path: root/src/lightstreamer_client.rs

use crate::client_listener::ClientListener;
use crate::client_message_listener::ClientMessageListener;
use crate::connection_details::ConnectionDetails;
use crate::connection_options::ConnectionOptions;
use crate::subscription::Subscription;
use crate::IllegalStateException;

use cookie::Cookie;

/// Facade class for the management of the communication to Lightstreamer Server. Used to provide
/// configuration settings, event handlers, operations for the control of the connection lifecycle,
/// Subscription handling and to send messages.
///
/// An instance of `LightstreamerClient` handles the communication with Lightstreamer Server on a
/// specified endpoint. Hence, it hosts one "Session"; or, more precisely, a sequence of Sessions,
/// since any Session may fail and be recovered, or it can be interrupted on purpose. So, normally,
/// a single instance of `LightstreamerClient` is needed.
///
/// However, multiple instances of `LightstreamerClient` can be used, toward the same or multiple
/// endpoints.
///
/// You can listen to the events generated by a session by registering an event listener, such as
/// `ClientListener` or `SubscriptionListener`. These listeners allow you to handle various events,
/// such as session creation, connection status, subscription updates, and server messages. However,
/// you should be aware that the event notifications are dispatched by a single thread, the so-called
/// event thread. This means that if the operations of a listener are slow or blocking, they will
/// delay the processing of the other listeners and affect the performance of your application.
/// Therefore, you should delegate any slow or blocking operations to a dedicated thread, and keep
/// the listener methods as fast and simple as possible. Note that even if you create multiple
/// instances of `LightstreamerClient`, they will all use a single event thread, that is shared
/// among them.
///
/// # Parameters
///
/// * `server_address`: the address of the Lightstreamer Server to which this `LightstreamerClient`
///   will connect to. It is possible to specify it later by using `None` here. See
///   `ConnectionDetails.setServerAddress()` for details.
/// * `adapter_set`: the name of the Adapter Set mounted on Lightstreamer Server to be used to handle
///   all requests in the Session associated with this `LightstreamerClient`. It is possible not to
///   specify it at all or to specify it later by using `None` here. See `ConnectionDetails.setAdapterSet()`
///   for details.
///
/// # Raises
///
/// * `IllegalArgumentException`: if a not valid address is passed. See `ConnectionDetails.setServerAddress()`
///   for details.
pub struct LightstreamerClient {
    server_address: Option<String>,
    adapter_set: Option<String>,
    /// Data object that contains the details needed to open a connection to a Lightstreamer Server.
    /// This instance is set up by the `LightstreamerClient` object at its own creation. Properties
    /// of this object can be overwritten by values received from a Lightstreamer Server.
    pub connection_details: ConnectionDetails,
    /// Data object that contains options and policies for the connection to the server. This instance
    /// is set up by the `LightstreamerClient` object at its own creation. Properties of this object
    /// can be overwritten by values received from a Lightstreamer Server.
    pub connection_options: ConnectionOptions,
    listeners: Vec<Box<dyn ClientListener>>,
    subscriptions: Vec<Subscription>,
}

impl LightstreamerClient {
    /// A constant string representing the name of the library.
    pub const LIB_NAME: &'static str = "rust_client";

    /// A constant string representing the version of the library.
    pub const LIB_VERSION: &'static str = "0.1.0";

    /// Static method that can be used to share cookies between connections to the Server (performed by
    /// this library) and connections to other sites that are performed by the application. With this
    /// method, cookies received by the application can be added (or replaced if already present) to
    /// the cookie set used by the library to access the Server. Obviously, only cookies whose domain
    /// is compatible with the Server domain will be used internally.
    ///
    /// This method should be invoked before calling the `LightstreamerClient.connect()` method.
    /// However it can be invoked at any time; it will affect the internal cookie set immediately
    /// and the sending of cookies on the next HTTP request or WebSocket establishment.
    ///
    /// # Parameters
    ///
    /// * `uri`: the URI from which the supplied cookies were received. It cannot be `None`.
    /// * `cookies`: an instance of `http.cookies.SimpleCookie`.
    ///
    /// See also `getCookies()`
    pub fn add_cookies(uri: &str, cookies: &Cookie) {
        // Implementation for add_cookies
    }

