import 'package:flutter/material.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:go_router/go_router.dart';
import 'package:intaleq_maps/intaleq_maps.dart';
import '../../../core/l10n/app_localizations.dart';
import '../../../core/design/tokens.dart';
import '../../../core/ui/tripz_button.dart';
import '../../trip/bloc/trip_bloc.dart';
import '../../trip/bloc/trip_state.dart';
import '../../trip/bloc/trip_event.dart';
import '../cubit/quote_cubit.dart';
import '../data/models/place_model.dart';
import '../data/models/route_model.dart';
import '../data/maps_repository.dart';
import '../../../core/di.dart';
import 'widgets/ride_class_card.dart';

List<LatLng> _decodePolyline(String encoded) {
  return PolylineUtils.decode(encoded);
}

class RoutePreviewScreen extends StatefulWidget {
  final PlaceModel pickup;
  final PlaceModel destination;

  const RoutePreviewScreen({
    super.key,
    required this.pickup,
    required this.destination,
  });

  @override
  State<RoutePreviewScreen> createState() => _RoutePreviewScreenState();
}

class _RoutePreviewScreenState extends State<RoutePreviewScreen> {
  IntaleqMapController? _mapController;
  RouteModel? _route;
  List<LatLng> _polylinePoints = [];
  bool _routeLoading = true;
  String? _routeError;
  final _promoController = TextEditingController();

  @override
  void initState() {
    super.initState();
    _fetchRoute();
    WidgetsBinding.instance.addPostFrameCallback((_) {
      context.read<QuoteCubit>().fetchQuote(
            pickupLat: widget.pickup.lat,
            pickupLng: widget.pickup.lng,
            pickupAddress: widget.pickup.name,
            dropoffLat: widget.destination.lat,
            dropoffLng: widget.destination.lng,
            dropoffAddress: widget.destination.name,
          );
    });
  }

  @override
  void dispose() {
    _promoController.dispose();
    super.dispose();
  }

  Future<void> _fetchRoute() async {
    setState(() {
      _routeLoading = true;
      _routeError = null;
    });
    try {
      final repo = getIt<MapsRepository>();
      final route = await repo.getRoute(
        fromLat: widget.pickup.lat,
        fromLng: widget.pickup.lng,
        toLat: widget.destination.lat,
        toLng: widget.destination.lng,
      );
      final points = await compute(_decodePolyline, route.polyline ?? '');
      if (!mounted) return;
      setState(() {
        _route = route;
        _polylinePoints = points;
        _routeLoading = false;
      });
      _fitCamera();
    } catch (e) {
      if (!mounted) return;
      setState(() {
        _routeError = e.toString();
        _routeLoading = false;
      });
    }
  }

  void _fitCamera() {
    if (_mapController == null) return;
    final bounds = _route?.getLatLngBounds();
    if (bounds != null) {
      _mapController!.moveCamera(CameraUpdate.newLatLngBounds(bounds));
    } else {
      _mapController!.moveCamera(CameraUpdate.newLatLngZoom(
        LatLng(widget.pickup.lat, widget.pickup.lng),
        15,
      ));
    }
  }

  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context)!;
    final cs = Theme.of(context).colorScheme;
    final pickupLoc = LatLng(widget.pickup.lat, widget.pickup.lng);
    final destLoc = LatLng(widget.destination.lat, widget.destination.lng);

