import 'injection_site.dart';

/// Immutable record of a single GLP-1 administration event.
///
/// The entity is pure Dart (no framework imports) so it can be shared by the
/// pharmacokinetic use cases, the drift-backed repository, and the Riverpod
/// presentation layer without leaking infrastructure concerns into the
/// domain.
class DoseEntry {
  DoseEntry({
    this.id,
    required this.compoundName,
    required this.doseMg,
    required this.administeredAt,
    DateTime? scheduledAt,
    this.injectionSite,
    this.notes,
  }) : scheduledAt = scheduledAt ?? administeredAt;

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

  /// Commercial or compounded agonist name (e.g. `Tirzepatide`).
  final String compoundName;

  /// Total injected quantity in milligrams.
  final double doseMg;

  /// When the dose was actually administered. Drives the pharmacokinetic
  /// decay calculation (`t_i` in C(t)).
  final DateTime administeredAt;

  /// Titration-schedule anchor the dose was prescribed for. Defaults to
  /// [administeredAt] for immediately logged injections.
  final DateTime scheduledAt;

  /// Rotation quadrant used for this injection; `null` for legacy rows that
  /// predate site tracking.
  final InjectionSite? injectionSite;

  /// Free-form clinician/patient notes.
  final String? notes;

  /// Whether a rotation quadrant was recorded.
  bool get hasInjectionSite => injectionSite != null;
}