janus_session.dart

part of janus_client;

class JanusSession {
  late JanusTransport? _transport;
  late JanusClient _context;
  int? _sessionId;
  Timer? _keepAliveTimer;
  Map<int?, JanusPlugin> _pluginHandles = {};

  int? get sessionId => _sessionId;

  JanusSession(
      {int? refreshInterval,
      required JanusTransport transport,
      required JanusClient context}) {
    _context = context;
    _transport = transport;
  }

  Future<void> create() async {
    try {
      String transaction = getUuid().v4();
      Map<String, dynamic> request = {
        "janus": "create",
        "transaction": transaction,
        ..._context._tokenMap,
        ..._context._apiMap
      }..removeWhere((key, value) => value == null);
      Map<String, dynamic>? response;
      if (_transport is RestJanusTransport) {
        RestJanusTransport rest = (_transport as RestJanusTransport);
        response = (await rest.post(request)) as Map<String, dynamic>?;
        if (response != null) {
          if (response.containsKey('janus') && response.containsKey('data')) {
            _sessionId = response['data']['id'];
            rest.sessionId = sessionId;
          }
        } else {
          throw "Janus Server not live or incorrect url/path specified";
        }
      } else if (_transport is WebSocketJanusTransport) {
        WebSocketJanusTransport ws = (_transport as WebSocketJanusTransport);
        if (!ws.isConnected) {
          ws.connect();
        }
        response = await ws.send(request, handleId: null);
        if (response!.containsKey('janus') && response.containsKey('data')) {
          _sessionId = response['data']['id'] as int?;
          ws.sessionId = sessionId;
        }
      }
      _keepAlive();
    } on WebSocketChannelException catch (e) {
      throw "Connection to given url can't be established\n reason:-" +
          e.message!;
    } catch (e) {
      throw "Connection to given url can't be established\n reason:-" +
          e.toString();
    }
  }

  /// This can be used to attach plugin handle to the session.<br><br>
  /// [opaqueId] : opaque id is an optional string identifier used for client side correlations in event handlers or admin API.<br>
  Future<T> attach<T extends JanusPlugin>({String? opaqueId}) async {
    JanusPlugin plugin;
    int? handleId;
    String transaction = getUuid().v4();
    Map<String, dynamic> request = {
      "janus": "attach",
      "transaction": transaction,
      ..._context._apiMap,
      ..._context._tokenMap
    };
    if (opaqueId != null) {
      request["opaque_id"] = opaqueId;
    }
    request["session_id"] = sessionId;
    Map<String, dynamic>? response;
    if (T == JanusVideoRoomPlugin) {
      plugin = JanusVideoRoomPlugin(
          transport: _transport,
          context: _context,
          handleId: handleId,
          session: this);
    } else if (T == JanusVideoCallPlugin) {
      plugin = JanusVideoCallPlugin(
          transport: _transport,
          context: _context,
          handleId: handleId,
          session: this);
    } else if (T == JanusStreamingPlugin) {
      plugin = JanusStreamingPlugin(
          transport: _transport,
          context: _context,
          handleId: handleId,
          session: this);
    } else if (T == JanusAudioBridgePlugin) {
      plugin = JanusAudioBridgePlugin(
          transport: _transport,
          context: _context,
          handleId: handleId,
          session: this);
    } else if (T == JanusTextRoomPlugin) {
      plugin = JanusTextRoomPlugin(
          transport: _transport,
          context: _context,
          handleId: handleId,
          session: this);
    } else if (T == JanusEchoTestPlugin) {
      plugin = JanusEchoTestPlugin(
          transport: _transport,
          context: _context,
          handleId: handleId,
          session: this);
    } else if (T == JanusSipPlugin) {
      plugin = JanusSipPlugin(
          transport: _transport,
          context: _context,
          handleId: handleId,
          session: this);
    } else {
      throw UnimplementedError(
          '''This Plugin is not defined kindly refer to Janus Server Docs
      make sure you specify the type of plugin you want to attach like session.attach<JanusVideoRoomPlugin>();
      ''');
    }
    request.putIfAbsent("plugin", () => plugin.plugin);
    _context._logger.fine(request);
    if (_transport is RestJanusTransport) {
      _context._logger.info('using rest transport for creating plugin handle');
      RestJanusTransport rest = (_transport as RestJanusTransport);
      response = (await rest.post(request)) as Map<String, dynamic>?;
      _context._logger.fine(response);
      if (response != null &&
          response.containsKey('janus') &&
          response.containsKey('data')) {
        handleId = response['data']['id'];
        rest.sessionId = sessionId;
      } else {
        throw "Network error or janus server not running";
      }
    } else if (_transport is WebSocketJanusTransport) {
      _context._logger
          .info('using web socket transport for creating plugin handle');
      WebSocketJanusTransport ws = (_transport as WebSocketJanusTransport);
      if (!ws.isConnected) {
        ws.connect();
      }
      response = await ws.send(request, handleId: null);
      if (response!.containsKey('janus') && response.containsKey('data')) {
        handleId = response['data']['id'] as int?;
        _context._logger.fine(response);
      }
    }
    plugin.handleId = handleId;
    _pluginHandles[handleId] = plugin;
    try {
      await plugin._init();
    } on MissingPluginException {
      _context._logger.info(
          'Platform exception: i believe you are trying in unit tests, platform specific api not accessible');
    }
    plugin.onCreate();
    return plugin as T;
  }

  void dispose() {
    if (_keepAliveTimer != null) {
      _keepAliveTimer!.cancel();
    }
    if (_transport != null) {
      _transport?.dispose();
    }
  }

  _keepAlive() {
    if (sessionId != null) {
      this._keepAliveTimer = Timer.periodic(
          Duration(seconds: _context._refreshInterval), (timer) async {
        try {
          String transaction = getUuid().v4();
          Map<String, dynamic>? response;
          if (_transport is RestJanusTransport) {
            RestJanusTransport rest = (_transport as RestJanusTransport);
            _context._logger.finer("keep alive using RestTransport");
            response = (await rest.post({
              "janus": "keepalive",
              "session_id": sessionId,
              "transaction": transaction,
              ..._context._apiMap,
              ..._context._tokenMap
            })) as Map<String, dynamic>;
            _context._logger.finest(response);
          } else if (_transport is WebSocketJanusTransport) {
            _context._logger.finest("keep alive using WebSocketTransport");
            WebSocketJanusTransport ws =
                (_transport as WebSocketJanusTransport);
            if (!ws.isConnected) {
              _context._logger.finest(
                  "not connected trying to establish connection to webSocket");
              ws.connect();
            }
            response = await ws.send({
              "janus": "keepalive",
              "session_id": sessionId,
              "transaction": transaction,
              ..._context._apiMap,
              ..._context._tokenMap
            }, handleId: null);
            _context._logger.finest("keepalive request sent to webSocket");
            _context._logger.finest(response);
          }
        } catch (e) {
          timer.cancel();
        }
      });
    }
  }
}