    return BlocListener<TripBloc, TripState>(
      listenWhen: (prev, cur) =>
          prev.requestStatus != cur.requestStatus &&
          cur.requestStatus == TripRequestStatus.searching,
      listener: (context, state) {
        context.pushReplacement('/trip-tracking');
      },
      child: Scaffold(
        body: Stack(
          children: [
            // الخريطة بكامل الشاشة
            if (_routeLoading)
              const Center(child: CircularProgressIndicator())
            else if (_routeError != null)
              Center(
                child: Column(
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    Text(l10n.errorGeneric),
                    const SizedBox(height: T.s12),
                    TripzButton(
                      label: l10n.retry,
                      onPressed: _fetchRoute,
                    ),
                  ],
                ),
              )
            else
              IntaleqMap(
                apiKey: '',
                initialCameraPosition: CameraPosition(
                  target: LatLng(
                    (pickupLoc.latitude + destLoc.latitude) / 2,
                    (pickupLoc.longitude + destLoc.longitude) / 2,
                  ),
                  zoom: 14,
                ),
                mapType: Theme.of(context).brightness == Brightness.dark
                    ? IntaleqMapType.normal
                    : IntaleqMapType.light,
                myLocationEnabled: false,
                zoomControlsEnabled: false,
                compassEnabled: false,
                onMapCreated: (c) {
                  _mapController = c;
                  _fitCamera();
                },
                markers: {
                  Marker(
                    markerId: const MarkerId('pickup'),
                    position: pickupLoc,
                    icon: InlqBitmap.defaultMarkerWithHue(210),
                    anchor: const Offset(0.5, 1.0),
                  ),
                  Marker(
                    markerId: const MarkerId('destination'),
                    position: destLoc,
                    icon: InlqBitmap.defaultMarkerWithHue(0),
                    anchor: const Offset(0.5, 1.0),
                  ),
                },
                polylines: {
                  // حماية محرك C++ من الانهيار إذا كانت النقاط أقل من 2
                  if (_polylinePoints.length >= 2)
                    Polyline(
                      polylineId: const PolylineId('route'),
                      points: _polylinePoints,
                      color: cs.primary,
                      width: T.polylineWidth,
                    ),
                },
              ),

            // زر الرجوع العائم (Top Left)
            Positioned(
              top: MediaQuery.of(context).padding.top + T.s8,
              left: T.s12,
              child: FloatingActionButton.small(
                heroTag: 'back',
                backgroundColor: cs.surface.withValues(alpha: 0.9),
                elevation: 4,
                onPressed: () => context.pop(),
                child: Icon(Icons.arrow_back_rounded, color: cs.onSurface),
              ),
            ),

            // ملخص المسار العائم (Top Right)
            Positioned(
              top: MediaQuery.of(context).padding.top + T.s12,
              right: T.s12,
              child: BlocBuilder<QuoteCubit, QuoteState>(
                builder: (context, state) {
                  if (state.quote == null) return const SizedBox.shrink();
                  return Container(
                    padding: const EdgeInsets.symmetric(
                        horizontal: T.s16, vertical: T.s12),
                    decoration: BoxDecoration(
                      color: cs.surface.withValues(alpha: 0.95),
                      borderRadius: BorderRadius.circular(T.r24),
                      boxShadow: const [T.shadowSm],
                    ),
                    child: Text(
                      l10n.routeSummary(
                        state.quote!.distanceText ?? '',
                        state.quote!.durationText ?? '',
                      ),
                      style: Theme.of(context).textTheme.labelLarge?.copyWith(
                            fontWeight: FontWeight.w700,
                            color: cs.onSurface,
                          ),
                    ),
                  );
                },
              ),
            ),

            // Bottom Sheet: فئات الرحلات
            Align(
              alignment: Alignment.bottomCenter,
              child: Container(
                constraints: BoxConstraints(
                  maxHeight: MediaQuery.of(context).size.height * 0.55,
                ),
                decoration: BoxDecoration(
                  color: cs.surface,
                  borderRadius: const BorderRadius.vertical(
                    top: Radius.circular(24),
                  ),
                  boxShadow: [
                    BoxShadow(
                      color: Colors.black.withValues(alpha: 0.1),
                      blurRadius: 20,
                      offset: const Offset(0, -5),
                    )
                  ],
                ),
                child: Column(
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    // شريط السحب (Grab handle)
                    const SizedBox(height: T.s12),
                    Container(
                      width: 40,
                      height: 5,
                      decoration: BoxDecoration(
                        color: cs.outlineVariant.withValues(alpha: 0.5),
                        borderRadius: BorderRadius.circular(10),
                      ),
                    ),
                    const SizedBox(height: T.s12),

