topic%`
     *
     * Example: `uagv/v2/KIT/0001/order`
     */
    topicFormat?: string;
    /**
     * The MQTT protocol version used to connect to the broker (optional).
     *
     * If not specified, value defaults to `"3.1.1"`.
     */
    protocolVersion?: "3.1.1" | "5.0";
    /**
     * Heartbeat interval in seconds for exchanging keep alive messages between
     * MQTT broker and client (optional).
     *
     * Defaults to 15 seconds (as recommended by VDA 5050 specification); set to
     * 0 to disable.
     */
    heartbeat?: number;
    /**
     * Interval in milliseconds between two reconnection attempts (optional).
     *
     * Defaults to 1000 ms. Disable auto reconnect by setting to 0.
     */
    reconnectPeriod?: number;
    /**
     * Time in milliseconds to wait for a connection acknowledgement message
     * from the broker (optional).
     *
     * Defaults to 30000 ms. If no CONNACK is received within the given time,
     * the connection is aborted.
     */
    connectTimeout?: number;
    /**
     * The MQTT client ID used to identify this client to the broker (optional).
     *
     * If not specified, a unique client ID is auto-generated. Providing an
     * explicit client ID is useful when the broker applies security filters or
     * access-control policies based on a specific, known client identity.
     *
     * @remarks
     * The MQTT specification requires client IDs to be unique per connected
     * client. Reusing the same ID across multiple simultaneous connections
     * will cause the broker to disconnect the earlier session.
     */
    clientId?: string;
    /**
     * The username required by your MQTT broker (optional).
     */
    username?: string;
    /**
     * The password required by your MQTT broker (optional).
     */
    password?: string;
    /**
     * Connection options for mqtts - MQTT over TLS (optional).
     *
     * Default is `{}`. Options are passed through to
     * [`tls.connect()`](https://nodejs.org/api/tls.html#tls_tls_createsecurecontext_options).
     *
     * @remarks If you run your MQTT connection over WebSockets, use `wsOptions`
     * instead.
     */
    tlsOptions?: {
        /**
         * Private keys in PEM format (optional).
         */
        key?: string | string[] | Buffer | Buffer[] | Array<{
            pem: string | Buffer;
            passphrase?: string;
        }>;
        /**
         * Cert chains in PEM format (optional).
         */
        cert?: string | string[] | Buffer | Buffer[];
        /**
         * Optionally override the trusted CA certificates in PEM format (optional).
         */
        ca?: string | string[] | Buffer | Buffer[];
        /**
         * PFX or PKCS12 encoded private key and certificate chain. pfx is an
         * alternative to providing `key` and `cert` individually. PFX is
         * usually encrypted, if it is, `passphrase` will be used to decrypt it.
         */
        pfx?: string | string[] | Buffer | Buffer[] | Array<{
            buf: string | Buffer;
            passphrase?: string;
        }>;
        /**
         * Shared passphrase used for a single private key and/or a PFX.
         */
        passphrase?: string;
        /**
         * If not false, the server certificate is verified against the list of
         * supplied CAs (optional). Defaults to true.
         *
         * @remarks If you are using a self-signed certificate, additionally
         * pass the `rejectUnauthorized: false` option. Beware that you are
         * exposing yourself to man in the middle attacks, so it is a
         * configuration that should never be used for production environments.
         */
        rejectUnauthorized?: boolean;
        /**
         * Any other option supported by
         * [`tls.connect()`](https://nodejs.org/api/tls.html#tls_tls_createsecurecontext_options).
         */
        [option: string]: any;
    };
    /**
     * WebSocket specific connection options (optional).
     *
     * Default is `{}`. Only used for WebSocket connections.
     *
     * For possible options have a look at:
     * https://github.com/websockets/ws/blob/master/doc/ws.md.
     */
    wsOptions?: object;
    /**
     * For WebSocket ws/wss protocols only (optional). Can be used to implement
     * signing urls or authentication options which upon reconnect can have
     * become expired.
     *
     * For details, see
     * [here](https://github.com/mqttjs/MQTT.js#refresh-authentication-options--signed-urls-with-transformwsurl-websocket-only).
