Added fallback DNS servers

lib/l10n/app_en.arb

@@ -706,5 +706,9 @@
     "queryLogsAndStatistics": "Query logs and statistics",
     "ignoreClientQueryLog": "Ignore this client in query log",
     "ignoreClientStatistics": "Ignore this client in statistics",
-    "savingChanges": "Saving changes..."
+    "savingChanges": "Saving changes...",
+    "fallbackDnsServers": "Fallback DNS servers",
+    "fallbackDnsServersDescription": "Configure fallback DNS servers",
+    "fallbackDnsServersInfo": "List of fallback DNS servers used when upstream DNS servers are not responding. The syntax is the same as in the main upstreams field above.",
+    "noFallbackDnsAdded": "No fallback DNS servers added."
 }

lib/l10n/app_es.arb

@@ -706,5 +706,9 @@
     "queryLogsAndStatistics": "Registro de consultas y estadísticas",
     "ignoreClientQueryLog": "Ignorar este cliente en el registro de consultas",
     "ignoreClientStatistics": "Ignorar este cliente en las estadísticas",
-    "savingChanges": "Guardando cambios..."
+    "savingChanges": "Guardando cambios...",
+    "fallbackDnsServers": "Servidores DNS alternativos",
+    "fallbackDnsServersDescription": "Configura los servidores DNS alternativos",
+    "fallbackDnsServersInfo": "Lista de servidores DNS alternativos utilizados cuando los servidores DNS de subida no responden. La sintaxis es la misma que en el campo de los principales DNS de subida anterior.",
+    "noFallbackDnsAdded": "No hay servidores DNS alternativos añadidos."
 }

lib/models/dns_info.dart

@@ -2,6 +2,7 @@ class DnsInfo {
   List<String> upstreamDns;
   String? upstreamDnsFile;
   List<String> bootstrapDns;
+  List<String>? fallbackDns;
   bool protectionEnabled;
   int ratelimit;
   String blockingMode;
@@ -26,6 +27,7 @@ class DnsInfo {
     required this.upstreamDns,
     required this.upstreamDnsFile,
     required this.bootstrapDns,
+    required this.fallbackDns,
     required this.protectionEnabled,
     required this.ratelimit,
     required this.blockingMode,
@@ -51,6 +53,7 @@ class DnsInfo {
     upstreamDns: json["upstream_dns"] != null ? List<String>.from(json["upstream_dns"].map((x) => x)) : [],
     upstreamDnsFile: json["upstream_dns_file"],
     bootstrapDns: json["bootstrap_dns"] != null ? List<String>.from(json["bootstrap_dns"].map((x) => x)) : [],
+    fallbackDns: json["fallback_dns"] != null ? List<String>.from(json["fallback_dns"].map((x) => x)) : [],
     protectionEnabled: json["protection_enabled"],
     ratelimit: json["ratelimit"],
     blockingMode: json["blocking_mode"],
@@ -76,6 +79,7 @@ class DnsInfo {
     "upstream_dns": List<dynamic>.from(upstreamDns.map((x) => x)),
     "upstream_dns_file": upstreamDnsFile,
     "bootstrap_dns": List<dynamic>.from(bootstrapDns.map((x) => x)),
+    "fallback_dns": List<dynamic>.from(bootstrapDns.map((x) => x)),
     "protection_enabled": protectionEnabled,
     "ratelimit": ratelimit,
     "blocking_mode": blockingMode,

lib/providers/dns_provider.dart

@@ -112,6 +112,22 @@ class DnsProvider with ChangeNotifier {
     }
   }
 
+  Future<ApiResponse> saveFallbackDnsConfig(Map<String, dynamic> value) async {
+    final result = await _serversProvider!.apiClient2!.setDnsConfig(
+      data: value
+    );
+
+    if (result.successful == true) {
+      DnsInfo data = dnsInfo!;
+      data.bootstrapDns = List<String>.from(value['fallback_dns']);
+      setDnsInfoData(data);
+      return result;
+    }
+    else {
+      return result;
+    }
+  }
+
   Future<ApiResponse> saveCacheCacheConfig(Map<String, dynamic> value) async {
     final result = await _serversProvider!.apiClient2!.setDnsConfig(
       data: value