                    Expanded(
                      child: BlocBuilder<QuoteCubit, QuoteState>(
                        builder: (context, state) {
                          if (state.loading) {
                            return const Center(
                                child: CircularProgressIndicator());
                          }
                          if (state.error != null) {
                            return Center(
                              child: Column(
                                mainAxisSize: MainAxisSize.min,
                                children: [
                                  Text(l10n.errorGeneric,
                                      style: Theme.of(context)
                                          .textTheme
                                          .bodyLarge
                                          ?.copyWith(color: cs.error)),
                                  const SizedBox(height: T.s12),
                                  TripzButton(
                                    label: l10n.retry,
                                    onPressed: () => context
                                        .read<QuoteCubit>()
                                        .fetchQuote(
                                          pickupLat: widget.pickup.lat,
                                          pickupLng: widget.pickup.lng,
                                          pickupAddress: widget.pickup.name,
                                          dropoffLat: widget.destination.lat,
                                          dropoffLng: widget.destination.lng,
                                          dropoffAddress:
                                              widget.destination.name,
                                        ),
                                  ),
                                ],
                              ),
                            );
                          }

                          final classes = state.quote?.classes ?? [];
                          if (classes.isEmpty) {
                            return Center(child: Text(l10n.noResults));
                          }

                          return Column(
                            crossAxisAlignment: CrossAxisAlignment.stretch,
                            children: [
                              Padding(
                                padding: const EdgeInsets.symmetric(
                                    horizontal: T.pagePadding),
                                child: Text(
                                  l10n.rideClasses,
                                  style: Theme.of(context)
                                      .textTheme
                                      .titleLarge
                                      ?.copyWith(
                                        fontWeight: FontWeight.w800,
                                        letterSpacing: -0.5,
                                      ),
                                ),
                              ),
                              const SizedBox(height: T.s12),
                              Expanded(
                                child: ListView.separated(
                                  padding: const EdgeInsets.symmetric(
                                      horizontal: T.pagePadding),
                                  itemCount: classes.length,
                                  separatorBuilder: (_, __) =>
                                      const SizedBox(height: T.s12),
                                  itemBuilder: (context, index) {
                                    final cls = classes[index];
                                    return RideClassCard(
                                      quoteClass: cls,
                                      selected: state.selectedClass ==
                                          cls.vehicleClass,
                                      onTap: () => context
                                          .read<QuoteCubit>()
                                          .selectClass(cls.vehicleClass),
                                    );
                                  },
                                ),
                              ),
                              // شريط الدفع وكود الخصم
                              Container(
                                padding: const EdgeInsets.fromLTRB(
                                    T.pagePadding, T.s12, T.pagePadding, T.s8),
                                decoration: BoxDecoration(
                                  color: cs.surface,
                                  border: Border(
                                    top: BorderSide(
                                      color: cs.outlineVariant
                                          .withValues(alpha: 0.3),
                                    ),
                                  ),
                                ),
                                child: Column(
                                  children: [
                                    _PaymentRow(
                                      method: state.paymentMethod,
                                      onChanged: (m) => context
                                          .read<QuoteCubit>()
                                          .setPaymentMethod(m),
                                    ),
                                    const SizedBox(height: T.s12),
                                    _PromoRow(
                                      controller: _promoController,
                                      onApply: (code) => context
                                          .read<QuoteCubit>()
                                          .setCouponCode(code),
                                    ),
                                  ],
                                ),
                              ),
                              // زر طلب الرحلة
                              SafeArea(
                                top: false,
                                child: Padding(
                                  padding: const EdgeInsets.fromLTRB(
                                      T.pagePadding, 0, T.pagePadding, T.s12),
                                  child: BlocBuilder<TripBloc, TripState>(
                                    builder: (context, tripState) {
                                      final isLoading =
                                          tripState.requestStatus ==
                                              TripRequestStatus.loading;
                                      return TripzButton(
                                        label: isLoading
                                            ? l10n.loading
                                            : l10n.requestRide,
                                        onPressed:
                                            (state.selectedClass != null &&
                                                    !isLoading)
                                                ? () =>
                                                    _requestTrip(context, state)
                                                : null,
                                      );
                                    },
                                  ),
                                ),
                              ),
                            ],
                          );
                        },
                      ),
                    ),
                  ],
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }

