feat(i18n): add localization foundation

TODO.md

@@ -2,10 +2,11 @@
 
 ## Internacionalización AAA
 
+- [x] Diseñar una base de internacionalización profesional con ficheros ARB separados por idioma.
+- [x] Permitir que el usuario cambie el idioma manualmente desde la aplicación, sin depender únicamente del idioma del sistema.
+- [x] Añadir traducción inicial español/inglés para el shell, navegación, timer de sueño y selector de idioma.
 - [ ] Repasar absolutamente todos los literales de la aplicación en todas las pantallas, componentes, servicios con mensajes visibles y notificaciones.
-- [ ] Diseñar una arquitectura de internacionalización profesional con ficheros separados por idioma.
-- [ ] Permitir que el usuario cambie el idioma manualmente desde la aplicación, sin depender únicamente del idioma del sistema.
-- [ ] Soportar formatos locales de fecha, hora, números y duración.
+- [ ] Soportar formatos locales de fecha, hora, números y duración usando helpers centralizados.
 - [ ] Resolver correctamente singular/plural y variantes por cantidad, por ejemplo `1 emisora` vs `2 emisoras`.
 - [ ] Preparar traducciones para la mayoría de idiomas más usados del planeta.
 - [ ] Revisar la aplicación de Farolero como referencia para detectar el conjunto de idiomas que nos interesa mantener.

l10n.yaml

@@ -0,0 +1,6 @@
+arb-dir: lib/l10n
+template-arb-file: app_es.arb
+output-localization-file: app_localizations.dart
+output-class: AppLocalizations
+output-dir: lib/l10n/gen
+nullable-getter: false

lib/app.dart

@@ -3,6 +3,8 @@ import 'package:flutter/material.dart';
 import 'package:provider/provider.dart';
 import 'estado/estado_radio.dart';
 import 'estado/estado_alarmas.dart';
+import 'estado/estado_idioma.dart';
+import 'l10n/gen/app_localizations.dart';
 import 'modelos/alarma_musical.dart';
 import 'pantallas/pantalla_alarmas.dart';
 import 'pantallas/pantalla_alarma_sonando.dart';
@@ -27,14 +29,21 @@ class PluriWaveApp extends StatelessWidget {
       providers: [
         ChangeNotifierProvider(create: (_) => EstadoRadio()),
         ChangeNotifierProvider(create: (_) => EstadoAlarmas()),
+        ChangeNotifierProvider(create: (_) => EstadoIdioma()),
       ],
-      child: MaterialApp(
-        title: 'PluriWave',
-        debugShowCheckedModeBanner: false,
-        theme: PluriWaveTheme.dark(),
-        darkTheme: PluriWaveTheme.dark(),
-        themeMode: ThemeMode.dark,
-        home: const _PaginaPrincipal(),
+      child: Consumer<EstadoIdioma>(
+        builder:
+            (context, estadoIdioma, _) => MaterialApp(
+              title: 'PluriWave',
+              debugShowCheckedModeBanner: false,
+              theme: PluriWaveTheme.dark(),
+              darkTheme: PluriWaveTheme.dark(),
+              themeMode: ThemeMode.dark,
+              localizationsDelegates: AppLocalizations.localizationsDelegates,
+              supportedLocales: AppLocalizations.supportedLocales,
+              locale: estadoIdioma.localeSeleccionado,
+              home: const _PaginaPrincipal(),
+            ),
       ),
     );
   }
@@ -63,27 +72,12 @@ class _PaginaPrincipalState extends State<_PaginaPrincipal> {
     PantallaAjustes(),
   ];
 
-  static const _navItems = [
-    PluriNavItem(
-      glyph: PluriIconGlyph.home,
-      label: 'Inicio',
-    ),
-    PluriNavItem(
-      glyph: PluriIconGlyph.search,
-      label: 'Buscar',
-    ),
-    PluriNavItem(
-      glyph: PluriIconGlyph.favorites,
-      label: 'Favoritos',
-    ),
-    PluriNavItem(
-      glyph: PluriIconGlyph.alarm,
-      label: 'Alarmas',
-    ),
-    PluriNavItem(
-      glyph: PluriIconGlyph.settings,
-      label: 'Ajustes',
-    ),
+  List<PluriNavItem> _navItems(AppLocalizations l10n) => [
+    PluriNavItem(glyph: PluriIconGlyph.home, label: l10n.navHome),
+    PluriNavItem(glyph: PluriIconGlyph.search, label: l10n.navSearch),
+    PluriNavItem(glyph: PluriIconGlyph.favorites, label: l10n.navFavorites),
+    PluriNavItem(glyph: PluriIconGlyph.alarm, label: l10n.navAlarms),
+    PluriNavItem(glyph: PluriIconGlyph.settings, label: l10n.navSettings),
   ];
 
   @override
@@ -101,7 +95,10 @@ class _PaginaPrincipalState extends State<_PaginaPrincipal> {
         SnackBar(
           content: Text(msg),
           duration: const Duration(seconds: 3),
-          action: SnackBarAction(label: 'OK', onPressed: () {}),
+          action: SnackBarAction(
+            label: AppLocalizations.of(context).actionOk,
+            onPressed: () {},
+          ),
         ),
       );
     });
@@ -133,13 +130,15 @@ class _PaginaPrincipalState extends State<_PaginaPrincipal> {
 
