feat: 4423 - specific "Not connected to internet" displayed error

Impacted files:
* `barcode_product_query.dart`: removed useless `try` as already `catch`'ed
* `continuous_scan_model.dart`: removed the `codeInvalid` case that could never happen
* `fetched_product.dart`: refactored with explicit constructors and additional exception and connectivity fields; removed the `codeInvalid` case that could never happen
* `new_product_page.dart`: minor refactoring
* `product_dialog_helper.dart`: removed the `codeInvalid` case that could never happen; minor refactoting
* `product_list_item_simple.dart`: removed the `codeInvalid` case that could never happen
* `product_loader_page.dart`: removed useless `try` as already `catch`'ed
* `product_refresher.dart`: added a specific "You're not connected to the internet" error message; refactored using more `FetchedProduct`; removed useless method
* `pubspec.lock`: wtf
* `pubspec.yaml`: added package `connectivity_plus`
* `question_card.dart`: refactored using `FetchedProduct`

packages/smooth_app/lib/data_models/continuous_scan_model.dart

@@ -224,9 +224,6 @@ class ContinuousScanModel with ChangeNotifier {
       case FetchedProductStatus.internetError:
         _setBarcodeState(barcode, ScannedProductState.ERROR_INTERNET);
         return;
-      case FetchedProductStatus.codeInvalid:
-        _setBarcodeState(barcode, ScannedProductState.ERROR_INVALID_CODE);
-        return;
       case FetchedProductStatus.userCancelled:
         // we do nothing
         return;
@@ -247,9 +244,6 @@ class ContinuousScanModel with ChangeNotifier {
       case FetchedProductStatus.internetError:
         _setBarcodeState(barcode, ScannedProductState.ERROR_INTERNET);
         return;
-      case FetchedProductStatus.codeInvalid:
-        _setBarcodeState(barcode, ScannedProductState.ERROR_INVALID_CODE);
-        return;
       case FetchedProductStatus.userCancelled:
         // we do nothing
         return;

packages/smooth_app/lib/data_models/fetched_product.dart

@@ -1,28 +1,54 @@
+import 'package:connectivity_plus/connectivity_plus.dart';
 import 'package:openfoodfacts/openfoodfacts.dart';
 
 /// Status of a "fetch [Product]" operation
 enum FetchedProductStatus {
+  // found locally or from internet
   ok,
   internetNotFound,
   internetError,
   userCancelled,
-  codeInvalid,
   // TODO(monsieurtanuki): time-out
 }
 
 /// A [Product] that we tried to fetch, but was it successful?..
 class FetchedProduct {
+  const FetchedProduct._({
+    required this.status,
+    this.product,
+    this.connectivityResult,
+    this.exceptionString,
+  });
+
   // The reason behind the "ignore": I want to force "product" to be not null
-  FetchedProduct(final Product product)
+  const FetchedProduct.found(final Product product)
       // ignore: prefer_initializing_formals
-      : product = product,
-        status = FetchedProductStatus.ok;
+      : this._(
+          status: FetchedProductStatus.ok,
+          product: product,
+        );
+
+  /// The internet Product search said it couldn't find the product.
+  const FetchedProduct.internetNotFound()
+      : this._(status: FetchedProductStatus.internetNotFound);
+
+  /// The user cancelled the operation.
+  const FetchedProduct.userCancelled()
+      : this._(status: FetchedProductStatus.userCancelled);
 
