feature/#104 - support for the new "Image Refresh" API (#289)

Impacted files:
* `Product.dart`: added a dedicated field and its computing method
* `ProductFields.dart`: added a dedicated field belonging to the "in languages" category
* `api_getProduct_test.dart`: added a dedicated test

lib/model/Product.dart

@@ -179,6 +179,13 @@ class Product extends JsonObject {
       includeIfNull: false)
   Map<OpenFoodFactsLanguage, List<String>>? ingredientsTagsInLanguages;
 
+  /// Images Freshness in seconds
+  ///
+  /// 0 seconds means we don't have the picture at all.
+  /// Read-only
+  /// cf. https://github.com/openfoodfacts/openfoodfacts-dart/issues/104
+  Map<OpenFoodFactsLanguage, Map<ImageField, int>>? imagesFreshnessInLanguages;
+
   @JsonKey(
       name: 'ingredients_analysis_tags',
       includeIfNull: false,
@@ -412,6 +419,16 @@ class Product extends JsonObject {
           result.ingredientsTagsInLanguages ??= {};
           result.ingredientsTagsInLanguages![lang] = values;
         }
+      } else if (key
+          .startsWith(ProductField.IMAGES_FRESHNESS_IN_LANGUAGES.key)) {
+        final OpenFoodFactsLanguage lang =
+            _langFrom(key, ProductField.IMAGES_FRESHNESS_IN_LANGUAGES.key);
+        if (lang != OpenFoodFactsLanguage.UNDEFINED) {
+          final Map<ImageField, int> values =
+              _jsonValueToImagesFreshness(json[key], lang);
+          result.imagesFreshnessInLanguages ??= {};
+          result.imagesFreshnessInLanguages![lang] = values;
+        }
       } else if (key.startsWith(ProductField.LABELS_TAGS_IN_LANGUAGES.key)) {
         OpenFoodFactsLanguage lang =
             _langFrom(key, ProductField.LABELS_TAGS_IN_LANGUAGES.key);
@@ -449,6 +466,18 @@ class Product extends JsonObject {
     return (value as List?)?.map((e) => e as String).toList();
   }
 
+  static Map<ImageField, int> _jsonValueToImagesFreshness(
+      Map value, OpenFoodFactsLanguage language) {
+    final Map<ImageField, int> result = {};
+    for (final ImageField imageField in ImageField.values) {
+      final int? timestamp = value['${imageField.value}_${language.code}'];
+      if (timestamp != null) {
+        result[imageField] = timestamp;
+      }
+    }
+    return result;
+  }
+
   Map<String, String> toServerData() {
     final json = toJson();
     return JsonObject.toDataStatic(json);

lib/utils/ProductFields.dart

@@ -30,6 +30,7 @@ enum ProductField {
   INGREDIENTS,
   INGREDIENTS_TAGS,
   INGREDIENTS_TAGS_IN_LANGUAGES,
+  IMAGES_FRESHNESS_IN_LANGUAGES,
   NUTRIMENTS,
   ADDITIVES,
   NUTRIENT_LEVELS,
@@ -87,6 +88,7 @@ extension ProductFieldExtension on ProductField {
     ProductField.INGREDIENTS: 'ingredients',
     ProductField.INGREDIENTS_TAGS: 'ingredients_tags',
     ProductField.INGREDIENTS_TAGS_IN_LANGUAGES: 'ingredients_tags_',
+    ProductField.IMAGES_FRESHNESS_IN_LANGUAGES: 'images_to_update_',
     ProductField.NUTRIMENTS: 'nutriments',
     ProductField.ADDITIVES: 'additives_tags',
     ProductField.NUTRIENT_LEVELS: 'nutrient_levels',
@@ -130,6 +132,7 @@ List<String> convertFieldsToStrings(
     ProductField.COUNTRIES_TAGS_IN_LANGUAGES,
     ProductField.INGREDIENTS_TEXT_IN_LANGUAGES,
     ProductField.INGREDIENTS_TAGS_IN_LANGUAGES,
+    ProductField.IMAGES_FRESHNESS_IN_LANGUAGES,
   ];
 
   for (final field in fields) {

test/api_getProduct_test.dart

@@ -1560,4 +1560,33 @@ void main() {
     assert(invalidBarcodes.isBlacklisted('15600703'));
     assert(!invalidBarcodes.isBlacklisted(_BARCODE_DANISH_BUTTER_COOKIES));
   });
+
+  test('get images freshness', () async {
+    final List<OpenFoodFactsLanguage> languages = [
+      OpenFoodFactsLanguage.ENGLISH,
+      OpenFoodFactsLanguage.RUSSIAN,
+      OpenFoodFactsLanguage.GERMAN,
+      OpenFoodFactsLanguage.FRENCH,
+    ];
+    final ProductResult productResult = await OpenFoodAPIClient.getProduct(
+      ProductQueryConfiguration(
+        _BARCODE_DANISH_BUTTER_COOKIES,
+        languages: languages,
+        fields: [ProductField.IMAGES_FRESHNESS_IN_LANGUAGES],
+      ),
+    );
+    final Product product = productResult.product!;
+    const int TEN_YEARS = 10 * 365 * 24 * 3600;
+    for (final OpenFoodFactsLanguage language in languages) {
+      final Map<ImageField, int> freshnesses =
+          product.imagesFreshnessInLanguages![language]!;
+      for (final ImageField imageField in ImageField.values) {
+        final int? freshness = freshnesses[imageField];
+        if (freshness != null) {
+          expect(freshness >= 0, isTrue);
+          expect(freshness < TEN_YEARS, isTrue);
+        }
+      }
+    }
+  });
 }

test/api_saveProduct_test.dart

@@ -148,9 +148,8 @@ void main() {
       var frenchResult = await OpenFoodAPIClient.getProduct(
         frenchConfig,
       );
-      assert(frenchResult.product != null);
-      assert(frenchResult.product!.productName != null);
-      assert(frenchResult.product!.productName == frenchProductName);
+      expect(frenchResult.product, isNotNull);
+      expect(frenchResult.product!.productName, frenchProductName);
 
       // get german fields for product
       ProductQueryConfiguration germanConfig = ProductQueryConfiguration(
@@ -165,9 +164,8 @@ void main() {
         germanConfig,
       );
 
-      assert(germanResult.product != null);
-      assert(germanResult.product!.productName != null);
-      assert(germanResult.product!.productName == germanProductName);
+      expect(germanResult.product, isNotNull);
+      expect(germanResult.product!.productName, germanProductName);
 
       // get preferably French, then German fields for product
       ProductQueryConfiguration frenchGermanConfig =
@@ -183,9 +181,8 @@ void main() {
         frenchGermanConfig,
       );
 
-      assert(frenchGermanResult.product != null);
-      assert(frenchGermanResult.product!.productName != null);
-      assert(frenchGermanResult.product!.productName == frenchProductName);
+      expect(frenchGermanResult.product, isNotNull);
+      expect(frenchGermanResult.product!.productName, frenchProductName);
     });
 
     test('add new product test 2', () async {
@@ -421,7 +418,7 @@ void main() {
         ),
         product,
       );
-      assert(status.isWrongUsernameOrPassword());
+      expect(status.isWrongUsernameOrPassword(), isTrue);
     });
   });
 }