Fixes for LTC electrum nodes available.

lib/bitcoin/electrum.dart

@@ -8,16 +8,6 @@ import 'package:cake_wallet/bitcoin/script_hash.dart';
 import 'package:flutter/foundation.dart';
 import 'package:rxdart/rxdart.dart';
 
-class UriParseException implements Exception {
-  UriParseException(this.uri);
-
-  final String uri;
-
-  @override
-  String toString() =>
-      'Cannot parse host and port from uri. Invalid uri format. Uri: $uri';
-}
-
 String jsonrpcparams(List<Object> params) {
   final _params = params?.map((val) => '"${val.toString()}"')?.join(',');
   return '[$_params]';
@@ -54,17 +44,8 @@ class ElectrumClient {
   Timer _aliveTimer;
   String unterminatedString;
 
-  Future<void> connectToUri(String uri) async {
-    final splittedUri = uri.split(':');
-
-    if (splittedUri.length != 2) {
-      throw UriParseException(uri);
-    }
-
-    final host = splittedUri.first;
-    final port = int.parse(splittedUri.last);
-    await connect(host: host, port: port);
-  }
+  Future<void> connectToUri(Uri uri) async =>
+    await connect(host: uri.host, port: uri.port);
 
   Future<void> connect({@required String host, @required int port}) async {
     try {

lib/entities/default_settings_migration.dart

@@ -149,7 +149,7 @@ Future<void> replaceNodesMigration({@required Box<Node> nodes}) async {
     final nodeToReplace = replaceNodes[node.uri];
 
     if (nodeToReplace != null) {
-      node.uri = nodeToReplace.uri;
+      node.uriRaw = nodeToReplace.uriRaw;
       node.login = nodeToReplace.login;
       node.password = nodeToReplace.password;
       await node.save();
@@ -319,11 +319,11 @@ Future<void> changeDefaultMoneroNode(
   final currentMoneroNode =
       nodeSource.values.firstWhere((node) => node.key == currentMoneroNodeId);
   final needToReplaceCurrentMoneroNode =
-      currentMoneroNode.uri.contains(cakeWalletMoneroNodeUriPattern);
+      currentMoneroNode.uri.toString().contains(cakeWalletMoneroNodeUriPattern);
 
   nodeSource.values.forEach((node) async {
     if (node.type == WalletType.monero &&
-        node.uri.contains(cakeWalletMoneroNodeUriPattern)) {
+        node.uri.toString().contains(cakeWalletMoneroNodeUriPattern)) {
       await node.delete();
     }
   });
@@ -389,10 +389,10 @@ Future<void> resetBitcoinElectrumServer(
   final currentElectrumSeverId =
       sharedPreferences.getInt(PreferencesKey.currentBitcoinElectrumSererIdKey);
   final oldElectrumServer = nodeSource.values.firstWhere(
-      (node) => node.uri.contains('electrumx.cakewallet.com'),
+      (node) => node.uri.toString().contains('electrumx.cakewallet.com'),
       orElse: () => null);
   var cakeWalletNode = nodeSource.values.firstWhere(
-      (node) => node.uri == cakeWalletBitcoinElectrumUri,
+      (node) => node.uri.toString() == cakeWalletBitcoinElectrumUri,
       orElse: () => null);
 
   if (cakeWalletNode == null) {

lib/entities/node.dart

@@ -1,3 +1,5 @@
+import 'dart:io';
+
 import 'package:cake_wallet/utils/mobx.dart';
 import 'package:flutter/foundation.dart';
 import 'dart:convert';
@@ -8,19 +10,23 @@ import 'package:cake_wallet/entities/digest_request.dart';
 
 part 'node.g.dart';
 
+Uri createUriFromElectrumAddress(String address) =>
+   Uri.tryParse('tcp://$address');
+
 @HiveType(typeId: Node.typeId)
 class Node extends HiveObject with Keyable {
   Node(
-      {@required this.uri,
+      {@required String uri,
       @required WalletType type,
       this.login,
       this.password,
       this.useSSL}) {
+    uriRaw = uri;
     this.type = type;
   }
 
   Node.fromMap(Map map)
-      : uri = map['uri'] as String ?? '',
+      : uriRaw = map['uri'] as String ?? '',
         login = map['login'] as String,
         password = map['password'] as String,
         typeRaw = map['typeRaw'] as int,
@@ -30,7 +36,7 @@ class Node extends HiveObject with Keyable {
   static const boxName = 'Nodes';
 
   @HiveField(0)
-  String uri;
+  String uriRaw;
 
   @HiveField(1)
   String login;
@@ -46,6 +52,19 @@ class Node extends HiveObject with Keyable {
 
   bool get isSSL => useSSL ?? false;
 
