dmc/app/lib/ui/screens/plan/plan_screen.dart

import 'dart:async';
import 'dart:math' as math;

import 'package:flutter/material.dart';
import 'package:flutter_map/flutter_map.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:latlong2/latlong.dart';

import '../../../domain/mission/default_drone_profile.dart';
import '../../../domain/mission/mission_stats.dart';
import '../../../domain/mission/mission_warnings.dart';
import '../../../domain/mission/route_geometry.dart';
import '../../../domain/waypoint/flat_waypoint_list.dart';
import '../../../domain/wind/wind_math.dart';
import '../../providers/active_drone_profile_provider.dart';
import '../../providers/current_mission_provider.dart';
import '../../providers/map_controller_provider.dart';
import '../../providers/mission_meta_provider.dart';
import '../../providers/terrain_provider.dart';
import '../../providers/wind_provider.dart';
import '../settings/settings_screen.dart';
import '../../widgets/halo_menu.dart';
import '../../widgets/mission_footer_bar.dart';
import '../../widgets/mission_map.dart';
import '../../widgets/reticle_button.dart';
import '../../widgets/value_wheel.dart';
import '../../widgets/waypoint_list_panel.dart';
import '../../widgets/warnings_panel.dart';
import '../../widgets/wind_marker_pill.dart';

/// Reticle-Zustand (HTML-Demonstrator: Variable `mode`).
/// idle: kein Wegpunkt in der Naehe, Tap legt einen neuen an.
/// snapped: Kartenmitte ist auf einen bestehenden Wegpunkt eingerastet.
/// editing: Wegpunkt wird bearbeitet - Kartenverschieben repositioniert ihn
/// live, das Halo-Menue (Loiter/Landing/Entfernen) ist sichtbar.
enum _ReticleMode { idle, snapped, editing }

/// Missionsplanung: Karte + Wegpunktliste (Architektur-Doku 3.6/3.7).
/// Kein eigenes Scaffold - die Kopfleiste (Plan/Fly-Umschalter) und der
/// gemeinsame Scaffold-Rahmen liegen im AppShell darueber.
class PlanScreen extends ConsumerStatefulWidget {
  const PlanScreen({super.key});

  @override
  ConsumerState<PlanScreen> createState() => _PlanScreenState();
}

class _PlanScreenState extends ConsumerState<PlanScreen> {
  // Geteilter, app-lebenslanger Controller statt einer PlanScreen-eigenen
  // Instanz (siehe mapControllerProvider) - PlanScreen besitzt ihn nicht
  // mehr und darf ihn daher auch nicht disposen.
  late final MapController _mapController;
  StreamSubscription<MapEvent>? _mapEventSub;

  _ReticleMode _mode = _ReticleMode.idle;
  int _targetIndex = -1;
  bool _mapReady = false;

  // Rein UI-seitige Darstellungsdetails der Drehraeder; die eigentlichen
  // Wertebereiche kommen aus DefaultDroneProfile (Doku 3.5-Platzhalter).
  static const _altPxPerStep = 14.0;
  static const _altMajorEvery = 5;
  static const _speedPxPerStep = 14.0;
  static const _speedMajorEvery = 5;

  double _curAlt = DefaultDroneProfile.altitudeM;
  double _curSpeed = DefaultDroneProfile.speedMs;

  // Radius des Reticle-Buttons (siehe ReticleButton: 55px Durchmesser).
  static const _reticleRadiusPx = 55 / 2;

  static const _distance = Distance(roundResult: false);

  @override
  void initState() {
    super.initState();
    _mapController = ref.read(mapControllerProvider);
    _mapEventSub = _mapController.mapEventStream.listen(_onMapEvent);
    // Erstbefuellung der Kopfleisten-Wind-Pille (Doku 3.8) - erst nach dem
    // ersten Frame, da die Kartenkamera (Fallback-Referenzort ohne
    // Wegpunkte) vor dem initialen Layout noch nicht bereit ist.
    WidgetsBinding.instance.addPostFrameCallback((_) async {
      if (!mounted) return;
      ref.read(headerWindProvider.notifier).refresh();
      // Bootstrap der Persistenz (Doku 4.15/7.5): mindestens ein
      // Drohnenprofil sicherstellen/laden, danach ggf. den zuletzt
      // bearbeiteten Autosave-Draft wiederherstellen.
      await ref.read(activeDroneProfileProvider.notifier).initialize();
      await ref.read(currentMissionMetaProvider.notifier).restoreLastSession();
      if (mounted) {
        setState(() {
          _curSpeed = ref.read(activeDroneProfileProvider).cruiseSpeed;
        });
      }
    });
    // Wechselt der Nutzer waehrend der Bearbeitung das aktive Drohnenprofil,
    // muss die aktuell eingestellte Soll-Geschwindigkeit in dessen
    // gueltigen Bereich geklemmt werden (sonst zeigt das Drehrad einen
    // Wert ausserhalb seiner eigenen Skala).
    ref.listenManual(activeDroneProfileProvider, (previous, next) {
      final clamped = _curSpeed.clamp(next.minSpeed, next.maxSpeed);
      if (clamped != _curSpeed) setState(() => _curSpeed = clamped);
    });
  }