    /// Adds a listener that will receive events from the `LightstreamerClient` instance.
    ///
    /// The same listener can be added to several different `LightstreamerClient` instances.
    ///
    /// A listener can be added at any time. A call to add a listener already present will be ignored.
    ///
    /// # Parameters
    ///
    /// * `listener`: An object that will receive the events as documented in the `ClientListener`
    ///   interface.
    ///
    /// See also `removeListener()`
    pub fn add_listener(&mut self, listener: Box<dyn ClientListener>) {
        self.listeners.push(listener);
    }

    /// Operation method that requests to open a Session against the configured Lightstreamer Server.
    ///
    /// When `connect()` is called, unless a single transport was forced through `ConnectionOptions.setForcedTransport()`,
    /// the so called "Stream-Sense" mechanism is started: if the client does not receive any answer
    /// for some seconds from the streaming connection, then it will automatically open a polling
    /// connection.
    ///
    /// A polling connection may also be opened if the environment is not suitable for a streaming
    /// connection.
    ///
    /// Note that as "polling connection" we mean a loop of polling requests, each of which requires
    /// opening a synchronous (i.e. not streaming) connection to Lightstreamer Server.
    ///
    /// Note that the request to connect is accomplished by the client in a separate thread; this
    /// means that an invocation to `getStatus()` right after `connect()` might not reflect the change
    /// yet.
    ///
    /// When the request to connect is finally being executed, if the current status of the client
    /// is not `DISCONNECTED`, then nothing will be done.
    ///
    /// # Raises
    ///
    /// * `IllegalStateException`: if no server address was configured.
    ///
    /// See also `getStatus()`
    ///
    /// See also `disconnect()`
    ///
    /// See also `ClientListener.onStatusChange()`
    ///
    /// See also `ConnectionDetails.setServerAddress()`
    pub fn connect(&mut self) -> Result<(), IllegalStateException> {
        if self.server_address.is_none() {
            return Err(IllegalStateException::new("No server address was configured."));
        }

        // Implementation for connect
        Ok(())
    }

    /// Operation method that requests to close the Session opened against the configured Lightstreamer
    /// Server (if any).
    ///
    /// When `disconnect()` is called, the "Stream-Sense" mechanism is stopped.
    ///
    /// Note that active `Subscription` instances, associated with this `LightstreamerClient` instance,
    /// are preserved to be re-subscribed to on future Sessions.
    ///
    /// Note that the request to disconnect is accomplished by the client in a separate thread; this
    /// means that an invocation to `getStatus()` right after `disconnect()` might not reflect the
    /// change yet.
    ///
    /// When the request to disconnect is finally being executed, if the status of the client is
    /// "DISCONNECTED", then nothing will be done.
    ///
    /// See also `connect()`
    pub fn disconnect(&mut self) {
        // Implementation for disconnect
    }

    /// Static inquiry method that can be used to share cookies between connections to the Server
    /// (performed by this library) and connections to other sites that are performed by the application.
    /// With this method, cookies received from the Server can be extracted for sending through other
    /// connections, according with the URI to be accessed.
    ///
    /// See `addCookies()` for clarifications on when cookies are directly stored by the library and
    /// when not.
    ///
    /// # Parameters
    ///
    /// * `uri`: the URI to which the cookies should be sent, or `None`.
    ///
    /// # Returns
    ///
    /// A list with the various cookies that can be sent in a HTTP request for the specified URI.
    /// If a `None` URI was supplied, all available non-expired cookies will be returned.
    pub fn get_cookies(uri: Option<&str>) -> Cookie {
        // Implementation for get_cookies
        unimplemented!()
    }

    /// Returns a list containing the `ClientListener` instances that were added to this client.
    ///
    /// # Returns
    ///
    /// A list containing the listeners that were added to this client.
    ///
    /// See also `addListener()`
    pub fn get_listeners(&self) -> &Vec<Box<dyn ClientListener>> {
        &self.listeners
    }

