Add support for imperial units (#242)

Co-authored-by: mhmdanas <triallax@tutanota.com>

packages/clima_data/lib/data_sources/unit_system_local_data_source.dart

@@ -0,0 +1,38 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+import 'package:clima_core/either.dart';
+import 'package:clima_core/failure.dart';
+import 'package:clima_data/models/unit_system_model.dart';
+import 'package:clima_data/providers.dart';
+import 'package:riverpod/riverpod.dart';
+import 'package:shared_preferences/shared_preferences.dart';
+
+const _prefsKey = 'unit_system';
+
+class UnitSystemLocalDataSource {
+  UnitSystemLocalDataSource(this._prefs);
+
+  final SharedPreferences _prefs;
+
+  Future<Either<Failure, UnitSystemModel?>> getUnitSystem() async {
+    final string = _prefs.getString(_prefsKey);
+
+    if (string == null) return const Right(null);
+
+    return Right(UnitSystemModel.parse(string));
+  }
+
+  Future<Either<Failure, void>> setUnitSystem(UnitSystemModel model) async {
+    await _prefs.setString(_prefsKey, model.toString());
+
+    return const Right(null);
+  }
+}
+
+final unitSystemLocalDataSourceProvider = Provider(
+  (ref) => UnitSystemLocalDataSource(ref.watch(sharedPreferencesProvider)),
+);

packages/clima_data/lib/models/full_weather_model.dart

@@ -9,6 +9,7 @@ import 'package:clima_domain/entities/city.dart';
 import 'package:clima_domain/entities/daily_forecast.dart';
 import 'package:clima_domain/entities/full_weather.dart';
 import 'package:clima_domain/entities/hourly_forecast.dart';
+import 'package:clima_domain/entities/unit_system.dart';
 import 'package:clima_domain/entities/weather.dart';
 import 'package:equatable/equatable.dart';
 
@@ -26,8 +27,10 @@ class FullWeatherModel extends Equatable {
     return FullWeatherModel(
       FullWeather(
         city: city,
+        unitSystem: UnitSystem.metric,
         timeZoneOffset: Duration(seconds: json['timezone_offset'] as int),
         currentWeather: Weather(
+          unitSystem: UnitSystem.metric,
           temperature: (currentWeatherJson['temp'] as num).toDouble(),
           tempFeel: (currentWeatherJson['feels_like'] as num).toDouble(),
           // We multiply by 3.6 to convert from m/s to km/h.
@@ -46,6 +49,7 @@ class FullWeatherModel extends Equatable {
         dailyForecasts: (json['daily'] as List)
             .map(
               (forecastJson) => DailyForecast(
+                unitSystem: UnitSystem.metric,
                 maxTemperature: (forecastJson['temp']['max'] as num).toDouble(),
                 minTemperature: (forecastJson['temp']['min'] as num).toDouble(),
                 date:
@@ -62,6 +66,7 @@ class FullWeatherModel extends Equatable {
         hourlyForecasts: [
           for (final forecastJson in json['hourly'] as List)
             HourlyForecast(
+              unitSystem: UnitSystem.metric,
               date: date_time_utils.fromUtcUnixTime(forecastJson['dt'] as int),
               iconCode: forecastJson['weather'][0]['icon'] as String,
               temperature: (forecastJson['temp'] as num).toDouble(),

packages/clima_data/lib/models/unit_system_model.dart

@@ -0,0 +1,41 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+import 'package:clima_domain/entities/unit_system.dart';
+import 'package:equatable/equatable.dart';
+
+class UnitSystemModel extends Equatable {
+  const UnitSystemModel(this.unitSystem);
+
+  final UnitSystem unitSystem;
+
+  factory UnitSystemModel.parse(String string) {
+    switch (string) {
+      case 'metric':
+        return const UnitSystemModel(UnitSystem.metric);
+
+      case 'imperial':
+        return const UnitSystemModel(UnitSystem.imperial);
+
+      default:
+        throw ArgumentError();
+    }
+  }
+
+  @override
+  String toString() {
+    switch (unitSystem) {
+      case UnitSystem.metric:
+        return 'metric';
+
+      case UnitSystem.imperial:
+        return 'imperial';
+    }
+  }
+
+  @override
+  List<Object?> get props => [unitSystem];
+}

