Compass App: Add "server" dart shelf-app and "shared" dart package (#2359)

This PR introduces two new subprojects:

- `compass_server` under `compass_app/server`.
- `compass_model` under `compass_app/model`.

**`compass_server`**

- Dart server implemented using `shelf`.
- Created with the `dart create -t server-shelf` template.
- Implements two REST endpoints:
  - `GET /continent`: Returns the list of `Continent` as JSON.
  - `GET /destination`: Returns the list of `Destination` as JSON.
- Generated Docker files have been removed.
- Implemented tests.
- TODO: Implement some basic auth.

**`compass_model`**

- Dart package to share data model classes between the `server` and
`app`.
- Contains the data model classes (`Continent`, `Destination`).
- Generated JSON from/To methods and data classes using `freezed`.
- The sole purpose of this package is to host the data model. Other
shared code should go in a different package.

**Other changes**

- Created an API Client to connect to the local dart server.
- Created "remote" repositories, which also implement a basic in-memory
caching strategy.
- Created two dependency configurations, one with local repositories and
one with remote repos.
- Created two application main targets to select configuration:
- `lib/main_development.dart` which starts the app with the "local" data
configuration.
- `lib/main_staging.dart` which starts the app with the "remove" (local
dart server) configuration.
  - `lib/main.dart` still works as default entry point.
- Implemented tests for remote repositories.

- [x] I read the [Flutter Style Guide] _recently_, and have followed its
advice.
- [x] I signed the [CLA].
- [x] I read the [Contributors Guide].
- [x] I updated/added relevant documentation (doc comments with `///`).
- [x] All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-devrel
channel on [Discord].

<!-- Links -->
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[CLA]: https://cla.developers.google.com/
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https://github.com/flutter/flutter/blob/master/docs/contributing/Chat.md
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WIP

implement activity repository local

wip activity repository

updates and iOS stuff

implement navigation logic to activities

implement tests

fixing navigation with query parameters

refactor search queries

cleanup and comments

cleanup

add ItineraryConfig, refactor SearchScreen to use it

fix tests

refactor with Commands

refactor commands

add progress indicator to commands

simplify command

command tests

cleanup

simplify activity repository

cleanup

cleanup

cleanup

fix comment

should be Command0

refactor assets, server, and add activities endpoint

fix assets refactor

wip activities screen

add error state to commands

Added comments

handle errors in Command

add comments

WIP error indicator

widget lifecycle

wip activities and error handling

Add random errors to repositories to simulate recovering from errors

implement activites

WIP tests

create test activities screen

finish Activities UI

Author: miquelbeltran

compass_app/app/lib/config/assets.dart

@@ -0,0 +1,4 @@
+class Assets {
+  static const activities = 'assets/activities.json';
+  static const destinations = 'assets/destinations.json';
+}

compass_app/app/lib/data/repositories/activity/activity_repository_local.dart

@@ -1,8 +1,11 @@
 import 'dart:convert';
+import 'dart:math';
 
 import 'package:compass_model/model.dart';
+import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 
+import '../../../config/assets.dart';
 import '../../../utils/result.dart';
 import 'activity_repository.dart';
 
@@ -11,6 +14,12 @@ import 'activity_repository.dart';
 class ActivityRepositoryLocal implements ActivityRepository {
   @override
   Future<Result<List<Activity>>> getByDestination(String ref) async {
+    // Simulate network loading and random errors
+    // await Future.delayed(Durations.long1);
+    // if (Random().nextBool()) {
+    //   return Result.error(Exception('Random error!'));
+    // }
+
     try {
       final localData = await _loadAsset();
       final list = _parse(localData);
@@ -25,7 +34,7 @@ class ActivityRepositoryLocal implements ActivityRepository {
   }
 
   Future<String> _loadAsset() async {
-    return await rootBundle.loadString('assets/activities.json');
+    return await rootBundle.loadString(Assets.activities);
   }
 
   List<Activity> _parse(String localData) {

compass_app/app/lib/data/repositories/continent/continent_repository_local.dart

@@ -1,12 +1,21 @@
+import 'dart:math';
+
 import 'package:compass_model/model.dart';
+import 'package:flutter/material.dart';
 
 import '../../../utils/result.dart';
 import 'continent_repository.dart';
 
