/**

* Notifications Plugin

*

* Fastify plugin that adds WebSocket notification support.

* Implements the legacy "solid-0.1" protocol for SolidOS compatibility.

*

* Usage:

* createServer({ notifications: true })

*

* Discovery:

* OPTIONS /resource returns Updates-Via header with WebSocket URL

*

* Client usage:

* const ws = new WebSocket(updatesViaUrl);

* ws.send('sub http://example.org/resource');

* ws.onmessage = (e) => { if (e.data.startsWith('pub ')) ... }

*/

import websocket from '@fastify/websocket';

import { handleWebSocket, getConnectionCount, getSubscriptionCount } from './websocket.js';

import { getWebIdFromRequestAsync } from '../auth/token.js';

export { emitChange } from './events.js';

/**

* Register the notifications plugin with Fastify

* @param {FastifyInstance} fastify

* @param {object} options

*/

export async function notificationsPlugin(fastify, options) {

// Register the WebSocket plugin

await fastify.register(websocket);

// WebSocket route for notifications (dedicated path to avoid route conflicts)

// Clients discover this via Updates-Via header

// In @fastify/websocket v8, handler receives (connection, request) where connection.socket is the raw WebSocket

fastify.get('/.notifications', { websocket: true }, async (connection, request) => {

// Get WebID from auth token (if present) for ACL checking on subscriptions

const { webId } = await getWebIdFromRequestAsync(request);

handleWebSocket(connection.socket, request, webId);

});

// Optional: Status endpoint for monitoring

fastify.get('/.well-known/solid/notifications', async (request, reply) => {

return {

connections: getConnectionCount(),

subscriptions: getSubscriptionCount(),

protocol: 'solid-0.1'

};

});

}

export default notificationsPlugin;