import '../flight_model.dart';
import 'hud_features.dart';
import 'product_profile.dart';
import 'state/calibration_state.dart';

/// The calibration and maintenance wizards (plan P6b).
enum CalibrationKind {
  compass,
  imu,
  rc,
  gimbal,

  /// Roll / pitch / yaw trim against a horizon line over the live video.
  gimbalAdjust,
  lens,
  sensorCleaning,
  gravityCenter,
  propeller,

  /// No SDK call: GO 4 also only says "use DJI Assistant 2".
  visionSensors,
}

/// Titles, gating and availability per wizard.
abstract final class CalibrationKinds {
  static String title(CalibrationKind k) => switch (k) {
        CalibrationKind.compass => 'Compass calibration',
        CalibrationKind.imu => 'IMU calibration',
        CalibrationKind.rc => 'Remote controller calibration',
        CalibrationKind.gimbal => 'Gimbal auto calibration',
        CalibrationKind.gimbalAdjust => 'Adjust gimbal',
        CalibrationKind.lens => 'Lens calibration',
        CalibrationKind.sensorCleaning => 'Sensor cleaning',
        CalibrationKind.gravityCenter => 'Center of gravity calibration',
        CalibrationKind.propeller => 'Propeller calibration',
        CalibrationKind.visionSensors => 'Vision sensor calibration',
      };

  static String icon(CalibrationKind k) => switch (k) {
        CalibrationKind.compass => 'compass',
        CalibrationKind.imu => 'gauge',
        CalibrationKind.rc => 'rc',
        CalibrationKind.gimbal || CalibrationKind.gimbalAdjust => 'gimbal',
        CalibrationKind.lens => 'focus',
        CalibrationKind.sensorCleaning => 'aperture',
        CalibrationKind.gravityCenter || CalibrationKind.propeller => 'drone',
        CalibrationKind.visionSensors => 'obstacle',
      };

  static HudFeature feature(CalibrationKind k) => switch (k) {
        CalibrationKind.compass => HudFeatures.calibrationCompass,
        CalibrationKind.imu => HudFeatures.calibrationImu,
        CalibrationKind.rc => HudFeatures.calibrationRc,
        CalibrationKind.gimbal => HudFeatures.gimbalCalibration,
        CalibrationKind.gimbalAdjust => HudFeatures.gimbalAdjust,
        CalibrationKind.lens => HudFeatures.calibrationLens,
        CalibrationKind.sensorCleaning => HudFeatures.sensorCleaning,
        CalibrationKind.gravityCenter => HudFeatures.calibrationGravityCenter,
        CalibrationKind.propeller => HudFeatures.calibrationPropeller,
        CalibrationKind.visionSensors => HudFeatures.visionSensorGuide,
      };

  /// The wizards the hub lists: the profile's feature, then whatever the
  /// aircraft has since said it does not support. Unknown counts as offered.
  static List<CalibrationKind> available(ProductProfile p, CalibrationState c) => <CalibrationKind>[
        for (final CalibrationKind k in CalibrationKind.values)
          if ((!p.connected || feature(k).enabledFor(p)) && _runtime(k, c) != false) k,
      ];

  static bool? _runtime(CalibrationKind k, CalibrationState c) => switch (k) {
        CalibrationKind.compass => c.compassCount == null ? null : c.compassCount! > 0,
        CalibrationKind.gravityCenter => c.gravityCenterSupported,
        CalibrationKind.propeller => c.propellerSupported,
        CalibrationKind.lens => c.lensSupported,
        CalibrationKind.sensorCleaning => c.sensorCleaningSupported,
        CalibrationKind.rc => c.rcSupported,
        _ => null,
      };
}

enum RunPhase { idle, starting, running, succeeded, failed }

/// One wizard's progress, folded from the live model. A wizard calls [begin]
/// when its start command is sent and [observe] on every model change; the
/// result only counts once the aircraft was seen working since [begin], so a
/// stale SUCCESSFUL from an earlier run never ends a new one.
abstract class CalibrationRun {
  RunPhase phase = RunPhase.idle;
  String? failure;
  bool _seenActive = false;

  bool get active => phase == RunPhase.starting || phase == RunPhase.running;
  bool get finished => phase == RunPhase.succeeded || phase == RunPhase.failed;

  void begin() {
    phase = RunPhase.starting;
    failure = null;
    _seenActive = false;
  }

  /// The start command itself was refused.
  void startFailed(String reason) {
    phase = RunPhase.failed;
    failure = reason;
  }

