// Clone this Gist repo, install the packages with `npm install`, then run the test with `node --test`. The test should hang.
import { it, afterEach, describe, beforeEach } from 'node:test';

import Fastify from 'fastify';
import fastifyPlugin from 'fastify-plugin';
import fastifyWebSocket from '@fastify/websocket';
import WebSocket from 'ws';

/** @param {FastifyInstance} fastify  */
async function plugin(fastify) {
  fastify.addHook('onClose', async (instance) => {
    for (const client of instance.websocketServer.clients) {
      client.close(WebSocketStatus.GOING_AWAY);
    }
  });

  await fastify.register(fastifyWebSocket, {
    options: {
      clientTracking: true
    }
  });

  fastify.get('/signal', {
    websocket: true,
    preHandler: [ /* some handlers for authentication and validation (can post if relevant) */ ],
  }, async (socket, request) => {

    socket.on('message', async (data) => {
      try {
        console.log("Got a message");
        const message = JSON.parse(data.toString());
        console.log(message);
      } catch (error) {
        if (error instanceof SyntaxError) {
          // If the message isn't valid JSON...
          socket.close(1007, 'Invalid JSON format');
          return;
        }
      }
    });
  });
}

const signalling = fastifyPlugin(plugin, {
  name: 'signalling',
  fastify: '5.x'
});

/** @returns {Promise<FastifyInstance>} */
async function buildApp() {
  const fastify = Fastify();

  await fastify.register(signalling);

  return fastify;
}

describe('Signalling Endpoint Protocol', async () => {
  /** @type {FastifyInstance} */
  let app;
  
  /** @type {WebSocket} */
  let ws;

  beforeEach(async () => {
    app = await buildApp();
    await app.ready();
    ws = await app.injectWS('/signal');
  });

  afterEach(async () => {
    ws?.terminate();
    await app.close();
  });

  it.only('disconnects if the client sends malformed JSON', async (t) => {
    /**
     * @type {{promise: Promise<WebSocketStatus>, resolve: (value?: WebSocketStatus | PromiseLike<WebSocketStatus>) => void, reject: (reason?: any) => void}}
     */
    const {promise, resolve, reject} = Promise.withResolvers();

    ws.once('close', resolve);
    ws.once('error', reject);
    ws.send('fgsfds', (error) => {
      if (error) {
        console.error("Error sending malformed JSON:", error);
        reject(error);
      } else {
        console.log("Malformed JSON sent successfully");
      }
    });

    t.assert.equal(await promise, 1007); // invalid frame payload data
    // hang begins here
    // execution continues here after the test times out
    await t.waitFor(() => ws.readyState);
  });
});