/// A MAVLink severity value retained exactly as it appeared on the wire.
///
/// Known values follow MAVLink's numeric severity semantics. Unknown values
/// remain displayable so a newer vehicle cannot silently lose diagnostic
/// meaning before Ground Suite has been updated.
final class MavSeverity {
  const MavSeverity(this.wireValue);

  static const emergency = MavSeverity(0);
  static const alert = MavSeverity(1);
  static const critical = MavSeverity(2);
  static const error = MavSeverity(3);
  static const warning = MavSeverity(4);
  static const notice = MavSeverity(5);
  static const info = MavSeverity(6);
  static const debug = MavSeverity(7);

  final int wireValue;

  String get label => switch (wireValue) {
    0 => 'Emergency',
    1 => 'Alert',
    2 => 'Critical',
    3 => 'Error',
    4 => 'Warning',
    5 => 'Notice',
    6 => 'Info',
    7 => 'Debug',
    _ => 'Unknown ($wireValue)',
  };
}

/// A KAPTAN_SHUTDOWN reason retained exactly as it appeared on the wire.
final class KaptanShutdownReason {
  const KaptanShutdownReason(this.wireValue);

  static const operator = KaptanShutdownReason(1);
  static const safety = KaptanShutdownReason(2);

  final int wireValue;

  String get label => switch (wireValue) {
    1 => 'Operator',
    2 => 'Safety',
    _ => 'Unknown ($wireValue)',
  };
}

enum TelemetryKind {
  rawImu,
  distanceSensor,
  opticalFlow;

  String get label => switch (this) {
    TelemetryKind.rawImu => 'Raw IMU',
    TelemetryKind.distanceSensor => 'Distance sensor',
    TelemetryKind.opticalFlow => 'Optical flow',
  };
}

sealed class ObservedEvent {
  const ObservedEvent({required this.receivedAt});

  final DateTime receivedAt;
}

final class HeartbeatEvent extends ObservedEvent {
  const HeartbeatEvent({
    required super.receivedAt,
    required this.systemId,
    required this.componentId,
    required this.armed,
    required this.vehicleState,
  });

  final int systemId;
  final int componentId;
  final bool armed;
  final String vehicleState;
}

final class TelemetryEvent extends ObservedEvent {
  const TelemetryEvent({required super.receivedAt, required this.kind});

  final TelemetryKind kind;
}

final class LogEvent extends ObservedEvent {
  const LogEvent({
    required super.receivedAt,
    required this.level,
    required this.message,
    this.flags = 0,
  });

  static const traceFlag = 1;
  static const truncatedFlag = 2;
  static const coalescedFlag = 4;
  static const knownFlags = traceFlag | truncatedFlag | coalescedFlag;

  final MavSeverity level;
  final String message;
  final int flags;

  bool get isTrace => flags & traceFlag != 0;
  bool get isTruncated => flags & truncatedFlag != 0;
  bool get isCoalesced => flags & coalescedFlag != 0;
  int get unknownFlags => flags & ~knownFlags;
}

final class ErrorEvent extends ObservedEvent {
  const ErrorEvent({
    required super.receivedAt,
    required this.path,
    this.additionalInformation = '',
    this.flags = 0,
  });

  static const truncatedFlag = 2;
  static const coalescedFlag = 4;
  static const knownFlags = truncatedFlag | coalescedFlag;

  final String path;
  final String additionalInformation;
  final int flags;

  bool get isTruncated => flags & truncatedFlag != 0;
  bool get isCoalesced => flags & coalescedFlag != 0;
  int get unknownFlags => flags & ~knownFlags;
}

final class ShutdownEvent extends ObservedEvent {
  const ShutdownEvent({required super.receivedAt, required this.reason});

  final KaptanShutdownReason reason;
}