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/fallback_dns.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';
@@ -167,6 +168,12 @@ class _DnsSettingsState extends State<DnsSettings> {
                       onTap: () => navigate(const BootstrapDnsScreen()),
                       icon: Icons.dns_rounded,
                     ),
+                    if (dnsProvider.dnsInfo!.fallbackDns != null) CustomListTile(
+                      title: AppLocalizations.of(context)!.fallbackDnsServers,
+                      subtitle: AppLocalizations.of(context)!.fallbackDnsServersDescription,
+                      onTap: () => navigate(const FallbackDnsScreen()),
+                      icon: Icons.alt_route_rounded,
+                    ),
                     CustomListTile(
                       title: AppLocalizations.of(context)!.privateReverseDnsServers,
                       subtitle: AppLocalizations.of(context)!.privateReverseDnsDescription,

lib/screens/settings/dns/fallback_dns.dart

@@ -0,0 +1,224 @@
+// ignore_for_file: use_build_context_synchronously
+
+import 'package:flutter/material.dart';
+import 'package:provider/provider.dart';
+import 'package:flutter_gen/gen_l10n/app_localizations.dart';
+
+import 'package:adguard_home_manager/functions/desktop_mode.dart';
+import 'package:adguard_home_manager/classes/process_modal.dart';
+import 'package:adguard_home_manager/providers/dns_provider.dart';
+import 'package:adguard_home_manager/functions/snackbar.dart';
+import 'package:adguard_home_manager/providers/app_config_provider.dart';
+
+class FallbackDnsScreen extends StatefulWidget {
+  const FallbackDnsScreen({super.key});
+
+  @override
+  State<FallbackDnsScreen> createState() => _FallbackDnsScreenState();
+}
+
+class _FallbackDnsScreenState extends State<FallbackDnsScreen> {
+  List<Map<String, dynamic>> fallbackControllers = [];
+
+  bool validValues = false;
+
+  void validateIp(Map<String, dynamic> field, String value) {
+    RegExp ipAddress = RegExp(r'(?:^(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)(?:\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)){3}$)|(?:^(?:(?:[a-fA-F\d]{1,4}:){7}(?:[a-fA-F\d]{1,4}|:)|(?:[a-fA-F\d]{1,4}:){6}(?:(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)(?:\\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)){3}|:[a-fA-F\d]{1,4}|:)|(?:[a-fA-F\d]{1,4}:){5}(?::(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)(?:\\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)){3}|(?::[a-fA-F\d]{1,4}){1,2}|:)|(?:[a-fA-F\d]{1,4}:){4}(?:(?::[a-fA-F\d]{1,4}){0,1}:(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)(?:\\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)){3}|(?::[a-fA-F\d]{1,4}){1,3}|:)|(?:[a-fA-F\d]{1,4}:){3}(?:(?::[a-fA-F\d]{1,4}){0,2}:(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)(?:\\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)){3}|(?::[a-fA-F\d]{1,4}){1,4}|:)|(?:[a-fA-F\d]{1,4}:){2}(?:(?::[a-fA-F\d]{1,4}){0,3}:(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)(?:\\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)){3}|(?::[a-fA-F\d]{1,4}){1,5}|:)|(?:[a-fA-F\d]{1,4}:){1}(?:(?::[a-fA-F\d]{1,4}){0,4}:(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)(?:\\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)){3}|(?::[a-fA-F\d]{1,4}){1,6}|:)|(?::(?:(?::[a-fA-F\d]{1,4}){0,5}:(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)(?:\\.(?:25[0-5]|2[0-4]\d|1\d\d|[1-9]\d|\d)){3}|(?::[a-fA-F\d]{1,4}){1,7}|:)))(?:%[0-9a-zA-Z]{1,})?$)');
+    if (ipAddress.hasMatch(value) == true) {
+      setState(() => field['error'] = null);
+    }
+    else {
+      setState(() => field['error'] = AppLocalizations.of(context)!.invalidIp);
+    }
+    checkValidValues();
+  }
+
+  void checkValidValues() {
+    if (
+      fallbackControllers.isNotEmpty &&
+      fallbackControllers.every((element) => element['controller'].text != '') &&
+      fallbackControllers.every((element) => element['error'] == null)
+    ) {
+      setState(() => validValues = true);
+    }
+    else {
+      setState(() => validValues = false);
+    }
+  }
+
+  @override
+  void initState() {
+    final dnsProvider = Provider.of<DnsProvider>(context, listen: false);
+
+    for (var item in dnsProvider.dnsInfo!.fallbackDns!) {
+      final controller = TextEditingController();
+      controller.text = item;
+      fallbackControllers.add({
+        'controller': controller,
+        'error': null
+      });
+    }
+    validValues = true;
+    super.initState();
+  }
+
+  @override
+  Widget build(BuildContext context) {
+    final dnsProvider = Provider.of<DnsProvider>(context);
+    final appConfigProvider = Provider.of<AppConfigProvider>(context);
+
+    final width = MediaQuery.of(context).size.width;
+
+    void saveData() async {
+      ProcessModal processModal = ProcessModal();
+      processModal.open(AppLocalizations.of(context)!.savingConfig);
+
+      final result = await dnsProvider.saveFallbackDnsConfig({
+        "fallback_dns": fallbackControllers.map((e) => e['controller'].text).toList(),
+      });
+
+      processModal.close();
+
