import 'package:flutter/foundation.dart';

import 'fly/product_profile.dart';
import 'fly/state/aircraft_state.dart';
import 'fly/state/alert_state.dart';
import 'fly/state/battery_state.dart';
import 'fly/state/camera_state.dart';
import 'fly/state/gimbal_state.dart';
import 'fly/state/link_state.dart';
import 'fly/state/mission_state.dart';
import 'fly/state/vision_state.dart';
import 'uploader.dart';

enum RegistrationState { idle, registering, success, failed }

/// Camera capture family, mirrors the right-rail Photo/Video/Pano switch.
enum CaptureMode { photo, video, pano }

/// Exposure program — Auto (PROGRAM) vs Pro (MANUAL) tab on Camera settings.
enum ExposureProgram { auto, pro }

/// A media file listed off the aircraft's SD card by the native MediaManager.
class MediaItem {
  MediaItem({
    required this.index,
    required this.fileName,
    required this.isVideo,
    this.durationSeconds,
    this.sizeBytes,
    this.createdMs,
    this.thumbPath,
    this.localPath,
  });

  final int index;
  final String fileName;
  final bool isVideo;
  final int? durationSeconds;
  final int? sizeBytes;
  final int? createdMs;

  /// On-disk path of the fetched thumbnail (cache dir), once available.
  String? thumbPath;

  /// On-disk path of the fully downloaded original, once available.
  String? localPath;

  /// `null` for anything that shouldn't carry a duration. The SDK reports
  /// `durationInSeconds` for *every* file, so stills come back with junk —
  /// a Mavic Pro's photos yielded -36:35, -136:23 and 545:26 on the SD card.
  String? get durationLabel {
    if (!isVideo) return null;
    final int? s = durationSeconds;
    if (s == null || s <= 0) return null;
    final String mm = (s ~/ 60).toString();
    final String ss = (s % 60).toString().padLeft(2, '0');
    return '$mm:$ss';
  }

  factory MediaItem.fromMap(Map<String, dynamic> m) => MediaItem(
        index: (m['index'] as num).toInt(),
        fileName: (m['fileName'] as String?) ?? 'file',
        isVideo: (m['type'] as String?) == 'video',
        durationSeconds: (m['durationSeconds'] as num?)?.toInt(),
        sizeBytes: (m['sizeBytes'] as num?)?.toInt(),
        createdMs: (m['createdMs'] as num?)?.toInt(),
      );
}

/// Live aircraft/session state, shared across every screen. `_HomePageState`
/// owns the DJI/uploader plumbing and feeds bridge events through
/// [TelemetryReducer]; the screens observe it.
///
/// Telemetry lives in per-subsystem sub-models (plan P1) — [aircraft],
/// [battery], [links], [camera], [gimbal], [vision], [alerts], [mission] — each
/// its own [ChangeNotifier], so a HUD widget can listen to just the one it
/// draws (`ListenableBuilder(listenable: model.battery, …)`) instead of
/// rebuilding with every 10 Hz tick. The model itself re-notifies on any
/// sub-model change — once per [batch], not once per sub-model — which keeps
/// the pre-P2 screens (`AnimatedBuilder(animation: model)`) and their flat
/// getters below working unchanged.
class FlightModel extends ChangeNotifier {
  FlightModel() {
    for (final ChangeNotifier sub in _subs) {
      sub.addListener(_onSub);
    }
  }

  bool _batching = false;
  bool _dirty = false;

  void _onSub() {
    if (_batching) {
      _dirty = true;
    } else {
      notifyListeners();
    }
  }

  /// Runs [update] (several sub-model writes) and notifies this model's own
  /// listeners once at the end, if anything changed. Sub-model listeners still
  /// hear their own change immediately.
  void batch(void Function() update) {
    if (_batching) return update();
    _batching = true;
    try {
      update();
    } finally {
      _batching = false;
      if (_dirty) {
        _dirty = false;
        notifyListeners();
      }
    }
  }

  // ── Telemetry sub-models ───────────────────────────────────────────────────
  final AircraftState aircraft = AircraftState();
  final BatteryState battery = BatteryState();
  final LinkState links = LinkState();
  final CameraState camera = CameraState();
  final GimbalState gimbal = GimbalState();
  final VisionState vision = VisionState();
  final AlertState alerts = AlertState();
  final MissionState mission = MissionState();

  late final List<ChangeNotifier> _subs = <ChangeNotifier>[
    aircraft, battery, links, camera, gimbal, vision, alerts, mission, //
  ];

  /// Wipes the aircraft-bound sub-models on disconnect.
  void clearTelemetry() => batch(() {
        aircraft.clear();
        battery.clear();
        links.clear();
        camera.clear();
        gimbal.clear();
        vision.clear();
        alerts.clear();
      });

  // ── SDK / registration / connection ────────────────────────────────────────
  String sdkVersion = '…';
  RegistrationState registration = RegistrationState.idle;
  String? registrationError;
  bool connected = false;
  String? model;
  String? firmwareVersion;
  /// The remote controller's own firmware — distinct from the aircraft's above.
  String? controllerFirmwareVersion;

