Initial radio implementation

Notable changes:
- Add radio gRPC API protobuf definitation and generated files.
- Reworked existing single gRPC APIs library to split it into
  per-API libraries to avoid name collision issues.
- Add radio gRPC client class and associated radio state class
  and RiverPod providers.
- Split media controls and play list table classes into media
  player and radio specific versions to facilitate customization
  and wiring up their appropriate backends in a straightforward
  fashion.  Some potential rationalization of styling widgets
  may be done as a follow up to avoid some duplication.
- Added radio configuration and presets loading.  The presets
  will be populated with the contents of a radio-presets.yaml
  file from the configured location, the default location is
  the /etc/xdg/AGL/ics-homescreen directory.
- Implemented FM radio player against the radio gRPC API.
  For the sake of expediency, no attempt has been made to make
  the player able to handle AM band support.
- Reworked media page navigation state so that active player is
  restored when coming back to the page.  Logic has been added to
  start/stop the radio on navigating to or leaving the FM radio
  sub-page.  This will potentially be reworked before CES to work
  with the pause/stop button present on the other pages.
- Started pruning down global exports.dart a bit to remove files
  only used in a specific page/hierarchy, starting with media.

Bug-AGL: SPEC-5029

Change-Id: I1ae0aca4a7a8218e69e4286c863f01509a1cccb7
Signed-off-by: Scott Murray <scott.murray@konsulko.com>

11 files changed, 463 insertions, 46 deletions

diff --git a/lib/data/data_providers/app_config_provider.dart b/lib/data/data_providers/app_config_provider.dart
index 7e0ddc6..a60a462 100644
--- a/lib/data/data_providers/app_config_provider.dart
+++ b/lib/data/data_providers/app_config_provider.dart
@@ -35,14 +35,40 @@ class KuksaConfig {
   }
 }
 
+class RadioConfig {
+  final String hostname;
+  final int port;
+  final String presets;
+
+  static String defaultHostname = 'localhost';
+  static int defaultPort = 50053;
+  static String defaultPresets =
+      '/etc/xdg/AGL/ics-homescreen/radio-presets.yaml';
+
+  RadioConfig(
+      {required this.hostname, required this.port, required this.presets});
+
+  static RadioConfig defaultConfig() {
+    return RadioConfig(
+        hostname: RadioConfig.defaultHostname,
+        port: RadioConfig.defaultPort,
+        presets: RadioConfig.defaultPresets);
+  }
+}
+
 class AppConfig {
   final bool disableBkgAnimation;
   final bool randomHybridAnimation;
   final KuksaConfig kuksaConfig;
+  final RadioConfig radioConfig;
 
   static String configFilePath = '/etc/xdg/AGL/ics-homescreen.yaml';
 
-  AppConfig({required this.disableBkgAnimation, required this.randomHybridAnimation, required this.kuksaConfig});
+  AppConfig(
+      {required this.disableBkgAnimation,
+      required this.randomHybridAnimation,
+      required this.kuksaConfig,
+      required this.radioConfig});
 
   static KuksaConfig parseKuksaConfig(YamlMap kuksaMap) {
     try {
@@ -64,7 +90,7 @@ class AppConfig {
             debugPrint("Reading authorization token $s");
             try {
               token = File(s).readAsStringSync();
-            } on Exception catch (_) {
+            } catch (_) {
               print("ERROR: Could not read authorization token file $token");
               token = "";
             }
@@ -89,7 +115,7 @@ class AppConfig {
       }
       try {
         ca_cert = File(ca_path).readAsBytesSync();
-      } on Exception catch (_) {
+      } catch (_) {
         print("ERROR: Could not read CA certificate file $ca_path");
         ca_cert = [];
       }
@@ -107,10 +133,33 @@ class AppConfig {
           use_tls: use_tls,
           ca_certificate: ca_cert,
           tls_server_name: tls_server_name);
-    } on Exception catch (_) {
+    } catch (_) {
       return KuksaConfig.defaultConfig();
     }
   }
+
+  static RadioConfig parseRadioConfig(YamlMap radioMap) {
+    try {
+      String hostname = RadioConfig.defaultHostname;
+      if (radioMap.containsKey('hostname')) {
+        hostname = radioMap['hostname'];
+      }
+
+      int port = RadioConfig.defaultPort;
+      if (radioMap.containsKey('port')) {
+        port = radioMap['port'];
+      }
+
+      String presets = RadioConfig.defaultPresets;
+      if (radioMap.containsKey('presets')) {
+        hostname = radioMap['presets'];
+      }
+
+      return RadioConfig(hostname: hostname, port: port, presets: presets);
+    } catch (_) {
+      return RadioConfig.defaultConfig();
+    }
+  }
 }
 
