/// Nutritional macros for a single recipe serving.
///
/// Pure Dart (no framework imports) so the value can travel from the
/// schema.org scraper through the drift-backed repository into the
/// presentation layer without leaking infrastructure concerns into the
/// domain.
class MacroProfile {
  const MacroProfile({
    this.calories = 0,
    this.proteinGrams = 0,
    this.carbsGrams = 0,
    this.fatGrams = 0,
  });

  /// Energy content in kilocalories per serving.
  final int calories;

  /// Protein in grams; the primary lean-mass tracking metric for GLP-1
  /// therapy (muscle-preservation target).
  final double proteinGrams;

  /// Carbohydrate content in grams per serving.
  final double carbsGrams;

  /// Fat content in grams per serving.
  final double fatGrams;

  /// `true` when no macro could be extracted (e.g. OpenGraph-only imports).
  bool get isEmpty =>
      calories == 0 &&
      proteinGrams == 0 &&
      carbsGrams == 0 &&
      fatGrams == 0;

  MacroProfile copyWith({
    int? calories,
    double? proteinGrams,
    double? carbsGrams,
    double? fatGrams,
  }) =>
      MacroProfile(
        calories: calories ?? this.calories,
        proteinGrams: proteinGrams ?? this.proteinGrams,
        carbsGrams: carbsGrams ?? this.carbsGrams,
        fatGrams: fatGrams ?? this.fatGrams,
      );

  @override
  bool operator ==(Object other) =>
      other is MacroProfile &&
      other.calories == calories &&
      other.proteinGrams == proteinGrams &&
      other.carbsGrams == carbsGrams &&
      other.fatGrams == fatGrams;

  @override
  int get hashCode => Object.hash(calories, proteinGrams, carbsGrams, fatGrams);

  @override
  String toString() =>
      'MacroProfile($calories kcal, P $proteinGrams g, '
      'C $carbsGrams g, F $fatGrams g)';
}