Refactor favorite status to type-safe enum and fix DateTime comparison

lib/domain/repositories/api_drink_repository.dart

@@ -80,7 +80,7 @@ class ApiDrinkRepository implements DrinkRepository {
   @override
   Future<String?> getFavoriteStatus(String festivalId, String drinkId) {
     final item = _favoritesService.getFavoriteItem(festivalId, drinkId);
-    return Future.value(item?.status);
+    return Future.value(item?.status.value);
   }
 
   @override

lib/models/favorite_item.dart

@@ -1,3 +1,25 @@
+/// Status values for favorite items in the festival log.
+enum FavoriteStatus {
+  /// Drink is on the 'want to try' list.
+  wantToTry('want_to_try'),
+
+  /// Drink has been tasted at least once.
+  tasted('tasted');
+
+  const FavoriteStatus(this.value);
+
+  /// The string value used for JSON serialization.
+  final String value;
+
+  /// Creates a FavoriteStatus from a string value.
+  static FavoriteStatus fromString(String value) {
+    return values.firstWhere(
+      (status) => status.value == value,
+      orElse: () => FavoriteStatus.wantToTry,
+    );
+  }
+}
+
 /// Represents a drink in the user's festival log.
 ///
 /// Tracks whether a drink is on the 'want to try' list or has been tasted,
@@ -16,8 +38,8 @@ class FavoriteItem {
   /// Drink ID.
   final String id;
 
-  /// Status: 'want_to_try' or 'tasted'.
-  final String status;
+  /// Current status of this drink in the festival log.
+  final FavoriteStatus status;
 
   /// List of tasting timestamps (empty if want_to_try).
   final List<DateTime> tries;
@@ -35,7 +57,9 @@ class FavoriteItem {
   factory FavoriteItem.fromJson(Map<String, dynamic> json) {
     return FavoriteItem(
       id: json['id'] as String,
-      status: json['status'] as String? ?? 'want_to_try',
+      status: FavoriteStatus.fromString(
+        json['status'] as String? ?? 'want_to_try',
+      ),
       tries: (json['tries'] as List?)
               ?.map((e) => DateTime.parse(e as String))
               .toList() ??
@@ -50,7 +74,7 @@ class FavoriteItem {
   Map<String, dynamic> toJson() {
     return {
       'id': id,
-      'status': status,
+      'status': status.value,
       'tries': tries.map((t) => t.toIso8601String()).toList(),
       if (notes != null) 'notes': notes,
       'createdAt': createdAt.toIso8601String(),
@@ -61,10 +85,10 @@ class FavoriteItem {
   /// Creates a copy with updated fields.
   ///
   /// To explicitly clear notes, pass an empty Optional: `notes: Optional.value(null)`.
-  /// To keep existing notes, omit the parameter: `copyWith(status: 'tasted')`.
+  /// To keep existing notes, omit the parameter: `copyWith(status: FavoriteStatus.tasted)`.
   FavoriteItem copyWith({
     String? id,
-    String? status,
+    FavoriteStatus? status,
     List<DateTime>? tries,
     Optional<String?>? notes,
     DateTime? createdAt,
@@ -80,6 +104,13 @@ class FavoriteItem {
     );
   }
 
+  /// Equality comparison based on drink ID only.
+  ///
+  /// Two FavoriteItems are considered equal if they have the same id,
+  /// regardless of status, tries, notes, or timestamps. This design
+  /// allows FavoriteItem to be used in Sets and as Map keys where
+  /// uniqueness is determined by the drink being tracked, not its
+  /// specific state.
   @override
   bool operator ==(Object other) =>
       identical(this, other) ||
@@ -92,6 +123,23 @@ class FavoriteItem {
 }
 
 /// Wrapper class for explicitly passing null values in copyWith methods.
+///
+/// Used to distinguish between omitting a parameter (keep existing value)
+/// and explicitly passing null (clear the value). This is particularly
+/// useful for optional fields like notes where both "no change" and
+/// "set to null" are valid operations.
+///
+/// Example usage:
+/// ```dart
+/// // Keep existing notes
+/// item.copyWith(status: FavoriteStatus.tasted);
+///
+/// // Clear notes (set to null)
+/// item.copyWith(notes: Optional.value(null));
+///
+/// // Set new notes value
+/// item.copyWith(notes: Optional.value('Great beer!'));
+/// ```
 class Optional<T> {
   const Optional.value(this.value);
 

lib/services/storage_service.dart

@@ -51,7 +51,7 @@ class FavoritesService {
 
     favorites[drinkId] = FavoriteItem(
       id: drinkId,
-      status: 'want_to_try',
+      status: FavoriteStatus.wantToTry,
       tries: [],
       createdAt: now,
       updatedAt: now,
@@ -78,7 +78,7 @@ class FavoritesService {
       final now = DateTime.now();
       favorites[drinkId] = FavoriteItem(
         id: drinkId,
-        status: 'want_to_try',
+        status: FavoriteStatus.wantToTry,
         tries: [],
         createdAt: now,
         updatedAt: now,
@@ -109,15 +109,15 @@ class FavoritesService {
       // Not in log yet, add as tasted
       favorites[drinkId] = FavoriteItem(
         id: drinkId,
-        status: 'tasted',
+        status: FavoriteStatus.tasted,
         tries: [now],
         createdAt: now,
         updatedAt: now,
       );
     } else {
       // Already in log, add timestamp and update status
       favorites[drinkId] = existing.copyWith(
-        status: 'tasted',
+        status: FavoriteStatus.tasted,
         tries: [...existing.tries, now],
         updatedAt: now,
       );
@@ -136,12 +136,14 @@ class FavoritesService {
     final existing = favorites[drinkId];
     if (existing == null) return;
 
