Added test upstream dns servers

lib/l10n/app_en.arb

@@ -695,5 +695,7 @@
     "resetEncryptionSettingsDescription": "Are you sure you want to reset to default values the encryption settings?",
     "resettingConfig": "Resetting configuration...",
     "configurationResetSuccessfully": "Configuration resetted successfully",
-    "configurationResetError": "The configuration couldn't be resetted"
+    "configurationResetError": "The configuration couldn't be resetted",
+    "testUpstreamDnsServers": "Test upstream DNS servers",
+    "errorTestUpstreamDns": "Error when testing upstream DNS servers."
 }

lib/l10n/app_es.arb

@@ -695,5 +695,7 @@
     "resetEncryptionSettingsDescription": "Estás seguro que deseas restaurar a valores por defecto la configuración de encriptación?",
     "resettingConfig": "Reseteando configuración...",
     "configurationResetSuccessfully": "Configuración reseteada correctamente",
-    "configurationResetError": "La configuración no ha podido ser reseteada"
+    "configurationResetError": "La configuración no ha podido ser reseteada",
+    "testUpstreamDnsServers": "Probar servidores DNS de subida",
+    "errorTestUpstreamDns": "Error al probar los servidores DNS de subida."
 }

lib/screens/settings/dns/dns.dart

@@ -5,6 +5,7 @@ import 'package:flutter_split_view/flutter_split_view.dart';
 import 'package:provider/provider.dart';
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 
+import 'package:adguard_home_manager/screens/settings/dns/test_upstream_dns_modal.dart';
 import 'package:adguard_home_manager/screens/settings/dns/clear_dns_cache_dialog.dart';
 import 'package:adguard_home_manager/screens/settings/dns/cache_config.dart';
 import 'package:adguard_home_manager/screens/settings/dns/dns_server_settings.dart';
@@ -84,6 +85,14 @@ class _DnsSettingsState extends State<DnsSettings> {
         title:  Text(AppLocalizations.of(context)!.dnsSettings),
         surfaceTintColor: isDesktop(width) ? Colors.transparent : null,
         actions: [
+          IconButton(
+            onPressed: () => showDialog(
+              context: context, 
+              builder: (ctx) => const TestUpstreamDnsModal()
+            ),
+            icon: const Icon(Icons.upload_rounded),
+            tooltip: AppLocalizations.of(context)!.testUpstreamDnsServers,
+          ),
           PopupMenuButton(
             itemBuilder: (context) => [
               PopupMenuItem(

