import 'package:flutter/foundation.dart';

import '../hud_geometry.dart';
import 'parse.dart';

/// How a fly zone (or the aircraft's standing towards one) should look.
enum ZoneLevel { none, info, caution, danger }

/// One part of a GEO zone: a circle, or a polygon with its own height limit.
@immutable
class SubFlyZone {
  const SubFlyZone({required this.shape, this.latitude, this.longitude, this.radius, this.maxHeight, this.vertices = const <(double, double)>[]});

  factory SubFlyZone.fromMap(Map<String, dynamic> m) => SubFlyZone(
        shape: asString(m['shape']) ?? 'UNKNOWN',
        latitude: finite(m['latitude']),
        longitude: finite(m['longitude']),
        radius: finite(m['radius']),
        maxHeight: asInt(m['maxHeight']),
        vertices: <(double, double)>[
          if (m['vertices'] is List)
            for (final Object? v in m['vertices'] as List)
              if (v is List && v.length == 2 && finite(v[0]) != null && finite(v[1]) != null) (finite(v[0])!, finite(v[1])!),
        ],
      );

  /// `CYLINDER` or `POLYGON`.
  final String shape;
  final double? latitude;
  final double? longitude;
  final double? radius; // m
  /// Height limit inside this part, m (0 = no flight).
  final int? maxHeight;
  final List<(double, double)> vertices;

  bool get isPolygon => shape == 'POLYGON' && vertices.length >= 3;

  /// Where the height label goes: the circle's centre, or the polygon's vertex average.
  (double, double)? get labelPoint {
    if (isPolygon) {
      double la = 0, lo = 0;
      for (final (double, double) v in vertices) {
        la += v.$1;
        lo += v.$2;
      }
      return (la / vertices.length, lo / vertices.length);
    }
    return latitude == null || longitude == null ? null : (latitude!, longitude!);
  }

  /// `NO FLY` at 0 m, `120 m` for a ceiling, null when the part sets none.
  String? get heightLabel {
    final int? h = maxHeight;
    if (h == null || h < 0) return null;
    return h == 0 ? 'NO FLY' : '$h m';
  }
}

/// One DJI GEO zone (`FlyZoneInformation`).
@immutable
class FlyZone {
  const FlyZone({
    required this.id,
    this.name = '',
    this.category = 'UNKNOWN',
    this.reason,
    this.latitude,
    this.longitude,
    this.radius,
    this.startTime,
    this.endTime,
    this.unlockStartTime,
    this.unlockEndTime,
    this.subZones = const <SubFlyZone>[],
  });

  factory FlyZone.fromMap(Map<String, dynamic> m) => FlyZone(
        id: asInt(m['id']) ?? 0,
        name: (asString(m['name']) ?? '').trim(),
        category: asString(m['category']) ?? 'UNKNOWN',
        reason: asString(m['reason']),
        latitude: finite(m['latitude']),
        longitude: finite(m['longitude']),
        radius: finite(m['radius']),
        startTime: _blank(asString(m['startTime'])),
        endTime: _blank(asString(m['endTime'])),
        unlockStartTime: _blank(asString(m['unlockStartTime'])),
        unlockEndTime: _blank(asString(m['unlockEndTime'])),
        subZones: <SubFlyZone>[for (final Map<String, dynamic> s in asMapList(m['subZones'])) SubFlyZone.fromMap(s)],
      );

  static String? _blank(String? s) => s == null || s.trim().isEmpty ? null : s.trim();

  final int id;
  final String name;

  /// `WARNING`, `ENHANCED_WARNING`, `AUTHORIZATION`, `RESTRICTED`, `UNKNOWN`.
  final String category;

  /// `FlyZoneReason` name: `AIRPORT`, `MILITARY`, `PRISON`, …
  final String? reason;
  final double? latitude;
  final double? longitude;
  final double? radius; // m
  final String? startTime;
  final String? endTime;
  final String? unlockStartTime;
  final String? unlockEndTime;
  final List<SubFlyZone> subZones;

  bool get unlockable => category == 'AUTHORIZATION';

  ZoneLevel get level => switch (category) {
        'RESTRICTED' => ZoneLevel.danger,
        'AUTHORIZATION' || 'ENHANCED_WARNING' => ZoneLevel.caution,
        'WARNING' => ZoneLevel.info,
        _ => ZoneLevel.none,
      };