  /// For calibrations the SDK reports nothing about: the start was accepted,
  /// so it is running until the pilot says it ended ([complete]).
  void accepted() {
    if (phase != RunPhase.starting) return;
    phase = RunPhase.running;
    _seenActive = true;
  }

  void complete() {
    if (active) phase = RunPhase.succeeded;
  }

  void reset() {
    phase = RunPhase.idle;
    failure = null;
    _seenActive = false;
  }

  void observe(FlightModel m);

  /// Common folding: [working] while the aircraft reports progress, then
  /// [ok] / [failed] once it has worked.
  void fold({required bool working, bool ok = false, bool failed = false, String? reason}) {
    if (!active) return;
    if (working) {
      _seenActive = true;
      phase = RunPhase.running;
      return;
    }
    if (!_seenActive) return;
    if (failed) {
      phase = RunPhase.failed;
      failure = reason;
    } else if (ok) {
      phase = RunPhase.succeeded;
    }
  }
}

// ── Compass ─────────────────────────────────────────────────────────────────

enum CompassStep { horizontal, vertical }

class CompassRun extends CalibrationRun {
  CompassStep? step;

  @override
  void observe(FlightModel m) {
    final String? s = m.aircraft.compassCalibrationState;
    step = switch (s) {
      'HORIZONTAL' => CompassStep.horizontal,
      'VERTICAL' => CompassStep.vertical,
      _ => step,
    };
    final bool working = s == 'HORIZONTAL' || s == 'VERTICAL' || (m.aircraft.compassCalibrating == true && s != 'SUCCESSFUL' && s != 'FAILED');
    // After SUCCESSFUL the state drops back to NOT_CALIBRATING; an end without
    // a verdict counts by the compass's own error flag.
    final bool ended = !working && (s == 'SUCCESSFUL' || s == 'FAILED' || s == 'NOT_CALIBRATING');
    final bool failed = s == 'FAILED' || (s == 'NOT_CALIBRATING' && m.aircraft.compassHasError == true);
    fold(
      working: working,
      ok: ended && !failed,
      failed: ended && failed,
      reason: 'Move away from metal, cars and buildings, then try again.',
    );
  }
}

// ── IMU ─────────────────────────────────────────────────────────────────────

/// GO 4's order for the multi-side sequence.
abstract final class ImuOrientations {
  static const List<String> order = <String>['BOTTOM_DOWN', 'TOP_DOWN', 'NOSE_DOWN', 'TAIL_DOWN', 'LEFT_DOWN', 'RIGHT_DOWN'];

  static String label(String o) => switch (o) {
        'BOTTOM_DOWN' => 'Flat, upright',
        'TOP_DOWN' => 'Upside down',
        'NOSE_DOWN' => 'Nose down',
        'TAIL_DOWN' => 'Tail down',
        'LEFT_DOWN' => 'Left side down',
        'RIGHT_DOWN' => 'Right side down',
        _ => o,
      };
}

class ImuRun extends CalibrationRun {
  /// 0..1 across the units that report progress.
  double? progress;

  /// The side to put down now, in a multi-side calibration.
  String? orientation;

  /// The multi-side sequence: every side and whether it is done.
  List<(String, bool)> sides = const <(String, bool)>[];

  @override
  void observe(FlightModel m) {
    final CalibrationState c = m.calibration;
    final List<ImuUnit> units = <ImuUnit>[for (final ImuUnit u in c.imuUnits) if (u.connected != false) u];
    final List<int> p = <int>[for (final ImuUnit u in units) if (u.progress != null) u.progress!];
    progress = p.isEmpty ? null : p.reduce((int a, int b) => a + b) / p.length / 100;

    final Set<String> done = c.imuCalibrated.toSet();
    final Set<String> wanted = <String>{...c.imuToCalibrate, ...done};
    sides = <(String, bool)>[
      for (final String o in ImuOrientations.order)
        if (wanted.contains(o)) (o, done.contains(o)),
    ];
    orientation = c.imuMultiSide == true
        ? ImuOrientations.order.where((String o) => wanted.contains(o) && !done.contains(o)).firstOrNull
        : null;

    final bool working = units.any((ImuUnit u) => u.state == 'CALIBRATING') || c.imuOrientationState == 'CALIBRATING';
    final bool failed = units.any((ImuUnit u) => u.state == 'FAILED');
    final bool ok = units.isNotEmpty && units.every((ImuUnit u) => u.state == 'SUCCESSFUL');
    fold(working: working && !failed, ok: ok, failed: failed, reason: 'Keep the aircraft still on a level surface and try again.');
  }
}

// ── Remote controller ───────────────────────────────────────────────────────

enum RcStep { middle, limits }

/// The remote's calibration as GO 4 / the UX SDK run it: record the centre
/// (MIDDLE), sweep every stick and dial (LIMITS), then QUIT to save.
class RcRun extends CalibrationRun {
  RcStep? step;
  bool _quitting = false;