 final appConfigProvider = Provider((ref) {
@@ -133,6 +182,13 @@ final appConfigProvider = Provider((ref) {
           tls_server_name: "");
     }
 
+    RadioConfig radioConfig;
+    if (yamlMap.containsKey('radio')) {
+      radioConfig = AppConfig.parseRadioConfig(yamlMap['radio']);
+    } else {
+      radioConfig = RadioConfig.defaultConfig();
+    }
+
     bool disableBkgAnimation = disableBkgAnimationDefault;
     if (yamlMap.containsKey('disable-bg-animation')) {
       var value = yamlMap['disable-bg-animation'];
@@ -152,11 +208,13 @@ final appConfigProvider = Provider((ref) {
     return AppConfig(
         disableBkgAnimation: disableBkgAnimation,
         randomHybridAnimation: randomHybridAnimation,
-        kuksaConfig: kuksaConfig);
-  } on Exception catch (_) {
+        kuksaConfig: kuksaConfig,
+        radioConfig: radioConfig);
+  } catch (_) {
     return AppConfig(
         disableBkgAnimation: false,
         randomHybridAnimation: false,
-        kuksaConfig: KuksaConfig.defaultConfig());
+        kuksaConfig: KuksaConfig.defaultConfig(),
+        radioConfig: RadioConfig.defaultConfig());
   }
 });
diff --git a/lib/data/data_providers/app_launcher.dart b/lib/data/data_providers/app_launcher.dart
index b0199d3..8762643 100644
--- a/lib/data/data_providers/app_launcher.dart
+++ b/lib/data/data_providers/app_launcher.dart
@@ -1,5 +1,6 @@
 import 'package:flutter_ics_homescreen/export.dart';
-import 'package:protos/protos.dart';
+import 'package:protos/applauncher-api.dart';
+import 'package:protos/agl-shell-api.dart';
 
 class AppLauncher {
   final Ref ref;
@@ -9,20 +10,18 @@ class AppLauncher {
   late ClientChannel appLauncherChannel;
   late AppLauncherClient appLauncher;
 
-  List<String> appStack = [ 'homescreen' ];
+  List<String> appStack = ['homescreen'];
 
   AppLauncher({required this.ref}) {
-    aglShellChannel =
-      ClientChannel('localhost',
-                    port: 14005,
-                    options: ChannelOptions(credentials: ChannelCredentials.insecure()));
+    aglShellChannel = ClientChannel('localhost',
+        port: 14005,
+        options: ChannelOptions(credentials: ChannelCredentials.insecure()));
 
     aglShell = AglShellManagerServiceClient(aglShellChannel);
 
-    appLauncherChannel =
-      ClientChannel('localhost',
-                    port: 50052,
-                    options: ChannelOptions(credentials: ChannelCredentials.insecure()));
+    appLauncherChannel = ClientChannel('localhost',
+        port: 50052,
+        options: ChannelOptions(credentials: ChannelCredentials.insecure()));
     appLauncher = AppLauncherClient(appLauncherChannel);
   }
 
@@ -58,13 +57,23 @@ class AppLauncher {
         debugPrint("Got app:");
         debugPrint("$info");
         // Existing icons are currently not usable, so leave blank for now
-        apps.add(AppLauncherInfo(id: info.id, name: info.name, icon: "", internal: false));
+        apps.add(AppLauncherInfo(
+            id: info.id, name: info.name, icon: "", internal: false));
       }
       apps.sort((a, b) => a.name.compareTo(b.name));
 