-  /// When the "fetch product" operation didn't go well (no status "ok" here)
-  FetchedProduct.error(this.status)
-      : product = null,
-        assert(status != FetchedProductStatus.ok);
+  /// When the "fetch product" operation had an internet error.
+  const FetchedProduct.error({
+    required final String exceptionString,
+    required final ConnectivityResult connectivityResult,
+  }) : this._(
+          status: FetchedProductStatus.internetError,
+          connectivityResult: connectivityResult,
+          exceptionString: exceptionString,
+        );
 
   final Product? product;
   final FetchedProductStatus status;
+  final ConnectivityResult? connectivityResult;
+  final String? exceptionString;
+  // TODO(monsieurtanuki): add a "ping" action in order to check if the server is alive?
 }

packages/smooth_app/lib/pages/hunger_games/question_card.dart

@@ -3,6 +3,7 @@ import 'package:openfoodfacts/openfoodfacts.dart';
 import 'package:provider/provider.dart';
 import 'package:shimmer/shimmer.dart';
 import 'package:smooth_app/cards/product_cards/product_title_card.dart';
+import 'package:smooth_app/data_models/fetched_product.dart';
 import 'package:smooth_app/database/dao_product.dart';
 import 'package:smooth_app/database/local_database.dart';
 import 'package:smooth_app/generic_lib/design_constants.dart';
@@ -24,22 +25,22 @@ class QuestionCard extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    final Future<Product?> productFuture = _getProduct(
+    final Future<FetchedProduct> productFuture = _getProduct(
       question.barcode!,
       context.read<LocalDatabase>(),
     );
 
     final Size screenSize = MediaQuery.of(context).size;
 
-    return FutureBuilder<Product?>(
+    return FutureBuilder<FetchedProduct>(
       future: productFuture,
       builder: (
         BuildContext context,
-        AsyncSnapshot<Product?> snapshot,
+        AsyncSnapshot<FetchedProduct> snapshot,
       ) {
         Product? product;
         if (snapshot.connectionState == ConnectionState.done) {
-          product = snapshot.data;
+          product = snapshot.data?.product;
           // TODO(monsieurtanuki): do something aggressive if product is null here and we don't have a fallback value - like an error widget
         }
         // fallback version
@@ -131,13 +132,13 @@ class QuestionCard extends StatelessWidget {
     );
   }
 
-  Future<Product?> _getProduct(
+  Future<FetchedProduct> _getProduct(
     final String barcode,
     final LocalDatabase localDatabase,
   ) async {
     final Product? result = await DaoProduct(localDatabase).get(barcode);
     if (result != null) {
-      return result;
+      return FetchedProduct.found(result);
     }
     return ProductRefresher().silentFetchAndRefresh(
       barcode: question.barcode!,

packages/smooth_app/lib/pages/product/common/product_dialog_helper.dart

@@ -38,7 +38,7 @@ class ProductDialogHelper {
   Future<FetchedProduct> openBestChoice() async {
     final Product? product = await DaoProduct(localDatabase).get(barcode);
     if (product != null) {
-      return FetchedProduct(product);
+      return FetchedProduct.found(product);
     }
     return openUniqueProductSearch();
   }
@@ -52,7 +52,7 @@ class ProductDialogHelper {
             isScanned: false,
           ).getFetchedProduct(),
           title: '${AppLocalizations.of(context).looking_for}: $barcode') ??
-      FetchedProduct.error(FetchedProductStatus.userCancelled);
+      const FetchedProduct.userCancelled();
 
   void _openProductNotFoundDialog() => showDialog<Widget>(
       context: context,
@@ -175,9 +175,6 @@ class ProductDialogHelper {
       case FetchedProductStatus.internetNotFound:
         _openProductNotFoundDialog();
         return;
-      case FetchedProductStatus.codeInvalid:
-        _openErrorMessage(appLocalizations.barcode_invalid_error);
-        return;
     }
   }
 }

packages/smooth_app/lib/pages/product/common/product_list_item_simple.dart

@@ -100,8 +100,6 @@ class _ProductListItemSimpleState extends State<ProductListItemSimple> {
     switch (_model.downloadingStatus) {
       case null:
         break;
-      case FetchedProductStatus.codeInvalid:
-        return appLocalizations.barcode_invalid_error;
       case FetchedProductStatus.internetNotFound:
         return appLocalizations.product_internet_error;
       default:

