import 'meal_type.dart';

/// Immutable record of a single meal or snack intake.
///
/// Pure Dart (no framework imports) so the entity can be shared by the
/// nutrition use cases, the drift-backed repository, and the Riverpod
/// presentation layer without leaking infrastructure concerns into the
/// domain.
class FoodLogEntry {
  const FoodLogEntry({
    this.id,
    required this.timestamp,
    required this.mealType,
    required this.description,
    required this.proteinGrams,
    required this.calories,
    this.carbsGrams,
    this.fatGrams,
  });

  /// Database primary key; `null` until the entry has been persisted.
  final int? id;

  /// When the food was consumed.
  final DateTime timestamp;

  /// Meal slot the entry belongs to (drives diary grouping).
  final MealType mealType;

  /// Free-text description of the meal (e.g. "Greek yogurt with berries").
  final String description;

  /// Protein content in grams; the primary lean-mass tracking metric.
  final double proteinGrams;

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

  /// Carbohydrate content in grams; optional per the Phase 3 contract.
  final double? carbsGrams;

  /// Fat content in grams; optional per the Phase 3 contract.
  final double? fatGrams;

  /// Copy helper preserving the database identifier.
  FoodLogEntry copyWith({
    int? id,
    DateTime? timestamp,
    MealType? mealType,
    String? description,
    double? proteinGrams,
    int? calories,
    double? carbsGrams,
    double? fatGrams,
  }) =>
      FoodLogEntry(
        id: id ?? this.id,
        timestamp: timestamp ?? this.timestamp,
        mealType: mealType ?? this.mealType,
        description: description ?? this.description,
        proteinGrams: proteinGrams ?? this.proteinGrams,
        calories: calories ?? this.calories,
        carbsGrams: carbsGrams ?? this.carbsGrams,
        fatGrams: fatGrams ?? this.fatGrams,
      );
}