  String get categoryLabel => switch (category) {
        'RESTRICTED' => 'Restricted zone',
        'AUTHORIZATION' => 'Authorization zone',
        'ENHANCED_WARNING' => 'Enhanced warning zone',
        'WARNING' => 'Warning zone',
        _ => 'Fly zone',
      };

  /// `COMMERCIAL_AIRPORTS` → `Commercial airports`.
  String? get reasonLabel {
    final String? r = reason;
    if (r == null || r == 'UNKNOWN') return null;
    final String s = r.replaceAll('_', ' ').toLowerCase();
    return s[0].toUpperCase() + s.substring(1);
  }

  /// Metres from ([lat], [lon]) to the zone's centre, minus its radius (0 inside).
  double? distanceFrom(double lat, double lon) {
    if (latitude == null || longitude == null) return null;
    final double d = HudGeometry.distance(lat, lon, latitude!, longitude!) - (radius ?? 0);
    return d < 0 ? 0 : d;
  }
}

/// One FlySafe notification: transient advice from DJI's GEO system.
@immutable
class FlySafeNotice {
  const FlySafeNotice({required this.kind, this.event, this.description, this.heightLimit, this.countdown, this.zoneIds = const <int>[], required this.at});

  factory FlySafeNotice.fromMap(Map<String, dynamic> m, DateTime at) => FlySafeNotice(
        kind: asString(m['kind']) ?? 'UNKNOWN',
        event: asString(m['event']),
        description: (asString(m['description']) ?? '').trim(),
        heightLimit: asInt(m['heightLimit']),
        countdown: asInt(m['countdown']),
        zoneIds: <int>[if (m['zones'] is List) for (final Object? z in m['zones'] as List) if (z is int) z],
        at: at,
      );

  /// `FLYING_SAFETY_TIP`, `WARNING`, `SERIOUS_WARNING`, `RETURN_TO_HOME`.
  final String kind;
  final String? event;
  final String? description;
  final int? heightLimit;
  final int? countdown;
  final List<int> zoneIds;
  final DateTime at;

  ZoneLevel get level => switch (kind) {
        'SERIOUS_WARNING' => ZoneLevel.danger,
        'WARNING' || 'RETURN_TO_HOME' => ZoneLevel.caution,
        _ => ZoneLevel.info,
      };

  /// A short title when the SDK's description is empty.
  String get title => switch (event) {
        'IN_NO_FLY_ZONE' => 'In a no-fly zone: the aircraft is landing',
        'IN_LIMIT_HEIGHT_AREA' => 'In a height-limited zone',
        'IN_AUTHORIZATION_ZONE_WITHOUT_UNLOCKING' => 'In an authorization zone that is not unlocked',
        'TAKE_OFF_FAILED_IN_NO_FLY_ZONE' || 'TAKE_OFF_FAILED_IN_NO_FLY_ZONE_WITHOUT_GPS' => 'Take-off refused: no-fly zone',
        'TAKE_OFF_FAILED_IN_AUTHORIZED_ZONE_WITHOUT_UNLOCKING' ||
        'TAKE_OFF_FAILED_IN_AUTHORIZED_AREA_WITHOUT_GPS_AND_UNLOCKING' =>
          'Take-off refused: unlock the authorization zone first',
        'NEAR_NO_FLY_ZONE' => 'Return to Home passes near a no-fly zone',
        'CROSS_NO_FLY_ZONE' => 'Return to Home would cross a no-fly zone',
        'TOUCH_NO_FLY_ZONE' => 'At the edge of a no-fly zone',
        'TOUCH_AUTHORIZATION_ZONE' => 'At the edge of an authorization zone',
        'REACH_MAXIMUM_FLIGHT_HEIGHT' => 'At the zone\'s height limit',
        'TAKE_OFF_NEAR_NO_FLY_ZONE' => 'Near a no-fly zone',
        'AUTHORIZED_ZONE_WITHOUT_UNLOCKING_NEARBY' || 'AUTHORIZED_ZONE_AND_RESTRICTIONS_NEARBY' => 'Authorization zone nearby',
        'IN_AUTHORIZATION_ZONE' || 'TAKE_OFF_FAILED_IN_AUTHORIZED_ZONE' => 'In an authorization zone',
        'LIMITED_RESTRICTIONS_NEARBY' || 'RESTRICTIONS_IN_LIMITED_FLY_ZONE_NEARBY' => 'Height-limited zone nearby',
        'TAKE_OFF_IN_ENHANCED_WARNING_ZONE' => 'In an enhanced warning zone',
        'TAKE_OFF_IN_WARNING_AREA' => 'In a warning zone',
        'TAKE_OFF_IN_HEIGHT_LIMIT_ZONE' || 'TAKE_OFF_IN_HEIGHT_LIMIT_ZONE_WITHOUT_GPS' => 'Taking off in a height-limited zone',
        'RTH_AFFECTED_AT_BOUNDARY_OF_GEO_ZONE' => 'Return to Home is limited by a fly zone',
        _ => kind == 'SERIOUS_WARNING' ? 'Fly zone warning' : 'Fly zone notice',
      };
}