       // Add built-in app widgets
-      apps.insert(0, AppLauncherInfo(id: "clock", name: "Clock", icon: "clock.svg", internal: true));
-      apps.insert(0, AppLauncherInfo(id: "weather", name: "Weather", icon: "weather.svg", internal: true));
+      apps.insert(
+          0,
+          AppLauncherInfo(
+              id: "clock", name: "Clock", icon: "clock.svg", internal: true));
+      apps.insert(
+          0,
+          AppLauncherInfo(
+              id: "weather",
+              name: "Weather",
+              icon: "weather.svg",
+              internal: true));
 
       ref.read(appLauncherListProvider.notifier).update(apps);
     } catch (e) {
@@ -104,5 +113,4 @@ class AppLauncher {
       }
     }
   }
-
 }
diff --git a/lib/data/data_providers/app_provider.dart b/lib/data/data_providers/app_provider.dart
index 1670eba..ad3dd22 100644
--- a/lib/data/data_providers/app_provider.dart
+++ b/lib/data/data_providers/app_provider.dart
@@ -4,8 +4,10 @@ import 'package:flutter_ics_homescreen/data/data_providers/time_notifier.dart';
 import 'package:flutter_ics_homescreen/data/data_providers/units_notifier.dart';
 import 'package:flutter_ics_homescreen/data/data_providers/audio_notifier.dart';
 import 'package:flutter_ics_homescreen/data/data_providers/users_notifier.dart';
+import 'package:flutter_ics_homescreen/data/data_providers/radio_notifier.dart';
 import 'package:flutter_ics_homescreen/data/data_providers/val_client.dart';
 import 'package:flutter_ics_homescreen/data/data_providers/app_launcher.dart';
+import 'package:flutter_ics_homescreen/data/data_providers/radio_client.dart';
 import 'package:flutter_ics_homescreen/export.dart';
 
 import '../models/users.dart';
@@ -16,7 +18,7 @@ enum AppState {
   dashboard,
   hvac,
   apps,
-  mediaPlayer,
+  media,
   settings,
   splash,
   dateTime,
@@ -48,7 +50,14 @@ final appLauncherProvider = Provider((ref) {
   return AppLauncher(ref: ref);
 });
 
-final appLauncherListProvider = NotifierProvider<AppLauncherList, List<AppLauncherInfo>>(AppLauncherList.new);
+final appLauncherListProvider =
+    NotifierProvider<AppLauncherList, List<AppLauncherInfo>>(
+        AppLauncherList.new);
+
+final radioClientProvider = Provider((ref) {
+  RadioConfig config = ref.watch(appConfigProvider).radioConfig;
+  return RadioClient(config: config, ref: ref);
+});
 
 final vehicleProvider =
     NotifierProvider<VehicleNotifier, Vehicle>(VehicleNotifier.new);
@@ -62,7 +71,10 @@ final unitStateProvider = StateNotifierProvider<UnitsNotifier, Units>((ref) {
 });
 
 final audioStateProvider =
-    NotifierProvider<AudioNotifier, Audio>(AudioNotifier.new);
+    NotifierProvider<AudioStateNotifier, AudioState>(AudioStateNotifier.new);
+
+final radioStateProvider =
+    NotifierProvider<RadioStateNotifier, RadioState>(RadioStateNotifier.new);
 
 final usersProvider = StateNotifierProvider<UsersNotifier, Users>((ref) {
   return UsersNotifier(Users.initial());
@@ -77,4 +89,3 @@ final currentTimeProvider =
     StateNotifierProvider<CurrentTimeNotifier, DateTime>((ref) {
   return CurrentTimeNotifier();
 });
-
diff --git a/lib/data/data_providers/audio_notifier.dart b/lib/data/data_providers/audio_notifier.dart
index 32ab409..a601095 100644
--- a/lib/data/data_providers/audio_notifier.dart
+++ b/lib/data/data_providers/audio_notifier.dart
@@ -1,10 +1,10 @@
 import 'package:flutter_ics_homescreen/export.dart';
-import 'package:protos/protos.dart';
+import 'package:protos/val-api.dart';
 
