import 'package:flutter/material.dart';
import 'package:get/get.dart';
import 'package:intaleq_maps/intaleq_maps.dart';
import '../services/offline_road_graph_engine.dart';
import '../services/offline_routing_engine.dart';
import '../services/offline_routing_package_service.dart';
import '../services/tactical_api_service.dart';
import '../services/turn_by_turn_navigation_engine.dart';
import '../services/valhalla_offline_engine.dart';

/// ============================================================================
/// [NavigationController] - وحدة التحكم بالملاحة وتوجيه القوافل التكتيكية
/// ============================================================================
class NavigationController extends GetxController {
  // ── Observables / الحالات التفاعلية ──────────────────────────────────────
  final Rx<OfflineRoutePlan?> activeRoute = Rx<OfflineRoutePlan?>(null);
  final Rx<TacticalVehicleProfile> vehicleProfile =
      Rx<TacticalVehicleProfile>(TacticalVehicleProfile.convoy);
  final RxBool isCalculating = false.obs;

  /// هل التوجيه المحلي الحقيقي (شبكة الطرق الكاملة) جاهز على الجهاز؟
  final RxBool isRealRoadEngineReady = false.obs;

  NavigationController() {
    _refreshEngineStatus();
  }

  Future<void> _refreshEngineStatus() async {
    final pkgInstalled = await OfflineRoutingPackageService.isInstalled();
    final dbReady = await OfflineRoadGraphEngine.isDatabaseAvailable();
    isRealRoadEngineReady.value = pkgInstalled || dbReady;
  }

  /// Calculate Hybrid Tactical Route / احتساب مسار تكتيكي هجين
  Future<OfflineRoutePlan?> calculateRoute({
    required LatLng origin,
    required LatLng destination,
    TacticalVehicleProfile? profile,
    bool autoStart = false,
    IntaleqMapController? mapController,
  }) async {
    final activeProfile = profile ?? vehicleProfile.value;
    vehicleProfile.value = activeProfile;
    isCalculating.value = true;

    OfflineRoutePlan? plan;

    // 1. Try Online NestJS Server Routing API
    try {
      final serverRoute = await TacticalApiService.calculateTacticalRoute(
        origin: origin,
        destination: destination,
        profile: activeProfile.name,
      );

      if (serverRoute != null && serverRoute.points.isNotEmpty) {
        plan = OfflineRoutePlan(
          polylinePoints: serverRoute.points,
          totalDistanceKm: serverRoute.distanceKm,
          estimatedDurationMinutes: serverRoute.durationMinutes,
          profile: activeProfile,
          tacticalWaypoints: const ['موقع الانطلاق', 'الهدف التكتيكي المحدد'],
          isOffline: false,
          usesRealRoadNetwork: true,
        );
      }
    } catch (e) {
      debugPrint('Online route fallback: $e');
    }

    // ── Offline chain preparation ──
    // تأكد من وجود حزمة التوجيه محلياً؛ إن غابت وحُاول الحساب أثناء توفر
    // الشبكة تُنزَّل مرة واحدة تلقائياً (يفشل بسرعة عند انقطاع الإنترنت).
    final routingPackageReady = await OfflineRoutingPackageService.ensureInstalled();
    if (!routingPackageReady) {
      debugPrint('Navigation: routing package unavailable — offline engines will degrade gracefully');
    }

    // 2. On-Device SQLite road graph engine (667K real edges, Arabic street names)
    //    الأولوية الأعلى أوفلاين: يحتوي على كامل شبكة طرق الأردن الحقيقية
    //    (1.99 مليون عقدة، 667 ألف حافة) مع أسماء شوارع عربية وانحناءات واقعية.
    //    يعمل بسرعة < 150ms حتى للمسافات الطويلة (عمان ← العقبة).
    plan ??= await OfflineRoadGraphEngine.calculateRoute(
      start: origin,
      destination: destination,
      profile: activeProfile,
    );

    // 3. On-Device Valhalla engine (native bridge — may not be available on all platforms)
    //    يحترم الاتجاه الممنوع وقيود الدوران + ارتفاعات SRTM.
    plan ??= await ValhallaOfflineEngine.calculateOfflineRoute(
      start: origin,
      destination: destination,
      profile: activeProfile,
      regionDir: await OfflineRoutingPackageService.installDirPath(),
    );

    if (plan != null) {
      debugPrint('Navigation: using real road network route '
          '(${plan.polylinePoints.length} pts, ${plan.totalDistanceKm.toStringAsFixed(1)} km, '
          '${plan.maneuvers.length} maneuvers, offline=${plan.isOffline})');
    }

    // 4. Last resort: legacy built-in synthetic graph (36 strategic nodes only)
    plan ??= OfflineRoutingEngine.calculateOnDeviceRoute(
      start: origin,
      destination: destination,
      profile: activeProfile,
    );

    activeRoute.value = plan;
    isCalculating.value = false;

    if (autoStart) {
      startNavigation(mapController: mapController);
    }

    return plan;
  }

  /// Start Active Turn-by-Turn Guidance / بدء الإرشاد الملاحي الحي
  void startNavigation({IntaleqMapController? mapController}) {
    if (activeRoute.value == null) return;
    TurnByTurnNavigationEngine.startNavigation(
      plan: activeRoute.value!,
      simulate: false,
      controller: mapController,
    );
  }

  /// Stop Navigation / إنهاء الملاحة
  void stopNavigation() {
    TurnByTurnNavigationEngine.stopNavigation();
  }

  /// Reset Route State / إعادة ضبط المسار
  void reset() {
    stopNavigation();
    activeRoute.value = null;
  }
}