+      if (result.successful == true) {
+        showSnacbkar(
+          appConfigProvider: appConfigProvider,
+          label: AppLocalizations.of(context)!.dnsConfigSaved, 
+          color: Colors.green
+        );
+      }
+      else if (result.successful == false && result.statusCode == 400) {
+        showSnacbkar(
+          appConfigProvider: appConfigProvider,
+          label: AppLocalizations.of(context)!.someValueNotValid, 
+          color: Colors.red
+        );
+      }
+      else {
+        showSnacbkar(
+          appConfigProvider: appConfigProvider,
+          label: AppLocalizations.of(context)!.dnsConfigNotSaved, 
+          color: Colors.red
+        );
+      } 
+    }
+
+    return Scaffold(
+      appBar: AppBar(
+        title: Text(AppLocalizations.of(context)!.fallbackDnsServers),
+        surfaceTintColor: isDesktop(width) ? Colors.transparent : null,
+        actions: [
+          IconButton(
+            onPressed: validValues == true
+              ? () => saveData()
+              : null, 
+            icon: const Icon(Icons.save_rounded),
+            tooltip: AppLocalizations.of(context)!.save,
+          ),
+          const SizedBox(width: 10)
+        ],
+      ),
+      body: SafeArea(
+        child: ListView(
+          padding: const EdgeInsets.only(top: 10),
+          children: [
+            Card(
+              margin: const EdgeInsets.only(
+                left: 16, right: 16, bottom: 20
+              ),
+              child: Padding(
+                padding: const EdgeInsets.all(20),
+                child: Row(
+                  children: [
+                    Icon(
+                      Icons.info_rounded,
+                      color: Theme.of(context).listTileTheme.iconColor,
+                    ),
+                    const SizedBox(width: 20),
+                    Flexible(
+                      child: Text(
+                        AppLocalizations.of(context)!.fallbackDnsServersInfo,
+                        style: TextStyle(
+                          color: Theme.of(context).colorScheme.onSurface
+                        ),
+                      )
+                    )
+                  ],
+                ),
+              ),
+            ),
+            const SizedBox(height: 10),
+            if (fallbackControllers.isEmpty) Column(
+              children: [
+                Padding(
+                  padding: const EdgeInsets.all(10),
+                  child: Center(
+                    child: Text(
+                      AppLocalizations.of(context)!.noFallbackDnsAdded,
+                      style: TextStyle(
+                        color: Theme.of(context).colorScheme.onSurfaceVariant,
+                        fontSize: 16
+                      ),
+                    ),
+                  ),
+                ),
+                const SizedBox(height: 20),
+              ],
+            ),
+            ...fallbackControllers.map((c) => Padding(
+              padding: const EdgeInsets.only(
+                left: 16, right: 6, bottom: 20
+              ),
+              child: Row(
+                mainAxisAlignment: MainAxisAlignment.spaceBetween,
+                children: [
+                  Expanded(
+                    child: TextFormField(
+                      controller: c['controller'],
+                      onChanged: (value) => validateIp(c, value),
+                      decoration: InputDecoration(
+                        prefixIcon: const Icon(Icons.dns_rounded),
+                        border: const OutlineInputBorder(
+                          borderRadius: BorderRadius.all(
+                            Radius.circular(10)
+                          )
+                        ),
+                        errorText: c['error'],
+                        labelText: AppLocalizations.of(context)!.dnsServer,
+                      )
+                    ),
+                  ),
+                  const SizedBox(width: 8),
+                  IconButton(
+                    onPressed: () {
+                      setState(() => fallbackControllers = fallbackControllers.where((con) => con != c).toList());
+                      checkValidValues();
+                    }, 
+                    icon: const Icon(Icons.remove_circle_outline)
+                  )
+                ],
+              ),
+            )),
+            Row(
+              mainAxisAlignment: MainAxisAlignment.center,
+              mainAxisSize: MainAxisSize.min,
+              children: [
+                ElevatedButton.icon(
+                  onPressed: () {
+                    setState(() => fallbackControllers.add({
+                      'controller': TextEditingController(),
+                      'error': null
+                    }));
+                    checkValidValues();
+                  }, 
+                  icon: const Icon(Icons.add), 
+                  label: Text(AppLocalizations.of(context)!.addItem)
+                ),
+              ],
+            ),
+            const SizedBox(height: 20)
+          ],
+        ),
+      ),
+    );
+  }
+}