/// DJI GEO fly zones (plan P8): the aircraft's standing (`flyZone.state`), the
/// latest FlySafe notification, the zones around, and which are unlocked.
class FlyZoneState extends ChangeNotifier {
  /// `FlyZoneState` name, null until reported.
  String? state;

  FlySafeNotice? notice;

  List<FlyZone> zones = const <FlyZone>[];

  /// Where [zones] were fetched around, and when.
  (double, double)? zonesAround;
  DateTime? zonesAt;

  Set<int> unlocked = const <int>{};

  /// A notice stays on screen this long (a serious one with a countdown, until replaced).
  static const Duration noticeLife = Duration(seconds: 15);

  ZoneLevel get stateLevel => switch (state) {
        'IN_RESTRICTED_ZONE' || 'SUSPECTED_IN_RESTRICTED_ZONE' || 'PHONE_IN_RESTRICTED_ZONE' => ZoneLevel.danger,
        'IN_AUTHORIZED_ZONE' || 'SUSPECTED_IN_AUTHORIZED_ZONE' || 'IN_ENHANCE_WARNING_ZONE' || 'NEAR_RESTRICTED_ZONE' => ZoneLevel.caution,
        'IN_WARNING_ZONE' ||
        'IN_WARNING_ZONE_WITH_HEIGHT_LIMITATION' ||
        'SUSPECTED_IN_WARNING_ZONE_WITH_HEIGHT_LIMITATION' ||
        'PHONE_IN_WARNING_ZONE_WITH_HEIGHT_LIMITATION' ||
        'NEAR_HEIGHT_LIMITED_ZONE' ||
        'NEAR_AUTHORIZED_ZONE' ||
        'NEAR_AUTHORIZED_ZONE_WITH_LICENSE' ||
        'NEAR_MULTIPLE_TYPE_FLY_ZONE' ||
        'IN_AUTHORIZED_ZONE_WITH_LICENSE' =>
          ZoneLevel.info,
        _ => ZoneLevel.none,
      };

  String get stateLabel => switch (state) {
        'IN_RESTRICTED_ZONE' || 'SUSPECTED_IN_RESTRICTED_ZONE' => 'In a restricted zone',
        'PHONE_IN_RESTRICTED_ZONE' => 'You are in a restricted zone',
        'NEAR_RESTRICTED_ZONE' => 'Near a restricted zone',
        'IN_AUTHORIZED_ZONE' || 'SUSPECTED_IN_AUTHORIZED_ZONE' => 'In an authorization zone',
        'IN_AUTHORIZED_ZONE_WITH_LICENSE' => 'In an unlocked authorization zone',
        'NEAR_AUTHORIZED_ZONE' || 'NEAR_AUTHORIZED_ZONE_WITH_LICENSE' => 'Near an authorization zone',
        'IN_ENHANCE_WARNING_ZONE' => 'In an enhanced warning zone',
        'IN_WARNING_ZONE' => 'In a warning zone',
        'IN_WARNING_ZONE_WITH_HEIGHT_LIMITATION' ||
        'SUSPECTED_IN_WARNING_ZONE_WITH_HEIGHT_LIMITATION' ||
        'PHONE_IN_WARNING_ZONE_WITH_HEIGHT_LIMITATION' =>
          'In a height-limited zone',
        'NEAR_HEIGHT_LIMITED_ZONE' => 'Near a height-limited zone',
        'NEAR_MULTIPLE_TYPE_FLY_ZONE' => 'Near several fly zones',
        _ => 'No fly zone around',
      };

