Dotenv setup with environment selector & interceptors (#108)

---------

Co-authored-by: aguskoll <aguskoll@gmail.com>

Author: agustinkoll-rootstrap

.gitignore

@@ -121,8 +121,6 @@ app.*.symbols
 !**/ios/**/default.perspectivev3
 !/packages/flutter_tools/test/data/dart_dependencies_test/**/.packages
 !/dev/ci/**/Gemfile.lock
-/app/env/
-
 
 /modules/common/.flutter-plugins
 /modules/common/.flutter-plugins-dependencies

app/.gitignore

@@ -125,9 +125,8 @@ app.*.symbols
 /env*.json
 
 # Environment and configuration files (contain sensitive data)
-env/.env
-env/.settings
-env/env_*.json
+../env/.env
+../env/env_*.json
 .env
 .env.*
 *.env
@@ -141,4 +140,4 @@ firebase-debug.log
 
 # Local development files
 local.properties
-*.properties
+*.properties

app/env/.env.example

@@ -0,0 +1,13 @@
+#    The .env file MUST be in .gitignore
+#    Delete this file after creating .env
+#
+#   Each flavor (dev/qa/prod) uses the same .env file but reads
+#    different variables based on the suffix:
+#    - Development (main_dev.dart)  → reads *_DEV variables
+#    - QA/Staging (main_qa.dart)    → reads *_QA variables
+#    - Production (main.dart)       → reads *_PROD variables
+
+API_URL_DEV=https://your-api-url-dev.com
+API_URL_QA=https://your-api-url-qa.com
+API_URL_PROD=https://your-api-url-prod.com
+

app/lib/main/env/env_config.dart

@@ -1,9 +1,10 @@
+import 'package:domain/env/env_config.dart';
+
 enum Flavor { dev, qa, prod }
 
 class FlavorValues {
-  final String baseUrl;
 
-  FlavorValues({required this.baseUrl});
+  FlavorValues();
 }
 
 class FlavorConfig {
@@ -22,6 +23,17 @@ class FlavorConfig {
       flavor.toString(),
       values,
     );
+    switch(flavor) {
+      case Flavor.dev:
+        EnvConfig.env = EnvConfig.kDevEnv;
+        break;
+      case Flavor.qa:
+        EnvConfig.env = EnvConfig.kQaEnv;
+        break;
+      case Flavor.prod:
+        EnvConfig.env = EnvConfig.kProdEnv;
+        break;
+    }
     return _instance!;
   }
 
@@ -34,4 +46,26 @@ class FlavorConfig {
   static bool isDevelopment() => instance.flavor == Flavor.dev;
 
   static bool isQA() => instance.flavor == Flavor.qa;
+
+  /// Returns the environment file path (single .env file for all flavors)
+  ///
+  /// SETUP INSTRUCTIONS:
+  /// 1. Navigate to app/env/ directory
+  /// 2. Create a .env file (must be in .gitignore):
+  ///    cp .env.example .env
+  /// 3. Add your environment variables with flavor suffixes:
+  ///    API_URL_DEV=https://dev-api.example.com
+  ///    API_URL_QA=https://qa-api.example.com
+  ///    API_URL_PROD=https://api.example.com
+  /// 4. The active flavor determines which suffix is used (_DEV, _QA, _PROD)
+  /// 5. Access variables in domain/lib/env/env_config.dart using:
+  ///    static String get apiUrl => dotenv.env['API_URL_$env']?.toString() ?? '';
+  ///    (The $env automatically appends DEV, QA, or PROD based on active flavor)
+  /// 6. Go to pubspec.yaml and add the following:
+  ///    assets:
+  ///     - env/.env
+
+  static String getEnvFilePath() {
+    return 'env/.env.example';
+  }
 }

app/lib/main/env/main.dart

@@ -1,13 +1,12 @@
 import 'package:flutter/material.dart';
 import 'package:app/main/env/env_config.dart';
 import 'package:app/main/init.dart';
-import 'package:domain/env.dart';
 
 void main() async {
   WidgetsFlutterBinding.ensureInitialized();
   FlavorConfig(
     flavor: Flavor.prod,
-    values: FlavorValues(baseUrl: EnvConfig.apiUrl),
+    values: FlavorValues(),
   );
   //Add your firebase configuration here
   /*await Firebase.initializeApp(

app/lib/main/env/main_dev.dart

@@ -6,7 +6,7 @@ void main() async {
   WidgetsFlutterBinding.ensureInitialized();
   FlavorConfig(
     flavor: Flavor.dev,
-    values: FlavorValues(baseUrl: "https://demo_dev/web_api.json"),
+    values: FlavorValues(),
   );
   //Add your firebase configuration here
   /*await Firebase.initializeApp(

app/lib/main/env/main_qa.dart

@@ -6,7 +6,7 @@ void main() async {
   WidgetsFlutterBinding.ensureInitialized();
   FlavorConfig(
     flavor: Flavor.qa,
-    values: FlavorValues(baseUrl: "https://demo_qa/web_api.json"),
+    values: FlavorValues(),
   );
   //Add your firebase configuration here
   /*await Firebase.initializeApp(

app/lib/main/init.dart

@@ -5,9 +5,12 @@ import 'package:domain/init.dart';
 import 'package:example_domain/init.dart';
 import 'package:example_data/init.dart';
 import 'package:flutter/material.dart';
+import 'package:flutter_dotenv/flutter_dotenv.dart';
 import 'package:get_it/get_it.dart';
 import 'package:url_strategy/url_strategy.dart';
 