    /// Inquiry method that gets the current client status and transport (when applicable).
    ///
    /// # Returns
    ///
    /// The current client status. It can be one of the following values:
    ///
    /// - `"CONNECTING"`: the client is waiting for a Server's response in order to establish a connection;
    /// - `"CONNECTED:STREAM-SENSING"`: the client has received a preliminary response from the server
    ///   and is currently verifying if a streaming connection is possible;
    /// - `"CONNECTED:WS-STREAMING"`: a streaming connection over WebSocket is active;
    /// - `"CONNECTED:HTTP-STREAMING"`: a streaming connection over HTTP is active;
    /// - `"CONNECTED:WS-POLLING"`: a polling connection over WebSocket is in progress;
    /// - `"CONNECTED:HTTP-POLLING"`: a polling connection over HTTP is in progress;
    /// - `"STALLED"`: the Server has not been sending data on an active streaming connection for
    ///   longer than a configured time;
    /// - `"DISCONNECTED:WILL-RETRY"`: no connection is currently active but one will be opened
    ///   (possibly after a timeout);
    /// - `"DISCONNECTED:TRYING-RECOVERY"`: no connection is currently active, but one will be opened
    ///   as soon as possible, as an attempt to recover the current session after a connection issue;
    /// - `"DISCONNECTED"`: no connection is currently active.
    ///
    /// See also `ClientListener.onStatusChange()`
    pub fn get_status(&self) -> &str {
        // Implementation for get_status
        unimplemented!()
    }

    /// Inquiry method that returns a list containing all the `Subscription` instances that are
    /// currently "active" on this `LightstreamerClient`.
    ///
    /// Internal second-level `Subscription` are not included.
    ///
    /// # Returns
    ///
    /// A list, containing all the `Subscription` currently "active" on this `LightstreamerClient`.
    /// The list can be empty.
    ///
    /// See also `subscribe()`
    pub fn get_subscriptions(&self) -> &Vec<Subscription> {
        &self.subscriptions
    }

    /// Removes a listener from the `LightstreamerClient` instance so that it will not receive
    /// events anymore.
    ///
    /// A listener can be removed at any time.
    ///
    /// # Parameters
    ///
    /// * `listener`: The listener to be removed.
    ///
    /// See also `addListener()`
    pub fn remove_listener(&mut self, listener: Box<dyn ClientListener>) {
        unimplemented!("Implement mechanism to remove listener from LightstreamerClient");
        //self.listeners.remove(&listener);
    }