-class AudioNotifier extends Notifier<Audio> {
+class AudioStateNotifier extends Notifier<AudioState> {
   @override
-  Audio build() {
-    return Audio.initial();
+  AudioState build() {
+    return AudioState.initial();
   }
 
   void resetToDefaults() {
diff --git a/lib/data/data_providers/radio_client.dart b/lib/data/data_providers/radio_client.dart
new file mode 100644
index 0000000..2cde65e
--- /dev/null
+++ b/lib/data/data_providers/radio_client.dart
@@ -0,0 +1,161 @@
+import 'package:flutter_ics_homescreen/export.dart';
+import 'package:protos/radio-api.dart' as api;
+
+class RadioClient {
+  final RadioConfig config;
+  final Ref ref;
+  late api.ClientChannel channel;
+  late api.RadioClient stub;
+
+  RadioClient({required this.config, required this.ref}) {
+    debugPrint(
+        "Connecting to radio service at ${config.hostname}:${config.port}");
+    api.ChannelCredentials creds = const api.ChannelCredentials.insecure();
+    channel = api.ClientChannel(config.hostname,
+        port: config.port, options: api.ChannelOptions(credentials: creds));
+    stub = api.RadioClient(channel);
+  }
+
+  void run() async {
+    getBandParameters();
+
+    try {
+      var responseStream = stub.getStatusEvents(api.StatusRequest());
+      await for (var event in responseStream) {
+        handleStatusEvent(event);
+      }
+    } catch (e) {
+      print(e);
+    }
+  }
+
+  void getBandParameters() async {
+    try {
+      var response = await stub.getBandParameters(
+          api.GetBandParametersRequest(band: api.Band.BAND_FM));
+      ref.read(radioStateProvider.notifier).updateBandParameters(
+          freqMin: response.min,
+          freqMax: response.max,
+          freqStep: response.step);
+
+      // Get initial frequency
+      var freqResponse = await stub.getFrequency(api.GetFrequencyRequest());
+      ref
+          .read(radioStateProvider.notifier)
+          .updateFrequency(freqResponse.frequency);
+    } catch (e) {
+      print(e);
+    }
+  }
+
+  void handleStatusEvent(api.StatusResponse response) {
+    switch (response.whichStatus()) {
+      case api.StatusResponse_Status.frequency:
+        var status = response.frequency;
+        ref.read(radioStateProvider.notifier).updateFrequency(status.frequency);
+        break;
+      case api.StatusResponse_Status.play:
+        var status = response.play;
+        ref.read(radioStateProvider.notifier).updatePlaying(status.playing);
+        break;
+      case api.StatusResponse_Status.scan:
+        var status = response.scan;
+        if (status.stationFound) {
+          ref.read(radioStateProvider.notifier).updateScanning(false);
+        }
+        break;
+      default:
+        break;
+    }
+  }
+
+  void start() async {
+    try {
+      var response = await stub.start(api.StartRequest());
+    } catch (e) {
+      print(e);
+    }
+  }
+
+  void stop() async {
+    try {
+      var response = await stub.stop(api.StopRequest());
+    } catch (e) {
+      print(e);
+    }
+  }
+
+  void setFrequency(int frequency) async {
+    var radioState = ref.read(radioStateProvider);
+    if ((frequency < radioState.freqMin) ||
+        (frequency > radioState.freqMax) ||
+        ((frequency - radioState.freqMin) % radioState.freqStep) != 0) {
+      debugPrint("setFrequency: invalid frequency $frequency!");
+      return;
+    }
+    try {
+      var response = await stub
+          .setFrequency(api.SetFrequencyRequest(frequency: frequency));
+    } catch (e) {
+      print(e);
+    }
+  }
+
+  void tuneForward() async {
+    var radioState = ref.read(radioStateProvider);
+    if (radioState.freqCurrent < radioState.freqMax) {
+      int frequency = radioState.freqCurrent + radioState.freqStep;
+      if (frequency > radioState.freqMax) {
+        frequency = radioState.freqMax;
+      }
+      try {
+        var response = await stub
+            .setFrequency(api.SetFrequencyRequest(frequency: frequency));
+      } catch (e) {
+        print(e);
+      }
+    }
+  }
+
+  void tuneBackward() async {
+    var radioState = ref.read(radioStateProvider);