lib/screens/settings/dns/test_upstream_dns_modal.dart

@@ -0,0 +1,168 @@
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:flutter_gen/gen_l10n/app_localizations.dart';
+
+import 'package:adguard_home_manager/constants/enums.dart';
+import 'package:adguard_home_manager/providers/dns_provider.dart';
+import 'package:adguard_home_manager/providers/servers_provider.dart';
+
+class _Item {
+  final String url;
+  final bool value;
+
+  const _Item({
+    required this.url,
+    required this.value
+  });
+}
+
+class TestUpstreamDnsModal extends StatefulWidget {
+  const TestUpstreamDnsModal({super.key});
+
+  @override
+  State<TestUpstreamDnsModal> createState() => _TestUpstreamDnsModalState();
+}
+
+class _TestUpstreamDnsModalState extends State<TestUpstreamDnsModal> {
+  LoadStatus loadStatus = LoadStatus.loading;
+  List<_Item>? values;
+
+  void checkDns() async {
+    final dnsProvider = Provider.of<DnsProvider>(context, listen: false);
+    final result = await Provider.of<ServersProvider>(context, listen: false).apiClient2!.testUpstreamDns(
+      body: {
+        "bootstrap_dns": dnsProvider.dnsInfo!.bootstrapDns,
+        "fallback_dns": [],
+        "private_upstream": dnsProvider.dnsInfo!.defaultLocalPtrUpstreams,
+        "upstream_dns": dnsProvider.dnsInfo!.upstreamDns
+      }
+    );
+    if (!mounted) return;
+    if (result.successful == true) {
+      setState(() {
+        values = List<_Item>.from(
+          (result.content as Map<String, dynamic>).entries.map((e) => _Item(
+            url: e.key, 
+            value: e.value == "OK" ? true : false
+          ))  
+        );
+        loadStatus = LoadStatus.loaded;
+      });
+    }
+    else {
+      setState(() => loadStatus = LoadStatus.error);
+    }
+  }
+
+  @override
+  void initState() {
+    checkDns();
+    super.initState();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    return AlertDialog(
+      title: Column(
+        children: [
+          Icon(
+            Icons.upload_rounded,
+            size: 24,
+            color: Theme.of(context).colorScheme.onSurfaceVariant
+          ),
+          const SizedBox(height: 16),
+          Text(
+            AppLocalizations.of(context)!.testUpstreamDnsServers,
+            textAlign: TextAlign.center,
+            style: TextStyle(
+              color: Theme.of(context).colorScheme.onSurface
+            ),
+          )
+        ],
+      ),
+      content: ConstrainedBox(
+        constraints: const BoxConstraints(
+          maxWidth: 500
+        ),
+        child: Builder(
+          builder: (context) {
+            switch (loadStatus) {
+              case LoadStatus.loading:
+                return const Padding(
+                  padding: EdgeInsets.symmetric(vertical: 16),
+                  child: Column(
+                    mainAxisSize: MainAxisSize.min,
+                    children: [
+                      CircularProgressIndicator()
+                    ],
+                  ),
+                );
+        
+              case LoadStatus.loaded:
+                return SingleChildScrollView(
+                  child: Wrap(
+                    children: values!.map((v) => Padding(
+                      padding: const EdgeInsets.symmetric(vertical: 4),
+                      child: Row(
+                        mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                        children: [
+                          Expanded(
+                            child: Text(
+                              v.url,
+                              overflow: TextOverflow.ellipsis,
+                            ),
+                          ),
+                          ...[
+                            const SizedBox(width: 8),
+                            if (v.value == true) const Icon(
+                              Icons.check_circle_rounded,
+                              color: Colors.green,
+                              size: 16,
+                            ),
+                            if (v.value == false) const Icon(
+                              Icons.cancel_rounded,
+                              color: Colors.red,
+                            )
+                          ]
+                        ],
+                      ),
+                    )).toList(),
+                  ),
+                );
+              
+              case LoadStatus.error:
+                return Column(
+                  mainAxisSize: MainAxisSize.min,
+                  children: [
+                    Icon(
+                      Icons.error_rounded,
+                      color: Theme.of(context).colorScheme.onSurfaceVariant,
+                      size: 30,
+                    ),
+                    const SizedBox(height: 16),
+                    Text(
+                      AppLocalizations.of(context)!.errorTestUpstreamDns,
+                      textAlign: TextAlign.center,
+                      style: TextStyle(
+                        fontSize: 18,
+                        color: Theme.of(context).colorScheme.onSurfaceVariant
+                      ),
+                    )
+                  ],
+                );
+        
+              default:
+                return const SizedBox();
+            }
+          },
+        ),
+      ),
+      actions: [
+        TextButton(
+          onPressed: () => Navigator.pop(context), 
+          child: Text(AppLocalizations.of(context)!.close)
+        ),
+      ],
+    );
+  }
+}

lib/screens/settings/dns/upstream_dns.dart

@@ -186,7 +186,7 @@ class _UpstreamDnsScreenState extends State<UpstreamDnsScreen> {
             icon: const Icon(Icons.save_rounded),
             tooltip: AppLocalizations.of(context)!.save,
           ),
-          const SizedBox(width: 10)
+          const SizedBox(width: 8)
         ],
       ),
       body: SafeArea(

lib/services/api_client.dart

@@ -853,4 +853,18 @@ class ApiClientV2 {
     );
     return ApiResponse(successful: result.successful);
   }
+
+  Future<ApiResponse> testUpstreamDns({
+    required Map<String, dynamic> body
+  }) async {
+    final result = await HttpRequestClient.post(
+      urlPath: '/test_upstream_dns', 
+      server: server,
+      body: body
+    );
+    return ApiResponse(
+      successful: result.successful,
+      content: result.body != null ? jsonDecode(result.body!) : null
+    );
+  }
 }