/// Represents authorized pay grades in the U.S. Army.
///
/// Covers Enlisted (E1–E9), Warrant Officer (W1–W5), and
/// Commissioned Officer (O1–O10) grades.
enum AuthorizedRank {
  // Enlisted
  e1,
  e2,
  e3,
  e4,
  e5,
  e6,
  e7,
  e8,
  e9,
  // Warrant Officers
  w1,
  w2,
  w3,
  w4,
  w5,
  // Commissioned Officers
  o1,
  o2,
  o3,
  o4,
  o5,
  o6,
  o7,
  o8,
  o9,
  o10;

  /// Returns the pay grade string (e.g., "E-4", "W-2", "O-3").
  String get payGrade {
    final name = this.name.toUpperCase();
    return '${name[0]}-${name.substring(1)}';
  }

  /// Returns the common rank title for this pay grade.
  String get rankTitle {
    switch (this) {
      case AuthorizedRank.e1:
        return 'Private';
      case AuthorizedRank.e2:
        return 'Private Second Class';
      case AuthorizedRank.e3:
        return 'Private First Class';
      case AuthorizedRank.e4:
        return 'Specialist / Corporal';
      case AuthorizedRank.e5:
        return 'Sergeant';
      case AuthorizedRank.e6:
        return 'Staff Sergeant';
      case AuthorizedRank.e7:
        return 'Sergeant First Class';
      case AuthorizedRank.e8:
        return 'Master Sergeant / First Sergeant';
      case AuthorizedRank.e9:
        return 'Sergeant Major / Command Sergeant Major';
      case AuthorizedRank.w1:
        return 'Warrant Officer 1';
      case AuthorizedRank.w2:
        return 'Chief Warrant Officer 2';
      case AuthorizedRank.w3:
        return 'Chief Warrant Officer 3';
      case AuthorizedRank.w4:
        return 'Chief Warrant Officer 4';
      case AuthorizedRank.w5:
        return 'Chief Warrant Officer 5';
      case AuthorizedRank.o1:
        return 'Second Lieutenant';
      case AuthorizedRank.o2:
        return 'First Lieutenant';
      case AuthorizedRank.o3:
        return 'Captain';
      case AuthorizedRank.o4:
        return 'Major';
      case AuthorizedRank.o5:
        return 'Lieutenant Colonel';
      case AuthorizedRank.o6:
        return 'Colonel';
      case AuthorizedRank.o7:
        return 'Brigadier General';
      case AuthorizedRank.o8:
        return 'Major General';
      case AuthorizedRank.o9:
        return 'Lieutenant General';
      case AuthorizedRank.o10:
        return 'General';
    }
  }

  /// Returns true if this rank is an enlisted grade.
  bool get isEnlisted => name.startsWith('e');

  /// Returns true if this rank is a warrant officer grade.
  bool get isWarrantOfficer => name.startsWith('w');

  /// Returns true if this rank is a commissioned officer grade.
  bool get isCommissionedOfficer => name.startsWith('o');

  /// Returns the numeric grade level (1–10 within each category).
  int get gradeLevel => int.parse(name.substring(1));

  /// Returns true if this rank meets or exceeds [minimum].
  bool meetsMinimum(AuthorizedRank minimum) {
    if (isEnlisted && minimum.isEnlisted) {
      return gradeLevel >= minimum.gradeLevel;
    }
    if (isWarrantOfficer && minimum.isWarrantOfficer) {
      return gradeLevel >= minimum.gradeLevel;
    }
    if (isCommissionedOfficer && minimum.isCommissionedOfficer) {
      return gradeLevel >= minimum.gradeLevel;
    }
    return false;
  }
}