  void _requestTrip(BuildContext context, QuoteState state) {
    if (state.selectedClass == null) return;
    context.read<TripBloc>().add(TripRequested(
          pickupLat: widget.pickup.lat,
          pickupLng: widget.pickup.lng,
          pickupAddress: widget.pickup.name,
          dropoffLat: widget.destination.lat,
          dropoffLng: widget.destination.lng,
          dropoffAddress: widget.destination.name,
          vehicleClass: state.selectedClass!,
          paymentMethod: state.paymentMethod,
          couponCode: state.couponCode,
        ));
  }
}

class _PaymentRow extends StatelessWidget {
  final String method;
  final ValueChanged<String> onChanged;

  const _PaymentRow({required this.method, required this.onChanged});

  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context)!;
    final cs = Theme.of(context).colorScheme;

    return Container(
      padding: const EdgeInsets.symmetric(
          horizontal: T.pagePadding, vertical: T.s12),
      decoration: BoxDecoration(
        color: cs.surfaceContainerHighest,
        borderRadius: BorderRadius.circular(T.r12),
      ),
      child: Row(
        children: [
          Icon(
            method == 'wallet'
                ? Icons.account_balance_wallet_outlined
                : Icons.money_rounded,
            color: cs.onSurfaceVariant,
          ),
          const SizedBox(width: T.s12),
          Text(l10n.paymentMethod,
              style: Theme.of(context).textTheme.bodyMedium),
          const Spacer(),
          DropdownButton<String>(
            value: method,
            underline: const SizedBox.shrink(),
            isDense: true,
            items: [
              DropdownMenuItem(value: 'cash', child: Text(l10n.cash)),
              DropdownMenuItem(
                  value: 'wallet', child: Text(l10n.walletPayment)),
            ],
            onChanged: (v) {
              if (v != null) onChanged(v);
            },
          ),
        ],
      ),
    );
  }
}

class _PromoRow extends StatefulWidget {
  final TextEditingController controller;
  final ValueChanged<String?> onApply;

  const _PromoRow({required this.controller, required this.onApply});

  @override
  State<_PromoRow> createState() => _PromoRowState();
}

class _PromoRowState extends State<_PromoRow> {
  @override
  Widget build(BuildContext context) {
    final l10n = AppLocalizations.of(context)!;
    final cs = Theme.of(context).colorScheme;

    return Container(
      padding:
          const EdgeInsets.symmetric(horizontal: T.pagePadding, vertical: T.s8),
      decoration: BoxDecoration(
        color: cs.surfaceContainerHighest,
        borderRadius: BorderRadius.circular(T.r12),
      ),
      child: Row(
        children: [
          Icon(
            Icons.local_offer_outlined,
            color: cs.onSurfaceVariant,
          ),
          const SizedBox(width: T.s12),
          Expanded(
            child: TextField(
              controller: widget.controller,
              decoration: InputDecoration(
                hintText: l10n.couponCode,
                border: InputBorder.none,
                isDense: true,
                contentPadding: EdgeInsets.zero,
              ),
              style: Theme.of(context).textTheme.bodyMedium,
            ),
          ),
          TripzButton(
            label: l10n.confirm,
            style: TripzButtonStyle.text,
            fullWidth: false,
            onPressed: () {
              final code = widget.controller.text.trim();
              widget.onApply(code.isEmpty ? null : code);
            },
          ),
        ],
      ),
    );
  }
}