+    if (radioState.freqCurrent > radioState.freqMin) {
+      int frequency = radioState.freqCurrent - radioState.freqStep;
+      if (frequency < radioState.freqMin) {
+        frequency = radioState.freqMin;
+      }
+      try {
+        var response = await stub
+            .setFrequency(api.SetFrequencyRequest(frequency: frequency));
+      } catch (e) {
+        print(e);
+      }
+    }
+  }
+
+  void scanForward() async {
+    try {
+      var response = await stub.scanStart(api.ScanStartRequest(
+          direction: api.ScanDirection.SCAN_DIRECTION_FORWARD));
+    } catch (e) {
+      print(e);
+    }
+  }
+
+  void scanBackward() async {
+    try {
+      var response = await stub.scanStart(api.ScanStartRequest(
+          direction: api.ScanDirection.SCAN_DIRECTION_BACKWARD));
+    } catch (e) {
+      print(e);
+    }
+  }
+
+  void scanStop() async {
+    try {
+      var response = await stub.scanStop(api.ScanStopRequest());
+    } catch (e) {
+      print(e);
+    }
+  }
+}
diff --git a/lib/data/data_providers/radio_notifier.dart b/lib/data/data_providers/radio_notifier.dart
new file mode 100644
index 0000000..90e0df5
--- /dev/null
+++ b/lib/data/data_providers/radio_notifier.dart
@@ -0,0 +1,31 @@
+import 'package:flutter_ics_homescreen/export.dart';
+
+class RadioStateNotifier extends Notifier<RadioState> {
+  @override
+  RadioState build() {
+    return RadioState.initial();
+  }
+
+  void updateBandParameters(
+      {required int freqMin, required freqMax, required freqStep}) {
+    state =
+        state.copyWith(freqMin: freqMin, freqMax: freqMax, freqStep: freqStep);
+  }
+
+  void updateFrequency(int frequency) {
+    state = state.copyWith(freqCurrent: frequency);
+  }
+
+  void setFrequency(int frequency) {
+    state = state.copyWith(freqCurrent: frequency);
+    ref.read(radioClientProvider).setFrequency(frequency);
+  }
+
+  void updatePlaying(bool playing) {
+    state = state.copyWith(playing: playing);
+  }
+
+  void updateScanning(bool scanning) {
+    state = state.copyWith(scanning: scanning);
+  }
+}
diff --git a/lib/data/data_providers/radio_presets_provider.dart b/lib/data/data_providers/radio_presets_provider.dart
new file mode 100644
index 0000000..9ee68ac
--- /dev/null
+++ b/lib/data/data_providers/radio_presets_provider.dart
@@ -0,0 +1,49 @@
+import 'dart:io';
+import 'package:flutter_ics_homescreen/export.dart';
+import 'package:yaml/yaml.dart';
+
+class RadioPreset {
+  final int frequency;
+  final String name;
+
+  RadioPreset({required this.frequency, required this.name});
+}
+
+class RadioPresets {
+  final List<RadioPreset> fmPresets;
+
+  RadioPresets({required this.fmPresets});
+}
+
+final radioPresetsProvider = Provider((ref) {
+  final presetsFilename = ref.read(appConfigProvider).radioConfig.presets;
+  if (presetsFilename.isEmpty) {
+    return RadioPresets(fmPresets: []);
+  }
+  try {
+    print("Reading radio presets $presetsFilename");
+    var presetsFile = File(presetsFilename);
+    String content = presetsFile.readAsStringSync();
+    final dynamic yamlMap = loadYaml(content);
+
+    List<RadioPreset> presets = [];
+    if (yamlMap.containsKey('fm')) {
+      dynamic list = yamlMap['fm'];
+      if (list is YamlList) {
+        for (var element in list) {
+          if ((element is YamlMap) &&
+              element.containsKey('frequency') &&
+              element.containsKey('name')) {
+            presets.add(RadioPreset(
+                frequency: element['frequency'].toInt(),
+                name: element['name'].toString()));
+          }
+        }
+      }
+    }
+    return RadioPresets(fmPresets: presets);
+  } catch (_) {
+    debugPrint("Exception reading presets!");
+    return RadioPresets(fmPresets: []);
+  }
+});
diff --git a/lib/data/data_providers/val_client.dart b/lib/data/data_providers/val_client.dart
index 28bb480..db962ee 100644
--- a/lib/data/data_providers/val_client.dart
+++ b/lib/data/data_providers/val_client.dart
@@ -1,5 +1,5 @@
 import 'package:flutter_ics_homescreen/export.dart';
-import 'package:protos/protos.dart';
+import 'package:protos/val-api.dart';
 