   @override
   Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context);
+
     return PluriWaveScaffold(
       appBar: AppBar(
-        title: const Text('PluriWave'),
+        title: Text(l10n.appTitle),
         actions: [
           IconButton(
             icon: const Icon(Icons.bedtime_outlined),
-            tooltip: 'Timer de sueño',
+            tooltip: l10n.sleepTimer,
             onPressed: () => _mostrarTimerDialog(context),
           ),
         ],
@@ -177,7 +176,7 @@ class _PaginaPrincipalState extends State<_PaginaPrincipal> {
             children: [
               const MiniReproductor(),
               PluriBottomNavigation(
-                items: _navItems,
+                items: _navItems(l10n),
                 selectedIndex: _indice,
                 onSelected: (i) => setState(() => _indice = i),
               ),
@@ -212,7 +211,11 @@ class _PaginaPrincipalState extends State<_PaginaPrincipal> {
       setState(() => _indice = 3);
       ScaffoldMessenger.of(context).showSnackBar(
         SnackBar(
-          content: Text('Omitida esta ejecución de ${alarma.nombre}.'),
+          content: Text(
+            AppLocalizations.of(context).skipCurrentAlarmExecution(
+              alarma.nombre,
+            ),
+          ),
         ),
       );
       return;
@@ -252,12 +255,12 @@ class _PaginaPrincipalState extends State<_PaginaPrincipal> {
                   crossAxisAlignment: CrossAxisAlignment.start,
                   children: [
                     Text(
-                      'Timer de sueño',
+                      AppLocalizations.of(ctx).sleepTimer,
                       style: Theme.of(ctx).textTheme.titleLarge,
                     ),
                     const SizedBox(height: PluriLayout.sectionGap),
                     Text(
-                      'Apagado suave de la radio con cuenta atrás exacta.',
+                      AppLocalizations.of(ctx).sleepTimerDescription,
                       style: Theme.of(ctx).textTheme.bodySmall,
                     ),
                     const SizedBox(height: PluriLayout.panelGap),
@@ -280,7 +283,9 @@ class _PaginaPrincipalState extends State<_PaginaPrincipal> {
                                   estado.cancelarTimer();
                                   Navigator.pop(ctx);
                                 },
-                                child: const Text('Cancelar timer'),
+                                child: Text(
+                                  AppLocalizations.of(ctx).cancelTimer,
+                                ),
                               ),
                             ],
                           );
@@ -308,7 +313,9 @@ class _PaginaPrincipalState extends State<_PaginaPrincipal> {
                             ),
                           ActionChip(
                             avatar: const Icon(Icons.tune_rounded, size: 18),
-                            label: const Text('Otro'),
+                            label: Text(
+                              AppLocalizations.of(ctx).optionOther,
+                            ),
                             onPressed: () async {
                               final duracion =
                                   await _pedirDuracionPersonalizada(ctx);
@@ -382,7 +389,11 @@ class _TimerPersonalizadoSheetState extends State<_TimerPersonalizadoSheet> {
     );
     if (duracion <= Duration.zero) {
       ScaffoldMessenger.of(context).showSnackBar(
-        const SnackBar(content: Text('Elegí una duración mayor que cero.')),
+        SnackBar(
+          content: Text(
+            AppLocalizations.of(context).durationGreaterThanZero,
+          ),
+        ),
       );
       return;
     }
@@ -403,30 +414,49 @@ class _TimerPersonalizadoSheetState extends State<_TimerPersonalizadoSheet> {
           crossAxisAlignment: CrossAxisAlignment.stretch,
           children: [
             Text(
-              'Duración personalizada',
+              AppLocalizations.of(context).customDurationTitle,
               style: Theme.of(context).textTheme.titleLarge,
             ),
             const SizedBox(height: PluriLayout.sectionGap),
             Row(
               children: [
-                Expanded(child: _campoTiempo(_horasCtrl, 'Horas')),
+                Expanded(
+                  child: _campoTiempo(
+                    _horasCtrl,
+                    AppLocalizations.of(context).hoursLabel,
+                  ),
+                ),
                 const SizedBox(width: PluriLayout.compactGap),
-                Expanded(child: _campoTiempo(_minutosCtrl, 'Minutos')),
+                Expanded(
+                  child: _campoTiempo(
+                    _minutosCtrl,
+                    AppLocalizations.of(context).minutesLabel,
+                  ),
+                ),
                 const SizedBox(width: PluriLayout.compactGap),
-                Expanded(child: _campoTiempo(_segundosCtrl, 'Segundos')),
+                Expanded(
+                  child: _campoTiempo(
+                    _segundosCtrl,
+                    AppLocalizations.of(context).secondsLabel,
+                  ),
+                ),
               ],
             ),
             const SizedBox(height: PluriLayout.compactGap),
             SwitchListTile.adaptive(
               contentPadding: EdgeInsets.zero,
-              title: const Text('Guardar como acceso rápido'),
+              title: Text(
+                AppLocalizations.of(context).saveQuickAccess,
+              ),
               value: _guardarPreset,
               onChanged: (value) => setState(() => _guardarPreset = value),
             ),
             const SizedBox(height: PluriLayout.sectionGap),
             FilledButton.icon(
               icon: const Icon(Icons.bedtime_rounded),
-              label: const Text('Iniciar timer'),
+              label: Text(
+                AppLocalizations.of(context).startTimer,
+              ),
               onPressed: _confirmar,
             ),
           ],