     */
    transformWsUrl?: (url: string, options: any, client: any) => string;
}
/**
 * Defines options for individual publications.
 *
 * @category Client
 */
export interface ClientPublishOptions {
    /**
     * Determines whether a publication should be dropped if the client is
     * currently offline due to a broken connection (optional).
     *
     * By default, any offline publication is queued until the client
     * reconnects.
     *
     * @remarks Use this option to disable offline buffering for *individual*
     * publications. For example, regular high frequency state messages on the
     * VDA 5050 "visualization" topic should be dropped while offline as they
     * would be outdated and create a spam wave if published later.
     */
    dropIfOffline?: boolean;
    /**
     * Determines whether to retain the published MQTT message at the MQTT
     * broker (optional).
     *
     * If not specified, the value defaults to `false`.
     */
    retainMessage?: boolean;
}
/**
 * Provides basic client functionality for publishing, subscribing, and
 * unsubscribing communication messages over an MQTT transport according to the
 * VDA 5050 communication interface definition.
 *
 * This class can be used to implement both the coordination plane (control
 * system like master control) as well as the vehicle plane (AGV) of a
 * driverless transport system (DTS). In addition, it can be used to implement
 * visualization, monitoring, or logging clients that passively observe VDA 5050
 * communication flows within the DTS.
 *
 * @remarks
 * This class also lays the basis for proprietary extensions, i.e. non-standard
 * operations between control system and AGVs.
 *
 * This class abstracts VDA 5050 messaging over MQTT, providing the following
 * features:
 *
 * - Runnable in browsers (over WebSocket) and Node.js (over TCP or WebSocket)
 * - Autogeneration of VDA 5050 object types from JSON schema
 * - Autogeneration of MQTT topic-payload from VDA 5050 objects
 * - Configurable MQTT protocol version (3.1.1, 5.0)
 * - Configurable MQTT topic structure to support cloud-based MQTT brokers
 * - Automatic reconnect (configurable)
 * - Regular heartbeat exchange with MQTT broker
 * - Offline buffering of publications and subscriptions
 * - Validation of inbound and outbound VDA 5050 communication messages
 * - Smart subscription-based dispatching of inbound messages
 * - Modern async-await style programming of asynchronous operations
 * - Support of all standard VDA 5050 communication topics and schemas
 * - Extensible by custom VDA 5050 communication topics and schemas
 *
 * By default, publications are buffered while the client is offline due to a
 * broken connection. They are published as soon as the client goes online again
 * upon automatic reconnection. You can also vote to disable offline buffering
 * for *individual* publications. For example, regular high frequency state
 * messages on the VDA 5050 "visualization" topic should be dropped while
 * offline.
 *
 * By default, all subscriptions issued while the client has been started are
 * remembered in case the client goes offline due to a broken connection. As
 * soon as the client goes online again upon automatic reconnection these
 * subscriptions are resubscribed.
 *
 * Note that the asynchronous publish/subscribe/unsubscribe methods throw
 * *synchronously* on *programming errors*, i.e. non-operational errors like
 * passing invalid arguments or or invoking the function while the client is not
 * started. In contrast, *operational errors* are always signaled by rejecting
 * the returned promise.
 *
 * @category Client
 */
export declare abstract class Client {
    private static readonly ILLEGAL_TOPIC_LEVEL_CHARS_REGEX;
    private static readonly DEFAULT_MQTT_TOPIC_FORMAT;
    /**
     * Gets the client's unique client ID to be used for logging purposes, etc.
     */
    readonly clientId: string;
    /**
     * Gets a debugger function associated with this client instance.
     *
     * Used to log informational, debug, and error messages. The first argument
     * is a formatter string with printf-style formatting supporting the
     * following directives: `%O` (object multi-line), `%o` (object
     * single-line), `%s` (string), `%d` (number), `%j` (JSON), `%%` (escape).
     *
     * To turn on debug output for this library, set the `DEBUG` environment
     * variable to `vda-5050:*`. To enable low-level MQTT debugging, use
     * `vda-5050:*,mqttjs*`. Use `*` to debug all debug-enabled modules in your
     * application.