 class ValClient {
   final KuksaConfig config;
@@ -9,7 +9,7 @@ class ValClient {
   late String authorization;
 
   ValClient({required this.config, required this.ref}) {
-    debugPrint("Using ${config.hostname}:${config.port}");
+    debugPrint("Connecting to KUKSA.val at ${config.hostname}:${config.port}");
     ChannelCredentials creds;
     if (config.use_tls && config.ca_certificate.isNotEmpty) {
       print("Using TLS");
@@ -25,11 +25,10 @@ class ValClient {
     }
     channel = ClientChannel(config.hostname,
         port: config.port, options: ChannelOptions(credentials: creds));
-    debugPrint('Start Listen on port: ${config.port}');
     stub = VALClient(channel);
   }
 
-  void startListen() async {
+  void run() async {
     List<String> fewSignals = VSSPath().getSignalsList();
     var request = SubscribeRequest();
     Map<String, String> metadata = {};
diff --git a/lib/data/data_providers/vehicle_notifier.dart b/lib/data/data_providers/vehicle_notifier.dart
index 78c5328..6fafb8c 100644
--- a/lib/data/data_providers/vehicle_notifier.dart
+++ b/lib/data/data_providers/vehicle_notifier.dart
@@ -3,7 +3,7 @@
 import 'dart:async';
 
 import 'package:flutter_ics_homescreen/export.dart';
-import 'package:protos/protos.dart';
+import 'package:protos/val-api.dart';
 
 class VehicleNotifier extends Notifier<Vehicle> {
   @override
diff --git a/lib/data/models/audio.dart b/lib/data/models/audio_state.dart
index 65490f9..cfa550b 100644
--- a/lib/data/models/audio.dart
+++ b/lib/data/models/audio_state.dart
@@ -3,13 +3,13 @@ import 'dart:convert';
 import 'package:flutter_ics_homescreen/export.dart';
 
 @immutable
-class Audio {
+class AudioState {
   final double volume;
   final double balance;
   final double fade;
   final double treble;
   final double bass;
-  const Audio({
+  const AudioState({
     required this.volume,
     required this.balance,
     required this.fade,
@@ -17,22 +17,21 @@ class Audio {
     required this.bass,
   });
 
-  const Audio.initial()
+  const AudioState.initial()
       : volume = 5.0,
         balance = 5.0,
         fade = 5.0,
         treble = 5.0,
         bass = 5.0;
-  
 
-  Audio copyWith({
+  AudioState copyWith({
     double? volume,
     double? balance,
     double? fade,
     double? treble,
     double? bass,
   }) {
-    return Audio(
+    return AudioState(
       volume: volume ?? this.volume,
       balance: balance ?? this.balance,
       fade: fade ?? this.fade,
@@ -51,8 +50,8 @@ class Audio {
     };
   }
 
-  factory Audio.fromMap(Map<String, dynamic> map) {
-    return Audio(
+  factory AudioState.fromMap(Map<String, dynamic> map) {
+    return AudioState(
       volume: map['volume']?.toDouble() ?? 0.0,
       balance: map['balance']?.toDouble() ?? 0.0,
       fade: map['fade']?.toDouble() ?? 0.0,
@@ -63,18 +62,19 @@ class Audio {
 
   String toJson() => json.encode(toMap());
 