 /// Local data source with all possible continents.
 class ContinentRepositoryLocal implements ContinentRepository {
   @override
-  Future<Result<List<Continent>>> getContinents() {
+  Future<Result<List<Continent>>> getContinents() async {
+    // Simulate network loading and random errors
+    // await Future.delayed(Durations.long1);
+    // if (Random().nextBool()) {
+    //   return Result.error(Exception('Random error!'));
+    // }
+
     return Future.value(
       Result.ok(
         [

compass_app/app/lib/data/repositories/destination/destination_repository_local.dart

@@ -1,8 +1,11 @@
 import 'dart:convert';
+import 'dart:math';
 
 import 'package:compass_model/model.dart';
+import 'package:flutter/material.dart';
 import 'package:flutter/services.dart' show rootBundle;
 
+import '../../../config/assets.dart';
 import '../../../utils/result.dart';
 import 'destination_repository.dart';
 
@@ -12,6 +15,12 @@ class DestinationRepositoryLocal implements DestinationRepository {
   /// Obtain list of destinations from local assets
   @override
   Future<Result<List<Destination>>> getDestinations() async {
+    // Simulate network loading and random errors
+    // await Future.delayed(Durations.long1);
+    // if (Random().nextBool()) {
+    //   return Result.error(Exception('Random error!'));
+    // }
+
     try {
       final localData = await _loadAsset();
       final list = _parse(localData);
@@ -22,7 +31,7 @@ class DestinationRepositoryLocal implements DestinationRepository {
   }
 
   Future<String> _loadAsset() async {
-    return await rootBundle.loadString('assets/destinations.json');
+    return await rootBundle.loadString(Assets.destinations);
   }
 
   List<Destination> _parse(String localData) {

compass_app/app/lib/data/repositories/itinerary_config/itinerary_config_repository_memory.dart

@@ -1,6 +1,7 @@
 import 'dart:async';
 
 import 'package:compass_model/model.dart';
+import 'package:flutter/material.dart';
 
 import '../../../utils/result.dart';
 import 'itinerary_config_repository.dart';

compass_app/app/lib/main.dart

@@ -1,3 +1,6 @@
+import 'package:flutter/services.dart';
+
+import 'config/assets.dart';
 import 'ui/core/themes/theme.dart';
 import 'routing/router.dart';
 import 'package:flutter/material.dart';
@@ -9,6 +12,13 @@ import 'main_development.dart' as development;
 void main() {
   // Launch development config by default
   development.main();
+  rootBundle.loadString('AssetManifest.json').then((assets) {
+    print(assets);
+  } );
+
+  rootBundle.loadString(Assets.destinations);
+  rootBundle.loadString(Assets.activities);
+
 }
 
 class MainApp extends StatelessWidget {

compass_app/app/lib/ui/activities/view_models/activities_viewmodel.dart

@@ -13,57 +13,76 @@ class ActivitiesViewModel extends ChangeNotifier {
   })  : _activityRepository = activityRepository,
         _itineraryConfigRepository = itineraryConfigRepository {
     loadActivities = Command0(_loadActivities)..execute();
+    saveActivities =
+        Command0(() async => Result.error(Exception('Not implemented')));
   }
 
   final ActivityRepository _activityRepository;
   final ItineraryConfigRepository _itineraryConfigRepository;
-  List<Activity> _activities = <Activity>[];
+  List<Activity> _daytimeActivities = <Activity>[];
+  List<Activity> _eveningActivities = <Activity>[];
   final Set<String> _selectedActivities = <String>{};
 
-  /// List of [Activity] per destination.
-  List<Activity> get activities => _activities;
+  /// List of daytime [Activity] per destination.
+  List<Activity> get daytimeActivities => _daytimeActivities;
+
+  /// List of evening [Activity] per destination.
+  List<Activity> get eveningActivities => _eveningActivities;
 
   /// Selected [Activity] by ref.
   Set<String> get selectedActivities => _selectedActivities;
 
   /// Load list of [Activity] for a [Destination] by ref.
   late final Command0 loadActivities;
 