  /// The notice to show at [now]: fresh, or a serious one still counting down.
  FlySafeNotice? noticeAt(DateTime now) {
    final FlySafeNotice? n = notice;
    if (n == null) return null;
    final Duration age = now.difference(n.at);
    if (age <= noticeLife) return n;
    if (n.kind == 'SERIOUS_WARNING' && (n.countdown ?? 0) > age.inSeconds) return n;
    return null;
  }

  /// The zone(s) a notice names, as loaded.
  List<FlyZone> zonesFor(FlySafeNotice n) => <FlyZone>[for (final FlyZone z in zones) if (n.zoneIds.contains(z.id)) z];

  /// Zones nearest first from ([lat], [lon]).
  List<FlyZone> nearest(double? lat, double? lon) {
    if (lat == null || lon == null) return zones;
    return <FlyZone>[...zones]..sort((FlyZone a, FlyZone b) =>
        (a.distanceFrom(lat, lon) ?? double.infinity).compareTo(b.distanceFrom(lat, lon) ?? double.infinity));
  }

  void applyState(Map<String, dynamic>? m) {
    state = asString(m?['state']);
    notifyListeners();
  }

  void applyNotice(Map<String, dynamic> m, {DateTime? now}) {
    notice = FlySafeNotice.fromMap(m, now ?? DateTime.now());
    notifyListeners();
  }

  void applyZones(List<Map<String, dynamic>> list, {required double latitude, required double longitude, DateTime? now}) {
    zones = <FlyZone>[for (final Map<String, dynamic> m in list) FlyZone.fromMap(m)];
    zonesAround = (latitude, longitude);
    zonesAt = now ?? DateTime.now();
    notifyListeners();
  }

  void applyUnlocked(Iterable<int> ids) {
    unlocked = ids.toSet();
    notifyListeners();
  }

  /// Whether a fresh fetch is due for a fix at ([lat], [lon]).
  bool needsZonesFor(double lat, double lon, {DateTime? now, double moveM = 2000, Duration maxAge = const Duration(minutes: 10)}) {
    final (double, double)? at = zonesAround;
    final DateTime? when = zonesAt;
    if (at == null || when == null) return true;
    if ((now ?? DateTime.now()).difference(when) > maxAge) return true;
    return HudGeometry.distance(at.$1, at.$2, lat, lon) > moveM;
  }

  // ── Licences and the GEO database ─────────────────────────────────────────

  /// Null until listed; false on aircraft without custom unlock zones.
  bool? licencesSupported;
  List<FlyZoneLicence> licences = const <FlyZoneLicence>[];

  FlyZoneDatabase? database;

  /// Basic database download, 0..1, while an upgrade runs; null otherwise.
  double? upgradeProgress;

  FlyZoneLicence? get enabledLicence => licences.where((FlyZoneLicence l) => l.enabled).firstOrNull;

  void applyLicences(Map<String, dynamic> m) {
    licencesSupported = asBool(m['supported']) ?? false;
    licences = <FlyZoneLicence>[for (final Map<String, dynamic> z in asMapList(m['zones'])) FlyZoneLicence.fromMap(z)]
      ..sort((FlyZoneLicence a, FlyZoneLicence b) => a.index.compareTo(b.index));
    notifyListeners();
  }

  void applyDatabase(Map<String, dynamic> m) {
    database = FlyZoneDatabase.fromMap(m);
    notifyListeners();
  }

  /// The SDK's progress float; read as a percentage when above 1. A complete
  /// download ends the upgrade (MSDK does not say whether the start call's
  /// completion waits for it).
  void applyUpgradeProgress(double? p) {
    final double? v = p == null ? null : (p > 1 ? p / 100 : p).clamp(0.0, 1.0);
    upgradeProgress = v != null && v >= 1 ? null : v;
    notifyListeners();
  }