packages/smooth_app/lib/pages/product/common/product_refresher.dart

@@ -1,8 +1,10 @@
+import 'package:connectivity_plus/connectivity_plus.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 import 'package:flutter_svg/svg.dart';
 import 'package:openfoodfacts/openfoodfacts.dart';
 import 'package:provider/provider.dart';
+import 'package:smooth_app/data_models/fetched_product.dart';
 import 'package:smooth_app/database/dao_product.dart';
 import 'package:smooth_app/database/local_database.dart';
 import 'package:smooth_app/generic_lib/dialogs/smooth_alert_dialog.dart';
@@ -93,14 +95,11 @@ class ProductRefresher {
   /// Fetches the product from the server and refreshes the local database.
   ///
   /// Silent version.
-  Future<Product?> silentFetchAndRefresh({
+  Future<FetchedProduct> silentFetchAndRefresh({
     required final String barcode,
     required final LocalDatabase localDatabase,
-  }) async {
-    final _MetaProductRefresher meta =
-        await _fetchAndRefresh(localDatabase, barcode);
-    return meta.product;
-  }
+  }) async =>
+      _fetchAndRefresh(localDatabase, barcode);
 
   /// Fetches the products from the server and refreshes the local database.
   ///
@@ -111,23 +110,6 @@ class ProductRefresher {
   }) async =>
       _fetchAndRefreshList(localDatabase, barcodes);
 
-  /// Fetches the product from the server and refreshes the local database.
-  /// In the case of an error, it will be send throw an [Exception]
-  /// Silent version.
-  Future<Product?> silentFetchAndRefreshWithException({
-    required final String barcode,
-    required final LocalDatabase localDatabase,
-  }) async {
-    final _MetaProductRefresher meta =
-        await _fetchAndRefresh(localDatabase, barcode);
-
-    if (meta.error != null) {
-      throw Exception(meta.error);
-    }
-
-    return meta.product;
-  }
-
   /// Fetches the product from the server and refreshes the local database.
   ///
   /// With a waiting dialog.
@@ -139,18 +121,40 @@ class ProductRefresher {
     final LocalDatabase localDatabase = widget.context.read<LocalDatabase>();
     final AppLocalizations appLocalizations =
         AppLocalizations.of(widget.context);
-    final _MetaProductRefresher? fetchAndRefreshed =
-        await LoadingDialog.run<_MetaProductRefresher>(
+    final FetchedProduct? fetchAndRefreshed =
+        await LoadingDialog.run<FetchedProduct>(
       future: _fetchAndRefresh(localDatabase, barcode),
       context: widget.context,
       title: appLocalizations.refreshing_product,
     );
     if (fetchAndRefreshed == null) {
+      // the user probably cancelled
       return false;
     }
     if (fetchAndRefreshed.product == null) {
       if (widget.mounted) {
-        await LoadingDialog.error(context: widget.context);
+        String getTitle(final FetchedProduct fetchedProduct) {
+          switch (fetchAndRefreshed.status) {
+            // TODO(monsieurtanuki): refine and localize
+            case FetchedProductStatus.ok:
+              return 'Not supposed to happen...';
+            case FetchedProductStatus.userCancelled:
+              return 'Not supposed to happen either...';
+            case FetchedProductStatus.internetNotFound:
+              return 'Product not found';
+            case FetchedProductStatus.internetError:
+              if (fetchAndRefreshed.connectivityResult ==
+                  ConnectivityResult.none) {
+                return 'You are not connected to the internet!';
+              }
+              return 'Server error (${fetchAndRefreshed.exceptionString})';
+          }
+        }
+
+        await LoadingDialog.error(
+          context: widget.context,
+          title: getTitle(fetchAndRefreshed),
+        );
       }
       return false;
     }
@@ -165,7 +169,7 @@ class ProductRefresher {
     return true;
   }
 