  @override
  void dispose() {
    _mapEventSub?.cancel();
    super.dispose();
  }

  void _onMapEvent(MapEvent event) {
    if (event is MapEventMoveEnd) {
      _handleMoveEnd();
    } else if (event is MapEventMove) {
      if (event.source == MapEventSource.mapController) {
        // Programmatischer Sprung (Suche/Home/Fit in der Kopfleiste,
        // Zeile-antippen in der Wegpunktliste) - im Gegensatz zu einer
        // Gesten-Verschiebung ist die Position hier sofort final, es
        // kommt aber nie ein MoveEnd fuer diesen Fall. Direkt reagieren
        // statt darauf zu warten.
        if (_mode != _ReticleMode.editing) _handleMoveEnd();
      } else if (_mode == _ReticleMode.editing && _targetIndex >= 0) {
        final waypoints = ref.read(currentMissionProvider);
        if (_targetIndex < waypoints.length) {
          final center = _mapController.camera.center;
          ref.read(currentMissionProvider.notifier).moveWaypoint(
                _targetIndex,
                center.latitude,
                center.longitude,
              );
        }
      } else if (_mode == _ReticleMode.idle) {
        // Nur fuer die gestrichelte Vorschaulinie neu zeichnen.
        setState(() {});
      }
    }
  }

  /// Metergenauer Fangradius des Reticle bei aktuellem Zoom/Breitengrad
  /// (HTML-Demonstrator: currentSnapMeters()).
  double _currentSnapMeters() {
    final camera = _mapController.camera;
    final metersPerPixel = 156543.03392 *
        math.cos(camera.center.latitude * math.pi / 180) /
        math.pow(2, camera.zoom);
    return _reticleRadiusPx * metersPerPixel;
  }

  void _handleMoveEnd() {
    if (_mode == _ReticleMode.editing) return;

    final waypoints = ref.read(currentMissionProvider);
    final center = _mapController.camera.center;
    final snapMeters = _currentSnapMeters();

    var bestIndex = -1;
    var bestDist = snapMeters;
    for (var i = 0; i < waypoints.length; i++) {
      final d = _distance(center, LatLng(waypoints[i].lat, waypoints[i].lon));
      if (d < bestDist) {
        bestDist = d;
        bestIndex = i;
      }
    }

    setState(() {
      if (bestIndex >= 0) {
        _mode = _ReticleMode.snapped;
        _targetIndex = bestIndex;
        final target = waypoints[bestIndex];
        final targetLatLng = LatLng(target.lat, target.lon);
        if (_distance(center, targetLatLng) > 0.5) {
          // flutter_map's MapController.move() emits MapEventMove, nicht
          // MoveEnd - anders als Leaflets panTo() droht hier also keine
          // Rekursion in _handleMoveEnd, ein Guard ist nicht noetig.
          _mapController.move(targetLatLng, _mapController.camera.zoom);
        }
      } else {
        _mode = _ReticleMode.idle;
        _targetIndex = -1;
      }
    });
  }