+  Uri get uri {
+    switch (type) {
+      case WalletType.monero:
+        return Uri.http(uriRaw, '');
+      case WalletType.bitcoin:
+        return createUriFromElectrumAddress(uriRaw);
+      case WalletType.litecoin:
+        return createUriFromElectrumAddress(uriRaw);
+      default:
+        return null;
+    }
+  }
+
   @override
   dynamic get keyIndex {
     _keyIndex ??= key;
@@ -64,7 +83,9 @@ class Node extends HiveObject with Keyable {
         case WalletType.monero:
           return requestMoneroNode();
         case WalletType.bitcoin:
-          return requestBitcoinElectrumServer();
+          return requestElectrumServer();
+        case WalletType.litecoin:
+          return requestElectrumServer();
         default:
           return false;
       }
@@ -80,15 +101,15 @@ class Node extends HiveObject with Keyable {
       if (login != null && password != null) {
         final digestRequest = DigestRequest();
         final response = await digestRequest.request(
-            uri: uri, login: login, password: password);
+            uri: uri.toString(), login: login, password: password);
         resBody = response.data as Map<String, dynamic>;
       } else {
-        final url = Uri.http(uri, '/json_rpc');
+        final rpcUri = Uri.http(uri.toString(), '/json_rpc');
         final headers = {'Content-type': 'application/json'};
         final body =
             json.encode({'jsonrpc': '2.0', 'id': '0', 'method': 'get_info'});
         final response =
-            await http.post(url.toString(), headers: headers, body: body);
+            await http.post(rpcUri.toString(), headers: headers, body: body);
         resBody = json.decode(response.body) as Map<String, dynamic>;
       }
 
@@ -98,8 +119,13 @@ class Node extends HiveObject with Keyable {
     }
   }
 
-  Future<bool> requestBitcoinElectrumServer() async {
-    // FIXME: IMPLEMENT ME
-    return true;
+  Future<bool> requestElectrumServer() async {
+    try {
+       await SecureSocket.connect(uri.host, uri.port,
+        timeout: Duration(seconds: 5), onBadCertificate: (_) => true);
+       return true;
+    } catch (_) {
+      return false;
+    }
   }
 }

lib/monero/monero_wallet.dart

@@ -152,7 +152,7 @@ abstract class MoneroWalletBase extends WalletBase<MoneroBalance,
     try {
       syncStatus = ConnectingSyncStatus();
       await monero_wallet.setupNode(
-          address: node.uri,
+          address: node.uri.toString(),
           login: node.login,
           password: node.password,
           useSSL: node.isSSL,

lib/reactions/check_connection.dart

@@ -7,19 +7,22 @@ import 'package:connectivity/connectivity.dart';
 
 Timer _checkConnectionTimer;
 
-void startCheckConnectionReaction(WalletBase wallet, SettingsStore settingsStore, {int timeInterval = 5}) {
+void startCheckConnectionReaction(
+    WalletBase wallet, SettingsStore settingsStore,
+    {int timeInterval = 5}) {
   _checkConnectionTimer?.cancel();
-  _checkConnectionTimer = Timer.periodic(Duration(seconds: timeInterval), (_) async {
-    final connectivityResult = await (Connectivity().checkConnectivity());
+  _checkConnectionTimer =
+      Timer.periodic(Duration(seconds: timeInterval), (_) async {
+    try {
+      final connectivityResult = await (Connectivity().checkConnectivity());
 
-    if (connectivityResult == ConnectivityResult.none) {
-      wallet.syncStatus = FailedSyncStatus();
-      return;
-    }
+      if (connectivityResult == ConnectivityResult.none) {
+        wallet.syncStatus = FailedSyncStatus();
+        return;
+      }
 
-    if (wallet.syncStatus is LostConnectionSyncStatus ||
-        wallet.syncStatus is FailedSyncStatus) {
-      try {
+      if (wallet.syncStatus is LostConnectionSyncStatus ||
+          wallet.syncStatus is FailedSyncStatus) {
         final alive =
             await settingsStore.getCurrentNode(wallet.type).requestNode();
 
@@ -27,9 +30,9 @@ void startCheckConnectionReaction(WalletBase wallet, SettingsStore settingsStore
           await wallet.connectToNode(
               node: settingsStore.getCurrentNode(wallet.type));
         }
-      } catch (_) {
-        // FIXME: empty catch clojure
       }
+    } catch (e) {
+      print(e.toString());
     }
   });
 }

lib/src/screens/nodes/nodes_list_page.dart

@@ -87,7 +87,7 @@ class NodeListPage extends BasePage {
                 final isSelected =
                     node.keyIndex == nodeListViewModel.currentNode?.keyIndex;
                 final nodeListRow = NodeListRow(
-                    title: node.uri,
+                    title: node.uriRaw,
                     isSelected: isSelected,
                     isAlive: node.requestNode(),
                     onTap: (_) async {
@@ -101,8 +101,9 @@ class NodeListPage extends BasePage {
                             return AlertWithTwoActions(
                                 alertTitle:
                                     S.of(context).change_current_node_title,
-                                alertContent:
-                                    S.of(context).change_current_node(node.uri),
+                                alertContent: S
+                                    .of(context)
+                                    .change_current_node(node.uriRaw),
                                 leftButtonText: S.of(context).cancel,
                                 rightButtonText: S.of(context).change,
                                 actionLeftButton: () =>