WIP - Redesigned login flow

lib/core/service/connectivity_status_service.dart

@@ -0,0 +1,113 @@
+import 'dart:io';
+
+import 'package:connectivity_plus/connectivity_plus.dart';
+import 'package:dio/adapter.dart';
+import 'package:dio/dio.dart';
+import 'package:paperless_mobile/features/login/model/client_certificate.dart';
+import 'package:paperless_mobile/features/login/model/reachability_status.dart';
+
+abstract class ConnectivityStatusService {
+  Future<bool> isConnectedToInternet();
+  Future<bool> isServerReachable(String serverAddress);
+  Stream<bool> connectivityChanges();
+  Future<ReachabilityStatus> isPaperlessServerReachable(
+    String serverAddress, [
+    ClientCertificate? clientCertificate,
+  ]);
+}
+
+class ConnectivityStatusServiceImpl implements ConnectivityStatusService {
+  final Connectivity _connectivity;
+
+  ConnectivityStatusServiceImpl(this._connectivity);
+
+  @override
+  Stream<bool> connectivityChanges() {
+    return _connectivity.onConnectivityChanged
+        .map(_hasActiveInternetConnection)
+        .asBroadcastStream();
+  }
+
+  @override
+  Future<bool> isConnectedToInternet() async {
+    return _hasActiveInternetConnection(
+        await (Connectivity().checkConnectivity()));
+  }
+
+  @override
+  Future<bool> isServerReachable(String serverAddress) async {
+    try {
+      var uri = Uri.parse(serverAddress);
+      final result = await InternetAddress.lookup(uri.host);
+      if (result.isNotEmpty && result.first.rawAddress.isNotEmpty) {
+        return true;
+      } else {
+        return false;
+      }
+    } on SocketException catch (_) {
+      return false;
+    }
+  }
+
+  bool _hasActiveInternetConnection(ConnectivityResult conn) {
+    return conn == ConnectivityResult.mobile ||
+        conn == ConnectivityResult.wifi ||
+        conn == ConnectivityResult.ethernet;
+  }
+
+  @override
+  Future<ReachabilityStatus> isPaperlessServerReachable(
+    String serverAddress, [
+    ClientCertificate? clientCertificate,
+  ]) async {
+    if (!RegExp(r"^https?://.*").hasMatch(serverAddress)) {
+      return ReachabilityStatus.unknown;
+    }
+    late SecurityContext context = SecurityContext();
+    try {
+      if (clientCertificate != null) {
+        context
+          ..usePrivateKeyBytes(
+            clientCertificate.bytes,
+            password: clientCertificate.passphrase,
+          )
+          ..useCertificateChainBytes(
+            clientCertificate.bytes,
+            password: clientCertificate.passphrase,
+          )
+          ..setTrustedCertificatesBytes(
+            clientCertificate.bytes,
+            password: clientCertificate.passphrase,
+          );
+      }
+
+      final adapter = DefaultHttpClientAdapter()
+        ..onHttpClientCreate = (client) => HttpClient(context: context)
+          ..badCertificateCallback =
+              (X509Certificate cert, String host, int port) => true;
+      final Dio dio = Dio()..httpClientAdapter = adapter;
+
+      final response = await dio.get('$serverAddress/api/');
+      if (response.statusCode == 200) {
+        return ReachabilityStatus.reachable;
+      }
+      return ReachabilityStatus.notReachable;
+    } on DioError catch (error) {
+      if (error.error is String) {
+        if (error.response?.data is String) {
+          if ((error.response!.data as String)
+              .contains("No required SSL certificate was sent")) {
+            return ReachabilityStatus.missingClientCertificate;
+          }
+        }
+      }
+      return ReachabilityStatus.notReachable;
+    } on TlsException catch (error) {
+      if (error.osError?.errorCode == 318767212) {
+        //INCORRECT_PASSWORD for certificate
+        return ReachabilityStatus.invalidClientCertificateConfiguration;
+      }
+      return ReachabilityStatus.notReachable;
+    }
+  }
+}