     */
    readonly debug: Debug.Debugger;
    private _mqtt;
    private _isStarted;
    private _isStopping;
    private _connectionState;
    private _connectionStateChangeCallback;
    private readonly _clientOptions;
    private readonly _headerIds;
    private readonly _subscriptionManager;
    private readonly _isWebPlatform;
    private readonly _extensionTopics;
    /**
     * Creates an instance of a `Client` subclass.
     *
     * @param options configuration options for the client
     * @throws if options are invalid
     */
    constructor(options: ClientOptions);
    /**
     * Gets the client configuration options as a readonly object.
     */
    get clientOptions(): Readonly<ClientOptions>;
    /**
     * Gets the semantic version of the VDA 5050 protocol this implementation
     * conforms to.
     *
     * @returns a string in the format
     * `"<major-version-number>.<minor-version-number>.<patch-version-number>"`
     */
    get protocolVersion(): VdaVersion;
    /**
     * Create a new Version 4 UUID to be used as a unique identifier for nodes,
     * edges, actions, etc.
     *
     * @returns a unique Version 4 UUID
     */
    createUuid(): string;
    /**
     * Starts client interaction by connecting to the configured MQTT broker.
     *
     * If client is already started, this operation is a noop.
     *
     * @remarks Always await this operation before invoking other operations on
     * this client instance.
     *
     * @returns a promise resolved when client is initially connected, and
     * rejected when connection fails
     */
    start(): Promise<void>;
    /**
     * Stops client interaction by disconnecting from the MQTT broker and
     * cleaning up all active subscriptions and registered extension topics.
     *
     * If client is not started, this operation is a noop.
     *
     * @remarks
     * Always await this operation before invoking other operations on this
     * client instance, such as `start`.
     *
     * After the client is stopped any publish, subscribe, and unsubscribe
     * operations will throw an error until the client is restarted.
     *
     * @returns a promise resolved when client is disconnected from the
     * underlying MQTT transport.
     */
    stop(): Promise<void>;
    /**
     * Unsubscribes the subscription issued for the given subscription ID.
     *
     * The subscription's handler function will be cleaned up and no longer
     * invoked. If there are no other active subscriptions on the associated VDA
     * 5050 topic, the corresponding MQTT topic will also be unsubscribed to
     * prevent unnecessary network traffic.
     *
     * If the given subscription ID is already unsubscribed, it is silently
     * ignored.
     *
     * @param subscriptionId the subscription ID related to an issued
     * subscription
     * @returns a promise that resolves on successful unsubscription
     * @throws synchronously if client is not started
     */
    unsubscribe(subscriptionId: SubscriptionId): Promise<void>;
    /**
     * Register a callback function invoked whenever the client's connection
     * state changes.
     *
     * @remarks
     * Upon registration, the given callback is invoked immediately with the
     * current connection state.
     *
     * You can only register one callback per client; any previously registered
     * callback is discarded.
     *
     * @param callback a callback function
     */
    registerConnectionStateChange(callback: ConnectionStateChangeCallback): void;
    /**
     * Registers a custom VDA 5050 communication topic with a validator function
     * to check structure and constraints of corresponding extension objects at
     * runtime.
     *
     * The `asInbound` and `asOutbound` parameters indicate whether the
     * registered extension topic should be allowed for inbound communication
     * and/or outbound communication. If inbound communication is not allowed,
     * subscribing to the topic will fail. Likewise, if outbound communication
     * is not allowed, publishing on the topic will fail.
     *
     * The validator function is invoked on inbound and/or outbound messages
     * with a registered extension topic according to the client option
     * `topicObjectValidation`.
     *
     * The validator function should throw a `TypeError` synchronously if the
     * passed extension object structure does not conform to the passed
     * extension topic and the direction of the message (inbound, outbound).
     *
     * @remarks
     * If the given topic is already registered, its registration will be
     * overridden with the new parameters.
     *
     * Use the function `createValidators` in the `create-validators` script
     * provided by this package to generate JS validation functions for your
     * custom JSON schemas. Use these functions in this method override.