  void _onReticleTap() {
    switch (_mode) {
      case _ReticleMode.idle:
        final center = _mapController.camera.center;
        final waypoints = ref.read(currentMissionProvider);
        ref.read(currentMissionProvider.notifier).addWaypoint(
              Waypoint(
                lat: center.latitude,
                lon: center.longitude,
                altitudeM: _curAlt,
                speedMs: _curSpeed,
                catchRadiusM: ref.read(activeDroneProfileProvider).catchRadius,
              ),
            );
        if (waypoints.isEmpty) {
          // Referenzort fuer die Wind-Pille wechselt vom Kartenzentrum auf
          // den ersten Wegpunkt (Doku 3.8) - neu abfragen.
          ref.read(headerWindProvider.notifier).refresh();
        }
        setState(() {
          _targetIndex = waypoints.length;
          _mode = _ReticleMode.snapped;
        });
      case _ReticleMode.snapped:
        final waypoints = ref.read(currentMissionProvider);
        if (_targetIndex >= 0 && _targetIndex < waypoints.length) {
          final target = waypoints[_targetIndex];
          setState(() {
            _mode = _ReticleMode.editing;
            _curAlt = target.altitudeM;
            _curSpeed = target.speedMs;
          });
        }
      case _ReticleMode.editing:
        setState(() => _mode = _ReticleMode.snapped);
    }
  }

  void _onHaloAction(HaloAction action) {
    if (_mode != _ReticleMode.editing || _targetIndex < 0) return;
    final notifier = ref.read(currentMissionProvider.notifier);

    switch (action) {
      case HaloAction.loiter:
        notifier.toggleAction(_targetIndex, WaypointAction.loiter);
        setState(() => _mode = _ReticleMode.snapped);
      case HaloAction.landing:
        notifier.toggleAction(_targetIndex, WaypointAction.landing);
        setState(() => _mode = _ReticleMode.snapped);
      case HaloAction.remove:
        notifier.removeAt(_targetIndex);
        setState(() {
          _mode = _ReticleMode.idle;
          _targetIndex = -1;
        });
    }
  }

  void _onAltChanged(double value) {
    setState(() => _curAlt = value);
    if (_mode == _ReticleMode.editing && _targetIndex >= 0) {
      ref.read(currentMissionProvider.notifier).setAltitude(_targetIndex, value);
    }
  }

  void _onSpeedChanged(double value) {
    setState(() => _curSpeed = value);
    if (_mode == _ReticleMode.editing && _targetIndex >= 0) {
      ref.read(currentMissionProvider.notifier).setSpeed(_targetIndex, value);
    }
  }

  // Wegpunktliste (Doku 3.6): Aenderungen wirken auf einen explizit
  // angegebenen Index, nicht zwingend den aktuellen Reticle-Zielpunkt.

  void _onRowAltitudeChanged(int index, double value) {
    ref.read(currentMissionProvider.notifier).setAltitude(index, value);
    if (_mode == _ReticleMode.editing && index == _targetIndex) {
      setState(() => _curAlt = value);
    }
  }

  void _onRowSpeedChanged(int index, double value) {
    ref.read(currentMissionProvider.notifier).setSpeed(index, value);
    if (_mode == _ReticleMode.editing && index == _targetIndex) {
      setState(() => _curSpeed = value);
    }
  }

  void _onRowCatchRadiusChanged(int index, double value) {
    ref.read(currentMissionProvider.notifier).setCatchRadius(index, value);
  }

  void _onRowActionChanged(int index, WaypointAction action) {
    ref.read(currentMissionProvider.notifier).setAction(index, action);
  }

  void _onRowDelete(int index) {
    ref.read(currentMissionProvider.notifier).removeAt(index);
    setState(() {
      if (_targetIndex == index) {
        _mode = _ReticleMode.idle;
        _targetIndex = -1;
      } else if (_targetIndex > index) {
        _targetIndex -= 1;
      }
    });
  }

  /// Zeile antippen zentriert die Karte auf diesen Wegpunkt (Doku 3.6). Die
  /// Snap-Erkennung reagiert automatisch ueber _onMapEvent (source ==
  /// mapController), ein manueller Folgeaufruf ist nicht noetig.
  void _onCenterOnWaypoint(int index) {
    final waypoints = ref.read(currentMissionProvider);
    if (index < 0 || index >= waypoints.length) return;
    final wp = waypoints[index];
    _mapController.move(LatLng(wp.lat, wp.lon), _mapController.camera.zoom);
  }