lib/estado/estado_idioma.dart

@@ -0,0 +1,68 @@
+import 'dart:ui';
+
+import 'package:flutter/foundation.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+class EstadoIdioma extends ChangeNotifier {
+  EstadoIdioma({SharedPreferences? sharedPreferences})
+    : _sharedPreferences = sharedPreferences {
+    _cargar();
+  }
+
+  static const String _keyLocale = 'idioma_manual_v1';
+
+  final SharedPreferences? _sharedPreferences;
+
+  Locale? _localeSeleccionado;
+
+  Locale? get localeSeleccionado => _localeSeleccionado;
+  bool get usaSistema => _localeSeleccionado == null;
+
+  Future<void> seleccionarSistema() async {
+    _localeSeleccionado = null;
+    notifyListeners();
+    final prefs = await _resolverPrefs();
+    await prefs.remove(_keyLocale);
+  }
+
+  Future<void> seleccionarLocale(Locale locale) async {
+    final tag = _serializarLocale(locale);
+    _localeSeleccionado = locale;
+    notifyListeners();
+    final prefs = await _resolverPrefs();
+    await prefs.setString(_keyLocale, tag);
+  }
+
+  Future<void> _cargar() async {
+    final prefs = await _resolverPrefs();
+    final localeGuardado = prefs.getString(_keyLocale);
+    _localeSeleccionado = _parsearLocale(localeGuardado);
+    notifyListeners();
+  }
+
+  Future<SharedPreferences> _resolverPrefs() async {
+    return _sharedPreferences ?? SharedPreferences.getInstance();
+  }
+
+  Locale? _parsearLocale(String? value) {
+    if (value == null || value.trim().isEmpty) return null;
+    final partes = value.split('_');
+    final languageCode = partes.first;
+    if (languageCode.isEmpty) return null;
+    final countryCode = partes.length > 1 && partes[1].isNotEmpty
+        ? partes[1]
+        : null;
+    return Locale.fromSubtags(
+      languageCode: languageCode,
+      countryCode: countryCode,
+    );
+  }
+
+  String _serializarLocale(Locale locale) {
+    final countryCode = locale.countryCode;
+    if (countryCode == null || countryCode.isEmpty) {
+      return locale.languageCode;
+    }
+    return '${locale.languageCode}_$countryCode';
+  }
+}

lib/l10n/app_en.arb

@@ -0,0 +1,47 @@
+{
+  "@@locale": "en",
+  "appTitle": "PluriWave",
+  "navHome": "Home",
+  "navSearch": "Search",
+  "navFavorites": "Favorites",
+  "navAlarms": "Alarms",
+  "navSettings": "Settings",
+  "actionOk": "OK",
+  "sleepTimer": "Sleep timer",
+  "sleepTimerDescription": "Smooth radio shutdown with an exact countdown.",
+  "cancelTimer": "Cancel timer",
+  "optionOther": "Other",
+  "customDurationTitle": "Custom duration",
+  "durationGreaterThanZero": "Choose a duration greater than zero.",
+  "hoursLabel": "Hours",
+  "minutesLabel": "Minutes",
+  "secondsLabel": "Seconds",
+  "saveQuickAccess": "Save as quick access",
+  "startTimer": "Start timer",
+  "skipCurrentAlarmExecution": "Skipped this execution of {alarmName}.",
+  "@skipCurrentAlarmExecution": {
+    "placeholders": {
+      "alarmName": {}
+    }
+  },
+  "settingsTitle": "Settings",
+  "settingsSubtitle": "Fine-grained sound control, backups, and custom stations.",
+  "languageSectionTitle": "Language",
+  "languageSectionDescription": "Choose how the app language is displayed.",
+  "languageSystemDefault": "System",
+  "languageSpanish": "Spanish",
+  "languageEnglish": "English",
+  "languageUpdated": "Language updated: {languageName}",
+  "@languageUpdated": {
+    "placeholders": {
+      "languageName": {}
+    }
+  },
+  "languageUpdatedSystem": "Language updated: System",
+  "timerSectionTitle": "Sleep timer",
+  "timerSectionAdd": "Add",
+  "timerSectionDescription": "Customize the quick presets shown when automatically stopping the radio.",
+  "timerSectionRestoreRecommended": "Restore recommended times",
+  "newQuickAccessTitle": "New quick access",
+  "saveQuickAccessButton": "Save quick access"
+}

lib/l10n/app_es.arb

@@ -0,0 +1,47 @@
+{
+  "@@locale": "es",
+  "appTitle": "PluriWave",
+  "navHome": "Inicio",
+  "navSearch": "Buscar",
+  "navFavorites": "Favoritos",
+  "navAlarms": "Alarmas",
+  "navSettings": "Ajustes",
+  "actionOk": "OK",
+  "sleepTimer": "Timer de sueño",
+  "sleepTimerDescription": "Apagado suave de la radio con cuenta atrás exacta.",
+  "cancelTimer": "Cancelar timer",
+  "optionOther": "Otro",
+  "customDurationTitle": "Duración personalizada",
+  "durationGreaterThanZero": "Elegí una duración mayor que cero.",
+  "hoursLabel": "Horas",
+  "minutesLabel": "Minutos",
+  "secondsLabel": "Segundos",
+  "saveQuickAccess": "Guardar como acceso rápido",
+  "startTimer": "Iniciar timer",
+  "skipCurrentAlarmExecution": "Omitida esta ejecución de {alarmName}.",
+  "@skipCurrentAlarmExecution": {
+    "placeholders": {
+      "alarmName": {}
+    }
+  },
+  "settingsTitle": "Ajustes",
+  "settingsSubtitle": "Control fino de sonido, copias de seguridad y emisoras personalizadas.",
+  "languageSectionTitle": "Idioma",
+  "languageSectionDescription": "Elegí cómo se muestra el idioma de la app.",
+  "languageSystemDefault": "Sistema",
+  "languageSpanish": "Español",
+  "languageEnglish": "Inglés",
+  "languageUpdated": "Idioma actualizado: {languageName}",
+  "@languageUpdated": {
+    "placeholders": {
+      "languageName": {}
+    }
+  },
+  "languageUpdatedSystem": "Idioma actualizado: Sistema",
+  "timerSectionTitle": "Timer de sueño",
+  "timerSectionAdd": "Añadir",
+  "timerSectionDescription": "Personalizá los accesos rápidos que aparecen al apagar la radio automáticamente.",
+  "timerSectionRestoreRecommended": "Restaurar tiempos recomendados",
+  "newQuickAccessTitle": "Nuevo acceso rápido",
+  "saveQuickAccessButton": "Guardar acceso rápido"
+}

