@akala/core/dist/esm/network/shared.socket-protocol-adapter.js

import { EventEmitter } from "../index.browser.js";
/**
 * Adapts a socket connection to handle protocol-level message transformations.
 * Provides an event-based interface for managing socket communication with custom
 * serialization/deserialization logic.
 * @template T The type of messages after transformation
 */
export class SocketProtocolAdapter extends EventEmitter {
    transform;
    socket;
    /**
     * Creates a new socket protocol adapter.
     * @param transform Configuration object containing receive, send, and optional close handlers
     * @param transform.receive Function to deserialize incoming data into application messages
     * @param transform.send Function to serialize application messages for transmission
     * @param transform.close Optional function to perform protocol-specific cleanup
     * @param socket The underlying socket adapter to wrap
     */
    constructor(transform, socket) {
        super();
        this.transform = transform;
        this.socket = socket;
        this.on(Symbol.dispose, () => socket.close());
    }
    /**
     * Pipes incoming messages to another socket adapter.
     * @param socket The destination socket to send messages to
     */
    pipe(socket) {
        this.on('message', (message) => socket.send(message));
        this.on('close', () => socket.close());
    }
    /**
     * Gets the open status of the underlying socket.
     */
    get open() {
        return this.socket.open;
    }
    /**
     * Closes the socket and performs any necessary protocol cleanup.
     */
    async close() {
        await this.transform.close?.(this.socket);
        await this.socket.close();
    }
    /**
     * Sends a message through the socket after applying the send transformation.
     * @param data The message to send
     */
    send(data) {
        return this.socket.send(this.transform.send(data, this));
    }
    messageListeners = [];
    messageSubscription;
    /**
     * Removes an event listener from the adapter.
     * @param event The event type to remove the listener from
     * @param handler The event handler to remove, or undefined to remove all handlers
     * @returns true if the listener was successfully removed
     */
    off(event, handler) {
        switch (event) {
            case 'message':
                {
                    let listeners = this.messageListeners;
                    if (handler)
                        this.messageListeners.splice(listeners.findIndex(f => f[0] == handler), 1);
                    else
                        this.messageListeners.length = 0;
                    if (this.messageListeners.length == 0)
                        this.messageSubscription?.();
                }
                break;
            case 'close':
            case 'error':
            case 'open':
                //eslint-disable-next-line @typescript-eslint/no-explicit-any
                this.socket.off(event, handler);
                break;
            default:
                throw new Error(`Unsupported event ${String(event)}`);
        }
        return true;
    }
    /**
     * Registers an event listener on the adapter.
     * @param event The event type to listen for
     * @param handler The callback to invoke when the event occurs
     * @param options Optional event listener configuration
     * @returns A subscription function to unsubscribe from the event
     */
    on(event, handler, options) {
        switch (event) {
            case 'message':
                {
                    if (this.messageListeners.length === 0)
                        this.messageSubscription = this.socket.on('message', message => {
                            const m = this.transform.receive(message, this);
                            for (const message of m)
                                for (const listener of this.messageListeners)
                                    listener(message);
                        }, options);
                    this.messageListeners.push(handler);
                    return () => {
                        this.messageListeners.splice(this.messageListeners.findIndex(x => x === handler), 1);
                        if (this.messageListeners.length === 0 && this.messageSubscription)
                            return this.messageSubscription();
                    };
                }
            case 'close':
            case 'error':
            case 'open':
            case Symbol.dispose:
                //eslint-disable-next-line @typescript-eslint/no-explicit-any
                return this.socket.on(event, handler);
            default:
                throw new Error(`Unsupported event ${String(event)}`);
        }
    }
    /**
     * Registers an event listener that fires only once.
     * @param event The event type to listen for
     * @param handler The callback to invoke when the event occurs
     * @returns A subscription function to unsubscribe from the event
     */
    once(event, handler) {
        switch (event) {
            case 'message':
                return this.on(event, handler, { once: true });
            case 'close':
            case 'error':
            case 'open':
                return this.on(event, handler, { once: true });
            default:
                throw new Error(`Unsupported event ${event?.toString()}`);
        }
    }
    /**
     * Emits an event to all registered listeners.
     * @param event The event type to emit
     * @param args Arguments to pass to event listeners
     * @returns The result of the emit operation
     */
    emit(event, ...args) {
        return super.emit(event, ...args);
    }
}
//# sourceMappingURL=shared.socket-protocol-adapter.js.map