  /// The *flight controller's* serial, which is the only serial MSDK v4 exposes —
  /// the airframe serial on the sticker (the one a drone is registered under) is
  /// unreadable over the SDK and is entered by hand in the Web App's fleet.
  String? flightControllerSerial;

  /// What the connected product can do (plan P0). [ProductProfile.disconnected]
  /// until the bridge's first `productProfile` event after connect.
  ProductProfile profile = ProductProfile.disconnected;

  // ── Flight controller telemetry (pre-P2 flat view of [aircraft]) ───────────
  int? get satellites => aircraft.satellites;
  int? get gpsSignalLevel => aircraft.gpsSignalLevel; // 0..5
  bool? get isFlying => aircraft.isFlying;
  bool? get motorsOn => aircraft.motorsOn;
  String? get flightMode => aircraft.flightMode;
  double? get altitude => aircraft.altitude; // m, relative to home
  double? get latitude => aircraft.latitude;
  double? get longitude => aircraft.longitude;
  double? get homeLatitude => aircraft.homeLatitude;
  double? get homeLongitude => aircraft.homeLongitude;
  double? get homeDistance => aircraft.homeDistance; // m, aircraft ↔ home
  double? get horizontalSpeed => aircraft.horizontalSpeed; // m/s
  double? get verticalSpeed => aircraft.verticalSpeed; // m/s (up positive)
  double? get heading => aircraft.heading; // deg
  int? get flightTimeSeconds => aircraft.flightTimeSeconds;
  double? get goHomeHeight => aircraft.goHomeHeight; // m

  // Phone's own GPS (independent of the drone's fix); streamed to the server as
  // a location fallback for the Web App's automatic bounding box.
  double? phoneLatitude;
  double? phoneLongitude;

  // ── Battery (flat view of [battery]) ────────────────────────────────────────
  int? get batteryPercent => battery.percent;
  double? get batteryVoltage => battery.voltage; // V
  double? get batteryTemperature => battery.temperature; // °C

  // ── Camera ──────────────────────────────────────────────────────────────────
  CaptureMode captureMode = CaptureMode.video;
  String? shootPhotoMode; // SINGLE / HDR / BURST / AEB / INTERVAL / PANORAMA
  bool get isRecording => camera.isRecording;
  int get recordSeconds => camera.recordSeconds;
  bool get sdInserted => camera.storage?.inserted ?? false;
  int? get sdRemainingMB => camera.storage?.remainingMB;
  int? get sdPhotoCount => camera.storage?.availableCaptureCount;
  int? get sdRecordSeconds => camera.storage?.availableRecordingSeconds;

  // ── Exposure ────────────────────────────────────────────────────────────────
  // Read back into [camera]; the camera settings page writes them optimistically
  // ahead of the next `exposure` event.
  ExposureProgram exposureProgram = ExposureProgram.auto;
  String? get iso => camera.iso; // "100", "AUTO", …
  set iso(String? v) => camera.iso = v;
  String? get shutter => camera.shutter; // "1/240"
  set shutter(String? v) => camera.shutter = v;
  String? get aperture => camera.aperture; // "f/2.8"
  set aperture(String? v) => camera.aperture = v;
  String? get ev => camera.ev; // "-0.3"
  set ev(String? v) => camera.ev = v;
  String? whiteBalance; // "5200K" / "AUTO"
  List<double>? histogram; // 0..1 normalized bins

  // ── Gimbal (flat view of [gimbal]) ──────────────────────────────────────────
  double? get gimbalPitch => gimbal.pitch; // deg (−90..30-ish)
  double? get gimbalRoll => gimbal.roll;
  double? get gimbalYaw => gimbal.yaw;

  // ── Flight settings (Safety / Control) ──────────────────────────────────────
  int? maxHeight; // m
  int? maxRadius; // m
  bool? maxRadiusEnabled;
  int? rthHeight; // m
  String? obstacleAvoidance; // "On" / "Bypass" / "Off"
  bool? noviceMode;
  bool arHomePoint = true; // client-side toggle (AR overlay)

  // ── Missions (flat view of [mission]) ───────────────────────────────────────
  String get missionState => mission.state; // idle / ready / uploading / executing / …
  bool get missionRunning => mission.running;
  bool get tracking => mission.tracking; // ActiveTrack engaged
  String? get missionError => mission.error;

  // ── On-drone media ──────────────────────────────────────────────────────────
  List<MediaItem> media = <MediaItem>[];
  bool mediaLoading = false;

  // ── DJI account (optional, in addition to PilotVault) ───────────────────────
  String djiAccountState = 'unknown'; // notLoggedIn / tokenOutOfDate / authorized / …
  String? djiAccountUser;

  // ── Telemetry upload channel ────────────────────────────────────────────────
  UploadStatus upload = UploadStatus.disabled;

  bool get registered => registration == RegistrationState.success;

  /// Notify observers after a batch of field writes.
  void bump() => notifyListeners();

  @override
  void dispose() {
    for (final ChangeNotifier sub in _subs) {
      sub.removeListener(_onSub);
      sub.dispose();
    }
    super.dispose();
  }
}