lib/l10n/gen/app_localizations.dart

@@ -0,0 +1,338 @@
+import 'dart:async';
+
+import 'package:flutter/foundation.dart';
+import 'package:flutter/widgets.dart';
+import 'package:flutter_localizations/flutter_localizations.dart';
+import 'package:intl/intl.dart' as intl;
+
+import 'app_localizations_en.dart';
+import 'app_localizations_es.dart';
+
+// ignore_for_file: type=lint
+
+/// Callers can lookup localized strings with an instance of AppLocalizations
+/// returned by `AppLocalizations.of(context)`.
+///
+/// Applications need to include `AppLocalizations.delegate()` in their app's
+/// `localizationDelegates` list, and the locales they support in the app's
+/// `supportedLocales` list. For example:
+///
+/// ```dart
+/// import 'gen/app_localizations.dart';
+///
+/// return MaterialApp(
+///   localizationsDelegates: AppLocalizations.localizationsDelegates,
+///   supportedLocales: AppLocalizations.supportedLocales,
+///   home: MyApplicationHome(),
+/// );
+/// ```
+///
+/// ## Update pubspec.yaml
+///
+/// Please make sure to update your pubspec.yaml to include the following
+/// packages:
+///
+/// ```yaml
+/// dependencies:
+///   # Internationalization support.
+///   flutter_localizations:
+///     sdk: flutter
+///   intl: any # Use the pinned version from flutter_localizations
+///
+///   # Rest of dependencies
+/// ```
+///
+/// ## iOS Applications
+///
+/// iOS applications define key application metadata, including supported
+/// locales, in an Info.plist file that is built into the application bundle.
+/// To configure the locales supported by your app, you’ll need to edit this
+/// file.
+///
+/// First, open your project’s ios/Runner.xcworkspace Xcode workspace file.
+/// Then, in the Project Navigator, open the Info.plist file under the Runner
+/// project’s Runner folder.
+///
+/// Next, select the Information Property List item, select Add Item from the
+/// Editor menu, then select Localizations from the pop-up menu.
+///
+/// Select and expand the newly-created Localizations item then, for each
+/// locale your application supports, add a new item and select the locale
+/// you wish to add from the pop-up menu in the Value field. This list should
+/// be consistent with the languages listed in the AppLocalizations.supportedLocales
+/// property.
+abstract class AppLocalizations {
+  AppLocalizations(String locale)
+    : localeName = intl.Intl.canonicalizedLocale(locale.toString());
+
+  final String localeName;
+
+  static AppLocalizations of(BuildContext context) {
+    return Localizations.of<AppLocalizations>(context, AppLocalizations)!;
+  }
+
+  static const LocalizationsDelegate<AppLocalizations> delegate =
+      _AppLocalizationsDelegate();
+
+  /// A list of this localizations delegate along with the default localizations
+  /// delegates.
+  ///
+  /// Returns a list of localizations delegates containing this delegate along with
+  /// GlobalMaterialLocalizations.delegate, GlobalCupertinoLocalizations.delegate,
+  /// and GlobalWidgetsLocalizations.delegate.
+  ///
+  /// Additional delegates can be added by appending to this list in
+  /// MaterialApp. This list does not have to be used at all if a custom list
+  /// of delegates is preferred or required.
+  static const List<LocalizationsDelegate<dynamic>> localizationsDelegates =
+      <LocalizationsDelegate<dynamic>>[
+        delegate,
+        GlobalMaterialLocalizations.delegate,
+        GlobalCupertinoLocalizations.delegate,
+        GlobalWidgetsLocalizations.delegate,
+      ];
+
+  /// A list of this localizations delegate's supported locales.
+  static const List<Locale> supportedLocales = <Locale>[
+    Locale('en'),
+    Locale('es'),
+  ];
+
+  /// No description provided for @appTitle.
+  ///
+  /// In es, this message translates to:
+  /// **'PluriWave'**
+  String get appTitle;
+
+  /// No description provided for @navHome.
+  ///
+  /// In es, this message translates to:
+  /// **'Inicio'**
+  String get navHome;
+
+  /// No description provided for @navSearch.
+  ///
+  /// In es, this message translates to:
+  /// **'Buscar'**
+  String get navSearch;
+
+  /// No description provided for @navFavorites.
+  ///
+  /// In es, this message translates to:
+  /// **'Favoritos'**
+  String get navFavorites;
+
+  /// No description provided for @navAlarms.
+  ///
+  /// In es, this message translates to:
+  /// **'Alarmas'**
+  String get navAlarms;
+
+  /// No description provided for @navSettings.
+  ///
+  /// In es, this message translates to:
+  /// **'Ajustes'**
+  String get navSettings;
+
+  /// No description provided for @actionOk.
+  ///
+  /// In es, this message translates to:
+  /// **'OK'**
+  String get actionOk;
+
+  /// No description provided for @sleepTimer.
+  ///
+  /// In es, this message translates to:
+  /// **'Timer de sueño'**
+  String get sleepTimer;
+
+  /// No description provided for @sleepTimerDescription.
+  ///
+  /// In es, this message translates to:
+  /// **'Apagado suave de la radio con cuenta atrás exacta.'**
+  String get sleepTimerDescription;
+
+  /// No description provided for @cancelTimer.
+  ///
+  /// In es, this message translates to:
+  /// **'Cancelar timer'**
+  String get cancelTimer;
+
+  /// No description provided for @optionOther.