     *
     * @param extensionTopic a custom VDA 5050 communication topic
     * @param asInbound whether topic should be allowed on inbound communication
     * @param asOutbound whether topic should be allowed on outbound
     * communication
     * @param validator a function that validates message objects against the
     * given extension topic
     */
    registerExtensionTopic(extensionTopic: string, asInbound: boolean, asOutbound: boolean, validator: ExtensionValidator): void;
    /**
     * Gets the semantic version of the VDA 5050 protocol this implementation
     * conforms to.
     *
     * To be overridden by subclasses that provide VDA 5050 extensions. The
     * default version returned by the base method is the standard VDA 5050
     * protocol version this `Client` class implements.
     *
     * @returns a string in the format
     * `"<major-version-number>.<minor-version-number>.<patch-version-number>"`
     */
    protected getProtocolVersion(): VdaVersion;
    /**
     * Determines whether the client has been started.
     *
     * @returns true if client has been started; false otherwise
     */
    protected get isStarted(): boolean;
    /**
     * Invoked after the client has successfully connected or reconnected.
     *
     * To be overridden by subclasses that need to perform additional
     * synchronous or asynchronous actions after the client goes online.
     *
     * The base method does nothing.
     */
    protected onStarted(): void | Promise<void>;
    /**
     * Invoked before the client disconnects actively.
     *
     * To be overridden by subclasses that need to perform additional
     * synchronous or asynchronous actions, such as publishing a message before
     * the client disconnects actively.
     *
     * The base method does nothing.
     */
    protected onStopping(): void | Promise<void>;
    /**
     * Gets the VDA 5050 communication topic with an associated object to be
     * registered as a last will message.
     *
     * Returns `undefined` if no last will should be registered (default). To be
     * overridden by subclasses.
     *
     * @returns a last will object with a topic, a headerless object, and a
     * retain indicator, or `undefined`
     */
    protected getLastWillTopic(): {
        topic: Topic;
        subject: AgvId;
        object: Headerless<Vda5050Object>;
        retainMessage: boolean;
    };
    /**
     * Publishes the given VDA 5050 core or extension object on the given VDA
     * 5050 communication topic related to the given AGV subject.
     *
     * The `AgvId` subject is used to automatically fill in header properties of
     * the object to be published. Each of its properties must specify a
     * non-empty string and must be valid as an MQTT topic level.
     *
     * On successful publication, this async function resolves a promise
     * containing a copy of the given headerless object including all header
     * properties as it has been published. If the publication is dropped
     * according to the `dropIfOffline` publish option, the promise resolves
     * with an `undefined` value.
     *
     * @param topic the VDA 5050 communication topic to publish on
     * @param subject identity of the AGV which is related to this publication
     * @param object a VDA 5050 core or extension object without header
     * properties
     * @param options client publish options (optional)
     * @returns a promise that resolves the published object if publication
     * succeeds or `undefined` if message should be dropped while offline
     * @throws synchronously if client is not started, if topic or subject is
     * not valid, if object validation fails
     */
    protected publishTopic<T extends string>(topic: T extends Topic ? T : string, subject: AgvId, object: Headerless<TopicObject<T>>, options?: ClientPublishOptions): Promise<TopicObject<T>>;
    /**
     * Subscribes to the given VDA 5050 communication topic for the given AGV
     * subject and registers a handler function to be invoked when matching
     * inbound publication messages are received by this client.
     *
     * In the given partial `AgvId` subject, any property must either specify a
     * non-empty string which is valid as an MQTT topic level or be `undefined`
     * or excluded, to support wildcard subscriptions by control clients.
     * Otherwise, an error is thrown.
     *
     * @remarks
     * If multiple subscription handlers are registered for a given
     * subscription, they are invoked synchronously in series, one after the
     * other, but in arbitrary order.
     *
     * A subscription handler should never perform long-lasting synchronous
     * operations as it blocks processing of other handlers and incoming
     * messages.
     *
     * A subscription handler may also perform asynchronous operations but these
     * are are not awaited and not synchronized with the invocation of other
     * handlers.
     *
     * A subscription handler is responsible for catching any errors. Uncaught
     * errors result in "Uncaught Error" or "Unhandled Promise Rejection"
     * reported by the runtime.
     *
     * Take care to invoke `Client.unsubscribe` method on any subscription ID
     * that is no longer needed by the application to clean up the
     * subscription's handler function and to reduce network traffic.