-  Future<void> _loadActivities() async {
+  /// Save list [selectedActivities] into itinerary configuration.
+  late final Command0 saveActivities;
+
+  Future<Result<void>> _loadActivities() async {
     final result = await _itineraryConfigRepository.getItineraryConfig();
     if (result is Error) {
       // TODO: Handle error
       print(result.asError.error);
-      return;
+      return result;
     }
 
     final destinationRef = result.asOk.value.destination;
     if (destinationRef == null) {
-      // TODO: Error here
-      return;
+      return Result.error(Exception('Destination not found'));
     }
 
     final resultActivities =
         await _activityRepository.getByDestination(destinationRef);
     switch (resultActivities) {
       case Ok():
         {
-          _activities = resultActivities.value;
-          print(_activities);
+          _daytimeActivities = resultActivities.value
+              .where((activity) =>
+                  ['morning', 'afternoon'].contains(activity.timeOfDay))
+              .toList();
+
+          _eveningActivities = resultActivities.value
+              .where((activity) =>
+                  ['evening', 'night'].contains(activity.timeOfDay))
+              .toList();
+          // print(_activities);
         }
       case Error():
         {
           // TODO: Handle error
           print(resultActivities.error);
         }
     }
+
     notifyListeners();
+    return resultActivities;
   }
 
   /// Add [Activity] to selected list.
   void addActivity(String activityRef) {
     assert(
-      activities.any((activity) => activity.ref == activityRef),
+      (_daytimeActivities + _eveningActivities)
+          .any((activity) => activity.ref == activityRef),
       "Activity $activityRef not found",
     );
     _selectedActivities.add(activityRef);
@@ -73,7 +92,8 @@ class ActivitiesViewModel extends ChangeNotifier {
   /// Remove [Activity] from selected list.
   void removeActivity(String activityRef) {
     assert(
-      activities.any((activity) => activity.ref == activityRef),
+      (_daytimeActivities + _eveningActivities)
+          .any((activity) => activity.ref == activityRef),
       "Activity $activityRef not found",
     );
     _selectedActivities.remove(activityRef);

compass_app/app/lib/ui/activities/widgets/activities_header.dart

@@ -0,0 +1,40 @@
+import 'package:flutter/material.dart';
+import 'package:go_router/go_router.dart';
+
+import '../../core/ui/back_button.dart';
+import '../../core/ui/home_button.dart';
+
+class ActivitiesHeader extends StatelessWidget {
+  const ActivitiesHeader({super.key});
+
+  @override
+  Widget build(BuildContext context) {
+    return Padding(
+      padding: const EdgeInsets.only(
+        top: 24,
+        bottom: 24,
+        left: 20,
+        right: 20,
+      ),
+      child: Row(
+        mainAxisAlignment: MainAxisAlignment.spaceBetween,
+        children: [
+          CustomBackButton(
+            onTap: () {
+              // Navigate to ResultsScreen and edit search
+              context.go('/results');
+            },
+          ),
+          Text(
+            'Activities',
+            style: Theme
+                .of(context)
+                .textTheme
+                .titleLarge,
+          ),
+          const HomeButton(),
+        ],
+      ),
+    );
+  }
+}

compass_app/app/lib/ui/activities/widgets/activities_list.dart

@@ -0,0 +1,51 @@
+import 'package:flutter/material.dart';
+
+import '../view_models/activities_viewmodel.dart';
+import 'activity_entry.dart';
+import 'activity_time_of_day.dart';
+
+class ActivitiesList extends StatelessWidget {
+  const ActivitiesList({
+    super.key,
+    required this.viewModel,
+    required this.activityTimeOfDay,
+  });
+
+  final ActivitiesViewModel viewModel;
+  final ActivityTimeOfDay activityTimeOfDay;
+
+  @override
+  Widget build(BuildContext context) {
+    final list = switch (activityTimeOfDay) {
+      ActivityTimeOfDay.daytime => viewModel.daytimeActivities,
+      ActivityTimeOfDay.evening => viewModel.eveningActivities,
+    };
+    return SliverPadding(
+      padding: const EdgeInsets.all(20),
+      sliver: SliverList(
+        delegate: SliverChildBuilderDelegate(
+          (context, index) {
+            final activity = list[index];
+            return Padding(
+              padding:
+                  EdgeInsets.only(bottom: index < list.length - 1 ? 20 : 0),
+              child: ActivityEntry(
+                key: ValueKey(activity.ref),
+                activity: activity,
+                selected: viewModel.selectedActivities.contains(activity.ref),
+                onChanged: (value) {
+                  if (value!) {
+                    viewModel.addActivity(activity.ref);
+                  } else {
+                    viewModel.removeActivity(activity.ref);
+                  }
+                },
+              ),
+            );
+          },
+          childCount: list.length,
+        ),
+      ),
+    );
+  }
+}