-    final updatedTries = existing.tries.where((t) => t != timestamp).toList();
+    final updatedTries = existing.tries
+        .where((t) => t.millisecondsSinceEpoch != timestamp.millisecondsSinceEpoch)
+        .toList();
 
     if (updatedTries.isEmpty) {
       // No more tries, revert to 'want to try'
       favorites[drinkId] = existing.copyWith(
-        status: 'want_to_try',
+        status: FavoriteStatus.wantToTry,
         tries: [],
         updatedAt: DateTime.now(),
       );

test/models_test.dart

@@ -1164,15 +1164,15 @@ void main() {
     test('creates favorite item with all fields', () {
       final item = FavoriteItem(
         id: 'drink-123',
-        status: 'want_to_try',
+        status: FavoriteStatus.wantToTry,
         tries: [],
         notes: 'Looks interesting',
         createdAt: now,
         updatedAt: now,
       );
 
       expect(item.id, 'drink-123');
-      expect(item.status, 'want_to_try');
+      expect(item.status, FavoriteStatus.wantToTry);
       expect(item.tries, isEmpty);
       expect(item.notes, 'Looks interesting');
       expect(item.createdAt, now);
@@ -1182,13 +1182,13 @@ void main() {
     test('creates tasted item with tries', () {
       final item = FavoriteItem(
         id: 'drink-456',
-        status: 'tasted',
+        status: FavoriteStatus.tasted,
         tries: [now, later],
         createdAt: now,
         updatedAt: later,
       );
 
-      expect(item.status, 'tasted');
+      expect(item.status, FavoriteStatus.tasted);
       expect(item.tries.length, 2);
       expect(item.tries, contains(now));
       expect(item.tries, contains(later));
@@ -1211,7 +1211,7 @@ void main() {
         final item = FavoriteItem.fromJson(json);
 
         expect(item.id, 'drink-789');
-        expect(item.status, 'tasted');
+        expect(item.status, FavoriteStatus.tasted);
         expect(item.tries.length, 2);
         expect(item.notes, 'Excellent beer');
       });
@@ -1226,7 +1226,7 @@ void main() {
         final item = FavoriteItem.fromJson(json);
 
         expect(item.id, 'drink-minimal');
-        expect(item.status, 'want_to_try'); // Default status
+        expect(item.status, FavoriteStatus.wantToTry); // Default status
         expect(item.tries, isEmpty);
         expect(item.notes, isNull);
       });
@@ -1250,7 +1250,7 @@ void main() {
       test('converts to JSON correctly', () {
         final item = FavoriteItem(
           id: 'drink-abc',
-          status: 'tasted',
+          status: FavoriteStatus.tasted,
           tries: [now],
           notes: 'Great!',
           createdAt: now,
@@ -1271,7 +1271,7 @@ void main() {
       test('excludes null notes from JSON', () {
         final item = FavoriteItem(
           id: 'drink-no-notes',
-          status: 'want_to_try',
+          status: FavoriteStatus.wantToTry,
           tries: [],
           createdAt: now,
           updatedAt: now,
@@ -1285,7 +1285,7 @@ void main() {
       test('roundtrip through JSON maintains data', () {
         final original = FavoriteItem(
           id: 'drink-roundtrip',
-          status: 'tasted',
+          status: FavoriteStatus.tasted,
           tries: [now, later],
           notes: 'Test notes',
           createdAt: now,
@@ -1311,20 +1311,20 @@ void main() {
       test('creates copy with updated fields', () {
         final original = FavoriteItem(
           id: 'drink-copy',
-          status: 'want_to_try',
+          status: FavoriteStatus.wantToTry,
           tries: [],
           createdAt: now,
           updatedAt: now,
         );
 
         final updated = original.copyWith(
-          status: 'tasted',
+          status: FavoriteStatus.tasted,
           tries: [later],
           updatedAt: later,
         );
 
         expect(updated.id, original.id); // Unchanged
-        expect(updated.status, 'tasted'); // Changed
+        expect(updated.status, FavoriteStatus.tasted); // Changed
         expect(updated.tries, [later]); // Changed
         expect(updated.createdAt, original.createdAt); // Unchanged
         expect(updated.updatedAt, later); // Changed
@@ -1333,7 +1333,7 @@ void main() {
       test('preserves unchanged fields', () {
         final original = FavoriteItem(
           id: 'drink-preserve',
-          status: 'tasted',
+          status: FavoriteStatus.tasted,
           tries: [now],
           notes: 'Original notes',
           createdAt: now,
@@ -1355,15 +1355,15 @@ void main() {
       test('equal items have same id', () {
         final item1 = FavoriteItem(
           id: 'drink-eq',
-          status: 'want_to_try',
+          status: FavoriteStatus.wantToTry,
           tries: [],
           createdAt: now,
           updatedAt: now,
         );
 
         final item2 = FavoriteItem(
           id: 'drink-eq',
-          status: 'tasted',
+          status: FavoriteStatus.tasted,
           tries: [later],
           createdAt: later,
           updatedAt: later,
@@ -1376,15 +1376,15 @@ void main() {
       test('different items have different ids', () {
         final item1 = FavoriteItem(
           id: 'drink-1',
-          status: 'want_to_try',
+          status: FavoriteStatus.wantToTry,
           tries: [],
           createdAt: now,
           updatedAt: now,
         );
 
         final item2 = FavoriteItem(
           id: 'drink-2',
-          status: 'want_to_try',
+          status: FavoriteStatus.wantToTry,
           tries: [],
           createdAt: now,
           updatedAt: now,