    /// Operation method that sends a message to the Server. The message is interpreted and handled
    /// by the Metadata Adapter associated to the current Session. This operation supports in-order
    /// guaranteed message delivery with automatic batching. In other words, messages are guaranteed
    /// to arrive exactly once and respecting the original order, whatever is the underlying transport
    /// (HTTP or WebSockets). Furthermore, high frequency messages are automatically batched, if
    /// necessary, to reduce network round trips.
    ///
    /// Upon subsequent calls to the method, the sequential management of the involved messages is
    /// guaranteed. The ordering is determined by the order in which the calls to `sendMessage` are
    /// issued.
    ///
    /// If a message, for any reason, doesn't reach the Server (this is possible with the HTTP transport),
    /// it will be resent; however, this may cause the subsequent messages to be delayed. For this
    /// reason, each message can specify a "delayTimeout", which is the longest time the message,
    /// after reaching the Server, can be kept waiting if one of more preceding messages haven't
    /// been received yet. If the "delayTimeout" expires, these preceding messages will be discarded;
    /// any discarded message will be notified to the listener through `ClientMessageListener.onDiscarded()`.
    /// Note that, because of the parallel transport of the messages, if a zero or very low timeout
    /// is set for a message and the previous message was sent immediately before, it is possible
    /// that the latter gets discarded even if no communication issues occur. The Server may also
    /// enforce its own timeout on missing messages, to prevent keeping the subsequent messages for
    /// long time.
    ///
    /// Sequence identifiers can also be associated with the messages. In this case, the sequential
    /// management is restricted to all subsets of messages with the same sequence identifier associated.
    ///
    /// Notifications of the operation outcome can be received by supplying a suitable listener. The
    /// supplied listener is guaranteed to be eventually invoked; listeners associated with a sequence
    /// are guaranteed to be invoked sequentially.
    ///
    /// The "UNORDERED_MESSAGES" sequence name has a special meaning. For such a sequence, immediate
    /// processing is guaranteed, while strict ordering and even sequentialization of the processing
    /// is not enforced. Likewise, strict ordering of the notifications is not enforced. However,
    /// messages that, for any reason, should fail to reach the Server whereas subsequent messages
    /// had succeeded, might still be discarded after a server-side timeout, in order to ensure that
    /// the listener eventually gets a notification.
    ///
    /// Moreover, if "UNORDERED_MESSAGES" is used and no listener is supplied, a "fire and forget"
    /// scenario is assumed. In this case, no checks on missing, duplicated or overtaken messages
    /// are performed at all, so as to optimize the processing and allow the highest possible throughput.
    ///
    /// Since a message is handled by the Metadata Adapter associated to the current connection, a
    /// message can be sent only if a connection is currently active. If the special `enqueueWhileDisconnected`
    /// flag is specified it is possible to call the method at any time and the client will take
    /// care of sending the message as soon as a connection is available, otherwise, if the current
    /// status is "DISCONNECTED*", the message will be abandoned and the `ClientMessageListener.onAbort()`
    /// event will be fired.
    ///
    /// Note that, in any case, as soon as the status switches again to "DISCONNECTED*", any message
    /// still pending is aborted, including messages that were queued with the `enqueueWhileDisconnected`
    /// flag set to `true`.
    ///
    /// Also note that forwarding of the message to the server is made in a separate thread, hence,
    /// if a message is sent while the connection is active, it could be aborted because of a subsequent
    /// disconnection. In the same way a message sent while the connection is not active might be
    /// sent because of a subsequent connection.
    ///
    /// # Parameters
    ///
    /// * `message`: a text message, whose interpretation is entirely demanded to the Metadata Adapter
    ///   associated to the current connection.
    /// * `sequence`: an alphanumeric identifier, used to identify a subset of messages to be managed
    ///   in sequence; underscore characters are also allowed. If the "UNORDERED_MESSAGES" identifier
    ///   is supplied, the message will be processed in the special way described above. The parameter
    ///   is optional; if set to `None`, "UNORDERED_MESSAGES" is used as the sequence name.
    /// * `delay_timeout`: a timeout, expressed in milliseconds. If higher than the Server configured
    ///   timeout on missing messages, the latter will be used instead. The parameter is optional; if
    ///   a negative value is supplied, the Server configured timeout on missing messages will be applied.
    ///   This timeout is ignored for the special "UNORDERED_MESSAGES" sequence, although a server-side
    ///   timeout on missing messages still applies.
    /// * `listener`: an object suitable for receiving notifications about the processing outcome. The
    ///   parameter is optional; if not supplied, no notification will be available.
    /// * `enqueue_while_disconnected`: if this flag is set to `true`, and the client is in a disconnected
    ///   status when the provided message is handled, then the message is not aborted right away but
    ///   is queued waiting for a new session. Note that the message can still be aborted later when
    ///   a new session is established.
    pub fn send_message(
        &mut self,
        message: &str,
        sequence: Option<&str>,
        delay_timeout: Option<u64>,
        listener: Option<Box<dyn ClientMessageListener>>,
        enqueue_while_disconnected: bool,
    ) {
        // Implementation for send_message
    }