+  ///
+  /// In es, this message translates to:
+  /// **'Otro'**
+  String get optionOther;
+
+  /// No description provided for @customDurationTitle.
+  ///
+  /// In es, this message translates to:
+  /// **'Duración personalizada'**
+  String get customDurationTitle;
+
+  /// No description provided for @durationGreaterThanZero.
+  ///
+  /// In es, this message translates to:
+  /// **'Elegí una duración mayor que cero.'**
+  String get durationGreaterThanZero;
+
+  /// No description provided for @hoursLabel.
+  ///
+  /// In es, this message translates to:
+  /// **'Horas'**
+  String get hoursLabel;
+
+  /// No description provided for @minutesLabel.
+  ///
+  /// In es, this message translates to:
+  /// **'Minutos'**
+  String get minutesLabel;
+
+  /// No description provided for @secondsLabel.
+  ///
+  /// In es, this message translates to:
+  /// **'Segundos'**
+  String get secondsLabel;
+
+  /// No description provided for @saveQuickAccess.
+  ///
+  /// In es, this message translates to:
+  /// **'Guardar como acceso rápido'**
+  String get saveQuickAccess;
+
+  /// No description provided for @startTimer.
+  ///
+  /// In es, this message translates to:
+  /// **'Iniciar timer'**
+  String get startTimer;
+
+  /// No description provided for @skipCurrentAlarmExecution.
+  ///
+  /// In es, this message translates to:
+  /// **'Omitida esta ejecución de {alarmName}.'**
+  String skipCurrentAlarmExecution(Object alarmName);
+
+  /// No description provided for @settingsTitle.
+  ///
+  /// In es, this message translates to:
+  /// **'Ajustes'**
+  String get settingsTitle;
+
+  /// No description provided for @settingsSubtitle.
+  ///
+  /// In es, this message translates to:
+  /// **'Control fino de sonido, copias de seguridad y emisoras personalizadas.'**
+  String get settingsSubtitle;
+
+  /// No description provided for @languageSectionTitle.
+  ///
+  /// In es, this message translates to:
+  /// **'Idioma'**
+  String get languageSectionTitle;
+
+  /// No description provided for @languageSectionDescription.
+  ///
+  /// In es, this message translates to:
+  /// **'Elegí cómo se muestra el idioma de la app.'**
+  String get languageSectionDescription;
+
+  /// No description provided for @languageSystemDefault.
+  ///
+  /// In es, this message translates to:
+  /// **'Sistema'**
+  String get languageSystemDefault;
+
+  /// No description provided for @languageSpanish.
+  ///
+  /// In es, this message translates to:
+  /// **'Español'**
+  String get languageSpanish;
+
+  /// No description provided for @languageEnglish.
+  ///
+  /// In es, this message translates to:
+  /// **'Inglés'**
+  String get languageEnglish;
+
+  /// No description provided for @languageUpdated.
+  ///
+  /// In es, this message translates to:
+  /// **'Idioma actualizado: {languageName}'**
+  String languageUpdated(Object languageName);
+
+  /// No description provided for @languageUpdatedSystem.
+  ///
+  /// In es, this message translates to:
+  /// **'Idioma actualizado: Sistema'**
+  String get languageUpdatedSystem;
+
+  /// No description provided for @timerSectionTitle.
+  ///
+  /// In es, this message translates to:
+  /// **'Timer de sueño'**
+  String get timerSectionTitle;
+
+  /// No description provided for @timerSectionAdd.
+  ///
+  /// In es, this message translates to:
+  /// **'Añadir'**
+  String get timerSectionAdd;
+
+  /// No description provided for @timerSectionDescription.
+  ///
+  /// In es, this message translates to:
+  /// **'Personalizá los accesos rápidos que aparecen al apagar la radio automáticamente.'**
+  String get timerSectionDescription;
+
+  /// No description provided for @timerSectionRestoreRecommended.
+  ///
+  /// In es, this message translates to:
+  /// **'Restaurar tiempos recomendados'**
+  String get timerSectionRestoreRecommended;
+
+  /// No description provided for @newQuickAccessTitle.
+  ///
+  /// In es, this message translates to:
+  /// **'Nuevo acceso rápido'**
+  String get newQuickAccessTitle;
+
+  /// No description provided for @saveQuickAccessButton.
+  ///
+  /// In es, this message translates to:
+  /// **'Guardar acceso rápido'**
+  String get saveQuickAccessButton;
+}
+
+class _AppLocalizationsDelegate
+    extends LocalizationsDelegate<AppLocalizations> {
+  const _AppLocalizationsDelegate();
+
+  @override
+  Future<AppLocalizations> load(Locale locale) {
+    return SynchronousFuture<AppLocalizations>(lookupAppLocalizations(locale));
+  }
+
+  @override
+  bool isSupported(Locale locale) =>
+      <String>['en', 'es'].contains(locale.languageCode);
+
+  @override
+  bool shouldReload(_AppLocalizationsDelegate old) => false;
+}
+
+AppLocalizations lookupAppLocalizations(Locale locale) {
+  // Lookup logic when only language code is specified.
+  switch (locale.languageCode) {
+    case 'en':
+      return AppLocalizationsEn();
+    case 'es':
+      return AppLocalizationsEs();
+  }
+
+  throw FlutterError(
+    'AppLocalizations.delegate failed to load unsupported locale "$locale". This is likely '
+    'an issue with the localizations generation tool. Please file an issue '
+    'on GitHub with a reproducible sample app and the gen-l10n configuration '
+    'that was used.',
+  );
+}