-  factory Audio.fromJson(String source) => Audio.fromMap(json.decode(source));
+  factory AudioState.fromJson(String source) =>
+      AudioState.fromMap(json.decode(source));
 
   @override
   String toString() {
-    return 'Audio(volume: $volume, balance: $balance, fade: $fade, treble: $treble, bass: $bass)';
+    return 'AudioState(volume: $volume, balance: $balance, fade: $fade, treble: $treble, bass: $bass)';
   }
 
   @override
   bool operator ==(Object other) {
     if (identical(this, other)) return true;
-  
-    return other is Audio &&
+
+    return other is AudioState &&
         other.volume == volume &&
         other.balance == balance &&
         other.fade == fade &&
diff --git a/lib/data/models/radio_state.dart b/lib/data/models/radio_state.dart
new file mode 100644
index 0000000..dd307d9
--- /dev/null
+++ b/lib/data/models/radio_state.dart
@@ -0,0 +1,100 @@
+import 'dart:convert';
+
+import 'package:flutter_ics_homescreen/export.dart';
+
+@immutable
+class RadioState {
+  final int freqMin;
+  final int freqMax;
+  final int freqStep;
+  final int freqCurrent;
+  final bool playing;
+  final bool scanning;
+  const RadioState(
+      {required this.freqMin,
+      required this.freqMax,
+      required this.freqStep,
+      required this.freqCurrent,
+      required this.playing,
+      required this.scanning});
+
+  const RadioState.initial()
+      : freqMin = 8790000,
+        freqMax = 1083000,
+        freqStep = 20000,
+        freqCurrent = 8790000,
+        playing = false,
+        scanning = false;
+
+  RadioState copyWith(
+      {int? freqMin,
+      int? freqMax,
+      int? freqStep,
+      int? freqCurrent,
+      bool? playing,
+      bool? scanning}) {
+    return RadioState(
+      freqMin: freqMin ?? this.freqMin,
+      freqMax: freqMax ?? this.freqMax,
+      freqStep: freqStep ?? this.freqStep,
+      freqCurrent: freqCurrent ?? this.freqCurrent,
+      playing: playing ?? this.playing,
+      scanning: scanning ?? this.scanning,
+    );
+  }
+
+  Map<String, dynamic> toMap() {
+    return {
+      'freqMin': freqMin,
+      'freqMax': freqMax,
+      'freqStep': freqStep,
+      'freqCurrent': freqCurrent,
+      'playing': playing,
+      'scanning': scanning,
+    };
+  }
+
+  factory RadioState.fromMap(Map<String, dynamic> map) {
+    return RadioState(
+      freqMin: map['freqMin']?.toInt().toUnsigned() ?? 0,
+      freqMax: map['freqMax']?.toInt().toUnsigned() ?? 0,
+      freqStep: map['freqStep']?.toInt().toUnsigned() ?? 0,
+      freqCurrent: map['freqCurrent']?.toInt().toUnsigned() ?? 0,
+      playing: map['playing']?.toBool() ?? false,
+      scanning: map['scanning']?.toBool() ?? false,
+    );
+  }
+
+  String toJson() => json.encode(toMap());
+
+  factory RadioState.fromJson(String source) =>
+      RadioState.fromMap(json.decode(source));
+
+  @override
+  String toString() {
+    return 'RadioState(freqMin: $freqMin, freqMax: $freqMax, freqStep: $freqStep, freqCurrent: $freqCurrent, playing: $playing, scanning: $scanning)';
+  }
+
+  @override
+  bool operator ==(Object other) {
+    if (identical(this, other)) return true;
+
+    return other is RadioState &&
+        other.freqMin == freqMin &&
+        other.freqMax == freqMax &&
+        other.freqStep == freqStep &&
+        other.freqCurrent == freqCurrent &&
+        other.playing == playing &&
+        other.scanning == scanning;
+  }
+
+  @override
+  int get hashCode {
+    return freqMin.hashCode ^
+        freqMax.hashCode ^
+        freqStep.hashCode ^
+        freqCurrent.hashCode ^
+        playing.hashCode ^
+        scanning.hashCode;
+  }
+}