-  Future<_MetaProductRefresher> _fetchAndRefresh(
+  Future<FetchedProduct> _fetchAndRefresh(
     final LocalDatabase localDatabase,
     final String barcode,
   ) async {
@@ -177,12 +181,17 @@ class ProductRefresher {
         await DaoProduct(localDatabase).put(result.product!);
         localDatabase.upToDate.setLatestDownloadedProduct(result.product!);
         localDatabase.notifyListeners();
-        return _MetaProductRefresher.product(result.product);
+        return FetchedProduct.found(result.product!);
       }
-      return const _MetaProductRefresher.error(null);
+      return const FetchedProduct.internetNotFound();
     } catch (e) {
       Logs.e('Refresh from server error', ex: e);
-      return _MetaProductRefresher.error(e.toString());
+      final ConnectivityResult connectivityResult =
+          await Connectivity().checkConnectivity();
+      return FetchedProduct.error(
+        exceptionString: e.toString(),
+        connectivityResult: connectivityResult,
+      );
     }
   }
 
@@ -212,12 +221,3 @@ class ProductRefresher {
     }
   }
 }
-
-class _MetaProductRefresher {
-  const _MetaProductRefresher.error(this.error) : product = null;
-
-  const _MetaProductRefresher.product(this.product) : error = null;
-
-  final String? error;
-  final Product? product;
-}

packages/smooth_app/lib/pages/product/new_product_page.dart

@@ -173,7 +173,7 @@ class _ProductPageState extends State<ProductPage>
     final LocalDatabase localDatabase = context.read<LocalDatabase>();
     final DaoProductList daoProductList = DaoProductList(localDatabase);
     return RefreshIndicator(
-      onRefresh: () => ProductRefresher().fetchAndRefresh(
+      onRefresh: () async => ProductRefresher().fetchAndRefresh(
         barcode: barcode,
         widget: this,
       ),
@@ -266,7 +266,7 @@ class _ProductPageState extends State<ProductPage>
       context,
       <String>{widget.product.barcode!},
     );
-    if (refreshed != null && refreshed) {
+    if (refreshed == true) {
       setState(() {});
     }
   }

packages/smooth_app/lib/pages/product/product_loader_page.dart

@@ -3,6 +3,7 @@ import 'package:flutter_gen/gen_l10n/app_localizations.dart';
 import 'package:flutter_svg/svg.dart';
 import 'package:openfoodfacts/openfoodfacts.dart';
 import 'package:provider/provider.dart';
+import 'package:smooth_app/data_models/fetched_product.dart';
 import 'package:smooth_app/database/local_database.dart';
 import 'package:smooth_app/generic_lib/buttons/smooth_large_button_with_icon.dart';
 import 'package:smooth_app/generic_lib/design_constants.dart';
@@ -42,28 +43,31 @@ class _ProductLoaderPageState extends State<ProductLoaderPage> {
       _state = _ProductLoaderState.loading;
     });
 
-    try {
-      final Product? product =
-          await ProductRefresher().silentFetchAndRefreshWithException(
-        barcode: widget.barcode,
-        localDatabase: context.read<LocalDatabase>(),
-      );
+    final FetchedProduct fetchedProduct =
+        await ProductRefresher().silentFetchAndRefresh(
+      barcode: widget.barcode,
+      localDatabase: context.read<LocalDatabase>(),
+    );
 
-      if (product != null && mounted) {
+    if (mounted) {
+      if (fetchedProduct.product != null) {
         navigator.pushReplacement(
           AppRoutes.PRODUCT(
             widget.barcode,
             heroTag: 'product_${widget.barcode}',
           ),
-          extra: product,
+          extra: fetchedProduct.product,
         );
-      } else {
+        return;
+      }
+      if (fetchedProduct.status == FetchedProductStatus.internetNotFound) {
         setState(() {
           _state = _ProductLoaderState.productNotFound;
         });
+        return;
       }
-    } catch (err) {
       setState(() {
+        // TODO(monsieurtanuki): put more details from FetchedProduct?
         _state = _ProductLoaderState.serverError;
       });
     }