clean up

lib/helpers/network_connectivity.dart

@@ -0,0 +1,68 @@
+import 'dart:async';
+import 'dart:io';
+
+import 'package:connectivity/connectivity.dart';
+import 'package:fcs/config.dart';
+import 'package:logging/logging.dart';
+
+import 'api_helper.dart';
+
+class NetworkConnectivity {
+  final log = Logger('NetworkConnectivity');
+
+  static final NetworkConnectivity instance = NetworkConnectivity._internal();
+  static String hostName;
+  NetworkConnectivity._internal() {
+    _initialise();
+    var uri = Uri.parse(Config.instance.apiURL);
+    hostName = uri.host;
+    log.info("host name:$hostName");
+  }
+
+  Connectivity connectivity = Connectivity();
+
+  final StreamController _controller = StreamController.broadcast();
+
+  Stream get statusStream => _controller.stream;
+
+  void _initialise() async {
+    ConnectivityResult result = await connectivity.checkConnectivity();
+    _checkStatus(result);
+    connectivity.onConnectivityChanged.listen((result) {
+      _checkStatus(result);
+    });
+  }
+
+  void _checkStatus(ConnectivityResult result) async {
+    bool isOnline = false;
+    // lookup if connectivity is not none
+    if (result != ConnectivityResult.none) {
+      try {
+        final hostNameLookup = await InternetAddress.lookup(hostName);
+        if (hostNameLookup.isNotEmpty &&
+            hostNameLookup[0].rawAddress.isNotEmpty) {
+          if (await checkHeartbeat()) {
+            isOnline = true;
+          }
+        } else
+          isOnline = false;
+      } on SocketException catch (_) {
+        isOnline = false;
+      }
+    }
+
+    if (_controller != null && !_controller.isClosed)
+      _controller.sink.add({"isOnline": isOnline});
+  }
+
+  Future<bool> checkHeartbeat() async {
+    var result = await requestAPI("/hb", "GET");
+    var status = result["status"];
+    if (status != null && status != "") {
+      return true;
+    }
+    return false;
+  }
+
+  void disposeStream() => _controller.close();
+}