  /// Oeffnet die Wegpunktliste als eigene Vollbild-Route statt als
  /// internen Stack-Overlay, damit sie wirklich alles ueberdeckt -
  /// inklusive der Kopfleiste im AppShell darueber. [initialTab] erlaubt
  /// gezieltes Oeffnen auf Altitude/Speed statt immer auf der Liste (Doku
  /// 3.10: Antippen einer Warnung).
  void _openWaypointList({PanelTab initialTab = PanelTab.list}) {
    Navigator.of(context).push(
      PageRouteBuilder<void>(
        opaque: true,
        transitionDuration: const Duration(milliseconds: 150),
        reverseTransitionDuration: const Duration(milliseconds: 150),
        pageBuilder: (routeContext, animation, secondaryAnimation) {
          return FadeTransition(
            opacity: animation,
            child: WaypointListPanel(
              activeIndex: _mode == _ReticleMode.idle ? -1 : _targetIndex,
              initialTab: initialTab,
              onClose: () => Navigator.of(routeContext).pop(),
              onCenterOnWaypoint: (index) {
                _onCenterOnWaypoint(index);
                Navigator.of(routeContext).pop();
              },
              onDelete: _onRowDelete,
              onAltitudeChanged: _onRowAltitudeChanged,
              onSpeedChanged: _onRowSpeedChanged,
              onCatchRadiusChanged: _onRowCatchRadiusChanged,
              onActionChanged: _onRowActionChanged,
            ),
          );
        },
      ),
    );
  }

  /// Oeffnet die Warnungsliste (Doku 3.10, HTML-Demonstrator:
  /// #warningsBtn/#warningsPanel). Antippen einer Warnung schliesst die
  /// Liste und navigiert zum passenden Screen: Altitude-/Speed-Tab der
  /// Wegpunktliste, oder ein Kartensprung auf die gesamte Route.
  void _openWarningsPanel(List<MissionWarning> warnings) {
    Navigator.of(context).push(MaterialPageRoute<void>(
      builder: (routeContext) => WarningsPanel(
        warnings: warnings,
        onClose: () => Navigator.of(routeContext).pop(),
        onWarningTap: (warning) {
          Navigator.of(routeContext).pop();
          switch (warning.action) {
            case WarningAction.altitude:
              _openWaypointList(initialTab: PanelTab.altitude);
            case WarningAction.speed:
              _openWaypointList(initialTab: PanelTab.speed);
            case WarningAction.map:
              fitMapToWaypoints(ref, ref.read(currentMissionProvider));
          }
        },
      ),
    ));
  }

  @override
  Widget build(BuildContext context) {
    final waypoints = ref.watch(currentMissionProvider);
    final showPerWaypointWind = ref.watch(headerWindProvider).showPerWaypoint;
    final droneProfile = ref.watch(activeDroneProfileProvider);

    final routeGeometry = buildRouteGeometry(
      waypoints,
      minTurnRadius: droneProfile.minTurnRadius,
      maxClimbRate: droneProfile.maxClimbRate,
      maxDescentRate: droneProfile.maxDescentRate,
    );
    final missionStats = computeMissionStats(waypoints);
    final terrainProfile = ref.watch(terrainProvider).profile;
    final warnings = computeMissionWarnings(
      waypoints: waypoints,
      routeGeometry: routeGeometry,
      legWindBad: computeLegWindBad(waypoints, droneProfile.maxSpeed),
      droneProfile: droneProfile,
      totalDistanceM: missionStats.distanceM,
      totalDurationSec: missionStats.durationSec,
      terrain: terrainProfile,
    );

    List<LatLng>? rubberBand;
    if (_mapReady && _mode == _ReticleMode.idle && waypoints.isNotEmpty) {
      final last = waypoints.last;
      rubberBand = [
        LatLng(last.lat, last.lon),
        _mapController.camera.center,
      ];
    }

    final targetWaypoint =
        (_targetIndex >= 0 && _targetIndex < waypoints.length)
            ? waypoints[_targetIndex]
            : null;

    final wheelBottomInset = math.max(
      MediaQuery.of(context).size.height * 0.06,
      124.0,
    );
    // Symmetrischer Randabstand auf beiden Seiten, damit z.B. eine
    // Frontkamera-Aussparung im Querformat die Raeder nicht verdeckt
    // (HTML-Demonstrator: max(env(safe-area-inset-left), env(safe-area-inset-right))).
    final safeEdgeInset = math.max(
      MediaQuery.of(context).padding.left,
      MediaQuery.of(context).padding.right,
    );

