feature/openfoodfacts#191 - added and computed possible product impro…

…vements

Impacted files:
* `api_getProduct_test.dart`: added checks for `getProductImprovements`
* `Product.dart`: create `enum ProductImprovement` and `Product.getProductImprovements()`

lib/model/Product.dart

@@ -17,6 +17,24 @@ import 'Nutriments.dart';
 
 part 'Product.g.dart';
 
+/// Possible improvements on a [Product] given its current data
+enum ProductImprovement {
+  /// * Possible message:
+  /// “The Eco-Score takes into account environmental labels. Please take them
+  /// into photo or edit the product so that they can be taken into account.”
+  /// * Asking your users for a photo should be enough.
+  /// * You can otherwise add toggles for explicit labels (please add a photo
+  /// of them to avoid mistakes)
+  LABELS_TO_BE_COMPLETED,
+
+  /// Possible message:
+  /// “The Eco-Score takes into account the origins of the ingredients.
+  /// Please take them into a photo (ingredient list and/or any geographic claim
+  /// or edit the product so that they can be taken into account. If it is not
+  /// clear, you can contact the food producer.”
+  ORIGINS_TO_BE_COMPLETED,
+}
+
 /// This class contains most of the data about a specific product.
 ///
 /// Please read the language mechanics explanation if you intend to display
@@ -461,4 +479,23 @@ class Product extends JsonObject {
     }
     return result;
   }
+
+  /// Returns all the potential improvements given the quality of the data
+  ///
+  /// For apps with contribution mode.
+  /// A typical use-case is to alert the end-users that they can improve
+  /// the quality of the OFF data by taking pictures (or something like that),
+  /// when displaying a [Product].
+  Set<ProductImprovement> getProductImprovements() {
+    final Set<ProductImprovement> result = {};
+    if (statesTags != null) {
+      if (statesTags!.contains('en:labels-to-be-completed')) {
+        result.add(ProductImprovement.LABELS_TO_BE_COMPLETED);
+      }
+      if (statesTags!.contains('en:origins-to-be-completed')) {
+        result.add(ProductImprovement.ORIGINS_TO_BE_COMPLETED);
+      }
+    }
+    return result;
+  }
 }

test/api_getProduct_test.dart

@@ -662,6 +662,13 @@ void main() {
 
       group = result.product!.attributeGroups!
           .singleWhere((element) => element.id == 'labels');
+
+      final Set<ProductImprovement> improvements =
+          result.product!.getProductImprovements();
+      expect(improvements.contains(ProductImprovement.LABELS_TO_BE_COMPLETED),
+          false);
+      expect(improvements.contains(ProductImprovement.ORIGINS_TO_BE_COMPLETED),
+          false);
     });
 
     test('get product without setting OpenFoodFactsLanguage or ProductField; ',
@@ -818,6 +825,13 @@ void main() {
                   image.language == OpenFoodFactsLanguage.GERMAN)
               .url,
           'https://static.openfoodfacts.net/images/products/500/011/254/8167/ingredients_de.7.400.jpg');
+
+      final Set<ProductImprovement> improvements =
+          result.product!.getProductImprovements();
+      expect(improvements.contains(ProductImprovement.LABELS_TO_BE_COMPLETED),
+          false);
+      expect(improvements.contains(ProductImprovement.ORIGINS_TO_BE_COMPLETED),
+          true);
     });
 
     test(