     * Unsubscribing in a handler function is also possible; use the
     * corresponding subscription id passed as argument. If you want to keep a
     * subscription for the lifetime of the client, there is no need to
     * explicitely unsubscribe it before stopping the client.
     *
     * @param topic the VDA 5050 communication topic to subscribe to
     * @param subject identity of the AGV(s) which are related to this
     * subscription
     * @param handler a function invoked on any inbound message matching the
     * subscription
     * @returns a promise that resolves a unique subscription ID when
     * subscription is set up successfully
     * @throws synchronously if client is not started, if topic or subject is
     * not valid
     */
    protected subscribeTopic<T extends string>(topic: T extends Topic ? T : string, subject: Partial<AgvId>, handler: SubscriptionHandler<T>): Promise<SubscriptionId>;
    /**
     * Performs a runtime validation check of a standard VDA 5050 communication
     * topic with respect to the direction of information exchange.
     *
     * The base method does nothing. Validation checks need to be defined by
     * subclasses depending on the role of the client (AGV, master control,
     * visualization/monitoring/logging systems, etc.). Such clients are
     * restricted to publish only on certain topics and to only subscribe to
     * certain topics.
     *
     * @param topic a standard VDA 5050 communication topic
     * @param forSubscription whether to validate the topic for subscription or
     * publication
     * @throws if the topic is not valid in the given context
     */
    protected validateTopicDirection(topic: Topic, forSubscription: boolean): void;
    /**
     * Performs a runtime validation check of the given AGV identity to be used
     * as subject of a subscription or publication.
     *
     * For publications, all `AgvId` properties must be specified and valid. For
     * subscriptions, any property may be omitted, but existing properties must
     * have valid values.
     *
     * @param agvId (partial) identity of AGV
     * @param forSubscription whether to validate as a subscription or
     * publication subject
     * @throws a `TypeError` if validation check fails
     */
    protected validateAgvId(agvId: Partial<AgvId>, forSubscription: boolean): void;
    /**
     * Performs a runtime validation check of a VDA 5050 core or extension
     * object with respect to a given VDA 5050 topic.
     *
     * @param topic a VDA 5050 communication topic
     * @param object a VDA 5050 core or extension object with header properties
     * @throws a `TypeError` if validation check fails
     */
    protected validateTopicObject(topic: string, object: Vda5050Object, vdaVersion: VdaVersion): void;
    /**
     * Invoked after client is stopped to reset internal client state.
     *
     * To be extended by subclasses. Ensure to call `super.reset()` in your
     * override.
     */
    protected reset(): void;
    private _connect;
    private _disconnect;
    private _emitConnectionStateChange;
    /**
     * Synchronously validate topic-payload of an inbound MQTT message, then
     * invoke all matching subscription handlers in series, one after the other,
     * but in arbitrary order.
     *
     * Note that although the local order of subscription handlers for a single
     * subscription topic could be determined (insertion order of handlers as
     * they were added to subscription manager), an overall order of handlers
     * belonging to different matching subscription topics (e.g. with wildcards)
     * is not defined.
     *
     * Incoming publication messages are processed in the order of their
     * arrival. All matching handlers of an incoming publication message are
     * invoked before the handlers of the next publication message received.
     *
     * Handlers can perform asynchronous operations using callbacks or promises
     * but these are not awaited and not synchronized with invocation of other
     * handlers of the current publication message or publication messages
     * received next.
     *
     * An inbound message is discarded, i.e. not dispatched to handlers, if its
     * validation check fails. Uncaught errors in subscription handlers result
     * in "Uncaught Error" or "Unhandled Promise Rejection" reported by the
     * runtime.
     *
     * @param mqttTopic inbound MQTT publication topic
     * @param mqttPayload inbound MQTT payload as an UTF-8 encoded byte array in
     * JSON format
     */
    private _dispatchMessage;
    private _validateOptions;
    private _isValidVdaVersion;
    private _validateTopic;
    private _isValidTopicLevel;
    private _createLastWill;
    private _withMqttProperties;
    private _withObjectHeader;
    private _nextHeaderId;
}