packages/clima_data/lib/repos/unit_system_repo_impl.dart

@@ -0,0 +1,32 @@
+/*
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/.
+ */
+
+import 'package:clima_core/either.dart';
+import 'package:clima_core/failure.dart';
+import 'package:clima_data/data_sources/unit_system_local_data_source.dart';
+import 'package:clima_data/models/unit_system_model.dart';
+import 'package:clima_domain/entities/unit_system.dart';
+import 'package:clima_domain/repos/unit_system_repo.dart';
+import 'package:riverpod/riverpod.dart';
+
+class UnitSystemRepoImpl implements UnitSystemRepo {
+  final UnitSystemLocalDataSource _localDataSource;
+
+  UnitSystemRepoImpl(this._localDataSource);
+
+  @override
+  Future<Either<Failure, UnitSystem>> getUnitSystem() async =>
+      (await _localDataSource.getUnitSystem())
+          .map((model) => model?.unitSystem ?? UnitSystem.metric);
+
+  @override
+  Future<Either<Failure, void>> setUnitSystem(UnitSystem unitSystem) =>
+      _localDataSource.setUnitSystem(UnitSystemModel(unitSystem));
+}
+
+final unitSystemRepoImplProvider = Provider(
+  (ref) => UnitSystemRepoImpl(ref.watch(unitSystemLocalDataSourceProvider)),
+);

packages/clima_data/test/models/full_weather_model_test.dart

@@ -11,6 +11,7 @@ import 'package:clima_data/utils/date_time.dart' as date_time_utils;
 import 'package:clima_domain/entities/city.dart';
 import 'package:clima_domain/entities/daily_forecast.dart';
 import 'package:clima_domain/entities/hourly_forecast.dart';
+import 'package:clima_domain/entities/unit_system.dart';
 import 'package:clima_domain/entities/weather.dart';
 import 'package:flutter_test/flutter_test.dart';
 
@@ -30,6 +31,7 @@ void main() {
       expect(
         fullWeather.currentWeather,
         Weather(
+          unitSystem: UnitSystem.metric,
           date: date_time_utils.fromUtcUnixTime(1634313115),
           temperature: 27.16,
           tempFeel: 29.5,
@@ -47,6 +49,7 @@ void main() {
       expect(
         fullWeather.hourlyForecasts[0],
         HourlyForecast(
+          unitSystem: UnitSystem.metric,
           temperature: 27.16,
           iconCode: "01n",
           date: date_time_utils.fromUtcUnixTime(1634310000),
@@ -55,6 +58,7 @@ void main() {
       );
 
       final dailyForecast = DailyForecast(
+        unitSystem: UnitSystem.metric,
         date: date_time_utils.fromUtcUnixTime(1634284800),
         sunrise: date_time_utils.fromUtcUnixTime(1634264178),
         sunset: date_time_utils.fromUtcUnixTime(1634307772),

packages/clima_domain/lib/entities/daily_forecast.dart

@@ -4,6 +4,8 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/.
  */
 
+import 'package:clima_domain/entities/unit_system.dart';
+import 'package:clima_domain/utils/unit_conversion.dart';
 import 'package:equatable/equatable.dart';
 
 class DailyForecast extends Equatable {
@@ -13,17 +15,17 @@ class DailyForecast extends Equatable {
 
   final DateTime sunset;
 
-  /// Minimum temperature at the moment. In degrees Celsius (for now).
   final double minTemperature;
 
-  /// Maximum temperature at the moment. In degrees Celsius (for now).
   final double maxTemperature;
 
   /// Probability of precipitation.
   final double pop;
 
   final String iconCode;
 
+  final UnitSystem unitSystem;
+
   const DailyForecast({
     required this.date,
     required this.sunrise,
@@ -32,9 +34,49 @@ class DailyForecast extends Equatable {
     required this.maxTemperature,
     required this.pop,
     required this.iconCode,
+    required this.unitSystem,
   });
 
   @override
-  List<Object?> get props =>
-      [date, sunrise, sunset, minTemperature, maxTemperature, pop, iconCode];
+  List<Object?> get props => [
+        date,
+        sunrise,
+        sunset,
+        minTemperature,
+        maxTemperature,
+        pop,
+        iconCode,
+        unitSystem
+      ];
+
+  DailyForecast changeUnitSystem(UnitSystem newUnitSystem) {
+    if (unitSystem == newUnitSystem) {
+      return this;
+    }
+
+    final double newMaxTemperature;
+    final double newMinTemperature;
+
+    switch (unitSystem) {
+      case UnitSystem.imperial:
+        newMaxTemperature = convertFahrenheitToCelsius(maxTemperature);
+        newMinTemperature = convertFahrenheitToCelsius(minTemperature);
+        break;
+
+      case UnitSystem.metric:
+        newMaxTemperature = convertCelsiusToFahrenheit(maxTemperature);
+        newMinTemperature = convertCelsiusToFahrenheit(minTemperature);
+    }
+
+    return DailyForecast(
+      date: date,
+      iconCode: iconCode,
+      sunrise: sunrise,
+      sunset: sunset,
+      pop: pop,
+      maxTemperature: newMaxTemperature,
+      minTemperature: newMinTemperature,
+      unitSystem: newUnitSystem,
+    );
+  }
 }

