import { emitter } from '@amatiasq/emitter';

import { SocketTransport } from '../transport.js';
import { JsonConnection } from './JsonConnection.js';

/**
 * The server side of the JSON layer: hand it each incoming socket and it hands
 * you back a `JsonConnection`.
 *
 * **It does not listen on anything.** This was `NiceSocketServer`, which
 * `extend`ed the `ws` server and took an `http.Server` in its constructor. Now
 * the caller owns the listening socket, which is what lets this run on Bun, Deno
 * and Workers as well as Node — see `SocketTransport`.
 *
 *     const server = new JsonServer<Incoming, Outgoing>();
 *     server.onConnection(client => client.send({ hello: true }));
 *
 *     // Node, with `ws`:
 *     wss.on('connection', ws => server.accept(fromEventEmitter(ws)));
 */
export class JsonServer<TIn = any, TOut = any> {
  private readonly emitConnection = emitter<JsonConnection<TIn, TOut>>();
  readonly onConnection = this.emitConnection.subscribe;

  accept(transport: SocketTransport) {
    const connection = new JsonConnection<TIn, TOut>(transport);
    this.emitConnection(connection);
    return connection;
  }
}