lib/l10n/gen/app_localizations_en.dart

@@ -0,0 +1,120 @@
+// ignore: unused_import
+import 'package:intl/intl.dart' as intl;
+import 'app_localizations.dart';
+
+// ignore_for_file: type=lint
+
+/// The translations for English (`en`).
+class AppLocalizationsEn extends AppLocalizations {
+  AppLocalizationsEn([String locale = 'en']) : super(locale);
+
+  @override
+  String get appTitle => 'PluriWave';
+
+  @override
+  String get navHome => 'Home';
+
+  @override
+  String get navSearch => 'Search';
+
+  @override
+  String get navFavorites => 'Favorites';
+
+  @override
+  String get navAlarms => 'Alarms';
+
+  @override
+  String get navSettings => 'Settings';
+
+  @override
+  String get actionOk => 'OK';
+
+  @override
+  String get sleepTimer => 'Sleep timer';
+
+  @override
+  String get sleepTimerDescription =>
+      'Smooth radio shutdown with an exact countdown.';
+
+  @override
+  String get cancelTimer => 'Cancel timer';
+
+  @override
+  String get optionOther => 'Other';
+
+  @override
+  String get customDurationTitle => 'Custom duration';
+
+  @override
+  String get durationGreaterThanZero => 'Choose a duration greater than zero.';
+
+  @override
+  String get hoursLabel => 'Hours';
+
+  @override
+  String get minutesLabel => 'Minutes';
+
+  @override
+  String get secondsLabel => 'Seconds';
+
+  @override
+  String get saveQuickAccess => 'Save as quick access';
+
+  @override
+  String get startTimer => 'Start timer';
+
+  @override
+  String skipCurrentAlarmExecution(Object alarmName) {
+    return 'Skipped this execution of $alarmName.';
+  }
+
+  @override
+  String get settingsTitle => 'Settings';
+
+  @override
+  String get settingsSubtitle =>
+      'Fine-grained sound control, backups, and custom stations.';
+
+  @override
+  String get languageSectionTitle => 'Language';
+
+  @override
+  String get languageSectionDescription =>
+      'Choose how the app language is displayed.';
+
+  @override
+  String get languageSystemDefault => 'System';
+
+  @override
+  String get languageSpanish => 'Spanish';
+
+  @override
+  String get languageEnglish => 'English';
+
+  @override
+  String languageUpdated(Object languageName) {
+    return 'Language updated: $languageName';
+  }
+
+  @override
+  String get languageUpdatedSystem => 'Language updated: System';
+
+  @override
+  String get timerSectionTitle => 'Sleep timer';
+
+  @override
+  String get timerSectionAdd => 'Add';
+
+  @override
+  String get timerSectionDescription =>
+      'Customize the quick presets shown when automatically stopping the radio.';
+
+  @override
+  String get timerSectionRestoreRecommended => 'Restore recommended times';
+
+  @override
+  String get newQuickAccessTitle => 'New quick access';
+
+  @override
+  String get saveQuickAccessButton => 'Save quick access';
+}

lib/l10n/gen/app_localizations_es.dart

@@ -0,0 +1,120 @@
+// ignore: unused_import
+import 'package:intl/intl.dart' as intl;
+import 'app_localizations.dart';
+
+// ignore_for_file: type=lint
+
+/// The translations for Spanish Castilian (`es`).
+class AppLocalizationsEs extends AppLocalizations {
+  AppLocalizationsEs([String locale = 'es']) : super(locale);
+
+  @override
+  String get appTitle => 'PluriWave';
+
+  @override
+  String get navHome => 'Inicio';
+
+  @override
+  String get navSearch => 'Buscar';
+
+  @override
+  String get navFavorites => 'Favoritos';
+
+  @override
+  String get navAlarms => 'Alarmas';
+
+  @override
+  String get navSettings => 'Ajustes';
+
+  @override
+  String get actionOk => 'OK';
+
+  @override
+  String get sleepTimer => 'Timer de sueño';
+
+  @override
+  String get sleepTimerDescription =>
+      'Apagado suave de la radio con cuenta atrás exacta.';
+
+  @override
+  String get cancelTimer => 'Cancelar timer';
+
+  @override
+  String get optionOther => 'Otro';
+
+  @override
+  String get customDurationTitle => 'Duración personalizada';
+
+  @override
+  String get durationGreaterThanZero => 'Elegí una duración mayor que cero.';
+
+  @override
+  String get hoursLabel => 'Horas';
+
+  @override
+  String get minutesLabel => 'Minutos';
+
+  @override
+  String get secondsLabel => 'Segundos';
+
+  @override
+  String get saveQuickAccess => 'Guardar como acceso rápido';
+
+  @override
+  String get startTimer => 'Iniciar timer';
+
+  @override
+  String skipCurrentAlarmExecution(Object alarmName) {
+    return 'Omitida esta ejecución de $alarmName.';
+  }
+
+  @override
+  String get settingsTitle => 'Ajustes';
+
+  @override
+  String get settingsSubtitle =>
+      'Control fino de sonido, copias de seguridad y emisoras personalizadas.';
+
+  @override
+  String get languageSectionTitle => 'Idioma';
+
+  @override
+  String get languageSectionDescription =>
+      'Elegí cómo se muestra el idioma de la app.';
+
+  @override
+  String get languageSystemDefault => 'Sistema';
+
+  @override
+  String get languageSpanish => 'Español';
+
+  @override
+  String get languageEnglish => 'Inglés';
+
+  @override
+  String languageUpdated(Object languageName) {
+    return 'Idioma actualizado: $languageName';
+  }
+
+  @override
+  String get languageUpdatedSystem => 'Idioma actualizado: Sistema';
+
+  @override
+  String get timerSectionTitle => 'Timer de sueño';
+
+  @override
+  String get timerSectionAdd => 'Añadir';
+
+  @override
+  String get timerSectionDescription =>
+      'Personalizá los accesos rápidos que aparecen al apagar la radio automáticamente.';
+
+  @override
+  String get timerSectionRestoreRecommended => 'Restaurar tiempos recomendados';
+
+  @override
+  String get newQuickAccessTitle => 'Nuevo acceso rápido';
+
+  @override
+  String get saveQuickAccessButton => 'Guardar acceso rápido';
+}

lib/pantallas/pantalla_ajustes.dart

@@ -9,7 +9,9 @@ import 'package:provider/provider.dart';
 import 'package:share_plus/share_plus.dart' show Share, XFile;
 import 'package:uuid/uuid.dart';
 