    return Stack(
      children: [
        MissionMap(
          mapController: _mapController,
          onMapReady: () => setState(() => _mapReady = true),
          routeSegments: routeGeometry.segments,
          rubberBandLine: rubberBand,
          waypointMarkers: [
            for (var i = 0; i < waypoints.length; i++)
              _markerFor(
                waypoints[i],
                isTarget: i == _targetIndex,
                isBad: i < routeGeometry.vertexBad.length &&
                    routeGeometry.vertexBad[i],
              ),
          ],
          windMarkers: [
            if (showPerWaypointWind)
              for (final wp in waypoints)
                if (wp.windSpeedMs != null && wp.windDirFromDeg != null)
                  Marker(
                    point: LatLng(wp.lat, wp.lon),
                    width: windMarkerWidth(wp.windSpeedMs!),
                    height: 22,
                    alignment: const Alignment(1.1, -1.5),
                    child: WindMarkerPill(
                      speedMs: wp.windSpeedMs!,
                      dirFromDeg: wp.windDirFromDeg!,
                    ),
                  ),
          ],
        ),
        if (_mode == _ReticleMode.editing && targetWaypoint != null)
          Align(
            alignment: Alignment.center,
            child: HaloMenu(
              loiterActive: targetWaypoint.action == WaypointAction.loiter,
              landingActive: targetWaypoint.action == WaypointAction.landing,
              onAction: _onHaloAction,
            ),
          ),
        Align(
          alignment: Alignment.center,
          child: ReticleButton(icon: _reticleIcon, onTap: _onReticleTap),
        ),
        Positioned(
          top: 56,
          bottom: wheelBottomInset,
          left: 14 + safeEdgeInset,
          child: ValueWheel(
            value: _curAlt,
            min: DefaultDroneProfile.altMin,
            max: droneProfile.maxAltitudeM,
            step: DefaultDroneProfile.altStep,
            pxPerStep: _altPxPerStep,
            majorEvery: _altMajorEvery,
            onChanged: _onAltChanged,
          ),
        ),
        Positioned(
          top: 56,
          bottom: wheelBottomInset,
          left: 70 + safeEdgeInset,
          child: Center(child: _readout('Alt', _curAlt, 'm')),
        ),
        Positioned(
          top: 56,
          bottom: wheelBottomInset,
          right: 14 + safeEdgeInset,
          child: ValueWheel(
            value: _curSpeed,
            min: droneProfile.minSpeed,
            max: droneProfile.maxSpeed,
            step: DefaultDroneProfile.speedStep,
            pxPerStep: _speedPxPerStep,
            majorEvery: _speedMajorEvery,
            onChanged: _onSpeedChanged,
          ),
        ),
        Positioned(
          top: 56,
          bottom: wheelBottomInset,
          right: 70 + safeEdgeInset,
          child: Center(child: _readout('Speed', _curSpeed, 'm/s')),
        ),
        Positioned(
          left: 0,
          right: 0,
          bottom: 0,
          child: MissionFooterBar(
            waypoints: waypoints,
            legClimbBad: routeGeometry.legClimbBad,
            vertexBad: routeGeometry.vertexBad,
            activeIndex: _mode == _ReticleMode.idle ? -1 : _targetIndex,
            totalDistanceM: missionStats.distanceM,
            totalDurationSec: missionStats.durationSec,
            warnings: warnings,
            onDetailsTap: _openWaypointList,
            onWarningsTap: () => _openWarningsPanel(warnings),
            onSettingsTap: () => Navigator.of(context).push(MaterialPageRoute(
              builder: (_) => const SettingsScreen(),
            )),
          ),
        ),
      ],
    );
  }

  Widget _readout(String label, double value, String unit) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 8, vertical: 4),
      decoration: BoxDecoration(
        color: Colors.black.withValues(alpha: 0.7),
        borderRadius: BorderRadius.circular(6),
      ),
      child: Text(
        '$label: ${value.round()} $unit',
        style: const TextStyle(
          color: Colors.white,
          fontSize: 15,
          fontWeight: FontWeight.w500,
        ),
      ),
    );
  }

  IconData get _reticleIcon => switch (_mode) {
        _ReticleMode.idle => Icons.add,
        _ReticleMode.snapped => Icons.edit,
        _ReticleMode.editing => Icons.check,
      };

  CircleMarker _markerFor(
    Waypoint wp, {
    required bool isTarget,
    required bool isBad,
  }) {
    final highlighted = isTarget && _mode != _ReticleMode.idle;
    return CircleMarker(
      point: LatLng(wp.lat, wp.lon),
      radius: highlighted ? 9 : 6,
      color: isBad ? const Color(0xFFE2574A) : const Color(0xFF2B2B28),
      borderStrokeWidth: highlighted ? 3 : 1.5,
      borderColor: Colors.white,
    );
  }
}