packages/clima_domain/lib/entities/full_weather.dart

@@ -6,6 +6,7 @@
 
 import 'package:clima_domain/entities/daily_forecast.dart';
 import 'package:clima_domain/entities/hourly_forecast.dart';
+import 'package:clima_domain/entities/unit_system.dart';
 import 'package:collection/collection.dart';
 import 'package:equatable/equatable.dart';
 
@@ -19,6 +20,7 @@ class FullWeather extends Equatable {
     required this.currentWeather,
     required this.dailyForecasts,
     required this.hourlyForecasts,
+    required this.unitSystem,
   });
 
   final City city;
@@ -31,6 +33,8 @@ class FullWeather extends Equatable {
 
   final List<HourlyForecast> hourlyForecasts;
 
+  final UnitSystem unitSystem;
+
   DailyForecast get currentDayForecast => minBy(
         dailyForecasts.where(
           (forecast) => forecast.date.weekday == currentWeather.date.weekday,
@@ -39,6 +43,33 @@ class FullWeather extends Equatable {
       )!;
 
   @override
-  List<Object> get props =>
-      [city, timeZoneOffset, currentWeather, dailyForecasts, hourlyForecasts];
+  List<Object> get props => [
+        city,
+        timeZoneOffset,
+        currentWeather,
+        dailyForecasts,
+        hourlyForecasts,
+        unitSystem
+      ];
+
+  FullWeather changeUnitSystem(UnitSystem newUnitSystem) {
+    if (unitSystem == newUnitSystem) {
+      return this;
+    }
+
+    return FullWeather(
+      unitSystem: newUnitSystem,
+      city: city,
+      timeZoneOffset: timeZoneOffset,
+      currentWeather: currentWeather.changeUnitSystem(newUnitSystem),
+      hourlyForecasts: [
+        for (final forecast in hourlyForecasts)
+          forecast.changeUnitSystem(newUnitSystem)
+      ],
+      dailyForecasts: [
+        for (final forecast in dailyForecasts)
+          forecast.changeUnitSystem(newUnitSystem)
+      ],
+    );
+  }
 }

packages/clima_domain/lib/entities/hourly_forecast.dart

@@ -4,26 +4,55 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/.
  */
 
+import 'package:clima_domain/entities/unit_system.dart';
+import 'package:clima_domain/utils/unit_conversion.dart';
 import 'package:equatable/equatable.dart';
 
 class HourlyForecast extends Equatable {
   final DateTime date;
 
-  /// In degrees Celsius (for now).
   final double temperature;
 
   /// Probability of precipitation.
   final double pop;
 
   final String iconCode;
 
+  final UnitSystem unitSystem;
+
   const HourlyForecast({
     required this.date,
     required this.temperature,
     required this.pop,
     required this.iconCode,
+    required this.unitSystem,
   });
 
   @override
-  List<Object?> get props => [date, temperature, pop, iconCode];
+  List<Object?> get props => [date, temperature, pop, iconCode, unitSystem];
+
+  HourlyForecast changeUnitSystem(UnitSystem newUnitSystem) {
+    if (unitSystem == newUnitSystem) {
+      return this;
+    }
+
+    final double newTemperature;
+
+    switch (unitSystem) {
+      case UnitSystem.imperial:
+        newTemperature = convertFahrenheitToCelsius(temperature);
+        break;
+
+      case UnitSystem.metric:
+        newTemperature = convertCelsiusToFahrenheit(temperature);
+    }
+
+    return HourlyForecast(
+      pop: pop,
+      date: date,
+      temperature: newTemperature,
+      iconCode: iconCode,
+      unitSystem: newUnitSystem,
+    );
+  }
 }

packages/clima_domain/lib/entities/unit.dart → packages/clima_domain/lib/entities/unit_system.dart

@@ -4,8 +4,4 @@
  * file, You can obtain one at https://mozilla.org/MPL/2.0/.
  */
 
-import 'package:riverpod/riverpod.dart';
-
 enum UnitSystem { metric, imperial }
-
-final unitProvider = StateProvider((ref) => UnitSystem.metric);