+import '../estado/estado_idioma.dart';
 import '../estado/estado_radio.dart';
+import '../l10n/gen/app_localizations.dart';
 import '../modelos/emisora.dart';
 import '../widgets/ecualizador_widget.dart';
 import '../widgets/pluri_glass_surface.dart';
@@ -22,20 +24,21 @@ class PantallaAjustes extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context);
+
     return ListView(
       padding: PluriLayout.pageListPadding,
-      children: const [
+      children: [
         PluriScreenHeader(
-          title: 'Ajustes',
-          subtitle:
-              'Control fino de sonido, copias de seguridad y emisoras personalizadas.',
+          title: l10n.settingsTitle,
+          subtitle: l10n.settingsSubtitle,
           glyph: PluriIconGlyph.settings,
-          trailing: PluriStatusPill(
+          trailing: const PluriStatusPill(
             icon: Icons.security_rounded,
             label: 'Seguro',
           ),
         ),
-        Padding(
+        const Padding(
           padding: PluriLayout.pageContentPadding,
           child: _AjustesContent(),
         ),
@@ -57,6 +60,8 @@ class _AjustesContent extends StatelessWidget {
         SizedBox(height: 12),
         _SeccionTimerSueno(),
         SizedBox(height: 12),
+        _SeccionIdioma(),
+        SizedBox(height: 12),
         _SeccionEmisoraPreferida(),
         SizedBox(height: 12),
         _SeccionEmisoras(),
@@ -165,6 +170,8 @@ class _SeccionTimerSueno extends StatelessWidget {
   const _SeccionTimerSueno();
 
   Future<void> _anadirPreset(BuildContext context) async {
+    final l10n = AppLocalizations.of(context);
+
     final duracion = await showModalBottomSheet<Duration>(
       context: context,
       isScrollControlled: true,
@@ -177,7 +184,7 @@ class _SeccionTimerSueno extends StatelessWidget {
     ScaffoldMessenger.of(context).showSnackBar(
       SnackBar(
         content: Text(
-          'Acceso rápido añadido: ${_formatearDuracionTimer(duracion)}',
+          '${l10n.saveQuickAccessButton}: ${_formatearDuracionTimer(duracion)}',
         ),
       ),
     );
@@ -185,6 +192,8 @@ class _SeccionTimerSueno extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context);
+
     final estado = context.watch<EstadoRadio>();
     final presets = estado.timerSuenoPresetsSegundos;
     return PluriGlassSurface(
@@ -196,20 +205,20 @@ class _SeccionTimerSueno extends StatelessWidget {
               const Icon(Icons.bedtime_rounded),
               const SizedBox(width: 12),
               Text(
-                'Timer de sueño',
+                l10n.timerSectionTitle,
                 style: Theme.of(context).textTheme.titleMedium,
               ),
               const Spacer(),
               TextButton.icon(
                 icon: const Icon(Icons.add_rounded),
-                label: const Text('Añadir'),
+                label: Text(l10n.timerSectionAdd),
                 onPressed: () => _anadirPreset(context),
               ),
             ],
           ),
           const SizedBox(height: 8),
           Text(
-            'Personalizá los accesos rápidos que aparecen al apagar la radio automáticamente.',
+            l10n.timerSectionDescription,
             style: Theme.of(context).textTheme.bodySmall,
           ),
           const SizedBox(height: 12),
@@ -236,7 +245,7 @@ class _SeccionTimerSueno extends StatelessWidget {
             alignment: Alignment.centerLeft,
             child: TextButton.icon(
               icon: const Icon(Icons.restore_rounded),
-              label: const Text('Restaurar tiempos recomendados'),
+              label: Text(l10n.timerSectionRestoreRecommended),
               onPressed:
                   () => context.read<EstadoRadio>().restaurarTimerSuenoPresets(),
             ),
@@ -247,6 +256,95 @@ class _SeccionTimerSueno extends StatelessWidget {
   }
 }
 
+class _SeccionIdioma extends StatelessWidget {
+  const _SeccionIdioma();
+
+  static const _codigoSistema = 'system';
+  static const _codigoEspanol = 'es';
+  static const _codigoIngles = 'en';
+
+  @override
+  Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context);
+    final estadoIdioma = context.watch<EstadoIdioma>();
+    final locale = estadoIdioma.localeSeleccionado;
+    final valorActual = switch (locale?.languageCode) {
+      _codigoEspanol => _codigoEspanol,
+      _codigoIngles => _codigoIngles,
+      _ => _codigoSistema,
+    };
+
+    return PluriGlassSurface(
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Row(
+            children: [
+              const Icon(Icons.language_rounded),
+              const SizedBox(width: 12),
+              Text(
+                l10n.languageSectionTitle,
+                style: Theme.of(context).textTheme.titleMedium,
+              ),
+            ],
+          ),
+          const SizedBox(height: 8),
+          Text(
+            l10n.languageSectionDescription,
+            style: Theme.of(context).textTheme.bodySmall,
+          ),
+          const SizedBox(height: 12),
+          DropdownButtonFormField<String>(
+            initialValue: valorActual,
+            decoration: InputDecoration(
+              labelText: l10n.languageSectionTitle,
+              border: const OutlineInputBorder(),
+            ),
+            items: [
+              DropdownMenuItem(
+                value: _codigoSistema,
+                child: Text(l10n.languageSystemDefault),
+              ),
+              DropdownMenuItem(
+                value: _codigoEspanol,
+                child: Text(l10n.languageSpanish),
+              ),
+              DropdownMenuItem(
+                value: _codigoIngles,
+                child: Text(l10n.languageEnglish),
+              ),
+            ],
+            onChanged: (codigo) async {
+              if (codigo == null) return;
+              if (codigo == _codigoSistema) {
+                await context.read<EstadoIdioma>().seleccionarSistema();
+                if (!context.mounted) return;
+                ScaffoldMessenger.of(context).showSnackBar(
+                  SnackBar(content: Text(l10n.languageUpdatedSystem)),
+                );
+                return;
+              }
+
+              final locale = Locale(codigo);
+              await context.read<EstadoIdioma>().seleccionarLocale(locale);
+              if (!context.mounted) return;
+
+              final nombre = switch (codigo) {
+                _codigoEspanol => l10n.languageSpanish,
+                _codigoIngles => l10n.languageEnglish,
+                _ => l10n.languageSystemDefault,
+              };
+              ScaffoldMessenger.of(context).showSnackBar(
+                SnackBar(content: Text(l10n.languageUpdated(nombre))),
+              );
+            },
+          ),
+        ],
+      ),
+    );
+  }
+}
+
 class _FormularioDuracionTimer extends StatefulWidget {
   const _FormularioDuracionTimer();
 