  /// Aircraft-bound parts only: the zones database is app-level and stays.
  void clearAircraft() {
    state = null;
    notice = null;
    unlocked = const <int>{};
    licencesSupported = null;
    licences = const <FlyZoneLicence>[];
    notifyListeners();
  }
}

/// One licence on the aircraft (`CustomUnlockZone`): a DJI-issued unlock for a
/// circle, polygon, height or whole country, valid between two dates. One at a
/// time is enabled.
@immutable
class FlyZoneLicence {
  const FlyZoneLicence({
    required this.id,
    this.index = 0,
    this.name = '',
    this.type = 'UNKNOWN',
    this.latitude,
    this.longitude,
    this.radius,
    this.height,
    this.country,
    this.points = const <(double, double)>[],
    this.startTime,
    this.endTime,
    this.expired = false,
    this.enabled = false,
  });

  factory FlyZoneLicence.fromMap(Map<String, dynamic> m) => FlyZoneLicence(
        id: asInt(m['id']) ?? 0,
        index: asInt(m['index']) ?? 0,
        name: (asString(m['name']) ?? '').trim(),
        type: asString(m['type']) ?? 'UNKNOWN',
        latitude: finite(m['latitude']),
        longitude: finite(m['longitude']),
        radius: finite(m['radius']),
        height: asInt(m['height']),
        country: asString(m['country']),
        points: <(double, double)>[
          if (m['points'] is List)
            for (final Object? v in m['points'] as List)
              if (v is List && v.length == 2 && finite(v[0]) != null && finite(v[1]) != null) (finite(v[0])!, finite(v[1])!),
        ],
        startTime: FlyZone._blank(asString(m['startTime'])),
        endTime: FlyZone._blank(asString(m['endTime'])),
        expired: asBool(m['expired']) ?? false,
        enabled: asBool(m['enabled']) ?? false,
      );

  final int id;
  final int index;
  final String name;

  /// `UnlockZoneType`: `GEO_UNLOCK`, `CIRCLE_UNLOCK_AREA`, `COUNTRY_UNLOCK`, `HEIGHT_UNLOCK`, `PENTAGON_UNLOCK`.
  final String type;
  final double? latitude;
  final double? longitude;
  final double? radius; // m
  final int? height; // m, for height unlocks
  final String? country;
  final List<(double, double)> points;
  final String? startTime;
  final String? endTime;
  final bool expired;
  final bool enabled;

  String get typeLabel => switch (type) {
        'GEO_UNLOCK' => 'GEO zone unlock',
        'CIRCLE_UNLOCK_AREA' => 'Circle unlock',
        'PENTAGON_UNLOCK' => 'Area unlock',
        'COUNTRY_UNLOCK' => 'Country unlock',
        'HEIGHT_UNLOCK' => 'Height unlock',
        _ => 'Licence',
      };

  /// Drawable on the map: a circle with a centre and radius, or a polygon.
  bool get hasArea => points.length >= 3 || (latitude != null && longitude != null && (radius ?? 0) > 0);

  String get validity => <String>[if (startTime != null) startTime!, if (endTime != null) endTime!].join(' → ');
}

/// The GEO database's versions and state (`FlyZoneDatabaseState` names).
@immutable
class FlyZoneDatabase {
  const FlyZoneDatabase({this.basicVersion, this.basicState, this.preciseVersion, this.preciseState});

  factory FlyZoneDatabase.fromMap(Map<String, dynamic> m) => FlyZoneDatabase(
        basicVersion: asString(m['basicVersion']),
        basicState: asString(m['basicState']),
        preciseVersion: asString(m['preciseVersion']),
        preciseState: asString(m['preciseState']),
      );

  final String? basicVersion;
  final String? basicState; // INITIALIZING / NO_INTERNET_CONNECTION / OUT_OF_DATE / UP_TO_DATE / UNKNOWN
  final String? preciseVersion;
  final String? preciseState;

  bool get outOfDate => basicState == 'OUT_OF_DATE' || preciseState == 'OUT_OF_DATE';

  static String stateLabel(String? s) => switch (s) {
        'UP_TO_DATE' => 'Up to date',
        'OUT_OF_DATE' => 'Out of date',
        'NO_INTERNET_CONNECTION' => 'No internet connection',
        'INITIALIZING' => 'Initializing',
        _ => 'Unknown',
      };
}