feat: define ScoreRating (#134)

packages/trashy_road/lib/src/maps/bloc/game_maps_state.dart

@@ -6,6 +6,21 @@ part of 'game_maps_bloc.dart';
 /// [GameMap] itself.
 typedef GameMapsCollection = UnmodifiableMapView<String, GameMap>;
 
+/// {@template RatingSteps}
+/// The steps that dictate the rating of the map score.
+///
+/// It expects three integers, where the first index is the minimum score
+/// (inclusive) required to achieve a bronze rating, the second index is the
+/// minimum score (inclusive) required to achieve a silver rating, and the third
+/// index is the minimum score (inclusive) required to achieve a gold rating.
+///
+/// For example, if the player completes the map in 75 steps, and the score
+/// steps are [100, 50, 25], then the player will achieve a bronze score.
+/// Whereas if the player completes the map in 25 steps, then the player will
+/// achieve a gold score.
+/// {@endtemplate}
+typedef RatingSteps = (int, int, int);
+
 class GameMapsState extends Equatable {
   GameMapsState({
     required Map<String, GameMap> maps,
@@ -18,12 +33,14 @@ class GameMapsState extends Equatable {
               identifier: 'map1',
               path: Assets.tiles.map1,
               score: 0,
+              ratingSteps: (100, 50, 25),
               locked: false,
             ),
             'map2': GameMap._(
               identifier: 'map2',
               path: Assets.tiles.map2,
               score: 0,
+              ratingSteps: (100, 50, 25),
               locked: true,
             ),
           },
@@ -55,6 +72,38 @@ class GameMapsState extends Equatable {
   List<Object> get props => [maps];
 }
 
+/// {@template ScoreRating}
+/// The rating of a score.
+///
+/// See also:
+///
+/// * [RatingSteps] for the steps that dictate the rating of the map score.
+/// {@endtemplate}
+enum ScoreRating {
+  none._(value: 0),
+  bronze._(value: 1),
+  silver._(value: 2),
+  gold._(value: 3);
+
+  const ScoreRating._({required this.value});
+
+  /// Creates a [ScoreRating] from the given [RatingSteps] and [score].
+  factory ScoreRating.fromSteps({
+    required int score,
+    required RatingSteps steps,
+  }) {
+    if (score >= steps.$3) return gold;
+    if (score >= steps.$2) return silver;
+    if (score >= steps.$1) return bronze;
+    return none;
+  }
+
+  /// The value of the score.
+  ///
+  /// The higher the value, the better the rating.
+  final int value;
+}
+
 /// {@template GameMapMetadata}
 /// Stores the metadata of a map game.
 ///
@@ -63,12 +112,16 @@ class GameMapsState extends Equatable {
 /// provided by the `PreloadCubit`.
 /// {@endtemplate}
 class GameMap extends Equatable {
-  const GameMap._({
+  GameMap._({
     required this.identifier,
     required this.score,
+    required this.ratingSteps,
     required this.locked,
     required this.path,
-  });
+  }) : scoreRating = ScoreRating.fromSteps(
+          score: score,
+          steps: ratingSteps,
+        );
 
   /// The identifier of the map.
   final String identifier;
@@ -78,6 +131,12 @@ class GameMap extends Equatable {
   /// A score of 0 means the map has not been played yet.
   final int score;
 
+  /// {@macro RatingSteps}
+  final RatingSteps ratingSteps;
+
+  /// {@macro ScoreRating}
+  final ScoreRating scoreRating;
+
   /// Whether the map is locked and cannot be played.
   ///
   /// A locked map is usually a map that is not yet available to the player.
@@ -89,17 +148,26 @@ class GameMap extends Equatable {
   GameMap copyWith({
     String? identifier,
     int? score,
+    RatingSteps? ratingSteps,
     bool? locked,
     String? path,
   }) {
     return GameMap._(
       identifier: identifier ?? this.identifier,
       score: score ?? this.score,
+      ratingSteps: ratingSteps ?? this.ratingSteps,
       locked: locked ?? this.locked,
       path: path ?? this.path,
     );
   }
 
   @override
-  List<Object?> get props => [identifier, score, locked, path];
+  List<Object?> get props => [
+        identifier,
+        score,
+        ratingSteps,
+        scoreRating,
+        locked,
+        path,
+      ];
 }

packages/trashy_road/test/src/maps/bloc/game_maps_state_test.dart

@@ -0,0 +1,42 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:trashy_road/src/maps/maps.dart';
+
+void main() {
+  group('$ScoreRating', () {
+    group('fromSteps', () {
+      test(
+        'returns ScoreRating.none when score is less than the first step',
+        () {
+          final rating = ScoreRating.fromSteps(score: 0, steps: (1, 2, 3));
+          expect(rating, ScoreRating.none);
+        },
+      );
+
+      test(
+        '''returns ScoreRating.bronze when score is greater or equal than the first step '''
+        'and less than the second step',
+        () {
+          final rating = ScoreRating.fromSteps(score: 1, steps: (1, 2, 3));
+          expect(rating, ScoreRating.bronze);
+        },
+      );
+
+      test(
+        '''returns ScoreRating.silver when score is greater or equal than the second step '''
+        'and less than the third step',
+        () {
+          final rating = ScoreRating.fromSteps(score: 2, steps: (1, 2, 3));
+          expect(rating, ScoreRating.silver);
+        },
+      );
+
+      test(
+        '''returns ScoreRating.gold when score is greater or equal than the third step''',
+        () {
+          final rating = ScoreRating.fromSteps(score: 3, steps: (1, 2, 3));
+          expect(rating, ScoreRating.gold);
+        },
+      );
+    });
+  });
+}