+import 'env/env_config.dart';
+
 void init() async {
   WidgetsFlutterBinding.ensureInitialized();
   await initialize();
@@ -18,11 +21,12 @@ void init() async {
 final getIt = GetIt.instance;
 
 Future<void> initialize() async {
+  await dotenv.load(fileName: FlavorConfig.getEnvFilePath());
   await CommonInit.initialize(getIt);
   await DataInit.initialize(getIt);
   await DomainInit.initialize(getIt);
 
   // Example Module init
-  await ExampleDomainInit.initialize(getIt);
   await ExampleDataInit.initialize(getIt);
+  await ExampleDomainInit.initialize(getIt);
 }

app/lib/presentation/ui/custom/environment_selector.dart

@@ -0,0 +1,50 @@
+import 'package:app/presentation/resources/resources.dart';
+import 'package:app/presentation/themes/local_theme.dart';
+import 'package:domain/env/env_config.dart';
+import 'package:domain/services/environment_service.dart';
+import 'package:flutter/material.dart';
+
+import '../../../main/init.dart';
+
+class EnvironmentSelector extends StatelessWidget {
+  EnvironmentSelector({
+    super.key,
+  });
+
+  final EnvironmentService environmentService = getIt<EnvironmentService>();
+
+  DropdownMenuItem<String> _item(
+          String value, String label, TextStyle textStyle) =>
+      DropdownMenuItem<String>(
+        value: value,
+        child: Padding(
+          padding: EdgeInsets.symmetric(horizontal: spacing.xs),
+          child: Text(label, style: textStyle),
+        ),
+      );
+
+  @override
+  Widget build(BuildContext context) {
+    final textStyle =
+        Theme.of(context).textTheme.bodyLarge?.copyWith(color: Theme.of(context).colorScheme.primary.v0);
+
+    final items = <DropdownMenuItem<String>>[
+      _item(EnvConfig.kDevEnv, 'Development', textStyle!),
+      _item(EnvConfig.kQaEnv, 'QA', textStyle),
+      _item(EnvConfig.kProdEnv, 'Production', textStyle),
+    ];
+
+    return DropdownButtonFormField<String>(
+      initialValue: EnvConfig.env,
+      style: textStyle,
+      decoration: InputDecoration(
+        labelText: 'Environment',
+        border: const OutlineInputBorder(),
+        prefixIcon: const Icon(Icons.settings),
+        labelStyle: textStyle,
+      ),
+      items: items,
+      onChanged: (value) => environmentService.setEnvironment(value!),
+    );
+  }
+}

app/lib/presentation/ui/pages/login/login_page.dart

@@ -1,13 +1,17 @@
 import 'package:app/main/init.dart';
+import 'package:app/presentation/resources/resources.dart';
 import 'package:app/presentation/themes/app_themes.dart';
+import 'package:app/presentation/ui/custom/app_theme_switch.dart';
+import 'package:app/presentation/ui/custom/loading_screen.dart';
 import 'package:common/core/resource.dart';
 import 'package:domain/bloc/auth/auth_cubit.dart';
 import 'package:domain/services/auth_service.dart';
+import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
-import 'package:app/presentation/ui/custom/app_theme_switch.dart';
-import 'package:app/presentation/ui/custom/loading_screen.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 
+import '../../custom/environment_selector.dart';
+
 class LoginPage extends StatelessWidget {
   AuthService get _authService => getIt();
 
@@ -21,12 +25,12 @@ class LoginPage extends StatelessWidget {
           appBar: AppBar(),
           backgroundColor: context.theme.colorScheme.surface,
           body: Padding(
-            padding: const EdgeInsets.all(16),
+            padding: EdgeInsets.all(spacing.m),
             child: Column(
               mainAxisAlignment: MainAxisAlignment.center,
               children: [
                 const AppThemeSwitch(),
-                const SizedBox(height: 16),
+                SizedBox(height: spacing.m),
                 SizedBox(
                   width: double.maxFinite,
                   child: ElevatedButton(
@@ -39,6 +43,10 @@ class LoginPage extends StatelessWidget {
                     },
                   ),
                 ),
+                SizedBox(height: spacing.xxxl),
+                if (kDebugMode) ...[
+                  EnvironmentSelector(),
+                ],
               ],
             ),
           ),