@@ -270,6 +368,8 @@ class _FormularioDuracionTimerState extends State<_FormularioDuracionTimer> {
   int _leer(TextEditingController ctrl) => int.tryParse(ctrl.text.trim()) ?? 0;
 
   void _guardar() {
+    final l10n = AppLocalizations.of(context);
+
     final duracion = Duration(
       hours: _leer(_horasCtrl),
       minutes: _leer(_minutosCtrl),
@@ -277,7 +377,7 @@ class _FormularioDuracionTimerState extends State<_FormularioDuracionTimer> {
     );
     if (duracion <= Duration.zero) {
       ScaffoldMessenger.of(context).showSnackBar(
-        const SnackBar(content: Text('Elegí una duración mayor que cero.')),
+        SnackBar(content: Text(l10n.durationGreaterThanZero)),
       );
       return;
     }
@@ -286,6 +386,8 @@ class _FormularioDuracionTimerState extends State<_FormularioDuracionTimer> {
 
   @override
   Widget build(BuildContext context) {
+    final l10n = AppLocalizations.of(context);
+
     final bottom = MediaQuery.viewInsetsOf(context).bottom;
     return SafeArea(
       child: Padding(
@@ -295,23 +397,23 @@ class _FormularioDuracionTimerState extends State<_FormularioDuracionTimer> {
           crossAxisAlignment: CrossAxisAlignment.stretch,
           children: [
             Text(
-              'Nuevo acceso rápido',
+              l10n.newQuickAccessTitle,
               style: Theme.of(context).textTheme.titleLarge,
             ),
             const SizedBox(height: 12),
             Row(
               children: [
-                Expanded(child: _campo(_horasCtrl, 'Horas')),
+                Expanded(child: _campo(_horasCtrl, l10n.hoursLabel)),
                 const SizedBox(width: 8),
-                Expanded(child: _campo(_minutosCtrl, 'Minutos')),
+                Expanded(child: _campo(_minutosCtrl, l10n.minutesLabel)),
                 const SizedBox(width: 8),
-                Expanded(child: _campo(_segundosCtrl, 'Segundos')),
+                Expanded(child: _campo(_segundosCtrl, l10n.secondsLabel)),
               ],
             ),
             const SizedBox(height: 16),
             FilledButton.icon(
               icon: const Icon(Icons.save_rounded),
-              label: const Text('Guardar acceso rápido'),
+              label: Text(l10n.saveQuickAccessButton),
               onPressed: _guardar,
             ),
           ],

pubspec.lock

@@ -350,7 +350,7 @@ packages:
     source: hosted
     version: "4.1.2"
   intl:
-    dependency: transitive
+    dependency: "direct main"
     description:
       name: intl
       sha256: "3df61194eb431efc39c4ceba583b95633a403f46c9fd341e550ce0bfa50e9aa5"

pubspec.yaml

@@ -11,6 +11,7 @@ dependencies:
     sdk: flutter
   flutter_localizations:
     sdk: flutter
+  intl: ^0.20.2
   
   # Audio
   just_audio: ^0.9.42
@@ -60,6 +61,7 @@ dev_dependencies:
   flutter_lints: ^5.0.0
 
 flutter:
+  generate: true
   uses-material-design: true
   
   assets:

test/estado/estado_idioma_test.dart

@@ -0,0 +1,40 @@
+import 'dart:ui';
+
+import 'package:flutter_test/flutter_test.dart';
+import 'package:pluriwave/estado/estado_idioma.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+void main() {
+  TestWidgetsFlutterBinding.ensureInitialized();
+
+  group('EstadoIdioma', () {
+    test('arranca en modo sistema cuando no hay preferencia', () async {
+      SharedPreferences.setMockInitialValues({});
+
+      final estado = EstadoIdioma();
+      await Future<void>.delayed(Duration.zero);
+
+      expect(estado.usaSistema, isTrue);
+      expect(estado.localeSeleccionado, isNull);
+    });
+
+    test('persiste locale manual y permite volver a sistema', () async {
+      SharedPreferences.setMockInitialValues({});
+
+      final estado = EstadoIdioma();
+      await Future<void>.delayed(Duration.zero);
+      await estado.seleccionarLocale(const Locale('en'));
+
+      expect(estado.usaSistema, isFalse);
+      expect(estado.localeSeleccionado?.languageCode, 'en');
+
+      final recargado = EstadoIdioma();
+      await Future<void>.delayed(Duration.zero);
+      expect(recargado.localeSeleccionado?.languageCode, 'en');
+
+      await recargado.seleccionarSistema();
+      expect(recargado.usaSistema, isTrue);
+      expect(recargado.localeSeleccionado, isNull);
+    });
+  });
+}