  /// The pilot asked to finish; the next NORMAL / QUIT ends the run.
  void finishing() => _quitting = true;

  @override
  void begin() {
    super.begin();
    step = null;
    _quitting = false;
  }

  @override
  void observe(FlightModel m) {
    final String? s = m.calibration.rcState;
    if (s == 'MIDDLE') step = RcStep.middle;
    if (s == 'LIMITS') step = RcStep.limits;
    fold(
      working: (s == 'MIDDLE' || s == 'LIMITS') && !_quitting,
      ok: _quitting,
      failed: s == 'TIMEOUT' || s == 'DISCONNECT',
      reason: s == 'TIMEOUT' ? 'The remote timed out. Start again.' : 'The remote disconnected.',
    );
  }
}

// ── Gimbal auto calibration ─────────────────────────────────────────────────

class GimbalRun extends CalibrationRun {
  int? progress;

  @override
  void observe(FlightModel m) {
    progress = m.gimbal.calibrationProgress;
    fold(
      working: m.gimbal.calibrating,
      ok: m.gimbal.lastCalibrationOk == true,
      failed: m.gimbal.lastCalibrationOk == false,
      reason: 'Make sure nothing blocks the gimbal and the aircraft is level, then try again.',
    );
  }
}

// ── Lens ────────────────────────────────────────────────────────────────────

class LensRun extends CalibrationRun {
  @override
  void observe(FlightModel m) {
    final String? r = m.calibration.lensResult;
    fold(
      working: m.calibration.lensState == 'CALIBRATING' && r != 'COMPLETED' && r != 'FAIL_NORMAL' && r != 'DATA_ERROR',
      ok: r == 'COMPLETED',
      failed: r == 'FAIL_NORMAL' || r == 'DATA_ERROR',
      reason: r == 'DATA_ERROR' ? 'The lens returned bad data. Check it is seated correctly.' : 'Calibration failed. Try again.',
    );
  }
}

// ── Center of gravity ───────────────────────────────────────────────────────

class GravityCenterRun extends CalibrationRun {
  @override
  void observe(FlightModel m) {
    final String? s = m.calibration.gravityCenterState;
    fold(
      working: s == 'CALCULATING',
      ok: s == 'SUCCESSFUL',
      failed: s == 'FAILED',
      reason: m.calibration.gravityCenterError ?? 'Hover steadily in calm air and try again.',
    );
  }
}

// ── Sensor cleaning ─────────────────────────────────────────────────────────

/// What the pilot does at each sensor-cleaning state.
enum CleaningStep { off, entering, removeLens, ready, cleaning, finishing, remountLens }

abstract final class SensorCleaning {
  static CleaningStep step(String? s) => switch (s) {
        'INITIATING' => CleaningStep.entering,
        'WAITING_FOR_LENS_REMOVAL' => CleaningStep.removeLens,
        'READY' => CleaningStep.ready,
        'CLEANING' => CleaningStep.cleaning,
        'FINISHING' => CleaningStep.finishing,
        'WAITING_FOR_LENS_REMOUNT' => CleaningStep.remountLens,
        _ => CleaningStep.off,
      };

  static String instruction(CleaningStep s) => switch (s) {
        CleaningStep.off => 'The camera vibrates its sensor to shake dust off. You will remove the lens and refit it afterwards.',
        CleaningStep.entering => 'Preparing the camera…',
        CleaningStep.removeLens => 'Remove the lens and hold the camera with the sensor facing down.',
        CleaningStep.ready => 'Keep the sensor facing down and start cleaning.',
        CleaningStep.cleaning => 'Cleaning… keep the sensor facing down.',
        CleaningStep.finishing => 'Finishing…',
        CleaningStep.remountLens => 'Refit the lens, then finish.',
      };
}

/// Sensor cleaning runs while the camera is in its cleaning mode, and ends
/// well once the pilot has left the mode ([exiting]) and the camera is idle.
class SensorCleaningRun extends CalibrationRun {
  CleaningStep step = CleaningStep.off;
  bool _exiting = false;

  void exiting() => _exiting = true;

  @override
  void begin() {
    super.begin();
    _exiting = false;
  }

  @override
  void observe(FlightModel m) {
    step = SensorCleaning.step(m.calibration.sensorCleaning);
    fold(working: step != CleaningStep.off && !_exiting, ok: _exiting && step == CleaningStep.off);
  }
}

/// Propeller calibration: the SDK has a start and a stop but reports no
/// progress, so the run lasts until the pilot ends it.
class PropellerRun extends CalibrationRun {
  @override
  void observe(FlightModel m) {}
}