// Copyright 2015 The Vanadium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
part of discovery;

typedef Future _StopFunction();

class _Client implements Client {
  final AdvertiserProxy _advertiserProxy = new AdvertiserProxy.unbound();
  final ScannerProxy _scannerProxy = new ScannerProxy.unbound();

  _Client(ConnectToServiceFunction cts, String url) {
    cts(url, _advertiserProxy);
    cts(url, _scannerProxy);
  }

  Future<Scanner> scan(String query) async {
    StreamController<Service> onFound = new StreamController<Service>();
    StreamController<String> onLost = new StreamController<String>();
    ScanHandlerStub handlerStub = new ScanHandlerStub.unbound();
    handlerStub.impl = new _ScanHandler(onFound, onLost);

    ScannerScanResponseParams scanResponse =
        await _scannerProxy.ptr.scan(query, handlerStub);
    if (scanResponse.err != null) {
      throw scanResponse.err;
    }

    Future stop() {
      return _scannerProxy.ptr.stop(scanResponse.handle);
    }
    return new _Scanner(stop, onFound.stream, onLost.stream);
  }

  Future<Advertiser> advertise(Service service,
      {List<String> visibility: null}) async {
    AdvertiserAdvertiseResponseParams advertiseResponse =
        await _advertiserProxy.ptr.advertise(service, visibility);

    if (advertiseResponse.err != null) {
      throw advertiseResponse.err;
    }

    Future stop() {
      return _advertiserProxy.ptr.stop(advertiseResponse.handle);
    }
    return new _Advertiser(stop);
  }
}

class _Scanner implements Scanner {
  final Stream<Service> onFound;
  final Stream<String> onLost;

  final _StopFunction _stop;
  _Scanner(this._stop, this.onFound, this.onLost) {}

  Future stop() {
    return _stop();
  }
}

class _Advertiser implements Advertiser {
  final _StopFunction _stop;
  _Advertiser(this._stop) {}

  Future stop() {
    return _stop();
  }
}

class _ScanHandler extends ScanHandler {
  StreamController<Service> _onFound;
  StreamController<String> _onLost;

  _ScanHandler(this._onFound, this._onLost);

  found(Service s) {
    _onFound.add(s);
  }

  lost(String instanceId) {
    _onLost.add(instanceId);
  }
}