    /// Static method that permits to configure the logging system used by the library. The logging
    /// system must respect the `LoggerProvider` interface. A custom class can be used to wrap any
    /// third-party logging system.
    ///
    /// If no logging system is specified, all the generated log is discarded.
    ///
    /// The following categories are available to be consumed:
    ///
    /// - `lightstreamer.stream`: logs socket activity on Lightstreamer Server connections; at INFO
    ///   level, socket operations are logged; at DEBUG level, read/write data exchange is logged.
    /// - `lightstreamer.protocol`: logs requests to Lightstreamer Server and Server answers; at INFO
    ///   level, requests are logged; at DEBUG level, request details and events from the Server are logged.
    /// - `lightstreamer.session`: logs Server Session lifecycle events; at INFO level, lifecycle events
    ///   are logged; at DEBUG level, lifecycle event details are logged.
    /// - `lightstreamer.subscriptions`: logs subscription requests received by the clients and the related
    ///   updates; at WARN level, alert events from the Server are logged; at INFO level, subscriptions
    ///   and unsubscriptions are logged; at DEBUG level, requests batching and update details are logged.
    /// - `lightstreamer.actions`: logs settings / API calls.
    ///
    /// # Parameters
    ///
    /// * `provider`: A `LoggerProvider` instance that will be used to generate log messages by the
    ///   library classes.
    pub fn set_logger_provider() {
        unimplemented!("Implement mechanism to set logger provider for LightstreamerClient.");
    }
    /*
    pub fn set_logger_provider(provider: LoggerProvider) {
        // Implementation for set_logger_provider
    }
    */

    /// Provides a mean to control the way TLS certificates are evaluated, with the possibility to
    /// accept untrusted ones.
    ///
    /// May be called only once before creating any `LightstreamerClient` instance.
    ///
    /// # Parameters
    ///
    /// * `factory`: an instance of `ssl.SSLContext`
    ///
    /// # Raises
    ///
    /// * `IllegalArgumentException`: if the factory is `None`
    /// * `IllegalStateException`: if a factory is already installed
    pub fn set_trust_manager_factory() {
        unimplemented!("Implement mechanism to set trust manager factory for LightstreamerClient.");
    }
    /*
    pub fn set_trust_manager_factory(factory: Option<SslContext>) -> Result<(), IllegalArgumentException> {
        if factory.is_none() {
            return Err(IllegalArgumentException::new(
                "Factory cannot be None",
            ));
        }

        // Implementation for set_trust_manager_factory
        Ok(())
    }
    */

    /// Operation method that adds a `Subscription` to the list of "active" Subscriptions. The `Subscription`
    /// cannot already be in the "active" state.
    ///
    /// Active subscriptions are subscribed to through the server as soon as possible (i.e. as soon
    /// as there is a session available). Active `Subscription` are automatically persisted across different
    /// sessions as long as a related unsubscribe call is not issued.
    ///
    /// Subscriptions can be given to the `LightstreamerClient` at any time. Once done the `Subscription`
    /// immediately enters the "active" state.
    ///
    /// Once "active", a `Subscription` instance cannot be provided again to a `LightstreamerClient`
    /// unless it is first removed from the "active" state through a call to `unsubscribe()`.
    ///
    /// Also note that forwarding of the subscription to the server is made in a separate thread.
    ///
    /// A successful subscription to the server will be notified through a `SubscriptionListener.onSubscription()`
    /// event.
    ///
    /// # Parameters
    ///
    /// * `subscription`: A `Subscription` object, carrying all the information needed to process real-time
    ///   values.
    ///
    /// See also `unsubscribe()`
    pub fn subscribe(&mut self, subscription: Subscription) {
        self.subscriptions.push(subscription);
        // Implementation for subscribe
    }

    /// Operation method that removes a `Subscription` that is currently in the "active" state.
    ///
    /// By bringing back a `Subscription` to the "inactive" state, the unsubscription from all its
    /// items is requested to Lightstreamer Server.
    ///
    /// Subscription can be unsubscribed from at any time. Once done the `Subscription` immediately
    /// exits the "active" state.
    ///
    /// Note that forwarding of the unsubscription to the server is made in a separate thread.
    ///
    /// The unsubscription will be notified through a `SubscriptionListener.onUnsubscription()` event.
    ///
    /// # Parameters
    ///
    /// * `subscription`: An "active" `Subscription` object that was activated by this `LightstreamerClient`
    ///   instance.
    pub fn unsubscribe(&mut self, subscription: Subscription) {
        unimplemented!("Implement mechanism to unsubscribe from LightstreamerClient.");
    }
    /*
    pub fn unsubscribe(&mut self, subscription: &Subscription) {
        if let Some(index) = self.subscriptions.iter().position(|s| s == subscription) {
            self.subscriptions.remove(index);
            // Implementation for unsubscribe
        }
    }
    */
}